Perspective Therapeutics Presents Promising [212Pb]Lapemelanotide Zapixetar (VMT01) Monotherapy Data from a Phase 1/2a Study in Heavily Pretreated Advanced Melanoma Patients at SITC 2026

Across 20 monotherapy patients, no treatment-related serious adverse events or adverse-event-related treatment discontinuations were reported.

Rhea-AI Summary

Perspective Therapeutics (CATX) reported interim Phase 1/2a results for lapemelanotide zapixetar monotherapy in heavily pretreated advanced melanoma, showing 75% disease control at the focus dose.

At 3.0 mCi, two of eight enrolled patients had partial tumor responses; one remained in partial response and on study approximately 40 weeks after first treatment. Disease control included two patients with long-lasting disease stabilization. The eighth patient was not yet eligible for a first tumor assessment.

Across 20 patients in three dose cohorts as of September 18, 2026, no dose-limiting toxicities, treatment-related serious adverse events or adverse-event-related treatment discontinuations were reported. Grade 3 or higher adverse events occurred in five patients (25%); none were considered treatment-related. The company plans continued evaluation and dose optimization to inform future development.

Positive

• Minor pointThe 3.0 mCi cohort had 75% disease control, including two patients with long-lasting disease stabilization.
• Minor pointPartial responses occurred in two of eight enrolled patients; one remained in response and on study approximately 40 weeks after first treatment.
• Minor pointAcross 20 patients, no dose-limiting toxicities, treatment-related serious adverse events or adverse-event-related treatment discontinuations were reported.
• Minor point. Forward-looking: it has not happened yet and may not happen.Perspective plans continued evaluation and dose optimization to inform future clinical development.

Negative

• Minor pointGrade 3 or higher adverse events occurred in five patients (25%); none were considered treatment-related.
• Minor pointThe interim Phase 1/2a update covered 20 treated patients; the eighth 3.0 mCi patient was not yet eligible for assessment.

Key Figures

Partial responses: 2 of 8 patients Disease control rate: 75% Durable partial response: Approximately 40 weeks +2 more

Partial responses

2 of 8 patients

3.0 mCi monotherapy cohort

Disease control rate

75%

3.0 mCi monotherapy dose

Durable partial response

Approximately 40 weeks

One responder remained on study in partial response

Dose-limiting toxicities and treatment-related serious adverse events

0 reported across 20 patients

Monotherapy dose cohorts

Grade 3 or higher treatment-emergent adverse events

5 patients (25%)

None considered treatment-related

Historical Context

1 past event · Latest: Oct 02

1 event

1. Oct 02

   Clinical data

   24h Move

   +1.5%

   Earlier VMT01 melanoma update reported two responders among seven patients at the 3.0 mCi dose.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

dose-limiting toxicities, treatment-emergent adverse events, disease control rate, dose escalation, +1 more

5 terms

dose-limiting toxicities medical

"no dose-limiting toxicities (DLTs), treatment-related serious treatment-emergent adverse events"

Dose-limiting toxicities are the harmful side effects seen in early clinical trials that are severe enough to stop researchers from raising a drug’s dose. Like a car’s speed limiter marking the safe top speed, DLTs define the maximum tolerable dose, and they matter to investors because they determine whether a medicine can reach effective levels, influence development timelines, costs, and regulatory chances, and thus affect a drug’s commercial prospects.

treatment-emergent adverse events medical

"Grade 3 or higher TEAEs occurred in five patients (25%)"

Events or symptoms that either appear for the first time or get worse after a patient starts a treatment; think of new or intensified side effects that show up once medicine or a medical device is used. Investors watch these closely because they affect whether a therapy can gain regulatory approval, be prescribed widely, or face legal and commercial setbacks—similar to how early customer complaints can sink a new product’s prospects.

disease control rate medical

"The disease control rate (DCR) was 75%"

The disease control rate is the share of patients in a clinical trial whose cancer or condition either shrinks or stops getting worse for a specified period after treatment. Think of it like the percentage of people for whom a treatment hits pause or nudges back the problem rather than letting it progress; higher rates suggest the therapy can meaningfully limit disease, which matters to investors assessing a drug’s potential efficacy and commercial value.

dose escalation medical

"a multi-center, open-label dose escalation, dose expansion study"

Dose escalation is the process of gradually increasing the amount of a treatment or substance over time. In finance, it can refer to slowly raising investments or commitments to manage risk and assess performance. For investors, understanding dose escalation helps gauge how companies or strategies adjust their approaches, which can impact future growth or stability.

targeted alpha therapy medical

"an investigational targeted alpha therapy"

A cancer treatment that attaches tiny, highly energetic bits of radiation called alpha particles to a molecule that seeks out tumor cells, delivering a powerful, localized dose much like a guided missile hitting only its target. Investors care because it can offer strong anti-tumor effects with fewer whole-body side effects than traditional radiation, creating significant commercial upside, clinical and regulatory risks, and clear milestones that affect company value.

