Von Hippel-Lindau Disease

SMARCA2和SMARCA4是SWI/SNF复合物的亚基，该复合物是一种染色质重塑复合物，是促进基因表达的关键表观遗传调控因子。SMARCA4功能突变缺失的肿瘤依赖于SMARCA2进行细胞存活，这种合成致死效应是治疗癌症的潜在治疗策略。这里综述了结合SMARCA2溴结构域的PROTAC分子专利。 1. 背景介绍 SWItch/Sucrose Non-Fermentable(SWI/SNF)染色质重塑复合物是一个多亚基复合物，在基因调控、生物体发育、DNA复制和DNA修复中发挥关键作用。SWI/SNF复合物的失活突变与～20%的人类癌症有关。SMARCA2（BRM）和SMARCA4（BRG1）是复合物中互排斥的ATPase亚基。SMARCA4的突变和缺失存在于多种癌症中。SMARCA4功能缺失导致染色质重塑活性依赖于剩余的SMARCA2活性。为此，选择性地靶向SMARCA2可抑制SMARCA4缺失癌细胞模型的生长。这种合成致死关系表明靶向SMARCA2是一种可行的治疗方法。 SMARCA2和SMARCA4蛋白由一个溴结构域、ATP酶结构域、解旋酶结构域、BRK和QLQ（QX3LX2Q基域）所组成（图1）。溴结构域与组蛋白或其他辅助因子上的乙酰化赖氨酸残基结合，而ATP酶结构域驱动DNA易位和核小体重新定位，从而增加调节蛋白对DNA的访问。解旋酶（解旋酶Sant相关）结构域刺激染色质重构活性和转录因子的招募。其他结构域BRK和QLQ的还功能不为人所知。 图1.SMARCA2和SMARCA4的各种目标域。 PFI-3 是一种高度特异性的VIII家族溴结构域结合剂，是一种具有细胞通透性的化学探针。然而，PFI-3 抑制剂细胞内缺乏抗增殖活性。此外，与野生型一样，SMARCA2的溴结构域突变体可以挽救SMARCA2突变体细胞中SMARCA2敲低的生长抑制作用，证实了溴结构域在SMARCA2功能中可有可无的作用。然而，ATP酶活性死亡突变体未能挽救表型，这表明抗增殖表型依赖于对SMARCA2的ATPase酶结构域的抑制。 虽然SMARCA2溴结构域抑制缺乏抗增殖作用，但溴结构域结合剂可以转化为双功能降解物PROTAC，以降解SMARCA2蛋白。因此，靶向降解 SMARCA2 蛋白治疗SMARCA4突变的肿瘤是一种可行的策略。 2.专利总览 专利申请按申请人的字母顺序列于表1中。 表1. 本文相关专利申请摘要 3. SMARCA2 基于溴结构域的PROTAC蛋白降解剂 PROTAC分子由三种不同的成分组成；一种针对目标蛋白（POI）的小分子结合剂、一种E3连接酶结合配体、和连接子。靶向降解SMARCA2，可以使用溴结构域结合剂或ATP酶抑制剂（不在本综述的范围内）来生成PROTACs。迄今为止最常见的E3连接酶是CRBN或VHL。SMARCA2和SMARCA4的溴结构域在乙酰赖氨酸结合位点上几乎相同，对选择性SMARCA2结合剂提出了挑战。所有已知的溴结构域结合剂都以接近相同的亲和力与SMARCA2和SMARCA4结合（图2）。然而，在TPD领域，越来越多的例子显示，使用相关蛋白的非选择性结合剂生成的PROTAC蛋白的选择性降解。在大多数情况下，选择性是通过连接子区域的变化来实现的，这归因于三元配合物的生产形成，三元配合物的稳定性，降解动力学和其他因素，如所考虑的蛋白质的比较周转率。然而，由于三元复合物晶体结构的有限，这种选择性降解剂的设计仍然是经验性的，并且由于对三元复合物所需的结构特征的理解不足而受到阻碍。与SMARCA2溴结构域结合的小分子的现有晶体结构有助于识别溶剂暴露区域，该区域可用于接入连接子（图3，黄色箭头）。 图2. 图3. PFI-3与SMARCA2溴结构域（PDB：5DKC）结合的晶体结构。黄色箭头表示了加入连接剂的溶剂暴露区域。 3.1. Amgen Amgen 使用VHL作为E3连接酶结合剂的SMARCA2/4降解剂。在2小时后评估A375黑色素瘤细胞的降解情况。在11个例子中，8个SMARCA2的DC50从22 nM到350 nM，以及不同水平的SMARCA4的2-3倍选择性。所公开的最具选择性的化合物是如图4 (化合物4)。但并没有提供进一步的深入研究降解水平和选择性的SAR。 图4.安进SMARCA2 PROTACs的典型例子 3.2. Arvinas/Genentech Arvinas和基因泰克在2019和2021年的专利申请类似的化合物，并利用了已知的氨基吡嗪（aminopyridazine）衍生的溴结构域结合剂和VHL。本文报道了各种溴结构域结合剂/连接子/VHL结合剂的组合，并列举了超过700种 PROTACs。在肿瘤细胞中，几种具有DC50 <2.5 nM和Dmax >75%的有效降解剂。公开了在SMARCA4上的非选择性和选择性降解剂的例子。专利申请中的一个示例（化合物5）在最近的文献[10.1038/s41467-022-34562-5]中被描述为 A947（图5）。本文描述了这种有效且有选择性的SMARCA2 PROTAC的发现。与野生型相比，这种降解活性在SMARCA4突变体模型中更有效。此外，基于全局泛素定位和全细胞蛋白质组分析，A947没有降解额外的脱靶点。 图5.Arvinas/基因泰克SMARCA2降解剂 最近，Arvinas/基因泰克发布了另一项专利（WO2023097031.），其中157种化合物同样来自氨基吡嗪衍生物。在本专利对更刚性的连接体以及对VHL配体的一些修改。在SW1573细胞中，许多化合物具有个低nM DC50和Dmax >75%；然而，没有提供选择性数据。他们还在一个单独的专利中披露了新型的咪唑嘧啶SMARCA2/4结合剂和其PROTACs。与之前的专利申请一样，化合物在SW1573细胞系中非常有效，但没有显示出选择性数据。 3.3. Aurigene 使用了已知的吡嗪衍生物作为SMARCA2/4结合剂，以及VHL和CRBN E3连接酶结合剂，以及一些具有高度柔性连接剂的类似物，如聚乙烯醚类和刚性连接子。试图用取代基修饰苯酚的pKa。在H929细胞中检测SMARCA2和SMARCA4的降解情况。有几个例子显示，>有90%的SMARCA2降解，同时对SMARCA4的降解较弱（在100nM时抑制率低于30%），表明SMARCA2对SMARCA4有选择性降解，其中一种代表性化合物8，如图6。此外，几种化合物在两种细胞系中均显示半抑制浓度值低于1µM。 图6. 使用3-氨基吡嗪骨架的Aurigene选择性降解剂的典型例子。 在另一个专利中，Aurigene采用基于吡嗪骨架的PROTACs，然而，3-氨基被去除了。E3连接酶配体仅限于VHL配体。通过Western blot检测，几种化合物（图7）在100 nM下选择性降解SMARCA2。 图7. 去氨基哒嗪骨架的蛋白降解剂 此外，几个实例（图8；例化合物10-13）显示了苯酚在溴结构域结合配体中的重要性。 图8. 苯酚异构体SAR 该专利中的例子还探讨了使用异恶唑作为分子VHL结合区酰胺连接子(图9)，并且对SMARCA2和SMARCA4的降解效率都显著降低。 图9. 异恶唑取代。 使用不同的SMARCA2/4结合剂的化合物17 (45)和不同的VHL结合配体的化合物18(49)都获得了显著的SMARCA4降解（图10）,但SMARCA2的降解效率被保留。 图10. 具有修饰的溴结构域或VHL配体的化合物。 3.4. Boehringer Ingelheim 勃林格殷格翰（BI）报道了使用氨基吡嗪作为SMARCA2/4结合配体的PROTACs，VHL配体通过乙醚连接子连接。评价了A549细胞中的降解能力，这些例子缺乏选择性（图11）。 图11. Boehringer Ingelheim 的SMARCA2/4 蛋白降解剂实例 在最近发表的另一项专利中，勃林格殷格翰报道了新型四环化合物benzo[4,5]imidazo[1,2-a]quinazolin-5(7H)-one 作为SMARCA2/4结合剂及其相应的PROTACs。PROTACs都由VHL E3连接酶配体组成，并探索了连接子的长度和VHL配体取代基的SAR分析。虽然没有提供Dmax数据，但DC50值表明，该系统可以实现选择性。具有代表性的化合物21（42a）是SMARCA2的有效降解剂（DC50 = 0.9 nM，SMARCA4 DC50 = 25 nM）（图12）。对化合物 22（42b）的SMARCA2/4配体和化合物23（42）中的连接子的修饰导致了更有选择性的SMARCA2降解物。这种新型骨架的细节，以及晶体学，体外和体内研究参见文献[ 10.1038/s41467-022-33430-6]。化合物 21（42a，即ACBI2），其口服生物利用度的22%（小鼠30mg/kg）。在80 mg/kg 每天共21天产生肿瘤生长抑制（TGI）47%。值得注意的是，这是VHL PROTACs显示口服生物利用度的罕见例子之一，尽管在仅限于高剂量和小鼠中，并没有披露大鼠或更高等物种中的生物利用度信息。 图12. Boehringer Ingelheim 新型四环配体PROTAC实例 3.5. C4 Therapeutics/Hoffmann-La Roche C4公司和罗氏公司发布了两个涉及CRBN和VHL E3连接酶的专利。其中一个专利描述了使用氨基吡嗪的PROTACs作为SMARCA2/4结合剂和CRBN E3连接酶结合剂。SMARCA2和SMARCA4 HiBiT降解分析被用于分析这些PROTACs。虽然提供了SMARCA4突变细胞系A549中SMARCA2降解的DC50，但没有提供野生型细胞系SMARCA4的降解数据。虽然大多数示例都在6小时时使用中等Dmax，但少量有实例提供了SMARCA2几乎完全降解，包括 化合物24（158）（图13）。柔性和刚性连接剂都举例使用波马利度胺，来那度胺和环尿素附着戊二酰亚胺。 图13. C4 的SMARCA2降解剂实例 另一个专利描述了使用VHL作为E3连接酶结合剂的PROTACs和氨基吡嗪类作为作为SMARCA2/4配体。在SMARCA2 HiBiT检测中，大多数PROTACs表现出中度降解，但同样缺乏对SMARCA4的降解数据，因此无法评估选择性。 3.6. Foghorn Therapeutics Foghorn 公司是研究 SMARCA2/4 ATP酶抑制剂最领先的公司，目前有两款靶向的ATP酶抑制剂已进入临床I期（FHD-286,非选择性ATP酶抑制剂、和FHD-909，选择性SMARCA2的ATP酶抑制剂,礼来合作）。但Foghorn 也申请了多项蛋白降解剂的专利，包括基于ATP酶抑制剂配体的PROTAC（这里未进行讨论）。Foghorn 的第一个使用溴结构域结合剂的PROTAC专利申请披露了267种化合物，使用CRBN，DCAF15，和VHL E3连接酶配体。连接子包含所有的碳链、聚乙二醇（PEG）和其他的刚性组合。以HiBiT SMARCA2/4形式的降解数据。267个化合物中有17个具有选择性，使用SMARCA2 DC50=10-100nM，Dmax>为75%，SMARCA4 DC50>1000nM，Dmax<为50%。化合物25（示例253）认为是一种有效的选择性PROTAC(SMARCA2 DC50 <10 nM，Dmax >75%；SMARCA4 DC50>1000nM，Dmax<50%)（图14）。17种选择性化合物中的大多数是VHL PROTACs。 图14.Foghorn 的 SMARCA2 选择性蛋白降解剂实例 Foghorn 另外两项专利，其中一个由105个化合物组成，SMARCA2/4结合剂类似于他们的第一个专利（图14），其中连接剂中的苯基环被一个bicyclo[1.1.1]pentane 取代。同时使用 CRBN和VHL的配体构建PROTACs。化合物在HeLa HiBiT试验中进行了检测，其中大多数化合物均无活性。化合物26-29 (实例40、50、94和101）具有中等效力和选择性（图15)。 图15.Foghorn 的 SMARCA2 选择性蛋白降解剂实例 另一个专利含有310个化合物，包括包含氨基吡嗪骨架的融合双环或三环SMARCA2/4 结合剂，具有代表性的化合物:化合物30（14 ，图16）。在某些情况下，有一个环吡咯吡啶或另一个与吡咯吡啶融合的环。CRBN和VHL都在本专利申请中为例。所有的例子都提供了以HeLa HiBiT形式存在的SMARCA2和SMARCA4的降解数据。310个化合物中的41个具有相当的有效性和选择性。 图16. Foghorn 的氨基吡嗪骨架的 SMARCA2 选择性蛋白降解剂实例 Foghorn的溴结构域PROTAC专利申请包括115个基于VHL 的PROTACs。大多数化合物都有一个噻吩吡啶SMARCA2/4 结合剂，也有一些化合物有附着在噻吩上。大多数连接子都是C-连接的。链接子通常是非常短和刚性的。大多数的VHL连接是通过一个异恶唑和一些酰胺在一个相似的位置。有所有化合物的SMARCA2和SMARCA4 HeLa HiBiT数据，其中9个化合物显示出最高的效价和选择性（图17），化合物31-32（示例87 和113）。 图17. Foghorn 的thienopyridazine骨架的 SMARCA2 选择性蛋白降解剂实例 3.7. 江苏先声 江苏先声制药于2023年6月发布了第一个专利，有超过500种化合物，都是基于VHL，与一种新型的aminopyrazolopyridazine骨架 SMARCA2/4结合剂。化合物33（示例004）作为具有有效和选择性的代表性PROTAC（图18）。 图18. 江苏先声eSMARCA2选择性降解剂的实例 在体内的TGI数据提供了三个例子，化合物34-36（实例27 、47和304 ，图19）。由于在体内的例子有限，很难理解它们在体外与体内的相关性。 图19. 江苏先声进入体内研究的PROTACs的实例 3.8. Kymera Therapeutics Kymera 多项有关SMARCA2/4蛋白降解剂的专利申请，包括新型/已知的SMARCA2/4结合剂和新型/已知的E3连接酶结合剂，以生成双功能PROTAC化合物作为SMARCA2蛋白降解物。 Kymera利用这种新型的E3连接酶结合剂和苯酚取代的氨基吡嗪SMARCA2/4结合剂生成PROTACs。研究人员探索了各种连接子，包括灵活的脂肪链和受约束的连接子。在这个早期的专利中，检测数据仅限于在H1299细胞系中对SMARCA2的降解。图20 公开了DC50 <100 nM和Dmax >90%的高效降解剂，化合物38-39（例85和144）。与线性烷基或烷氧基链相比，使用杂环或烯环化合物引入刚性连接子似乎可以增强SMARCA2的降解。然而，在没有SMARCA4降解数据。 图20. Kymera 公司的高效的SMARCA2降解剂实例 来自Kymera的另一个专利显示了55个实例，它们使用了已知的氨基吡嗪及其环化类型的吡嗪作为SMARCA2/4溴结构域结合剂。VHL和CRBN结合剂均被作为为E3连接酶结合剂，以及具有柔性和刚性连接子。在两种不同的肺癌细胞系中进行了SMARCA2降解情况的评估，并采用Western blot检测SMARCA2和SMARCA4的降解选择性。化合物46（例46，VHL）以对SMARCA2比SMARCA4更有选择性（图21）。 图 21. Kymera 公司的高效的SMARCA2降解剂实例 Kymera在随后专利中用展示了41个 VHL PROTACs。一些新型三环类似物被用作SMARCA2/4溴结构域结合剂。利用了各种小环的刚性连接子，如环丁基和螺旋环化分子。虽然没有提供所有典型化合物的降解或选择性数据，但在MV411细胞系中，SMARCA2对SMARCA4降解的降解选择性非常好（图22）。使用这些三环类似物作为SMARCA2/4粘合剂，他们后续专利展示了另外416个实例。在VHL 结合剂中引入炔烃和脲将VHL 结合剂附加到连接子上是值得一提的，部分实例显示了>100倍选择性（图23）. 图22.  Kymera公司的SMARCA2 高效的选择性的蛋白降解剂实例 图23.  Kymera公司的SMARCA2 高效的选择性的蛋白降解剂实例 另一个专利也例证了基于VHL的氨基吡啶嗪作为SMARCA2/4结合剂与各种刚性连接剂。类似的PROTACs在MV411细胞中对SMARCA2的降解比SMARCA4表现出不同程度的选择性。目前来说，根据Kymera公司的管线和专利情况，推测其主要焦点现已并非集中于SMARCA2/4了。 3.9. Prelude Therapeutics Prelude 是目前SMARCA2蛋白降解剂推进最为迅速的研发企业。来自Prelude公司的第一个专利包括102个基于VHL配体的化合物。SMARCA2/4 结合剂是一种苯酚取代的三环aminopyridazine。连接物的长度和组成不同，通过异恶唑与VHL相连。在NCI-H1693和NCI-H520肺癌细胞中，SMARCA2和SMARCA4的降解数据被报道。选择性最具选择性的PROTACs是化合物46-47（例子34 和92），活性为：SMARCA2 DC50 <100 nM，Dmax >75%和SMARCA4 DC50 >10µM，Dmax=50-75%（图24）。 图24. Prelude公司基于使用三环骨架与VHL的SMARCA2选择性降解剂实例 随后来自Prelude公司的专利申请包含282种化合物，所有这些化合物与之前的申请使用相同的SMARCA2/ 4 降解剂，但在本专利中针对的是CRBN配体。连接子的长度和组成都有所不同。CRBN配体由来那度胺、波马利度胺、苯基（铟）戊二酰亚胺和酰胺戊二酰亚胺组成。该专利还包括针对戊二酰亚胺的磷酸盐和酯前药。大约10%的化合物在H520 肺癌细胞检测中检测了SMARCA2和SMARCA4降解，其余的则在HeLa-HiBiT系统中进行评估。一些PROTACs 分子，化合物48-52 [实例86、91、176、182、206] 具有SMARCA2 DC50 <10 nM，Dmax >85%，SMARCA4 DC50=10-100nM，Dmax=50-75%（图25）。 图25. Prelude公司基于使用三环骨架与CRBN的SMARCA2选择性降解剂实例 在Prelude的第三项专利中，它们不是过去两次申请的三环SMARCA2/4 结合剂，而是与吡嗪融合的螺旋环SMARCA2/4 结合剂。该申请仅包含8个示例，它们都是基于VHL的PROTACs。8个例子中的2个显示出选择性，化合物53 （例1）对SMARCA2最有效和选择性（DC50 <100 nM；Dmax >75%；SMARCA4 DC50 >10000 nM；Dmax<50%）（图26）。 图26. Prelude公司基于使用螺旋环骨架与VHL的SMARCA2选择性降解剂实例 图26. Prelude公司 PRT7732分子复合物晶体结构（AACR2024） 根据clinicaltrials.gov网站，Prelude有2个化合物，PRT3789与PRT7732（WO2024059806A1），正在进入I期临床试验。其中，PRT3789是一种通过静脉输注的SMARCA2降解剂， PRT7732 则是基于CREB配体的可口服的蛋白降解剂。AACR 报告显示，PRT3789 在HeLa HiBiT系统中，SMARCA2的降解能力为0.73nM，SMARCA4的降解能力为26 nM。而 PRT7732 在HiBit 中的DC50显示为0.98nM，且对 SAMRCA4 蛋白降解DC50>3000 nM，选择性大于3000倍，细胞增殖的选择性>1000倍，于2024年8月进入临床（NCT06560645，针对SMARCA4 突变的晚期、复发、和转移的恶性实体瘤）。 4. 小结 自2019年以来，已有多家机构发布了大量关于SMARCA2溴结构域PROTACs的专利申请。此外除了 PRT7732 分子专利之外，文章未纳入2023年七月后的分子，但该靶点这两年确实发展非常迅速，是合成致死领域比较热门的靶点，后期可能会分享另一篇关于SMARCA2的ATP酶抑制剂的进展。 参考： 1.https://doi-org.libproxy1.nus.edu.sg/10.1080/13543776.2024.2355258 2.https://investors.preludetx.com/static-files/98d7ba33-ac65-48dc-a50e-a087a0e1ff03 声明：发表/转载本文仅仅是出于传播信息的需要，并不意味着代表本公众号观点或证实其内容的真实性。据此内容作出的任何判断，后果自负。若有侵权，告知必删！ 长按关注本公众号  粉丝群/投稿/授权/广告等 请联系公众号助手 觉得本文好看，请点这里↓

