[212Pb]VMT-α-NET

SEATTLE, WA, USA I May 30, 2025 I Perspective Therapeutics, Inc. (“Perspective” or the “Company”) (NYSE AMERICAN: CATX), a radiopharmaceutical company pioneering advanced treatments for cancers throughout the body, announced that updated interim results from its ongoing Phase 1/2a clinical trial of [ 212 Pb]VMT-α-NET were presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting taking place May 30-June 3, 2025 in Chicago, Illinois. This Phase 1/2a clinical trial is a multi-center open-label dose escalation and dose expansion study (clinicaltrials.gov identifier NCT05636618 ) of [ 212 Pb]VMT-α-NET in patients with unresectable or metastatic somatostatin receptor type 2 (SSTR2) expressing neuroendocrine tumors (NETs) who have not received prior radiopharmaceutical therapy (RPT) and whose tumors have shown radiological evidence of disease progression in the 12 months prior to enrollment. Updated interim efficacy data were presented for two patients in Cohort 1 and seven patients in Cohort 2 with a data cut-off date of April 30, 2025. These patients were enrolled for dose limiting toxicities observations. Results with a data cut-off date of January 10, 2025 from these patients were previously presented as a poster at the ASCO Gastrointestinal Cancers Symposium (ASCO-GI) in January 2025. Cohort 2 was reopened for enrollment in August 2024, and through April 30, 2025, a further 33 patients were enrolled in Cohort 2 and had received at least one treatment. Safety data were presented at the ASCO Annual Meeting for all 42 patients who had received at least one treatment with [ 212 Pb]VMT-α-NET. A modest number of patients experienced low grade hematologic toxicities. Observations of lymphocyte count decrease were generally low grade, with three events at Grade 3 and none at Grades 4 or 5. Increases in blood creatinine levels were all at Grade 1. No dysphagia or serious renal complications were reported. Seven out of nine patients in Cohorts 1 and 2 continued to experience disease control and remained in study. One patient experienced stable disease for 48 weeks after their first dose prior to experiencing progressive disease. One patient was previously reported to have progressive disease after one dose under RECIST v1.1, by unambiguous progression of non-target lesions. The first patient who experienced a confirmed objective response remained in response for over 10 months and in study. This patient received the first two [ 212 Pb]VMT-α-NET doses at administered dose of 5.0 mCi (equivalent to 84.6 µCi/kg), then received the remaining two doses at the next lower activity level of 2.5 mCi (equivalent to 42.4 µCi/kg). Two patients experienced initial responses after the end of their treatment periods as of the data cut-off date for the previous data presentation at ASCO-GI. Those responses have since been confirmed in subsequent scans. They remained in response and in study. These patients received four doses of 5.0 mCi (equivalent to 68.7 µCi/kg and 31.7 µCi/kg) of [ 212 Pb]VMT-α-NET. A fourth patient was observed to experience an initial (unconfirmed) response in the seventh scan at 48 weeks after their first dose, which was the third scan conducted after the end of their treatment period. This patient received four doses of 5.0 mCi (equivalent to 49.1 µCi/kg) of [ 212 Pb]VMT-α-NET. As stated in our August 12, 2024 business update for the second quarter of 2024, the observation period was completed for DLTs in seven patients enrolled in Cohort 2 during the second quarter of 2024. With no DLTs observed and minimal toxicity overall, the Safety Monitoring Committee (SMC) recommended proceeding with dose escalation and enrolling additional patients at 5 mCi to better understand efficacy and safety. Based on interactions with the U.S. Food and Drug Administration (FDA) prior to the initiation of patient dosing in this study in late 2023, the decision to dose patients in the next cohort will follow consultation and alignment with the FDA. “[ 212 Pb]VMT-α-NET is emerging as an exciting potential treatment option for patients with progressive NETs, with continued durability of anti-tumor activity at the dose level used in Cohort 2 and a favorable tolerability profile seen so far,” said Vikas Prasad, MD, Associate Professor of Radiology, Mallinckrodt Institute of Radiology, Siteman Cancer Center, Washington University School of Medicine. “I am eager to find more treatments to help my patients fight hard against their disease and return to their normal lives. I look forward to continuing to evaluate [ 212 Pb]VMT-α-NET as a new option to help my patients, by participating in this study.” Markus Puhlmann, Chief Medical Officer of Perspective, commented, “We are encouraged by the exciting overall