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• Meaningful antitumor activity observed at the 3.0 mCi monotherapy dose with 75% disease control rate and durable disease stabilization; one of two confirmed responders remains on study ~40 weeks after the first treatment
• No dose-limiting toxicities, treatment-related serious adverse events, or discontinuations due to adverse events were reported across 20 patients in three monotherapy dose cohorts as of the data cut-off
• Continued evaluation and dose optimization of lapemelanotide to inform future clinical development
  
  

SEATTLE, Nov. 06, 2026 (GLOBE NEWSWIRE) -- Perspective Therapeutics, Inc. (“Perspective,” the “Company,” “we,” “us,” and “our”) (NYSE AMERICAN: CATX), a radiopharmaceutical development company pioneering advanced systemic treatments for cancers, today announced updated interim monotherapy results from its ongoing Phase 1/2a clinical trial of [²¹²Pb]lapemelanotide zapixetar (VMT01), an investigational targeted alpha therapy. The Company presented the data as a poster at the Society for Immunotherapy of Cancer (SITC) 41st Annual Meeting, being held November 4 to 8, 2026, in Phoenix, Arizona.

The update covered 20 patients who received at least one monotherapy treatment of lapemelanotide as of September 18, 2026 (DCO date), across three dose cohorts of up to cumulative 4.5 mCi, 9 mCi, and 15 mCi, administered in three treatments of 1.5 mCi, 3.0 mCi, and 5.0 mCi, respectively, every eight weeks.

At the program’s focus dose of 3.0 mCi, two out of the eight patients enrolled in the monotherapy cohort had objective partial responses, one of whom remained in partial response and in study approximately 40 weeks after their first treatment. The disease control rate (DCR) was 75%, including two patients with long-lasting disease stabilization. As of the DCO date, eight patients had received at least one treatment in this dose cohort, with the eighth patient recently treated and not yet eligible for their first tumor assessment.

Across all 20 monotherapy patients, no dose-limiting toxicities (DLTs), treatment-related serious treatment-emergent adverse events (TEAEs), or adverse event-related treatment discontinuations were reported. Grade 3 or higher TEAEs occurred in five patients (25%), with none considered treatment-related.

“Despite significant advances in immunotherapy, many patients with advanced melanoma do not respond to checkpoint inhibitors, or they experience disease progression following treatment,” said Markus Puhlmann, MD, Perspective’s Chief Medical Officer. “The clinical activity observed with lapemelanotide, together with its safety profile to date, supports further investigation of targeted alpha therapy as a potential treatment option for patients with limited alternatives.”

“With lapemelanotide, we’re seeing responses and meaningful periods of disease stabilization in heavily pretreated patients,” said Thijs Spoor, Perspective’s Chief Executive Officer. “We believe there is an opportunity to make a difference for these patients. We’re continuing to learn from the data as we determine the best way to move the program forward.”

About [²¹²Pb]Lapemelanotide Zapixetar
Perspective designed lapemelanotide to target and deliver ²¹²Pb to metastatic melanoma tumor sites expressing MC1R, a protein that can be overexpressed in metastatic melanoma tumors.¹ The Company is conducting a multi-center, open-label dose escalation, dose expansion study (ClinicalTrials.gov identifier NCT05655312) in patients with histologically confirmed melanoma and MC1R-positive imaging scans obtained with the companion investigational imaging agent [²⁰³Pb]VMT01.

About Perspective Therapeutics, Inc.
Perspective Therapeutics, Inc. is a radiopharmaceutical development company pioneering advanced systemic treatments for cancers. The Company has proprietary technology that utilizes the alpha-generating isotope ²¹²Pb to deliver powerful radiation specifically to cancer cells via specialized targeting moieties. The Company is also developing complementary imaging techniques that incorporate the same targeting moieties, creating an opportunity to personalize treatment and optimize patient outcomes. This "theranostic" approach enables visualization of the specific tumor and subsequent treatment, potentially improving efficacy and minimizing toxicity.