October 14, 2024 8:00 am ET ALAMEDA, CALIF. & RAHWAY, N.J., Oct. 14, 2024 – Exelixis, Inc. (Nasdaq: EXEL) and Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced that the companies have entered into a clinical development collaboration to evaluate the combination of Exelixis’ investigational tyrosine kinase inhibitor (TKI) zanzalintinib with Merck’s anti-PD-1 therapy KEYTRUDA ® (pembrolizumab) in a Phase 3 pivotal trial for the treatment of patients with head and neck squamous cell carcinoma (HNSCC), and zanzalintinib with WELIREG ® (belzutifan), Merck’s oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor, in a Phase 1/2 trial and two Phase 3 pivotal trials for the treatment of patients with renal cell carcinoma (RCC). “This collaboration underscores our belief in zanzalintinib’s potential to drive patient benefit in combination with immunotherapy or targeted therapy in HNSCC and RCC indications that have unmet clinical need,” said Amy Peterson, M.D., executive vice president, product development & medical affairs, and chief medical officer, Exelixis. “KEYTRUDA and WELIREG are approved therapies that have led to improved outcomes for some cancer patients, and we are pleased to collaborate with Merck’s clinical development organization to evaluate the potential of these therapies in combination with zanzalintinib. This collaboration paves the way for further zanzalintinib development in RCC in a pragmatic manner.” “We look forward to working with our colleagues at Exelixis to advance these clinical trials,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “Merck remains committed to building upon the progress made to-date by strategically evaluating the potential of new combination regimens to improve outcomes for more patients.” Under the terms of the collaboration, Merck will supply KEYTRUDA for the ongoing, Exelixis-sponsored Phase 3 STELLAR-305 pivotal trial in previously untreated PD-L1 positive recurrent or metastatic HNSCC. In addition, Merck will sponsor a Phase 1/2 trial and two Phase 3 pivotal trials in RCC. Merck will fund one of these Phase 3 studies, and Exelixis will co-fund the Phase 1/2 trial and the other Phase 3 study, as well as supply zanzalintinib and cabozantinib. Exelixis maintains all global commercial and marketing rights to zanzalintinib. About head and neck cancer Head and neck cancer describes a number of different tumors that develop in or around the throat, larynx, nose, sinuses and mouth. Most head and neck cancers are squamous cell carcinomas that begin in the flat, squamous cells that make up the thin surface layer of the structures in the head and neck. There are several factors that greatly increase the risk of developing head and neck cancer, including tobacco and alcohol use and human papillomavirus (HPV). It is estimated there were more than 891,500 new cases of head and neck cancer diagnosed and over 458,100 deaths from the disease in 2022 globally. In the U.S., it is estimated there will be more than 58,450 new cases of head and neck cancer diagnosed and more than 12,230 deaths from the disease in 2024. About renal cell carcinoma Renal cell carcinoma is by far the most common type of kidney cancer; about nine out of 10 kidney cancer diagnoses are RCCs. Renal cell carcinoma is about twice as common in men than in women. Most cases of RCC are discovered incidentally during imaging tests for other abdominal diseases. Renal cell carcinoma is associated with a high risk of recurrence, with up to 40% of newly diagnosed patients experiencing recurrence within five years following surgery. In the U.S., it is estimated there will be approximately 81,600 new cases of kidney cancer diagnosed and approximately 14,400 deaths from the disease in 2024. Worldwide, it is estimated there were approximately 434,840 new cases of kidney cancer diagnosed and more than 155,953 deaths from the disease in 2022. About zanzalintinib Zanzalintinib inhibits multiple cancer-related pathways that play a role in resistance to multiple therapies, including immune checkpoint inhibitors. Encouraging results from the expansion cohort of the Phase 1b STELLAR-001 ( NCT03845166 ) clinical trial evaluating zanzalintinib in patients with previously treated clear cell RCC were reported at the 2023 International Kidney Cancer Symposium (IKCS): North America. About KEYTRUDA ® (pembrolizumab) injection, 100 mg KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD- L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells. Merck has the industry’s largest immuno-oncology clinical research program. There are currently more than 1,600 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient’s likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers. Selected KEYTRUDA ® (pembrolizumab) Indications in the U.S. Head and Neck Squamous Cell Cancer KEYTRUDA, in combination with platinum and fluorouracil (FU), is indicated for the first-line treatment of patients with metastatic or with unresectable, recurrent head and neck squamous cell carcinoma (HNSCC). KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with metastatic or with unresectable, recurrent HNSCC whose tumors express PD-L1 [Combined Positive Score (CPS) ≥1] as determined by an FDA-approved test. KEYTRUDA, as a single agent, is indicated for the treatment of patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy. Renal Cell Carcinoma KEYTRUDA, in combination with axitinib, is indicated for the first-line treatment of adult patients with advanced renal cell carcinoma (RCC). KEYTRUDA is indicated for the adjuvant treatment of patients with RCC at intermediate-high or high risk of recurrence following nephrectomy, or following nephrectomy and resection of metastatic lesions. See additional selected KEYTRUDA indications in the U.S. after the Selected Important Safety Information. Selected Important Safety Information for KEYTRUDA Severe and Fatal Immune-Mediated Adverse Reactions KEYTRUDA is a monoclonal antibody that belongs to a class of drugs that bind to either the programmed death receptor-1 (PD-1) or the programmed death ligand 1 (PD-L1), blocking the PD-1/PD-L1 pathway, thereby removing inhibition of the immune response, potentially breaking peripheral tolerance and inducing immune-mediated adverse reactions. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue, can affect more than one body system simultaneously, and can occur at any time after starting treatment or after discontinuation of treatment. Important immune-mediated adverse reactions listed here may not include all possible severe and fatal immune-mediated adverse reactions. Monitor patients closely for symptoms and signs that may be clinical manifestations of underlying immune-mediated adverse reactions. Early identification and management are essential to ensure safe use of anti–PD-1/PD-L1 treatments. Evaluate liver enzymes, creatinine, and thyroid function at baseline and periodically during treatment. For patients with TNBC treated with KEYTRUDA in the neoadjuvant setting, monitor blood cortisol at baseline, prior to surgery, and as clinically indicated. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate. Withhold or permanently discontinue KEYTRUDA depending on severity of the immune-mediated adverse reaction. In general, if KEYTRUDA requires interruption or discontinuation, administer systemic corticosteroid therapy (1 to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose adverse reactions are not controlled with corticosteroid therapy. Immune-Mediated Pneumonitis KEYTRUDA can cause immune-mediated pneumonitis. The incidence is higher in patients who have received prior thoracic radiation. Immune-mediated pneumonitis occurred in 3.4% (94/2799) of patients receiving KEYTRUDA, including fatal (0.1%), Grade 4 (0.3%), Grade 3 (0.9%), and Grade 2 (1.3%) reactions. Systemic corticosteroids were required in 67% (63/94) of patients. Pneumonitis led to permanent discontinuation of KEYTRUDA in 1.3% (36) and withholding in 0.9% (26) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 23% had recurrence. Pneumonitis resolved in 59% of the 94 patients. Pneumonitis occurred in 8% (31/389) of adult patients with cHL receiving KEYTRUDA as a single agent, including Grades 3-4 in 2.3% of patients. Patients received high-dose corticosteroids for a median duration of 10 days (range: 2 days to 53 months). Pneumonitis rates were similar in patients with and without prior thoracic radiation. Pneumonitis led to discontinuation of KEYTRUDA in 5.4% (21) of patients. Of the patients who developed pneumonitis, 42% interrupted KEYTRUDA, 68% discontinued KEYTRUDA, and 77% had resolution. Pneumonitis occurred in 7% (41/580) of adult patients with resected NSCLC who received KEYTRUDA as a single agent for adjuvant treatment of NSCLC, including fatal (0.2%), Grade 4 (0.3%), and Grade 3 (1%) adverse reactions. Patients received high-dose corticosteroids for a median duration of 10 days (range: 1 day to 2.3 months). Pneumonitis led to discontinuation of KEYTRUDA in 26 (4.5%) of patients. Of the patients who developed pneumonitis, 54% interrupted KEYTRUDA, 63% discontinued KEYTRUDA, and 71% had resolution. Immune-Mediated Colitis KEYTRUDA can cause immune-mediated colitis, which may present with diarrhea. Cytomegalovirus infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies. Immune-mediated colitis occurred in 1.7% (48/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (1.1%), and Grade 2 (0.4%) reactions. Systemic corticosteroids were required in 69% (33/48); additional immunosuppressant therapy was required in 4.2% of patients. Colitis led to permanent discontinuation of KEYTRUDA in 0.5% (15) and withholding in 0.5% (13) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 23% had recurrence. Colitis resolved in 85% of the 48 patients. Hepatotoxicity and Immune-Mediated Hepatitis KEYTRUDA as a Single Agent KEYTRUDA can cause immune-mediated hepatitis. Immune-mediated hepatitis occurred in 0.7% (19/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.4%), and Grade 2 (0.1%) reactions. Systemic corticosteroids were required in 68% (13/19) of patients; additional immunosuppressant therapy was required in 11% of patients. Hepatitis led to permanent discontinuation of KEYTRUDA in 0.2% (6) and withholding in 0.3% (9) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, none had recurrence. Hepatitis resolved in 79% of the 19 patients. KEYTRUDA With Axitinib KEYTRUDA in combination with axitinib can cause hepatic toxicity. Monitor liver enzymes before initiation of and periodically throughout treatment. Consider monitoring more frequently as compared to when the drugs are administered as single agents. For elevated liver enzymes, interrupt KEYTRUDA and axitinib, and consider administering corticosteroids as needed. With the combination of KEYTRUDA and axitinib, Grades 3 and 4 increased alanine aminotransferase (ALT) (20%) and increased aspartate aminotransferase (AST) (13%) were seen at a higher frequency compared to KEYTRUDA alone. Fifty-nine percent of the patients with increased ALT received systemic corticosteroids. In patients with ALT ≥3 times upper limit of normal (ULN) (Grades 2-4, n=116), ALT resolved to Grades 0-1 in 94%. Among the 92 patients who were rechallenged with either KEYTRUDA (n=3) or axitinib (n=34) administered