Chikungunya virus vaccine (Valneva)

The end of the FDA's rare pediatric PRV program could lead to increased value of the tropical disease PRVs, lawyers at Hyman, Phelps & McNamara recently suggested. The FDA approval of Vimkunya has given the chikungunya vaccine’s owner, Bavarian Nordic, an extra financial windfall.Bavarian Nordic has reached an agreement to sell a priority review voucher (PRV) gained from Vimkunya’s approval to an unnamed buyer for $160 million, the Danish company said Wednesday. The FDA awarded the PRV under its tropical disease program.Bavarian got the shot in 2023 as part of the company’s acquisition of Emergent BioSolutions’ travel health business for $270 million upfront. As the vaccine was originally licensed from the National Institutes of Health, the government research agency will receive 20% of the proceeds from the PRV sale.Gains from the PRV sale will be recorded as operating income, so Bavarian expects an increase in its projected profits for 2025.PRVs are coveted commodities in the biopharma industry because they can slash the FDA’s review time of drug applications from the standard 10 months to six months. And the price of PRVs seems to be on the rise.It was only in February 2024 that Valneva monetized a PRV obtained from the FDA approval of the U.S.’s first approved chikungunya vaccine, Ixchiq, for $103 million. The general understanding at that time was that PRVs could sell for about $100 million.A notable uptick in PRV prices started later in 2024. In August, Ipsen said it would receive $158 million from selling its PRV tied to the FDA approval of the company’s rare disease drug Sohonos.In three transactions unveiled in November and February, PTC Therapeutics, Acadia Pharmaceuticals and Zevra Therapeutics all sold their PRVs for $150 million.The rise in the monetary value of PRVs came as concerns mounted over declining supplies. The future of the FDA’s rare pediatric disease PRV program, which was designed to incentivize the development of therapies for rare pediatric diseases, came into serious question as the program was sunset in December 2024 after a lapse in its Congressional reauthorization. As a result, the FDA may only award PRVs under this pathway for drugs that have already received a rare pediatric disease designation before Dec. 20, 2024, and the agency may not award any such PRVs after Sep. 30, 2026.There have been calls for the renewal of the program, including at an FDA cell and gene therapy roundtable earlier this month. Still, there’s no clear sign that the initiative will be revived, and critics have raised concerns that the ability to sell PRVs at high prices distorted the original purpose of the program.The impact of the loss of the rare pediatric disease PRV program on the market supply of PRVs is significant. About 70% of all PRVs that have been awarded since 2009 were for therapies against rare pediatric diseases, according to a recent analysis by the law firm Hyman, Phelps & McNamara.In an article published in February, lawyers at HPM suggested the end of the rare pediatric PRV program could lead to increased value of the tropical disease PRVs, potentially to a level that’s on par with the record $350 million that AbbVie paid United Therapeutics in 2015.Meanwhile, the FDA just introduced a new PRV program, which is designed to shorten the drug review time to as little as one or two months. Called the “Commissioner’s National Priority Voucher” (CNPV), the coupon will be given to “companies aligned with U.S. national priorities,” the FDA said Tuesday. But unlike existing PRVs, CNPVs are non-transferrable, according to the FDA. As for Bavarian Nordic, the vaccine specialist is differentiating itself from rival Valneva not only when it comes to PRV sale prices. In May, the FDA and the CDC recommended a pause in the use of Valneva’s Ixchiq in people 60 years of age and older following postmarketing reports of some serious adverse events, including two deaths, in those who had received the vaccine.Before that, Bavarian’s Vimkunya in April picked up a recommendation from the CDC’s Advisory Committee on Immunization Practices for individuals aged 12 and older traveling to places where there is a chikungunya outbreak, as well as for people who plan extended stays in areas at elevated risk and for certain lab workers.Vimkunya was approved in April with a broader FDA label reaching individuals as young as 12 years of age, whereas Ixchiq is only cleared in adults. Ixchiq is a live-attenuated vaccine, compared with Vimkunya’s virus-like particle construct. 

