Perspective Therapeutics Provides Recent Business Highlights and Reports Fiscal 3Q 2024 Results

   -- Advancing investigation of [212Pb]VMT01 as a monotherapy and in 
      combination with the anti-PD-1 antibody, nivolumab, in patients with 
      previously treated metastatic melanoma, based on preliminary results 
      presented at the 21st International Congress of the Society of Melanoma 
      Research in October 
 
   -- Presenting initial results from the company-sponsored Phase 1/2a study of 
      [212Pb]VMT-<ALPHA>-NET in patients with RPT-naïve neuroendocrine 
      tumors at the upcoming 2024 North American Neuroendocrine Tumor Society 
      Symposium in November 
 
   -- Shipping of investigational product started in October from a second 
      manufacturing facility in Somerset, New Jersey; additional facility 
      expansion activities ongoing 
 
   -- On track to advance multiple pre-IND assets into the clinic in the next 
      9-18 months 
 
   -- Cash, cash equivalents, and short-term investments balance of 
      approximately $268 million expected to be sufficient to fund our current 
      planned operations and capital investments into mid-2026 

SEATTLE, Nov. 12, 2024 (GLOBE NEWSWIRE) -- Perspective Therapeutics, Inc. ("Perspective," the "Company," "we," "us," and "our") (NYSE AMERICAN: CATX), a radiopharmaceutical company that is pioneering advanced treatment applications for cancers throughout the body, today announced third quarter financial results for the period ended September 30, 2024.

"Since our team initiated dosing of U.S. patients in two clinical programs in 2023, important learnings on each of these two clinical-stage constructs and the applicability of our proprietary radiopharmaceutical platform in a variety of clinical settings have informed our strategy to bring innovative precision medicines to patients based on alpha-emitting isotopes and targeting moiety optimization," said Thijs Spoor, Perspective's CEO. "At the time same, we continue to invest in developing proprietary compounds and building out a network of regional manufacturing sites to service treatment centers and patients, which currently consists of two active sites as well as three buildings being modified in anticipation of delivery of equipment already on order. We look forward to continued progress in the coming months and in 2025."

Program Highlights

VMT-<ALPHA>-NET

Company-sponsored Phase 1/2a trial of [(212) Pb]VMT-<ALPHA>-NET

We are conducting a multi-center open-label dose escalation, dose expansion study (clinicaltrials.gov identifier NCT05636618) of [(212) Pb]VMT-<ALPHA>-NET in patients with unresectable or metastatic somatostatin receptor type 2 (SSTR2)-positive neuroendocrine tumors (NETs) who have not received prior radiopharmaceutical therapies $(RPT)$. We received Fast Track Designation for this program from the U.S. Food and Drug Administration (FDA) based on preclinical data for SSTR2-positive NETs regardless of prior treatment response.

As stated in our 2Q 2024 quarterly update in August 2024, the observation period was completed for dose limiting toxicity $(DLT.AU)$ in seven patients enrolled in Cohort 2 during the second quarter of 2024. Subsequently, the Safety Monitoring Committee $(SMC)$ determined that safety observations during the DLT period supported proceeding with dose escalation to Cohort 3 and increasing the number of patients dosed at 5 mCi (up to 40 more patients). Based on FDA interactions prior to the initiation of patient dosing in this study, the decision to open Cohort 3 will follow consultation and alignment with the agency.

During the quarter, data informing the SMC's recommendation were submitted to and accepted for presentation at the 2024 North American Neuroendocrine Tumor Society (NANETS) Multidisciplinary NET Medical Symposium taking place November 21-23, 2024 in Chicago. We will host an investor call at the start of the conference; details on the call will be available prior to the conference.

Investigator-initiated clinical research of [(212) Pb]VMT-<ALPHA>-NET

We are collaborating with a number of thought leaders to further elucidate the clinical profile of [(212) Pb]VMT-<ALPHA>-NET through investigator-initiated studies in the U.S. as well as overseas.

Investigator Led Study in India

This is an exploratory first-in-human use of [(212) Pb]VMT-<ALPHA>-NET in adult patients with histologically confirmed metastatic NETs and medullary thyroid carcinomas in an investigator-led research study. A total of 13 patients were enrolled: 10 patients with gastroenteropancreatic-NETs (GEP-NETs), one patient with breast NETs, and two patients with medullary thyroid carcinomas.