as a single agent or with both (n=55), recurrence of ALT ≥3 times ULN was observed in 1 patient receiving KEYTRUDA, 16 patients receiving axitinib, and 24 patients receiving both. All patients with a recurrence of ALT ≥3 ULN subsequently recovered from the event. Immune-Mediated Endocrinopathies Adrenal Insufficiency KEYTRUDA can cause primary or secondary adrenal insufficiency. For Grade 2 or higher, initiate symptomatic treatment, including hormone replacement as clinically indicated. Withhold KEYTRUDA depending on severity. Adrenal insufficiency occurred in 0.8% (22/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.3%), and Grade 2 (0.3%) reactions. Systemic corticosteroids were required in 77% (17/22) of patients; of these, the majority remained on systemic corticosteroids. Adrenal insufficiency led to permanent discontinuation of KEYTRUDA in <0.1% (1) and withholding in 0.3% (8) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. Hypophysitis KEYTRUDA can cause immune-mediated hypophysitis. Hypophysitis can present with acute symptoms associated with mass effect such as headache, photophobia, or visual field defects. Hypophysitis can cause hypopituitarism. Initiate hormone replacement as indicated. Withhold or permanently discontinue KEYTRUDA depending on severity. Hypophysitis occurred in 0.6% (17/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.3%), and Grade 2 (0.2%) reactions. Systemic corticosteroids were required in 94% (16/17) of patients; of these, the majority remained on systemic corticosteroids. Hypophysitis led to permanent discontinuation of KEYTRUDA in 0.1% (4) and withholding in 0.3% (7) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. Thyroid Disorders KEYTRUDA can cause immune-mediated thyroid disorders. Thyroiditis can present with or without endocrinopathy. Hypothyroidism can follow hyperthyroidism. Initiate hormone replacement for hypothyroidism or institute medical management of hyperthyroidism as clinically indicated. Withhold or permanently discontinue KEYTRUDA depending on severity. Thyroiditis occurred in 0.6% (16/2799) of patients receiving KEYTRUDA, including Grade 2 (0.3%). None discontinued, but KEYTRUDA was withheld in <0.1% (1) of patients. Hyperthyroidism occurred in 3.4% (96/2799) of patients receiving KEYTRUDA, including Grade 3 (0.1%) and Grade 2 (0.8%). It led to permanent discontinuation of KEYTRUDA in <0.1% (2) and withholding in 0.3% (7) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. Hypothyroidism occurred in 8% (237/2799) of patients receiving KEYTRUDA, including Grade 3 (0.1%) and Grade 2 (6.2%). It led to permanent discontinuation of KEYTRUDA in <0.1% (1) and withholding in 0.5% (14) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. The majority of patients with hypothyroidism required long-term thyroid hormone replacement. The incidence of new or worsening hypothyroidism was higher in 1185 patients with HNSCC, occurring in 16% of patients receiving KEYTRUDA as a single agent or in combination with platinum and FU, including Grade 3 (0.3%) hypothyroidism. The incidence of new or worsening hypothyroidism was higher in 389 adult patients with cHL (17%) receiving KEYTRUDA as a single agent, including Grade 1 (6.2%) and Grade 2 (10.8%) hypothyroidism. The incidence of new or worsening hyperthyroidism was higher in 580 patients with resected NSCLC, occurring in 11% of patients receiving KEYTRUDA as a single agent as adjuvant treatment, including Grade 3 (0.2%) hyperthyroidism. The incidence of new or worsening hypothyroidism was higher in 580 patients with resected NSCLC, occurring in 22% of patients receiving KEYTRUDA as a single agent as adjuvant treatment (KEYNOTE-091), including Grade 3 (0.3%) hypothyroidism. Type 1 Diabetes Mellitus (DM), Which Can Present With Diabetic Ketoacidosis Monitor patients for hyperglycemia or other signs and symptoms of diabetes. Initiate treatment with insulin as clinically indicated. Withhold KEYTRUDA depending on severity. Type 1 DM occurred in 0.2% (6/2799) of patients receiving KEYTRUDA. It led to permanent discontinuation in <0.1% (1) and withholding of KEYTRUDA in <0.1% (1) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. Immune-Mediated Nephritis With Renal Dysfunction KEYTRUDA can cause immune-mediated nephritis. Immune-mediated nephritis occurred in 0.3% (9/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.1%), and Grade 2 (0.1%) reactions. Systemic corticosteroids were required in 89% (8/9) of patients. Nephritis led to permanent discontinuation of KEYTRUDA in 0.1% (3) and withholding in 0.1% (3) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, none had recurrence. Nephritis resolved in 56% of the 9 patients. Immune-Mediated Dermatologic Adverse Reactions KEYTRUDA can cause immune-mediated rash or dermatitis. Exfoliative dermatitis, including Stevens-Johnson syndrome, drug rash with eosinophilia and systemic symptoms, and toxic epidermal necrolysis, has occurred with anti– PD-1/PD-L1 treatments. Topical emollients and/or topical corticosteroids may be adequate to treat mild to moderate nonexfoliative rashes. Withhold or permanently discontinue KEYTRUDA depending on severity. Immune-mediated dermatologic adverse reactions occurred in 1.4% (38/2799) of patients receiving KEYTRUDA, including Grade 3 (1%) and Grade 2 (0.1%) reactions. Systemic corticosteroids were required in 40% (15/38) of patients. These reactions led to permanent discontinuation in 0.1% (2) and withholding of KEYTRUDA in 0.6% (16) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 6% had recurrence. The reactions resolved in 79% of the 38 patients. Other Immune-Mediated Adverse Reactions The following clinically significant immune-mediated adverse reactions occurred at an incidence of <1% (unless otherwise noted) in patients who received KEYTRUDA or were reported with the use of other anti–PD-1/PD-L1 treatments. Severe or fatal cases have been reported for some of these adverse reactions. Cardiac/Vascular: Myocarditis, pericarditis, vasculitis; Nervous System: Meningitis, encephalitis, myelitis and demyelination, myasthenic syndrome/myasthenia gravis (including exacerbation), Guillain-Barré syndrome, nerve paresis, autoimmune neuropathy; Ocular: Uveitis, iritis and other ocular inflammatory toxicities can occur. Some cases can be associated with retinal detachment. Various grades of visual impairment, including blindness, can occur. If uveitis occurs in combination with other immune-mediated adverse reactions, consider a Vogt-Koyanagi-Harada-like syndrome, as this may require treatment with systemic steroids to reduce the risk of permanent vision loss; Gastrointestinal: Pancreatitis, to include increases in serum amylase and lipase levels, gastritis, duodenitis; Musculoskeletal and Connective Tissue: Myositis/polymyositis, rhabdomyolysis (and associated sequelae, including renal failure), arthritis (1.5%), polymyalgia rheumatica; Endocrine: Hypoparathyroidism; Hematologic/Immune: Hemolytic anemia, aplastic anemia, hemophagocytic lymphohistiocytosis, systemic inflammatory response syndrome, histiocytic necrotizing lymphadenitis (Kikuchi lymphadenitis), sarcoidosis, immune thrombocytopenic purpura, solid organ transplant rejection, other transplant (including corneal graft) rejection. Infusion-Related Reactions KEYTRUDA can cause severe or life-threatening infusion-related reactions, including hypersensitivity and anaphylaxis, which have been reported in 0.2% of 2799 patients receiving KEYTRUDA. Monitor for signs and symptoms of infusion-related reactions. Interrupt or slow the rate of infusion for Grade 1 or Grade 2 reactions. For Grade 3 or Grade 4 reactions, stop infusion and permanently discontinue KEYTRUDA. Complications of Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) Fatal and other serious complications can occur in patients who receive allogeneic HSCT before or after anti–PD-1/PD-L1 treatments. Transplant- related complications include hyperacute graft-versus-host disease (GVHD), acute and chronic GVHD, hepatic veno-occlusive disease after reduced intensity conditioning, and steroid-requiring febrile syndrome (without an identified infectious cause). These complications may occur despite intervening therapy between anti–PD-1/PD-L1 treatments and allogeneic HSCT. Follow patients closely for evidence of these complications and intervene promptly. Consider the benefit vs risks of using anti–PD-1/PD-L1 treatments prior to or after an allogeneic HSCT. Increased Mortality in Patients With Multiple Myeloma In trials in patients with multiple myeloma, the addition of KEYTRUDA to a thalidomide analogue plus dexamethasone resulted in increased mortality. Treatment of these patients with an anti–PD-1/PD-L1 treatment in this combination is not recommended outside of controlled trials. Embryofetal Toxicity Based on its mechanism of action, KEYTRUDA can cause fetal harm when administered to a pregnant woman. Advise women of this potential risk. In females of reproductive potential, verify pregnancy status prior to initiating KEYTRUDA and advise them to use effective contraception during treatment and for 4 months after the last dose. Adverse Reactions In KEYNOTE-006, KEYTRUDA was discontinued due to adverse reactions in 9% of 555 patients with advanced melanoma; adverse reactions leading to permanent discontinuation in more than one patient were colitis (1.4%), autoimmune hepatitis (0.7%), allergic reaction (0.4%), polyneuropathy (0.4%), and cardiac failure (0.4%). The most common adverse reactions (≥20%) with KEYTRUDA were fatigue (28%), diarrhea (26%), rash (24%), and nausea (21%). In KEYNOTE-054, when KEYTRUDA was administered as a single agent to patients with stage III melanoma, KEYTRUDA was permanently discontinued due to adverse reactions in 14% of 509 patients; the most common (≥1%) were pneumonitis (1.4%), colitis (1.2%), and diarrhea (1%). Serious adverse reactions occurred in 25% of patients receiving KEYTRUDA. The most common adverse reaction (≥20%) with KEYTRUDA was diarrhea (28%). In KEYNOTE-716, when