Familiar Therapeutics raises $5M seed to bring human drugs to dogs and cats

Familiar Therapeutics launched on October 22nd, 2026 with a $5M seed round to bring human drugs to dogs and cats. Pioneer Fund, Icehouse Ventures and BreakTHRU, a syndicate of animal-health leaders and veterinarians, led the round.

The Redwood City, California company was founded in May. It says it already has 13 programs, two drug development files open with FDA's Center for Veterinary Medicine and a first study opening this fall at the University of Illinois.

Pharma partners keep human rights and share vet sales

Familiar licenses veterinary rights to drugs with years of human research behind them. Then it runs the animal studies, manufacturing and FDA work itself.

Partners "keep their human rights and share in veterinary sales, so they earn a faster return on research they've already paid for," said Dan Knox, co-founder and COO. He also pitched the science running the other way, since data from dogs and cats with naturally occurring disease can "inform and de-risk" a partner's human program.

Familiar says FDA approves fewer than 10 new companion animal drugs a year, against more than 50 for people. For many serious conditions, vets still use human drugs off-label, without dosing or safety data for the species.

"Our goal is to give vets proven, FDA-approved treatments that change the course of serious diseases in dogs and cats, where today they often have very few options," said Elizabeth Iorns, co-founder and CEO.

A heart-sparing doxorubicin leads the 13-program pipeline

The lead program, FAM-010, is a new form of doxorubicin attached to albumin, built to carry more of the drug to the tumor and less of it to the heart. Doxorubicin is the usual chemotherapy after surgery for canine hemangiosarcoma, but heart toxicity caps how many doses a dog can get, according to Familiar's pipeline page.

No drug is FDA-approved for hemangiosarcoma in dogs, and median survival with surgery alone is under two months, the company said.

The Illinois pilot, led by veterinary oncologist Timothy Fan, will set the dose. Every dog gets FAM-010 by infusion every three weeks, and Familiar pays for study care.

The other lead programs are FAM-003 for lymphoma and atopic dermatitis, FAM-008 for breathing disorders in flat-faced breeds, and FAM-017 for intervertebral disc disease. Nine more sit in early development across oncology, immunology and dermatology, neurology, kidney disease and metabolic disease.

Loyal veterans run Familiar's regulatory work

Every program is designed for full FDA approval, and Familiar says it may also seek conditional approval where a program qualifies. Loyal took that route with its senior-dog drug, which has cleared FDA's efficacy and safety sections. A third Loyal candidate won its own efficacy acceptance in September.

Stacy Ross, head of CMC and regulatory, was Loyal's VP of CMC after roles at Zoetis, Bayer Animal Health and Elanco. Regulatory adviser Karen Greenwood spent more than 25 years at Pfizer Animal Health and Zoetis before building Loyal's regulatory path to market.

The founders have sold a company before. Iorns and Knox co-founded Science Exchange, an R&D outsourcing platform that Waud Capital Partners acquired in September 2024.

Investors keep backing dog drug developers this year. Gamgee raised a $4M seed round in August for personalized dog cancer vaccines, and Loyal closed a $100M Series C in February behind its longevity drug.

For vets, the only door open today is the Illinois study, which takes referrals for dogs newly diagnosed with hemangiosarcoma of the spleen.

Source: Familiar Therapeutics via Business Wire