Primmune to Present PRTX007 Data at SITC
Primmune Therapeutics will present two abstracts on its investigational drug polvitolimod HCl at the SITC 41st Annual Meeting in Phoenix.
Updated on Nov. 3, 2026 in Cancer
Primmune Therapeutics, a clinical-stage biotech company, will present two abstracts on polvitolimod HCl (PRTX007) at the SITC 41st Annual Meeting, held November 4-8, 2026, in Phoenix, Arizona. Posters will be available on the company's website on November 7, 2026.
Why it matters
The presentations cover a Phase 2 study of PRTX007 combined with pembrolizumab in resectable Stage III melanoma and a prospective Phase 1 study of the drug. The data concern an oral, systemically acting TLR7 agonist prodrug that is being evaluated as an immunotherapy approach in cancer.
The INFLECTION-003 study is a Phase 2 single-arm trial registered as NCT07565285, and the 118 healthy volunteers in the two Phase 1 studies reported no serious adverse events. Efficacy results from the Phase 2 study, measured as major pathologic response rate, have not yet been disclosed.
The players
Primmune Therapeutics
Primmune Therapeutics is a clinical-stage biotechnology company developing polvitolimod HCl (PRTX007), an orally administered TLR7 agonist prodrug.
Society for Immunotherapy of Cancer (SITC)
SITC is a professional organization that hosts an annual meeting focused on advances in cancer immunotherapy research.
The details
INFLECTION-003 evaluates oral PRTX007 given alongside intravenous pembrolizumab for 9 weeks before surgical resection in participants with resectable Stage III melanoma. PRTX007 is designed to shift immune signaling toward an IRF7-driven interferon response and away from NF-kB-mediated inflammatory cytokine signaling.
Timeline
November 4-8, 2026: SITC 41st Annual Meeting in Phoenix, Arizona.
November 6, 2026: INFLECTION-003 abstract presentation, 12:15-1:45 PM and 5:30-7 PM MT (Abstract #573).
November 7, 2026: Prospective Phase 1 PRTX007 abstract presentation (Abstract #138); posters available online.
Big Picture
The INFLECTION-003 study builds on the checkpoint-inhibitor framework established by pembrolizumab, testing whether adding an oral TLR7 agonist can strengthen the immune response alongside PD-1 blockade. The approach represents an effort to combine innate and adaptive immune activation in melanoma treatment.
The study is at an early stage and is not yet an available treatment option for patients. Participants in the trial receive oral PRTX007 together with intravenous pembrolizumab before surgery, and the results will indicate whether this combination warrants further development.
The takeaway
Early-stage trials combining innate immune activators with established checkpoint inhibitors are being tested to see whether they can improve responses in melanoma. Readers should await peer-reviewed efficacy results before drawing conclusions about the approach.
What happens next
Posters presenting the abstracts will be available on the Primmune Therapeutics website on November 7, 2026.
Further reading
Explore more on Cancer research and treatment developments in the United States.
More information
Details of the INFLECTION-003 study are listed in the ClinicalTrials.gov registry under identifier NCT07565285.