KEYTRUDA was administered as a single agent to patients with stage IIB or IIC melanoma, adverse reactions occurring in patients with stage IIB or IIC melanoma were similar to those occurring in 1011 patients with stage III melanoma from KEYNOTE-054. In KEYNOTE-189, when KEYTRUDA was administered with pemetrexed and platinum chemotherapy in metastatic nonsquamous NSCLC, KEYTRUDA was discontinued due to adverse reactions in 20% of 405 patients. The most common adverse reactions resulting in permanent discontinuation of KEYTRUDA were pneumonitis (3%) and acute kidney injury (2%). The most common adverse reactions (≥20%) with KEYTRUDA were nausea (56%), fatigue (56%), constipation (35%), diarrhea (31%), decreased appetite (28%), rash (25%), vomiting (24%), cough (21%), dyspnea (21%), and pyrexia (20%). In KEYNOTE-407, when KEYTRUDA was administered with carboplatin and either paclitaxel or paclitaxel protein-bound in metastatic squamous NSCLC, KEYTRUDA was discontinued due to adverse reactions in 15% of 101 patients. The most frequent serious adverse reactions reported in at least 2% of patients were febrile neutropenia, pneumonia, and urinary tract infection. Adverse reactions observed in KEYNOTE-407 were similar to those observed in KEYNOTE-189 with the exception that increased incidences of alopecia (47% vs 36%) and peripheral neuropathy (31% vs 25%) were observed in the KEYTRUDA and chemotherapy arm compared to the placebo and chemotherapy arm in KEYNOTE-407. In KEYNOTE-042, KEYTRUDA was discontinued due to adverse reactions in 19% of 636 patients with advanced NSCLC; the most common were pneumonitis (3%), death due to unknown cause (1.6%), and pneumonia (1.4%). The most frequent serious adverse reactions reported in at least 2% of patients were pneumonia (7%), pneumonitis (3.9%), pulmonary embolism (2.4%), and pleural effusion (2.2%). The most common adverse reaction (≥20%) was fatigue (25%). In KEYNOTE-010, KEYTRUDA monotherapy was discontinued due to adverse reactions in 8% of 682 patients with metastatic NSCLC; the most common was pneumonitis (1.8%). The most common adverse reactions (≥20%) were decreased appetite (25%), fatigue (25%), dyspnea (23%), and nausea (20%). In KEYNOTE-671, adverse reactions occurring in patients with resectable NSCLC receiving KEYTRUDA in combination with platinum-containing chemotherapy, given as neoadjuvant treatment and continued as single-agent adjuvant treatment, were generally similar to those occurring in patients in other clinical trials across tumor types receiving KEYTRUDA in combination with chemotherapy. The most common adverse reactions (reported in ≥20%) in patients receiving KEYTRUDA in combination with chemotherapy were fatigue/asthenia, nausea, constipation, diarrhea, decreased appetite, rash, vomiting, cough, dyspnea, pyrexia, alopecia, peripheral neuropathy, mucosal inflammation, stomatitis, headache, weight loss, abdominal pain, arthralgia, myalgia, insomnia, palmar- plantar erythrodysesthesia, urinary tract infection, and hypothyroidism. In the neoadjuvant phase of KEYNOTE-671, when KEYTRUDA was administered in combination with platinum-containing chemotherapy as neoadjuvant treatment, serious adverse reactions occurred in 34% of 396 patients. The most frequent (≥2%) serious adverse reactions were pneumonia (4.8%), venous thromboembolism (3.3%), and anemia (2%). Fatal adverse reactions occurred in 1.3% of patients, including death due to unknown cause (0.8%), sepsis (0.3%), and immune-mediated lung disease (0.3%). Permanent discontinuation of any study drug due to an adverse reaction occurred in 18% of patients who received KEYTRUDA in combination with platinum-containing chemotherapy; the most frequent adverse reactions (≥1%) that led to permanent discontinuation of any study drug were acute kidney injury (1.8%), interstitial lung disease (1.8%), anemia (1.5%), neutropenia (1.5%), and pneumonia (1.3%). Of the KEYTRUDA-treated patients who received neoadjuvant treatment, 6% of 396 patients did not receive surgery due to adverse reactions. The most frequent (≥1%) adverse reaction that led to cancellation of surgery in the KEYTRUDA arm was interstitial lung disease (1%). In the adjuvant phase of KEYNOTE-671, when KEYTRUDA was administered as a single agent as adjuvant treatment, serious adverse reactions occurred in 14% of 290 patients. The most frequent serious adverse reaction was pneumonia (3.4%). One fatal adverse reaction of pulmonary hemorrhage occurred. Permanent discontinuation of KEYTRUDA due to an adverse reaction occurred in 12% of patients who received KEYTRUDA as a single agent, given as adjuvant treatment; the most frequent adverse reactions (≥1%) that led to permanent discontinuation of KEYTRUDA were diarrhea (1.7%), interstitial lung disease (1.4%), increased aspartate aminotransferase (1%), and musculoskeletal pain (1%). Adverse reactions observed in KEYNOTE-091 were generally similar to those occurring in other patients with NSCLC receiving KEYTRUDA as a single agent, with the exception of hypothyroidism (22%), hyperthyroidism (11%), and pneumonitis (7%). Two fatal adverse reactions of myocarditis occurred. In KEYNOTE-048, KEYTRUDA monotherapy was discontinued due to adverse events in 12% of 300 patients with HNSCC; the most common adverse reactions leading to permanent discontinuation were sepsis (1.7%) and pneumonia (1.3%). The most common adverse reactions (≥20%) were fatigue (33%), constipation (20%), and rash (20%). In KEYNOTE-048, when KEYTRUDA was administered in combination with platinum (cisplatin or carboplatin) and FU chemotherapy, KEYTRUDA was discontinued due to adverse reactions in 16% of 276 patients with HNSCC. The most common adverse reactions resulting in permanent discontinuation of KEYTRUDA were pneumonia (2.5%), pneumonitis (1.8%), and septic shock (1.4%). The most common adverse reactions (≥20%) were nausea (51%), fatigue (49%), constipation (37%), vomiting (32%), mucosal inflammation (31%), diarrhea (29%), decreased appetite (29%), stomatitis (26%), and cough (22%). In KEYNOTE-012, KEYTRUDA was discontinued due to adverse reactions in 17% of 192 patients with HNSCC. Serious adverse reactions occurred in 45% of patients. The most frequent serious adverse reactions reported in at least 2% of patients were pneumonia, dyspnea, confusional state, vomiting, pleural effusion, and respiratory failure. The most common adverse reactions (≥20%) were fatigue, decreased appetite, and dyspnea. Adverse reactions occurring in patients with HNSCC were generally similar to those occurring in patients with melanoma or NSCLC who received KEYTRUDA as a monotherapy, with the exception of increased incidences of facial edema and new or worsening hypothyroidism. In KEYNOTE-204, KEYTRUDA was discontinued due to adverse reactions in 14% of 148 patients with cHL. Serious adverse reactions occurred in 30% of patients receiving KEYTRUDA; those ≥1% were pneumonitis, pneumonia, pyrexia, myocarditis, acute kidney injury, febrile neutropenia, and sepsis. Three patients died from causes other than disease progression: 2 from complications after allogeneic HSCT and 1 from unknown cause. The most common adverse reactions (≥20%) were upper respiratory tract infection (41%), musculoskeletal pain (32%), diarrhea (22%), and pyrexia, fatigue, rash, and cough (20% each). In KEYNOTE-087, KEYTRUDA was discontinued due to adverse reactions in 5% of 210 patients with cHL. Serious adverse reactions occurred in 16% of patients; those ≥1% were pneumonia, pneumonitis, pyrexia, dyspnea, GVHD, and herpes zoster. Two patients died from causes other than disease progression: 1 from GVHD after subsequent allogeneic HSCT and 1 from septic shock. The most common adverse reactions (≥20%) were fatigue (26%), pyrexia (24%), cough (24%), musculoskeletal pain (21%), diarrhea (20%), and rash (20%). In KEYNOTE-170, KEYTRUDA was discontinued due to adverse reactions in 8% of 53 patients with PMBCL. Serious adverse reactions occurred in 26% of patients and included arrhythmia (4%), cardiac tamponade (2%), myocardial infarction (2%), pericardial effusion (2%), and pericarditis (2%). Six (11%) patients died within 30 days of start of treatment. The most common adverse reactions (≥20%) were musculoskeletal pain (30%), upper respiratory tract infection and pyrexia (28% each), cough (26%), fatigue (23%), and dyspnea (21%). In KEYNOTE-A39, when KEYTRUDA was administered in combination with enfortumab vedotin to patients with locally advanced or metastatic urothelial cancer (n=440), fatal adverse reactions occurred in 3.9% of patients, including acute respiratory failure (0.7%), pneumonia (0.5%), and pneumonitis/ILD (0.2%). Serious adverse reactions occurred in 50% of patients receiving KEYTRUDA in combination with enfortumab vedotin; the serious adverse reactions in ≥2% of patients were rash (6%), acute kidney injury (5%), pneumonitis/ILD (4.5%), urinary tract infection (3.6%), diarrhea (3.2%), pneumonia (2.3%), pyrexia (2%), and hyperglycemia (2%). Permanent discontinuation of KEYTRUDA occurred in 27% of patients. The most common adverse reactions (≥2%) resulting in permanent discontinuation of KEYTRUDA were pneumonitis/ILD (4.8%) and rash (3.4%). The most common adverse reactions (≥20%) occurring in patients treated with KEYTRUDA in combination with enfortumab vedotin were rash (68%), peripheral neuropathy (67%), fatigue (51%), pruritus (41%), diarrhea (38%), alopecia (35%), weight loss (33%), decreased appetite (33%), nausea (26%), constipation (26%), dry eye (24%), dysgeusia (21%), and urinary tract infection (21%). In KEYNOTE-052, KEYTRUDA was discontinued due to adverse reactions in 11% of 370 patients with locally advanced or metastatic urothelial carcinoma. Serious adverse reactions occurred in 42% of patients; those ≥2% were urinary tract infection, hematuria, acute kidney injury, pneumonia, and urosepsis. The most common adverse reactions (≥20%) were fatigue (38%), musculoskeletal pain (24%), decreased appetite (22%), constipation (21%), rash (21%), and diarrhea (20%). In