Voltron Therapeutics, Inc., a Lucius Partners Portfolio Company, Announces Definitive Proof of Concept Data for its Second Oncology Candidate (VTX-0P4) in a Prostate Stem Cell Antigen (PSCA) Related Tumor Study in Combination with a Checkpoint…

• Study conducted at The Massachusetts General Hospital’s Vaccine and Immunotherapy Center demonstrated highly significant improvements in Overall Survival and other key endpoints
• VTX-0P4, in combination with a CPI, had a statistically significant improvement in survival versus a CPI alone
• Key targets include Urothelial, Prostate, and Renal Cancers 
• VTX-0P4 produced a safety profile similar to that seen in the control group and without evidence of reactogenicity 

NEW YORK, May 29, 2025 (GLOBE NEWSWIRE) -- Voltron Therapeutics, Inc., a Lucius Partners portfolio company, announced today that data from Study VTX-IO-004 demonstrated clear proof-of concept for the self-assembling therapeutic, VTX-0P4, in the treatment of cancers over-expressing prostate stem cell antigen (PSCA).  

/EIN News/ -- VTX-0P4 is a novel, modular, protein-based therapy candidate designed to provide a specific therapeutic T cell mediated immunogenic response to PSCA-expressing tumors. Prior VTX-0P4 immunogenicity studies demonstrated robust overall antigen-specific T cell responses for both CD4+ and CD8+ T cell populations, in a murine model. PSCA is a critical marker in several primary cancers, including bladder, prostate, and pancreatic cancers.

The primary objective of study VTX-IO-004 was to evaluate the anti-tumor effect of VTX-0P4 in a well-established mouse model utilizing PSCA-expressing TRAMP-C2 (T-C2) tumors. A key secondary objective was to evaluate the anti-tumor effect of VTX-0P4 in combination with a checkpoint inhibitor (CPI). Treatment with VTX-0P4 induced robust, statistically significant antigen specific cellular immune responses and anti-tumor effects compared to controls. In addition, the combination of VTX-0P4 with a CPI demonstrated statistically highly significant additive efficacy benefit over VTX-0P4 or a CPI as monotherapy. This study provides further evidence supporting the utility of Voltron’s modular immunotherapeutic platform, demonstrating its ability to enhance targeted oncologic immune responses when combined with a well-established tumor associated antigen and a CPI.

These results add important potential indications to Voltron’s growing pipeline which includes HPV positive cervical and head and neck cancers. 

Results of the study demonstrated: 

• Improved Overall Survival: VTX-0P4 + anti-mPD-1 had a highly significant, positive survival effect in the TC-1 tumor injected mice versus anti-mPD1 alone
• Tumor volume reduction: VTX-0P4 + PD-1 significantly slowed/reduced growth in T-C2 tumor volume  
• Dose response: there was a clear dose-response to the combination which matched the previously reported immunogenicity results (i.e., the T cells are getting to their target)
• Safety Profile: the SAV construct was well tolerated with no observed reactogenicity.  

Dr. Mark Poznansky, a Scientific Founder of Voltron Therapeutics Inc and Director, Vaccine and Immunotherapy Center, MGH commented: “These data clearly demonstrate that this novel tumor targeting platform, when combined with a PD-1 inhibitor, significantly controlled tumor growth and augmented survival versus VTX-0P4 or a CPI alone.  Additionally, these results are significant because it has now been shown that an effective cell mediated response against a self antigen, namely PSCA, can be generated by VTX-OP4.  This supports the view that this novel self-assembling immunotherapy could be broadly applicable to a wide variety of cancers that are known to express tumor specific antigens.”

Patrick J. Gallagher, Voltron’s Chief Executive Officer stated, “The results of this rigorously designed study highlight the great promise of Voltron’s platform technology.  The VTX-0P4 responses, as measured by survival and tumor volume, were significantly enhanced when combined with a CPI / PD-1. Physiologically this makes sense. As the anti-mPD-1 removes the tumor’s ability to ‘escape’ the immune system, it creates a tumor microenvironment (TME) that's more accessible to classic T cell-specific antitumor effects. Our approach activates and significantly increases the percentage of PSCA-specific antitumor T cells seeking to enter the TME, thus complementing the PD-1 inhibition mechanism of action.”

This important research and development milestone further demonstrates and supports the therapy platform’s unique capabilities: utility in driving efficacy in combination therapy, development speed, target/pathogen flexibility and significant engagement of the immune system. This work with a full-length protein dramatically expands the breadth of potential value/solutions that the platform could offer in the oncology and infectious disease settings.

“Checkpoint inhibitors and other immunotherapies have dramatically improved outcomes for many cancer patients. Nonetheless there are still significant opportunities to improve patient outcomes through combination therapies with complimentary mechanisms,” said James Ahern, Managing Partner of Laidlaw & Company and founder of Lucius Partners. “Our safety profile and compelling efficacy data could make us an ideal addition to current treatment algorithms. The Voltron team will continue to leverage our highly flexible platform to create new solutions for clinicians and patients and value for our shareholders.”

About Voltron Therapeutics, Inc. 

Voltron Therapeutics, Inc., a Delaware corporation, was founded in 2017 to lead and accelerate the development of the Vaccine and Immunotherapy Center (VIC), and the Massachusetts General Hospital’s novel platform technology in a variety of indications, including in Oncology and Emerging Infectious Diseases. Voltron holds an exclusive worldwide license to this technology. With the work of our world class team of researchers and development team, this technology has shown in certain pre-clinical studies initial proof of concept in two infectious diseases (including Lassa Fever) as well as six oncology indications (HPV Related Cancers, PSCA related cancers). For more information, please visit www.voltrontx.com. 

About Lucius Partners, LLC 

Lucius Partners is a consultancy that provides a broad suite of services to help healthcare companies grow, achieve milestones and generate value for their shareholders. 

Forward Looking Statements 

This press release includes “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements in this press release include, but are not limited to, statements that relate to the advancement and development of the VaxCelerate Platform, the commencement of clinical trials, the availability of data from clinical trials and other information that is not historical information. When used herein, words such as “anticipate”, “being”, “will”, “plan”, “may”, “continue”, and similar expressions are intended to identify forward-looking statements. In addition, any statements or information that refer to expectations, beliefs, plans, projections, objectives, performance or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking. All forward-looking statements are based upon Voltron’s current expectations and various assumptions. Voltron believes there is a reasonable basis for its expectations and beliefs, but they are inherently uncertain. Voltron may not realize its expectations, and its beliefs may not prove correct. Actual results could differ materially from those described or implied by such forward-looking statements as a result of various important factors, including, without limitation, market conditions and any Voltron filings made with the Securities and Exchange Commission. Consequently, forward-looking statements should be regarded solely as Voltron’s current plans, estimates and beliefs. Investors should not place undue reliance on forward-looking statements. Voltron cannot guarantee future results, events, levels of activity, performance or achievements. Voltron does not undertake and specifically declines any obligation to update, republish, or revise any forward-looking statements to reflect new information, future events or circumstances or to reflect the occurrences of unanticipated events, except as may be required by law. 

Contact: 
Patrick Gallagher, CEO
Voltron Therapeutics, Inc.
Managing Partner
Lucius Partners, LLC
pgallagher@luciuspartnersllc.com