近期，全球首个获批上市的基孔肯雅疫苗——由法国Valneva公司研发的单剂量减毒活疫苗IXCHIQ®，在65岁及以上人群中出现了多起严重不良反应案例，引发了包括美国、欧盟和法国在内的多国监管机构的密切关注。部分国家已经暂停该疫苗在老年人中的使用，并启动了进一步的安全审查。疫苗背景：首个获得FDA批准的基孔肯雅疫苗基孔肯雅病毒（Chikungunya virus，CHIKV）是一种通过蚊子传播的病毒，可引起突发性高热、严重关节疼痛，部分患者症状可能持续数月甚至更久，严重影响生活质量。根据WHO数据，自2004年起，该病毒已在超过110个国家或地区引发暴发，尤其在非洲、亚洲、印度洋地区和美洲流行。IXCHIQ®于2023年11月获美国FDA批准，用于18岁及以上人群，是首个针对CHIKV的疫苗。该疫苗采用减毒活病毒平台，仅需接种一剂即可产生免疫保护。根据Valneva的数据，在III期临床试验中：接种后28天，98.9%的受试者产生了中和抗体；三年后，96%的受试者仍保持高水平抗体滴度；各年龄组均表现出良好的免疫持久性。风险暴露：老年人群中出现严重不良事件然而，进入实际使用阶段后，一些老年接种者在接种疫苗后出现了与心脏或神经系统相关的严重不良事件，引起了全球公共卫生部门的高度警觉：美国：CDC和FDA通报称，有6名65岁以上接种者在接种疫苗一周内出现心脏或神经系统症状，包括心律异常和脑神经损伤等，其中多数人有基础病史。此外，还有约10余起国际类似案例被报告。欧盟：欧洲药品管理局（EMA）正在评估来自多个成员国的17起严重不良事件报告，患者年龄为62至89岁，报告中包括2例死亡。EMA已建议限制该疫苗在65岁及以上人群中的使用，等待进一步风险评估。法国：在海外属地留尼汪岛的疫苗接种活动中，共报告了3例严重不良事件，包括1例死亡。该岛自2025年初以来已报告超过4万例CHIKV感染病例，法国国家药品与健康产品安全局（ANSM）宣布暂停该疫苗在65岁以上人群的使用。全球监管应对举措针对以上情况，多国监管部门迅速做出响应：CDC疫苗顾问小组建议对65岁及以上人群使用IXCHIQ®时需特别谨慎，并呼吁医生与患者充分沟通风险与收益。同时，CDC还建议批准由Bavarian Nordic公司开发的另一款基孔肯雅疫苗Vimkunya，用于12岁及以上旅行者接种。EMA已启动正式安全审查程序（PSUR），并临时限制老年人接种。法国直接暂停使用，并强调将依据后续药物警戒分析决定是否恢复接种。老年人群或更易出现疫苗相关不良反应老年人群体免疫功能下降且常伴有基础慢性疾病（如高血压、心血管病、糖尿病等），在接种减毒活疫苗后可能更易诱发严重不良反应。虽然在III期临床中未观察到显著风险，但真实世界使用中的人群复杂性更高，往往会暴露出临床试验未覆盖的潜在安全隐患。这也说明疫苗在进入大规模接种后，持续的药物警戒和风险管理策略是必不可少的。Valneva的IXCHIQ®疫苗在疫苗研发史上具有重要意义，为应对基孔肯雅病毒这一全球性传染病提供了新的工具。然而，当前在老年人群中的安全信号提醒我们：不同人群需精准评估风险：尤其是高龄、有慢病者接种前应与医生充分沟通；监管部门应加强风险监测：早发现、早通报、早调整使用策略；疫苗开发需更关注老年人群数据积累：未来应在临床试验中更系统性评估老年组的长期安全性；公众应获取权威信息，理性看待疫苗接种利与弊。在全球旅行与气候变化背景下，蚊媒病毒感染风险日益加剧，疫苗仍是有效的防控手段之一。但疫苗安全性必须建立在科学、透明和持续监测的基础上。参考来源：https://www.pharmaceutical-technology.com/news/valnevas-chikungunya-vaccine-use-halted-in-older-adults-amid-safety-concerns/?cf-view&cf-closed识别微信二维码，可添加药时空小编请注明：姓名+研究方向！