KEYNOTE-045, KEYTRUDA was discontinued due to adverse reactions in 8% of 266 patients with locally advanced or metastatic urothelial carcinoma. The most common adverse reaction resulting in permanent discontinuation of KEYTRUDA was pneumonitis (1.9%). Serious adverse reactions occurred in 39% of KEYTRUDA-treated patients; those ≥2% were urinary tract infection, pneumonia, anemia, and pneumonitis. The most common adverse reactions (≥20%) in patients who received KEYTRUDA were fatigue (38%), musculoskeletal pain (32%), pruritus (23%), decreased appetite (21%), nausea (21%), and rash (20%). In KEYNOTE-057, KEYTRUDA was discontinued due to adverse reactions in 11% of 148 patients with high-risk NMIBC. The most common adverse reaction resulting in permanent discontinuation of KEYTRUDA was pneumonitis (1.4%). Serious adverse reactions occurred in 28% of patients; those ≥2% were pneumonia (3%), cardiac ischemia (2%), colitis (2%), pulmonary embolism (2%), sepsis (2%), and urinary tract infection (2%). The most common adverse reactions (≥20%) were fatigue (29%), diarrhea (24%), and rash (24%). Adverse reactions occurring in patients with MSI-H or dMMR CRC were similar to those occurring in patients with melanoma or NSCLC who received KEYTRUDA as a monotherapy. In KEYNOTE-158 and KEYNOTE-164, adverse reactions occurring in patients with MSI-H or dMMR cancer were similar to those occurring in patients with other solid tumors who received KEYTRUDA as a single agent. In KEYNOTE-811, when KEYTRUDA was administered in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, KEYTRUDA was discontinued due to adverse reactions in 6% of 217 patients with locally advanced unresectable or metastatic HER2+ gastric or GEJ adenocarcinoma. The most common adverse reaction resulting in permanent discontinuation was pneumonitis (1.4%). In the KEYTRUDA arm versus placebo, there was a difference of ≥5% incidence between patients treated with KEYTRUDA vs standard of care for diarrhea (53% vs 44%) and nausea (49% vs 44%). In KEYNOTE-859, when KEYTRUDA was administered in combination with fluoropyrimidine- and platinum-containing chemotherapy, serious adverse reactions occurred in 45% of 785 patients. Serious adverse reactions in >2% of patients included pneumonia (4.1%), diarrhea (3.9%), hemorrhage (3.9%), and vomiting (2.4%). Fatal adverse reactions occurred in 8% of patients who received KEYTRUDA including infection (2.3%) and thromboembolism (1.3%). KEYTRUDA was permanently discontinued due to adverse reactions in 15% of patients. The most common adverse reactions resulting in permanent discontinuation of KEYTRUDA (≥1%) were infections (1.8%) and diarrhea (1.0%). The most common adverse reactions (reported in ≥20%) in patients receiving KEYTRUDA in combination with chemotherapy were peripheral neuropathy (47%), nausea (46%), fatigue (40%), diarrhea (36%), vomiting (34%), decreased appetite (29%), abdominal pain (26%), palmar-plantar erythrodysesthesia syndrome (25%), constipation (22%), and weight loss (20%). In KEYNOTE-590, when KEYTRUDA was administered with cisplatin and fluorouracil to patients with metastatic or locally advanced esophageal or GEJ (tumors with epicenter 1 to 5 centimeters above the GEJ) carcinoma who were not candidates for surgical resection or definitive chemoradiation, KEYTRUDA was discontinued due to adverse reactions in 15% of 370 patients. The most common adverse reactions resulting in permanent discontinuation of KEYTRUDA (≥1%) were pneumonitis (1.6%), acute kidney injury (1.1%), and pneumonia (1.1%). The most common adverse reactions (≥20%) with KEYTRUDA in combination with chemotherapy were nausea (67%), fatigue (57%), decreased appetite (44%), constipation (40%), diarrhea (36%), vomiting (34%), stomatitis (27%), and weight loss (24%). Adverse reactions occurring in patients with esophageal cancer who received KEYTRUDA as a monotherapy were similar to those occurring in patients with melanoma or NSCLC who received KEYTRUDA as a monotherapy. In KEYNOTE-A18, when KEYTRUDA was administered with CRT (cisplatin plus external beam radiation therapy [EBRT] followed by brachytherapy [BT]) to patients with FIGO 2014 Stage III-IVA cervical cancer, fatal adverse reactions occurred in 1.4% of 292 patients, including 1 case each (0.3%) of large intestinal perforation, urosepsis, sepsis, and vaginal hemorrhage. Serious adverse reactions occurred in 30% of patients; those ≥1% included urinary tract infection (2.7%), urosepsis (1.4%), and sepsis (1%). KEYTRUDA was discontinued for adverse reactions in 7% of patients. The most common adverse reaction (≥1%) resulting in permanent discontinuation was diarrhea (1%). For patients treated with KEYTRUDA in combination with CRT, the most common adverse reactions (≥10%) were nausea (56%), diarrhea (50%), vomiting (33%), urinary tract infection (32%), fatigue (26%), hypothyroidism (20%), constipation (18%), decreased appetite and weight loss (17% each), abdominal pain and pyrexia (12% each), hyperthyroidism, dysuria, rash (11% each), and pelvic pain (10%). In KEYNOTE-826, when KEYTRUDA was administered in combination with paclitaxel and cisplatin or paclitaxel and carboplatin, with or without bevacizumab (n=307), to patients with persistent, recurrent, or first-line metastatic cervical cancer regardless of tumor PD-L1 expression who had not been treated with chemotherapy except when used concurrently as a radio- sensitizing agent, fatal adverse reactions occurred in 4.6% of patients, including 3 cases of hemorrhage, 2 cases each of sepsis and due to unknown causes, and 1 case each of acute myocardial infarction, autoimmune encephalitis, cardiac arrest, cerebrovascular accident, femur fracture with perioperative pulmonary embolus, intestinal perforation, and pelvic infection. Serious adverse reactions occurred in 50% of patients receiving KEYTRUDA in combination with chemotherapy with or without bevacizumab; those ≥3% were febrile neutropenia (6.8%), urinary tract infection (5.2%), anemia (4.6%), and acute kidney injury and sepsis (3.3% each). KEYTRUDA was discontinued in 15% of patients due to adverse reactions. The most common adverse reaction resulting in permanent discontinuation (≥1%) was colitis (1%). For patients treated with KEYTRUDA, chemotherapy, and bevacizumab (n=196), the most common adverse reactions (≥20%) were peripheral neuropathy (62%), alopecia (58%), anemia (55%), fatigue/asthenia (53%), nausea and neutropenia (41% each), diarrhea (39%), hypertension and thrombocytopenia (35% each), constipation and arthralgia (31% each), vomiting (30%), urinary tract infection (27%), rash (26%), leukopenia (24%), hypothyroidism (22%), and decreased appetite (21%). For patients treated with KEYTRUDA in combination with chemotherapy with or without bevacizumab, the most common adverse reactions (≥20%) were peripheral neuropathy (58%), alopecia (56%), fatigue (47%), nausea (40%), diarrhea (36%), constipation (28%), arthralgia (27%), vomiting (26%), hypertension and urinary tract infection (24% each), and rash (22%). In KEYNOTE-158, KEYTRUDA was discontinued due to adverse reactions in 8% of 98 patients with previously treated recurrent or metastatic cervical cancer. Serious adverse reactions occurred in 39% of patients receiving KEYTRUDA; the most frequent included anemia (7%), fistula, hemorrhage, and infections [except urinary tract infections] (4.1% each). The most common adverse reactions (≥20%) were fatigue (43%), musculoskeletal pain (27%), diarrhea (23%), pain and abdominal pain (22% each), and decreased appetite (21%). In KEYNOTE-394, KEYTRUDA was discontinued due to adverse reactions in 13% of 299 patients with previously treated hepatocellular carcinoma. The most common adverse reaction resulting in permanent discontinuation of KEYTRUDA was ascites (2.3%). The most common adverse reactions in patients receiving KEYTRUDA (≥10%) were pyrexia (18%), rash (18%), diarrhea (16%), decreased appetite (15%), pruritis (12%), upper respiratory tract infection (11%), cough (11%), and hypothyroidism (10%). In KEYNOTE-966, when KEYTRUDA was administered in combination with gemcitabine and cisplatin, KEYTRUDA was discontinued for adverse reactions in 15% of 529 patients with locally advanced unresectable or metastatic biliary tract cancer. The most common adverse reaction resulting in permanent discontinuation of KEYTRUDA (≥1%) was pneumonitis (1.3%). Adverse reactions leading to the interruption of KEYTRUDA occurred in 55% of patients. The most common adverse reactions or laboratory abnormalities leading to interruption of KEYTRUDA (≥2%) were decreased neutrophil count (18%), decreased platelet count (10%), anemia (6%), decreased white blood cell count (4%), pyrexia (3.8%), fatigue (3.0%), cholangitis (2.8%), increased ALT (2.6%), increased AST (2.5%), and biliary obstruction (2.3%). In KEYNOTE-017 and KEYNOTE-913, adverse reactions occurring in patients with MCC (n=105) were generally similar to those occurring in patients with melanoma or NSCLC who received KEYTRUDA as a single agent. In KEYNOTE-426, when KEYTRUDA was administered in combination with axitinib, fatal adverse reactions occurred in 3.3% of 429 patients. Serious adverse reactions occurred in 40% of patients, the most frequent (≥1%) were hepatotoxicity (7%), diarrhea (4.2%), acute kidney injury (2.3%), dehydration (1%), and pneumonitis (1%). Permanent discontinuation due to an adverse reaction occurred in 31% of patients; KEYTRUDA only (13%), axitinib only (13%), and the combination (8%); the most common were hepatotoxicity (13%), diarrhea/colitis (1.9%), acute kidney injury (1.6%), and cerebrovascular accident (1.2%). The most common adverse reactions (≥20%) were diarrhea (56%), fatigue/asthenia (52%), hypertension (48%), hepatotoxicity (39%), hypothyroidism (35%), decreased appetite (30%), palmar-plantar erythrodysesthesia (28%), nausea (28%), stomatitis/mucosal inflammation (27%), dysphonia (25%), rash (25%), cough (21%), and constipation (21%). In KEYNOTE-564, when KEYTRUDA was administered as a single agent for the