clinical profile already observed at the dose level used in Cohort 2. The robust participation in the re-opened Cohort 2 in this dose finding study of [ 212 Pb]VMT-α-NET enables us to learn more about how [ 212 Pb]VMT-α-NET can benefit patients and fit into the current treatment paradigm. We plan to submit longer safety follow-up data for all patients enrolled in the study and preliminary efficacy data for a subgroup for presentation at a scientific congress in the second half of this year. In keeping with the commitment we made to the FDA prior to the start of dosing in this study, we are engaging with the FDA as we wish to continue to pursue dose finding for [ 212 Pb]VMT-α-NET. An update will be provided once alignment is reached with the agency.” Thijs Spoor, Chief Executive Officer of Perspective, commented, “[ 212 Pb]VMT-α-NET is progressing expeditiously as one of three potential new medicines in clinical development based on our next generation targeted radiopharmaceutical technology platform. We continue to evaluate opportunities to enhance our operations and infrastructure so we can support patient demand for all of our programs.” Perspective will webcast a conference call on Monday, June 2, 2025 at 8:00 am ET to discuss the data presented at the ASCO Annual Meeting. Webcast details are available on the Events page of the Company’s website. Dr. Prasad will participate, along with members of Perspective’s management team. A live question and answer session will follow the formal presentation. About [ 212 Pb]VMT-α -NET Perspective designed [ 212 Pb]VMT-α-NET to target and deliver 212 Pb to tumor sites expressing SSTR2. The Company is conducting a multi-center, open-label dose escalation, dose expansion study (clinicaltrials.gov identifier NCT05636618 ) of [ 212 Pb]VMT-α-NET in patients with unresectable or metastatic SSTR2-positive neuroendocrine tumors who have not received prior radiopharmaceutical therapies (RPT). Results with a data cut-off date of January 10, 2025 from the first nine patients enrolled into Cohorts 1 and 2 of the study were previously presented as a poster at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium ( ASCO-GI ) in January 2025. Cohort 2 was reopened in August 2024. During 2H 2025, some of the 33 patients enrolled after the cohort reopened and through April 30, 2025, will have had the opportunity for at least 32 weeks of follow-up after their initial doses, sufficient time to receive at least one scan after their full treatment (up to four doses every eight weeks), if they receive all four doses of treatment per protocol. About Neuroendocrine Tumors Neuroendocrine tumors form in cells that interact with the nervous system or in glands that produce hormones. They can originate in various parts of the body, most often in the gut or the lungs and can be benign or malignant. Neuroendocrine tumors are typically classified as pancreatic neuroendocrine tumors or non-pancreatic neuroendocrine tumors. According to cancer.net, it is estimated that more than 12,000 people in the United States are diagnosed with a NET each year. Importantly, neuroendocrine tumors are associated with a relatively long duration of survival compared to other tumors and as a result, there are over 170,000 people living with this diagnosis. 1 About Perspective Therapeutics, Inc. Perspective Therapeutics, Inc. is a radiopharmaceutical development company that is pioneering advanced treatments for cancers throughout the body. The Company has proprietary technology that utilizes the alpha-emitting isotope 212 Pb to deliver powerful radiation specifically to cancer cells via specialized targeting moieties. The Company is also developing complementary imaging diagnostics that incorporate the same targeting moieties, which provides the opportunity to personalize treatment and optimize patient outcomes. This “theranostic” approach enables the ability to see the specific tumor and then treat it to potentially improve efficacy and minimize toxicity. The Company’s melanoma (VMT01), neuroendocrine tumor (VMT-α-NET) and solid tumor (PSV359) programs are in Phase 1/2a imaging and therapy trials in the U.S. The Company is growing its regional network of drug product candidate finishing facilities, enabled by its proprietary 212 Pb generator, to deliver patient-ready product candidates for clinical trials and commercial operations. For more information, please visit the Company’s website at www.perspectivetherapeutics.com . 1 Wu P, He D, Chang H, Zhang X. Epidemiologic trends of and factors associated with overall survival in patients with neuroendocrine tumors over the last two decades in the USA. Endocr Connect . 2023;12(12):e230331. Published 2023 Nov 23. doi:10.1530/EC-23-0331. SOURCE: Perspective Therapeutics