Atavistik Bio banks $160M to take novel blood disorder drugs into trials
What's the deal? Atavistik Bio, a Cambridge, Massachusetts-based biotech, has closed a $160 million Series B to advance its pipeline of allosteric small molecule therapies. The round — initially $120 million when announced in December 2025 — was extended by $40 million with new investor RA Capital Management. Existing backers include Nextech InvestDealroom has a profile for this one. Try Dealroom →, The Column GroupDealroom has a profile for this one. Try Dealroom →, Lux Capital, and Regeneron VenturesDealroom has a profile for this one. Try Dealroom →.
The money will fund two drug programmes. The first targets hereditary haemorrhagic telangiectasia (HHT), a rare inherited condition that causes abnormal, fragile blood vessels — leading to chronic bleeding, anaemia, and in severe cases, organ damage or heart failure. The second targets a group of rare blood cancers called myeloproliferative neoplasms (MPNs). Both drugs are taken orally.
Why now? HHT affects more than 1.6 million people worldwide and has no approved treatments — only symptom management. Atavistik believes it has found a way to tackle the disease at its root, by blocking the protein that triggers the abnormal vessel growth. Its lead drug, ATV-1601, already showed a clean safety profile in an early cancer trial, giving the company confidence to move into HHT testing later this year.
In MPNs, existing drugs work but come with significant side effects that often force patients to stop treatment. Atavistik's approach targets only the mutated form of the relevant protein, potentially reducing that collateral damage.
The signal: Atavistik's raise is part of a broader re-rating of precision small molecule drug discovery. Investors are increasingly willing to back platforms that move beyond conventional active-site chemistry. Allostery — targeting structural sites that modulate protein function indirectly — is gaining traction as a way to unlock previously undruggable targets and improve on drugs that work but cause too much collateral damage.
Atavistik has now raised $260 million in total, including a $100 million Series A, suggesting sustained conviction in its platform well before clinical proof of concept in its lead indication.
Sources:
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