adjuvant treatment of renal cell carcinoma, serious adverse reactions occurred in 20% of patients receiving KEYTRUDA; the serious adverse reactions (≥1%) were acute kidney injury, adrenal insufficiency, pneumonia, colitis, and diabetic ketoacidosis (1% each). Fatal adverse reactions occurred in 0.2% including 1 case of pneumonia. Discontinuation of KEYTRUDA due to adverse reactions occurred in 21% of 488 patients; the most common (≥1%) were increased ALT (1.6%), colitis (1%), and adrenal insufficiency (1%). The most common adverse reactions (≥20%) were musculoskeletal pain (41%), fatigue (40%), rash (30%), diarrhea (27%), pruritus (23%), and hypothyroidism (21%). In KEYNOTE-868, when KEYTRUDA was administered in combination with chemotherapy (paclitaxel and carboplatin) to patients with advanced or recurrent endometrial carcinoma (n=382), serious adverse reactions occurred in 35% of patients receiving KEYTRUDA in combination with chemotherapy, compared to 19% of patients receiving placebo in combination with chemotherapy (n=377). Fatal adverse reactions occurred in 1.6% of patients receiving KEYTRUDA in combination with chemotherapy, including COVID-19 (0.5%) and cardiac arrest (0.3%). KEYTRUDA was discontinued for an adverse reaction in 14% of patients. Adverse reactions occurring in patients treated with KEYTRUDA and chemotherapy were generally similar to those observed with KEYTRUDA alone or chemotherapy alone, with the exception of rash (33% all Grades; 2.9% Grades 3-4). Adverse reactions occurring in patients with MSI-H or dMMR endometrial carcinoma who received KEYTRUDA as a single agent were similar to those occurring in patients with melanoma or NSCLC who received KEYTRUDA as a single agent. Adverse reactions occurring in patients with TMB-H cancer were similar to those occurring in patients with other solid tumors who received KEYTRUDA as a single agent. Adverse reactions occurring in patients with recurrent or metastatic cSCC or locally advanced cSCC were similar to those occurring in patients with melanoma or NSCLC who received KEYTRUDA as a monotherapy. In KEYNOTE-522, when KEYTRUDA was administered with neoadjuvant chemotherapy (carboplatin and paclitaxel followed by doxorubicin or epirubicin and cyclophosphamide) followed by surgery and continued adjuvant treatment with KEYTRUDA as a single agent (n=778) to patients with newly diagnosed, previously untreated, high-risk early-stage TNBC, fatal adverse reactions occurred in 0.9% of patients, including 1 each of adrenal crisis, autoimmune encephalitis, hepatitis, pneumonia, pneumonitis, pulmonary embolism, and sepsis in association with multiple organ dysfunction syndrome and myocardial infarction. Serious adverse reactions occurred in 44% of patients receiving KEYTRUDA; those ≥2% were febrile neutropenia (15%), pyrexia (3.7%), anemia (2.6%), and neutropenia (2.2%). KEYTRUDA was discontinued in 20% of patients due to adverse reactions. The most common reactions (≥1%) resulting in permanent discontinuation were increased ALT (2.7%), increased AST (1.5%), and rash (1%). The most common adverse reactions (≥20%) in patients receiving KEYTRUDA were fatigue (70%), nausea (67%), alopecia (61%), rash (52%), constipation (42%), diarrhea and peripheral neuropathy (41% each), stomatitis (34%), vomiting (31%), headache (30%), arthralgia (29%), pyrexia (28%), cough (26%), abdominal pain (24%), decreased appetite (23%), insomnia (21%), and myalgia (20%). In KEYNOTE-355, when KEYTRUDA and chemotherapy (paclitaxel, paclitaxel protein-bound, or gemcitabine and carboplatin) were administered to patients with locally recurrent unresectable or metastatic TNBC who had not been previously treated with chemotherapy in the metastatic setting (n=596), fatal adverse reactions occurred in 2.5% of patients, including cardio-respiratory arrest (0.7%) and septic shock (0.3%). Serious adverse reactions occurred in 30% of patients receiving KEYTRUDA in combination with chemotherapy; the serious reactions in ≥2% were pneumonia (2.9%), anemia (2.2%), and thrombocytopenia (2%). KEYTRUDA was discontinued in 11% of patients due to adverse reactions. The most common reactions resulting in permanent discontinuation (≥1%) were increased ALT (2.2%), increased AST (1.5%), and pneumonitis (1.2%). The most common adverse reactions (≥20%) in patients receiving KEYTRUDA in combination with chemotherapy were fatigue (48%), nausea (44%), alopecia (34%), diarrhea and constipation (28% each), vomiting and rash (26% each), cough (23%), decreased appetite (21%), and headache (20%). Lactation Because of the potential for serious adverse reactions in breastfed children, advise women not to breastfeed during treatment and for 4 months after the last dose. Pediatric Use In KEYNOTE-051, 173 pediatric patients (65 pediatric patients aged 6 months to younger than 12 years and 108 pediatric patients aged 12 years to 17 years) were administered KEYTRUDA 2 mg/kg every 3 weeks. The median duration of exposure was 2.1 months (range: 1 day to 25 months). Adverse reactions that occurred at a ≥10% higher rate in pediatric patients when compared to adults were pyrexia (33%), leukopenia (31%), vomiting (29%), neutropenia (28%), headache (25%), abdominal pain (23%), thrombocytopenia (22%), Grade 3 anemia (17%), decreased lymphocyte count (13%), and decreased white blood cell count (11%). Geriatric Use Of the 564 patients with locally advanced or metastatic urothelial cancer treated with KEYTRUDA in combination with enfortumab vedotin, 44% (n=247) were 65-74 years and 26% (n=144) were 75 years or older. No overall differences in safety or effectiveness were observed between patients 65 years of age or older and younger patients. Patients 75 years of age or older treated with KEYTRUDA in combination with enfortumab vedotin experienced a higher incidence of fatal adverse reactions than younger patients. The incidence of fatal adverse reactions was 4% in patients younger than 75 and 7% in patients 75 years or older. Additional Selected KEYTRUDA Indications in the U.S. Melanoma KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic melanoma. KEYTRUDA is indicated for the adjuvant treatment of adult and pediatric (12 years and older) patients with Stage IIB, IIC, or III melanoma following complete resection. Non-Small Cell Lung Cancer KEYTRUDA, in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of patients with metastatic nonsquamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations. KEYTRUDA, in combination with carboplatin and either paclitaxel or paclitaxel protein-bound, is indicated for the first-line treatment of patients with metastatic squamous NSCLC. KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with NSCLC expressing PD-L1 [Tumor Proportion Score (TPS) ≥1%] as determined by an FDA-approved test, with no EGFR or ALK genomic tumor aberrations, and is: Stage III where patients are not candidates for surgical resection or definitive chemoradiation, or metastatic. KEYTRUDA, as a single agent, is indicated for the treatment of patients with metastatic NSCLC whose tumors express PD-L1 (TPS ≥1%) as determined by an FDA-approved test, with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving KEYTRUDA. KEYTRUDA is indicated for the treatment of patients with resectable (tumors ≥4 cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery. KEYTRUDA, as a single agent, is indicated as adjuvant treatment following resection and platinum-based chemotherapy for adult patients with Stage IB (T2a ≥4 cm), II, or IIIA NSCLC. Malignant Pleural Mesothelioma KEYTRUDA, in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of adult patients with unresectable advanced or metastatic malignant pleural mesothelioma (MPM). Classical Hodgkin Lymphoma KEYTRUDA is indicated for the treatment of adult patients with relapsed or refractory classical Hodgkin lymphoma (cHL). KEYTRUDA is indicated for the treatment of pediatric patients with refractory cHL, or cHL that has relapsed after 2 or more lines of therapy. Primary Mediastinal Large B-Cell Lymphoma KEYTRUDA is indicated for the treatment of adult and pediatric patients with refractory primary mediastinal large B-cell lymphoma (PMBCL), or who have relapsed after 2 or more prior lines of therapy. KEYTRUDA is not recommended for treatment of patients with PMBCL who require urgent cytoreductive therapy. Urothelial Cancer KEYTRUDA, in combination with enfortumab vedotin, is indicated for the treatment of adult patients with locally advanced or metastatic urothelial cancer. KEYTRUDA, as a single agent, is indicated for the treatment of patients with locally advanced or metastatic urothelial carcinoma: who are not eligible for any platinum-containing chemotherapy, or who have disease progression during or following platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy. KEYTRUDA, as a single agent, is indicated for the treatment of patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumors who are ineligible for or have elected not to undergo cystectomy. Microsatellite Instability-High or Mismatch Repair Deficient Cancer KEYTRUDA is indicated for the treatment of adult and pediatric patients with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. Microsatellite Instability-High or Mismatch Repair Deficient Colorectal Cancer KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic MSI-H or dMMR colorectal cancer (CRC) as determined by an FDA-approved test. Gastric Cancer KEYTRUDA, in combination with trastuzumab, fluoropyrimidine- and platinum containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test. This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval of this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. KEYTRUDA, in combination with fluoropyrimidine- and platinum-containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma. Esophageal Cancer KEYTRUDA is indicated for the treatment of patients with locally advanced or metastatic esophageal or gastroesophageal junction (GEJ) (tumors with epicenter 1 to 5 centimeters above the GEJ) carcinoma that