Primmune Therapeutics Secures $8.6M in Series B Funding

January 26, 2026 did not arrive with fireworks. It arrived with math. Primmune Therapeutics, out of Carlsbad, California, quietly closed an additional $8.6 million in Series B financing, bringing the round to $23.3 million and total equity raised to $61.7 million. No valuation talk. No victory laps. Just capital moving with purpose toward a Phase 2 moment that has been earned the long way.

Primmune Therapeutics was founded October 3, 2017 by James Appleman, Ph.D., Paulo Rangel, and Stephen Webber, Ph.D., a trio fluent in the language of compounds that work and programs that survive. This company came out of Evince Biosciences, built on lessons from Anadys, eFFECTOR, Polaris, and Agouron, and designed by people who already watched promising molecules fail for the same old reasons.

The problem was never whether TLR7 could wake the immune system. The problem was the hangover. Prior generations brought inflammation that burned the house down with the lights on. PRTX007 was engineered to do something cleaner. It leans into interferon driven immunity while suppressing the NF-kB signaling that historically made systemic TLR agonists a liability instead of a weapon.

That design choice now has receipts. PRTX007 completed Phase 1 across more than 100 healthy volunteers with no serious adverse events, no grade three toxicity, and a pharmacology profile that shows CD8 and NK cell activation without lighting up TNF-alpha, IL-6, or IL-1 beta. Oral dosing. Repeatable exposure. A signal that can live alongside checkpoint inhibitors instead of competing with them.

The new capital, backed again by Bioqube Ventures, Oberland Capital, and Samsara Biocapital, funds Study PRTX007-003, a Phase 2 neoadjuvant trial in Stage III resectable melanoma combining PRTX007 with standard anti-PD-1 therapy. The study runs through Australia with Novotech, a setting chosen for speed, precision, and proof rather than theater.

Leadership here reads like a reminder that execution matters. Charles McDermott as President and CEO has built and exited before. James Appleman brings three decades of drug discovery scars and wins. Paulo Rangel understands capital, partnerships, and timing. Stephen Webber discovered rucaparib. Andrew Sharabi, M.D., Ph.D., anchors the clinical strategy where immunology meets reality.

Add the $22.48 million non-dilutive DTRA contract supporting manufacturing and antiviral development, and the picture sharpens. Primmune is not chasing noise. It is tuning the immune system like an instrument, aiming for control over chaos. Phase 2 is now live, melanoma is first, and the market is listening closely to what happens when immunity gets precise instead of loud.