The Company is advancing a portfolio of clinical-stage programs in the U.S., including bamzireotide navoxetan (VMT-α-NET, neuroendocrine tumors), lapemelanotide zapixetar (VMT01, melanoma), and PSV359 (solid tumors).

The Company is expanding its regional finished drug product candidate supply network, enabled by its proprietary ²²⁴Ra/²¹²Pb generator platform used to manufacture clinical drug product candidates, to support the delivery of patient-ready drug product candidates for clinical trials and, if approved, commercial operations.

For more information, please visit the Company's website at www.perspectivetherapeutics.com.

Safe Harbor Statement

This press release contains forward-looking statements within the meaning of the United States Private Securities Litigation Reform Act of 1995. Statements in this press release that are not statements of historical fact are forward-looking statements. Words such as "may," "will," "should," "expect," "plan," "anticipate," "could," "intend," "target," "project," "estimate," "believe," "predict," "potential," or "continue," or the negative of these terms or other similar expressions are intended to identify forward-looking statements, though not all forward-looking statements contain these identifying words. Forward-looking statements in this press release include statements concerning, among other things, the Company’s proprietary technology, imaging techniques and product candidates, including VMT-α-NET, PSV359, and VMT01, and related treatment opportunities in connection therewith; the Company’s understanding regarding the clinical profiles of its product candidates, including VMT-α-NET, PSV359, and VMT01; the Company’s preclinical and clinical development plans and the expected timing for the release of additional data from its clinical programs; the anticipated clinical benefits of the Company’s product candidates relative to existing therapies; the Company’s expectations regarding regulatory engagement and pathways for its product candidates; the Company’s expectations regarding its interactions with regulatory agencies, including the FDA, and the expected timing thereof; the Company’s regional distribution and manufacturing capabilities; and other statements that are not historical fact.

The Company may not actually achieve the plans, intentions, or expectations disclosed in the forward-looking statements, and you should not place undue reliance on the forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause the Company's actual results to differ materially from the results described in or implied by the forward-looking statements. Known risk factors include (without limitation) that the Company’s clinical trials may be more costly or take longer to complete than anticipated, or may never be completed, or may not generate results that warrant future development of the tested product candidate; regulatory authorities may not grant or may delay approval for our product candidates; the Company may elect to change its strategy regarding its product candidates and clinical development and manufacturing activities; economic and market conditions may worsen; the Company’s ability to establish, maintain and expand its regional distribution and manufacturing capabilities; and risks related to the sufficiency of the Company’s cash resources for its future operating expenses and capital expenditures. A more complete discussion of the risks and uncertainties facing the Company appears under the heading “Risk Factors” in the Company’s most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”), in the Company’s other filings with the SEC, and in the Company’s future reports to be filed with the SEC and available at www.sec.gov. Forward-looking statements contained in this news release are made as of this date. Unless required to do so by law, we undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise.

Media and Investor Relations Contacts:

Perspective Therapeutics IR:
Annie J. Cheng, CFA
ir@perspectivetherapeutics.com

ENTENTE Network of Companies
Katie Morris, PhD
katiemorris@ententeinc.com

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¹ Su DG, Djureinovic D, Schoenfeld D, et al. Melanocortin-1 Receptor Expression as a Marker of Progression in Melanoma. JCO Precis Oncol. 2024;8:e2300702. doi:10.1200/PO.23.00702.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did Perspective Therapeutics report for VMT01 at the 3.0 mCi dose?

The 3.0 mCi monotherapy cohort had a 75% disease control rate, with partial responses in two of eight enrolled patients. One responder remained in partial response and on study approximately 40 weeks after first treatment. Two patients had long-lasting disease stabilization.

What safety results did CATX report for lapemelanotide monotherapy?

Across 20 monotherapy patients, no dose-limiting toxicities, treatment-related serious adverse events or adverse-event-related treatment discontinuations were reported as of September 18, 2026. Grade 3 or higher adverse events occurred in five patients (25%), with none considered treatment-related.

How were doses administered in Perspective Therapeutics' VMT01 trial?

The three monotherapy cohorts received 1.5 mCi, 3.0 mCi or 5.0 mCi per treatment, administered in three treatments every eight weeks. The corresponding cumulative doses were up to 4.5 mCi, 9 mCi and 15 mCi, respectively.

Which patients are eligible for Perspective Therapeutics' lapemelanotide study?

The study enrolls patients with histologically confirmed melanoma and MC1R-positive imaging scans obtained using the companion investigational imaging agent [203Pb]VMT01. It is a multicenter, open-label dose-escalation and dose-expansion study registered as NCT05655312.