is not amenable to surgical resection or definitive chemoradiation either: in combination with platinum- and fluoropyrimidine-based chemotherapy, or as a single agent after one or more prior lines of systemic therapy for patients with tumors of squamous cell histology that express PD-L1 (CPS ≥10) as determined by an FDA-approved test. Cervical Cancer KEYTRUDA, in combination with chemoradiotherapy (CRT), is indicated for the treatment of patients with FIGO 2014 Stage III-IVA cervical cancer. KEYTRUDA, in combination with chemotherapy, with or without bevacizumab, is indicated for the treatment of patients with persistent, recurrent, or metastatic cervical cancer whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test. KEYTRUDA, as a single agent, is indicated for the treatment of patients with recurrent or metastatic cervical cancer with disease progression on or after chemotherapy whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test. Hepatocellular Carcinoma KEYTRUDA is indicated for the treatment of patients with hepatocellular carcinoma (HCC) secondary to hepatitis B who have received prior systemic therapy other than a PD-1/PD-L1-containing regimen. Biliary Tract Cancer KEYTRUDA, in combination with gemcitabine and cisplatin, is indicated for the treatment of patients with locally advanced unresectable or metastatic biliary tract cancer (BTC). Merkel Cell Carcinoma KEYTRUDA is indicated for the treatment of adult and pediatric patients with recurrent locally advanced or metastatic Merkel cell carcinoma (MCC). Endometrial Carcinoma KEYTRUDA, in combination with carboplatin and paclitaxel, followed by KEYTRUDA as a single agent, is indicated for the treatment of adult patients with primary advanced or recurrent endometrial carcinoma. KEYTRUDA, as a single agent, is indicated for the treatment of adult patients with advanced endometrial carcinoma that is MSI-H or dMMR, as determined by an FDA-approved test, who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation. Tumor Mutational Burden-High Cancer KEYTRUDA is indicated for the treatment of adult and pediatric patients with unresectable or metastatic tumor mutational burden-high (TMB-H) [≥10 mutations/megabase (mut/Mb)] solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. The safety and effectiveness of KEYTRUDA in pediatric patients with TMB-H central nervous system cancers have not been established. Cutaneous Squamous Cell Carcinoma KEYTRUDA is indicated for the treatment of patients with recurrent or metastatic cutaneous squamous cell carcinoma (cSCC) or locally advanced cSCC that is not curable by surgery or radiation. Triple-Negative Breast Cancer KEYTRUDA is indicated for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery. KEYTRUDA, in combination with chemotherapy, is indicated for the treatment of patients with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (CPS ≥10) as determined by an FDA-approved test. Please see Prescribing Information for KEYTRUDA (pembrolizumab) at http://www.merck.com.libproxy1.nus.edu.sg/product/usa/pi_circulars/k/keytruda/keytruda_pi.pdf and Medication Guide for KEYTRUDA at https://www-merck-com.libproxy1.nus.edu.sg/product/usa/pi_circulars/k/keytruda/keytruda_mg.pdf . About WELIREG ® (belzutifan) 40 mg tablets, for oral use Indications in the U.S. Certain von Hippel-Lindau (VHL) disease-associated tumors WELIREG (belzutifan) is indicated for the treatment of adult patients with von Hippel-Lindau (VHL) disease who require therapy for associated renal cell carcinoma (RCC), central nervous system (CNS) hemangioblastomas, or pancreatic neuroendocrine tumors (pNET), not requiring immediate surgery. Advanced Renal Cell Carcinoma (RCC) WELIREG is indicated for the treatment of adult patients with advanced renal cell carcinoma (RCC) following a programmed death receptor-1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI). Selected Safety Information for WELIREG Warning: Embryo-Fetal Toxicity Exposure to WELIREG during pregnancy can cause embryo-fetal harm. Verify pregnancy status prior to the initiation of WELIREG. Advise patients of these risks and the need for effective non-hormonal contraception as WELIREG can render some hormonal contraceptives ineffective. Anemia WELIREG can cause severe anemia that can require blood transfusion. Monitor for anemia before initiation of, and periodically throughout, treatment. Transfuse patients as clinically indicated. For patients with hemoglobin <8 g/dL, withhold WELIREG until ≥8 g/dL, then resume at the same or reduced dose or permanently discontinue WELIREG, depending on the severity of anemia. For life-threatening anemia or when urgent intervention is indicated, withhold WELIREG until hemoglobin ≥8 g/dL, then resume at a reduced dose or permanently discontinue WELIREG. In LITESPARK-004 (N=61), decreased hemoglobin occurred in 93% of patients with VHL disease and 7% had Grade 3 events. Median time to onset of anemia was 31 days (range: 1 day to 8.4 months). The safety of erythropoiesis-stimulating agents (ESAs) for treatment of anemia in patients with VHL disease treated with WELIREG has not been established. In LITESPARK-005 (n=372), decreased hemoglobin occurred in 88% of patients with advanced RCC and 29% had Grade 3 events. Median time to onset of anemia was 29 days (range: 1 day to 16.6 months). Of the patients with anemia, 22% received transfusions only, 20% received ESAs only, and 12% received both transfusion and ESAs. Hypoxia WELIREG can cause severe hypoxia that may require discontinuation, supplemental oxygen, or hospitalization. Monitor oxygen saturation before initiation of, and periodically throughout, treatment. For decreased oxygen saturation with exercise (e.g., pulse oximeter <88% or PaO2 ≤55 mm Hg), consider withholding WELIREG until pulse oximetry with exercise is greater than 88%, then resume at the same or a reduced dose. For decreased oxygen saturation at rest (e.g., pulse oximeter <88% or PaO2 ≤55 mm Hg) or when urgent intervention is indicated, withhold WELIREG until resolved and resume at a reduced dose or discontinue. For life-threatening or recurrent symptomatic hypoxia, permanently discontinue WELIREG. Advise patients to report signs and symptoms of hypoxia immediately to a healthcare provider. In LITESPARK-004, hypoxia occurred in 1.6% of patients. In LITESPARK-005, hypoxia occurred in 15% of patients and 10% had Grade 3 events. Of the patients with hypoxia, 69% were treated with oxygen therapy. Median time to onset of hypoxia was 30.5 days (range: 1 day to 21.1 months). Embryo-Fetal Toxicity Based on findings in animals, WELIREG can cause fetal harm when administered to a pregnant woman. Advise pregnant women and females of reproductive potential of the potential risk to the fetus. Advise females of reproductive potential to use effective non-hormonal contraception during treatment with WELIREG and for 1 week after the last dose. WELIREG can render some hormonal contraceptives ineffective. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with WELIREG and for 1 week after the last dose. Adverse Reactions In LITESPARK-004, serious adverse reactions occurred in 15% of patients, including anemia, hypoxia, anaphylaxis reaction, retinal detachment, and central retinal vein occlusion (1 patient each). WELIREG was permanently discontinued due to adverse reactions in 3.3% of patients for dizziness and opioid overdose (1.6% each). Dosage interruptions due to an adverse reaction occurred in 39% of patients. Those which required dosage interruption in >2% of patients were fatigue, decreased hemoglobin, anemia, nausea, abdominal pain, headache, and influenza-like illness. Dose reductions due to an adverse reaction occurred in 13% of patients. The most frequently reported adverse reaction which required dose reduction was fatigue (7%). The most common adverse reactions (≥25%), including laboratory abnormalities, that occurred in patients who received WELIREG were decreased hemoglobin (93%), fatigue (64%), increased creatinine (64%), headache (39%), dizziness (38%), increased glucose (34%), and nausea (31%). In LITESPARK-005, serious adverse reactions occurred in 38% of patients. The most frequently reported serious adverse reactions were hypoxia (7%), anemia (5%), pneumonia (3.5%), hemorrhage (3%), and pleural effusion (2.2%). Fatal adverse reactions occurred in 3.2% of patients who received WELIREG, including sepsis (0.5%) and hemorrhage (0.5%). WELIREG was permanently discontinued due to adverse reactions in 6% of patients. Adverse reactions which resulted in permanent discontinuation (≥0.5%) were hypoxia (1.1%) and hemorrhage (0.5%). Dosage interruptions due to an adverse reaction occurred in 39% of patients. Of the patients who received WELIREG, 28% were 65 to 74 years, and 10% were 75 years and over. Dose interruptions occurred in 48% of patients ≥65 years of age and in 34% of younger patients. Adverse reactions which required dosage interruption in ≥2% of patients were anemia (8%), hypoxia (5%), COVID-19 (4.3%), fatigue (3.2%), and hemorrhage (2.2%). Dose reductions due to an adverse reaction occurred in 13% of patients. Dose reductions occurred in 18% of patients ≥65 years of age and in 10% of younger patients. The most frequently reported adverse reactions which required dose reduction (≥1.0%) were hypoxia (5%) and anemia (3.2%). The most common (≥25%) adverse reactions, including laboratory abnormalities, were decreased hemoglobin (88%), fatigue (43%), musculoskeletal pain (33%), increased creatinine (34%), decreased lymphocytes (34%), increased alanine aminotransferase (32%), decreased sodium (31%), increased potassium (29%), and increased aspartate aminotransferase (27%). Drug Interactions Coadministration of WELIREG with inhibitors of UGT2B17 or CYP2C19 increases plasma exposure of belzutifan, which may increase the incidence and severity of adverse reactions. Monitor for anemia and hypoxia and reduce the dosage of WELIREG as recommended. Coadministration of WELIREG with CYP3A4 substrates decreases concentrations of