Perspective Therapeutics (NYSEAMERICAN:CATX) presented updated clinical data for its VMT-α-NET program at the European Society for Medical Oncology Congress 2026, reporting tumor responses, an 18-month progression-free survival landmark rate of 72% across three cohorts and no dose-limiting toxicities in the study to date.
The company is developing VMT-α-NET for somatostatin receptor 2-positive gastroenteropancreatic neuroendocrine tumors, or GEP-NETs. Chief Executive Officer Thijs Spoor said patients whose disease progresses after treatment with a somatostatin analog have several available options, including Lutathera, everolimus, sunitinib and cabozantinib. He said Perspective believes its radiopharmaceutical could offer a favorable benefit-risk profile in this setting.
Response and Disease-Control Data
Spoor said the company has seen overall response rates of 37% among patients whose target lesions were all SSTR2-positive in the 20 mCi cohort, and 47% in the 24 mCi cohort under that more selective analysis. The broader intent-to-treat population includes patients with more heterogeneous SSTR2 expression.
The 18-month progression-free survival, or PFS, landmark rate was 72% across cohorts 1 through 3, according to the company. Spoor characterized the result as evidence of disease control, which he said is expected to be a key regulatory endpoint.
“The default setting or the backstop, no matter what, the FDA would look for is disease control,” Spoor said during the call. “What does the PFS look like as the clearest measure of disease control?”
Management also highlighted the apparent timing of responses in the 24 mCi cohort, saying the higher dose showed early indications of more rapid and deeper tumor shrinkage. Patients in the study receive four doses at weeks zero, eight, 16 and 24, then are followed for durability of response. Spoor noted that some responses have appeared as late as 60 weeks, which can cause response-rate calculations to rise as follow-up matures.
Chief Medical Officer Markus Puhlmann cautioned against direct comparisons with completed phase III trials such as NETTER-1 and NETTER-2, citing differences in study maturity and patient populations. The ongoing Perspective trial has enrolled patients with broader SSTR2 eligibility criteria, including some with heterogeneous receptor expression, he said.
Safety Profile and Renal Events
Perspective reported no grade 4 or grade 5 treatment-emergent adverse events, no treatment discontinuations related to adverse events and no dose-limiting toxicities. Spoor said the highest-grade treatment-emergent adverse events reported have been grade 3, while alopecia was the most frequently observed side effect and was described as reversible and generally mild.
The company also reported no clinically significant myelosuppression and no dysphagia. Puhlmann said the study has not observed cases of severe hematologic toxicity such as myelodysplastic syndrome or leukemia. He said the company has seen some low-grade thrombocytopenia and that leukopenia generally recovered within a treatment cycle.
Management discussed acute kidney injury events in two patients, including one event deemed unlikely to be related to VMT-α-NET that resolved and was attributed by the clinical site primarily to an allergic reaction to contrast media. Another patient had preexisting hypertension, diabetes and a history of acute kidney injury. Puhlmann also discussed a cohort 3 patient whose kidney event appeared associated with disease progression that obstructed a ureter rather than with the drug.
Spoor attributed the company’s renal-safety focus in part to the therapy’s net-neutral charge and proprietary chelator, which he said were designed to limit uptake outside the tumor and reduce leakage of alpha-emitting material.
Registrational Planning
Perspective said it is preparing for discussions with the Food and Drug Administration regarding an end-of-phase II meeting and plans to provide additional regulatory updates later this year. Belén Carrillo-Rivas, senior vice president of global regulatory affairs, said the company wants to incorporate its recently generated data into ongoing discussions with the agency.
The company said it believes the 20 mCi regimen has sufficient follow-up and a favorable benefit-risk profile to support movement into a registrational study. Spoor said Perspective could potentially begin such a study using the 20 mCi dose and, under a predefined protocol approach, later transition to 24 mCi if supported by additional data.
Management said it would prefer a treating-physician-choice control arm for a potential pivotal trial. Puhlmann said possible options in such an arm could include peptide receptor radionuclide therapy, VEGF tyrosine kinase inhibitors including sunitinib and cabozantinib, everolimus, and chemotherapy in certain more aggressive disease settings.
The company said approximately 60% to 75% of patients screened could fit a potential more narrowly defined registrational population requiring homogeneous SSTR2 expression. It also plans to present additional data at the upcoming North American Neuroendocrine Tumor Society meeting.
About Perspective Therapeutics (NYSEAMERICAN:CATX)
Perspective Therapeutics, Inc is a biotechnology company developing precision-targeted radiopharmaceutical treatments for cancer. The company’s platform is designed to deliver alpha-particle radiation directly to tumor cells by pairing radioactive isotopes with molecules that bind to specific cancer targets, with the goal of limiting damage to surrounding healthy tissue.
The company’s lead programs include VMT-α-NET, an investigational therapy directed at somatostatin receptor 2, a target commonly expressed by neuroendocrine tumors.
