• Proceeds will support the advancement of Atavistik Bio’s oral allosteric AKT1-selective inhibitor for Hereditary Hemorrhagic Telangiectasia (HHT) and the JAK2 V617F mutant-selective inhibitor program for myeloproliferative neoplasms (MPNs) through clinical proof of concept
• Atavistik Bio anticipates initiating its clinical trial in HHT in the first half of 2026

CAMBRIDGE, Mass., Dec. 18, 2025 (GLOBE NEWSWIRE) -- Atavistik Bio, a biotechnology company discovering the next generation of precision allosteric therapeutics, today announced that it has raised a $120 million Series B financing to support the advancement of selective allosteric small molecule therapeutics for the treatment of HHT and MPNs. The financing was led by Nextech Invest and The Column Group, with participation from existing investor Lux Capital and new investor Regeneron Ventures. Atavistik Bio will use the proceeds from the Series B financing to advance its oral allosteric AKT1-selective inhibitor for HHT and its JAK2 V617F mutant-selective inhibitor program for MPNs through clinical proof of concept.

“We’re thrilled to announce our Series B financing, and grateful for the support of both our existing and new investors. With this capital, we are well-positioned to advance both our HHT and MPN programs through key clinical proof-of-concept milestones, with the HHT program expected to enter the clinic in the first half of 2026,” said Bryan Stuart, Chief Executive Officer at Atavistik Bio. “Our precision allostery approach holds tremendous potential to deliver best-in-class therapeutics with superior efficacy and tolerability profiles. Our team is working with tremendous passion and momentum to translate that promise into meaningful outcomes for patients.”

HHT is a severe bleeding disorder that affects more than 1.6 million people globally, with no approved therapies currently available. This condition often leads to frequent bleeding episodes, resulting in chronic anemia, organ damage, and a reduced lifespan. AKT1 hyperactivation is a hallmark of HHT and has been shown to drive the vascular pathology of HHT. Selectively inhibiting AKT1, the primary AKT isoform and driver of abnormal endothelial growth implicated in HHT, offers a novel and potentially disease-modifying therapeutic approach for this difficult disease. Although there has been substantial investment in pan-AKT inhibitors, their use is limited by AKT2-driven toxicities, most notably hyperglycemia, which impact tolerability and restrict their use for chronic dosing. Atavistik Bio has developed an oral allosteric inhibitor that selectively inhibits AKT1, overcoming the shortcomings of pan-AKT inhibitors and offering improved therapeutic potential and tolerability.

MPNs are a group of rare chronic blood cancers for which current treatment options are limited. The JAK2 V617F mutation is the most common driver mutation in patients living with MPNs, affecting approximately 95% of patients with polycythemia vera, 60% of patients with essential thrombocythemia, and 55% of patients with myelofibrosis. Approved pan-JAK inhibitors, such as ruxolitinib, provide symptom relief, but non-selectively inhibit both mutant and wild-type JAK2. This limits the ability to reduce JAK2 V617F mutant allele burden and can disrupt normal blood cell production regulated by wild-type JAK2, contributing to adverse events and treatment discontinuation. Selectively targeting the JAK2 V617F mutation has the potential to reduce mutant allele burden, preserve normal bone marrow function, and have a disease modifying impact that will substantially improve long term outcomes for patients with MPNs.

“We’ve been continually impressed by the exceptional quality of the compounds discovered from Atavistik Bio’s proprietary AMPS™ platform and by the team’s ability to consistently execute against critical milestones,” said John A. Josey, PhD, Atavistik Board Chair. “Atavistik Bio’s HHT and MPN programs would represent enormous advancements in the treatment of these respective diseases. We look forward to seeing Atavistik Bio move these programs into the clinic and bring them closer to patients in need.”

About Atavistik Bio

Atavistik Bio is a clinical stage biotechnology company accelerating the discovery and development of transformative precision allosteric therapeutics to address serious unmet patient needs. Since its inception, Atavistik Bio has rapidly established an emerging pipeline of allosteric therapeutics with the potential to achieve superior efficacy and tolerability profiles by leveraging the power of allostery.

Atavistik Bio is led by an experienced team of drug hunters with a proven track record of developing marketed small molecule therapies and supported by top-tier investors, including The Column Group, Nextech Invest, Lux Capital, and Regeneron Ventures. To learn more, visit us at atavistikbio.com and follow us on LinkedIn.

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