CYP3A4 substrates, which may reduce the efficacy of these substrates or lead to therapeutic failures. Avoid coadministration with sensitive CYP3A4 substrates. If coadministration cannot be avoided, increase the sensitive CYP3A4 substrate dosage in accordance with its Prescribing Information. Coadministration of WELIREG with hormonal contraceptives may lead to contraceptive failure or an increase in breakthrough bleeding. Lactation Because of the potential for serious adverse reactions in breastfed children, advise women not to breastfeed during treatment with WELIREG and for 1 week after the last dose. Females and Males of Reproductive Potential WELIREG can cause fetal harm when administered to a pregnant woman. Verify the pregnancy status of females of reproductive potential prior to initiating treatment with WELIREG. Use of WELIREG may reduce the efficacy of hormonal contraceptives. Advise females of reproductive potential to use effective non-hormonal contraception during treatment with WELIREG and for 1 week after the last dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with WELIREG and for 1 week after the last dose. Based on findings in animals, WELIREG may impair fertility in males and females of reproductive potential and the reversibility of this effect is unknown. Pediatric Use Safety and effectiveness of WELIREG in pediatric patients under 18 years of age have not been established. Please see Prescribing Information, including information for the Boxed Warning about embryo-fetal toxicity, for WELIREG (belzutifan) at https://www-merck-com.libproxy1.nus.edu.sg/product/usa/pi_circulars/w/welireg/welireg_pi.pdf and Medication Guide for WELIREG at https://www-merck-com.libproxy1.nus.edu.sg/product/usa/pi_circulars/w/welireg/welireg_mg.pdf . About Exelixis Exelixis is a globally ambitious oncology company innovating next-generation medicines and regimens at the forefront of cancer care. Powered by drug discovery and development excellence, we are rapidly evolving our product portfolio to target an expanding range of tumor types and indications with our clinically differentiated pipeline of small molecules, antibody-drug conjugates and other biotherapeutics. This comprehensive approach harnesses decades of robust investment in our science and partnerships to advance our investigational programs and extend the impact of our flagship commercial product, CABOMETYX® (cabozantinib). Exelixis is driven by a bold scientific pursuit to create transformational treatments that give more patients hope for the future. For information about the company and its mission to help cancer patients recover stronger and live longer, visit www.exelixis.com , follow @ExelixisInc on X (Twitter), like Exelixis, Inc. on Facebook and follow Exelixis on LinkedIn. Merck’s focus on cancer Every day, we follow the science as we work to discover innovations that can help patients, no matter what stage of cancer they have. As a leading oncology company, we are pursuing research where scientific opportunity and medical need converge, underpinned by our diverse pipeline of more than 25 novel mechanisms. With one of the largest clinical development programs across more than 30 tumor types, we strive to advance breakthrough science that will shape the future of oncology. By addressing barriers to clinical trial participation, screening and treatment, we work with urgency to reduce disparities and help ensure patients have access to high-quality cancer care. Our unwavering commitment is what will bring us closer to our goal of bringing life to more patients with cancer. For more information, visit https://www-merck-com.libproxy1.nus.edu.sg/research/oncology . About Merck At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit www.merck.com and connect with us on X (formerly Twitter) , Facebook , Instagram , YouTube and LinkedIn . Exelixis Forward-Looking Statements This press release contains forward-looking statements, including, without limitation, statements related to the therapeutic potential of zanzalintinib to drive patient benefit in combination with immunotherapy or targeted therapy in HNSCC and RCC indications that have unmet clinical need and Exelixis’ scientific pursuit to create transformational treatments that give more patients hope for the future. Any statements that refer to expectations, projections or other characterizations of future events or circumstances are forward-looking statements and are based upon Exelixis’ current plans, assumptions, beliefs, expectations, estimates and projections. Forward-looking statements involve risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated in the forward-looking statements as a result of these risks and uncertainties, which include, without limitation: the potential failure of the combination of zanzalintinib with each of pembrolizumab and belzutifan, as applicable, to demonstrate safety and/or efficacy in clinical trials; complexities and the unpredictability of the regulatory review and approval processes in the U.S. and elsewhere; Exelixis’ and Merck’s continuing compliance with applicable legal and regulatory requirements; the costs of conducting clinical trials; Exelixis’ dependence on third-party vendors for the development, manufacture and supply of zanzalintinib; Exelixis’ and Merck’s ability to protect its intellectual property rights; market competition; changes in economic and business conditions; and other factors affecting Exelixis and its development programs detailed from time to time under the caption “Risk Factors” in Exelixis’ most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q, and in Exelixis’ future filings with the Securities and Exchange Commission. All forward-looking statements in this press release are based on information available to Exelixis as of the date of this press release, and Exelixis undertakes no obligation to update or revise any forward-looking statements contained herein, except as required by law. Forward-Looking Statement of Merck & Co., Inc., Rahway, N.J., USA This news release of Merck & Co., Inc., Rahway, N.J., USA (the “company”) includes “forward-looking statements” within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the company’s management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline candidates that the candidates will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements. Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; the company’s ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the company’s patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions. The company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in the company’s Annual Report on Form 10-K for the year ended December 31, 2023 and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site ( www.sec.gov ). Exelixis, the Exelixis logo and CABOMETYX are registered U.S. trademarks. KEYTRUDA® and WELIREG® are registered trademarks of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, N.J., USA. ### Media Contacts: Merck Julie Cunningham (617) 519-6264 Carly Myar (917) 227-5957 Exelixis Hal Mackins For Exelixis, Inc. (415) 994-0040 Investor Contacts: Merck Peter Dannenbaum (732) 594-1579 Damini Chokshi (732) 594-1577 Exelixis Susan Hubbard EVP, Public Affairs & Investor Relations Exelixis, Inc. (650) 837-8194

非小细胞肺癌(NSCLC)是全球癌症死亡的主要原因，其中SMARCA4基因突变十分常见，会导致SWI/SNF复合物功能失活，目前尚无有效治疗方案。近年来，一些研究表明，SMARCA2是SMARCA4的合成致死靶点，开发SMARCA2降解剂有望成为治疗SMARCA4突变型肺癌的新策略。 然而，开发SMARCA2的选择性抑制剂存在挑战，因为SMARCA2与SMARCA4的同源性很高，大多数小分子抑制剂会同时作用于两种蛋白。近年来，PROTAC技术应运而生，为开发高度选择性药物提供了新思路。 YD23：首个选择性SMARCA2降解剂 德克萨斯大学 MD 安德森癌症中心近日在Cell Chem. Bio上发表文章“Enhancer reprogramming underlies therapeutic utility of a SMARCA2 degrader in SMARCA4 mutant cancer”，通过对已知SMARCA2/4溴结构域配体Gen-1进行结构改造，将其与靶向Cereblon E3连接酶配体Pomalidomide连接，成功开发了首个文献报道的选择性SMARCA2降解剂YD23 (https://doi-org.libproxy1.nus.edu.sg/10.1016/j.chembiol.2024.09.004)。 通过与SMARCA2/4 PROTAC ACBI1作对比，证明了YD23对SMARCA2具有选择性降解活性，对SMARCA4的降解活性很弱，并通过一系列实验验证了YD23的PROTAC机制。 YD23能有效抑制SMARCA4突变型肺癌细胞的生长，而对SMARCA4野生型肺癌细胞的生长没有明显影响。 增强子重编程：YD23抑制肿瘤生长的机制 YD23能显著降低SMARCA4突变型肺癌细胞系中增强子区域的染色质可及性，而对SMARCA4野生型肺癌细胞系的染色质可及性没有明显影响。 YD23能显著抑制SMARCA4突变型肺癌细胞系中细胞周期相关基因的表达，而对SMARCA4野生型肺癌细胞系的细胞周期相关基因表达没有明显影响。 YAP/TEAD：SMARCA2的关键合作蛋白 YAP/TEAD与SMARCA2共同作用，在SMARCA4突变型肺癌细胞系中增强子区域的染色质可及性中起着至关重要的作用，从而促进SMARCA4突变型肺癌细胞的生长。 体内抗肿瘤活性 该研究使用了三种SMARCA4突变型肺癌异种移植模型：H1568、H322和H2126。这三种模型分别来自不同的患者，代表了不同类型的SMARCA4突变型肺癌。该研究表明，YD23对这三种模型都有显著的抗肿瘤活性。 总而言之，YD23能显著抑制SMARCA4突变型肺癌异种移植模型的肿瘤生长，并能降低肿瘤组织中SMARCA2的表达水平。 总结与展望 该文章的主要内容是开发了一种新的针对SMARCA4突变型肺癌的治疗方法，即通过靶向降解SMARCA2来抑制肿瘤生长。通过探讨其作用机制，SMARCA2降解剂是一种很有潜力的抗癌药物，并且它可能为治疗SMARCA4突变型肺癌患者提供一种新的治疗选择。 文章中的不足，以及关于SMARCA2 PROTAC 从YD23的结构上看，很明显其成药性存在巨大的缺陷。事实也确实如此。 根据文章，YD23 是通过腹腔注射给药的。它在体内代谢很快(醚键的O-脱烷基化导致失活)，导致其血浆浓度较低。为了提高YD23在体内的暴露量，作者尝试与利托那韦联合用药，利托那韦是CYP3A4/5的抑制剂，可以减缓YD23的代谢。联合给药可以显著提高YD23在体内的暴露量，并表现出抗肿瘤活性。 目前处于临床试验阶段的选择性的SMARCA2靶向剂有Prelude的PROTAC药物PRT3789与PRT7732，以及Foghorn的抑制剂FHD-909（LY4050784）。 抑制剂FHD-909不是本文的重点，其对SMARCA4的选择性并不高。当然现在也有一些针对FHD-909改造得到选择性更高的抑制剂专利就是另外的话题了。 说回PROTAC，PRT3789是一款基于VHL的选择性SMARCA2 PROTAC，该药是一款注射剂（基于VHL的PROTAC很难实现口服），对SMARCA4的选择性超1000倍。 基于最近公开的联用专利，PRT3789的结构很可能如下： 最近ESMO202上公开了PRT3789的初步临床数据，不尽如人意。 共有 46 名患者进行了疗效评估，但纪念斯隆凯特琳癌症中心的 RobinGuo 博士在展示数据时重点关注了 26 名患有非小细胞肺癌或食道癌的患者；在该人群中，有 3 例已确认部分缓解。郭指出，20 名患有其他肿瘤类型的患者的肿瘤没有缩小。 这一结果也对Prelude的股价实行了腰斩，同时也为SMARCA2 PROTAC蒙上了浓浓的阴影。同时ESMO2024上安斯泰来的KRAS G12D PROTAC【ESMO2024--安斯泰来的KRASG12D PROTAC令人失望】与C4的BRAF PROTAC给出的初步临床结果均显得差强人意，也动摇了大家对PROTAC在肿瘤上的信心。 当然，Prelude并未放弃该项目。ESMO 获悉，提高疗效的一种途径可能是针对 SMARCA4 功能丧失突变的患者。至于联合用药，该试验已经在测试 PRT3789 加多西紫杉醇，并计划将其与 Keytruda 联合使用。 此外，此前的文章【研发前沿|选择性SMARCA2 PROTAC：合成致死新选择？】中基于各家SMARCA2 PROTAC专利提出了假设：不同E3连接酶对选择性有影响，且VHL相较于CRBN更能提升SMARCA2 PROTAC的选择性。 但很明显，本文YD23给出的结果也狠狠地打了我的脸：通过适当的改造，基于CRBN的PROTAC也能表现出出色的选择性。 Prelude最新进入临床的高选择性降解剂PRT7732，是一款基于CRBN的口服制剂，再次证明了这一点。 从专利信息可知，Prelude选择了lenalidomide作为CRBN配体，对warhead做了极大的改造，也采用了新的linker结构，满足了高选择性的同时实现了高口服生物利用度，大大提升了成药性。 至于PRT7732具体结构，目前信息太少，无法判断。随便挑一个专利中高选择性的实施例： 就这样，后续有新进展再介绍。 声明：发表/转载本文仅仅是出于传播信息的需要，并不意味着代表本公众号观点或证实其内容的真实性。据此内容作出的任何判断，后果自负。若有侵权，告知必删！ 长按关注本公众号  粉丝群/投稿/授权/广告等 请联系公众号助手 觉得本文好看，请点这里↓