The most recent scientific conference presentation by the investigator was during the 37th Annual Congress of the European Association of Nuclear Medicine (EANM) meeting in October 2024. The investigator reported updated safety and anti-tumor activity of [(212) Pb]VMT-<ALPHA>-NET administered at 67 uCi/kg (2.5 MBq/kg) every 8 weeks for up to 6 doses in 10 patients with GEP-NETs as of the data cut-off date of September 15, 2024. All patients received prior treatments, seven of whom received prior RPT treatment.

The investigator concluded that the toxicity profile suggests the potential for dose escalation to achieve optimal treatment responses. Confirmed tumor response per RECIST 1.1 was reported to be observed in six of the 10 patients, while unconfirmed responses were observed in two additional patients who eventually had progressive disease and died. The investigator also reported higher absorbed doses in the tumors compared to select other tissues.

VMT01

We designed VMT01 to target and deliver (212) Pb to tumor sites expressing melanocortin 1 receptor (MC1R), a protein that can be overexpressed in metastatic melanoma tumors. We are conducting a multi-center, open-label dose escalation, dose expansion study (clinicaltrials.gov identifier NCT05655312) in previously treated patients with histologically confirmed melanoma and MC1R-positive imaging scans.

   -- In July 2024, we submitted a protocol amendment to explore the 
      combination of the checkpoint inhibitor nivolumab with [212Pb]VMT01 in 
      patients with histologically confirmed melanoma and positive MC1R imaging 
      scans in our ongoing Phase 1/2a study of [212Pb]VMT01. The first 
      combination cohort is now open for enrollment. The supply of nivolumab 
      was secured in March 2024, when we entered into a clinical trial 
      collaboration agreement with Bristol Myers Squibb $(BMY)$. 
 
   -- As of August 9, 2024, we initiated dosing of a total of 10 patients in 
      Cohort 1 and in Cohort 2 of the Phase 1/2a clinical study of [212Pb]VMT01 
      in patients with progressive MC1R-positive metastatic melanoma. A total 
      of seven patients received activities of 5mCi of [212Pb]VMT01 in Cohort 
      2. 
 
   -- On September 5, 2024, we announced the FDA granted Fast Track Designation 
      for the development of [212Pb]VMT01 for the diagnosis and treatment of 
      patients with unresectable or metastatic melanoma and who have 
      demonstrated MC1R tumor expression. 

On October 11, 2024, we announced initial results from the first two dosing cohorts. Three patients were enrolled in Cohort 1 (who received 3 mCi of [(212) Pb]VMT01), while seven patients were enrolled in Cohort 2 (who received 5 mCi of [(212) Pb]VMT01). Patients in each cohort received a median of five prior lines of systematic therapy, including a median of three prior lines of immunotherapy.

   -- Safety findings: No dose-limiting toxicities were observed among any 
      patients, and no adverse events led to treatment discontinuation. 
      Treatment emergent adverse events (TEAEs) were mostly Grades 1 and 2. 
      None of the four cases of grade 3 TEAEs were deemed to be treatment 
      related. There were no grade 4 or 5 TEAEs. No renal toxicities had been 
      reported as of October 11, 2024 (there were no clinically significant 
      changes in blood urea nitrogen or serum creatinine) in spite of dosimetry 
      estimated renal radiation that approached the higher end of conventional 
      dosing. 
 
   -- Efficacy findings: All patients in Cohort 1 completed three treatments, 
      with one patient experiencing an unconfirmed RECIST version 1.1 objective 
      response after completion of treatment, and two patients experiencing 
      stable disease at 9 and 11 months from the start of treatment, 
      respectively. In Cohort 2, patients progressed after either the first 
      cycle (three patients) or the second cycle (four patients). These 
      findings are consistent with published and ongoing preclinical studies 
      showing immunostimulatory effects at lower radiation doses. 

The SMC reviewed these findings and recommended exploring a lower dose level of 1.5 mCi per dose, both as a single agent and in combination with the anti-PD-1 antibody, nivolumab. The SMC's recommendation would allow for the monotherapy and combination cohorts to proceed concurrently. An amendment to further explore lower dose levels for monotherapy is planned. The combination cohort at 1.5 mCi per dose with nivolumab is active and now open for enrollment.

Status of pre-IND assets

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November 12, 2024 16:05 ET (21:05 GMT)