Therapeutics Startups funded by Y Combinator (YC) in the San Francisco Bay Area 2026

July 2026

Browse 24 of the top Therapeutics startups funded by Y Combinator. Headquartered in the San Francisco Bay Area, these are some of the hottest and fastest-growing startups. This doesn't include all companies originally founded in San Francisco Bay Area or by founders from there.

We also have a Startup Directory where you can search through over 5,000 companies.

  • Blank Bio
    Blank Bio
    Y Combinator LogoS2025
    Active • 6 employees • San Francisco
    Blank Bio is an applied AI research lab focused on increasing the success rates of clinical trials. We do this by training RNA foundation models that learn the patterns that shape disease progression and patient response to treatment. We aim to help pharma make more informed decisions in clinical trials by capturing the biology that makes each patient’s tumour unique. We’re a technical team of AI scientists and engineers from companies including Recursion, Deep Genomics, DeepMind, and Amazon, and institutions including Memorial Sloan Kettering Cancer Centre, Stanford, and the Vector Institute.
  • Uncommon Therapeutics
    Uncommon Therapeutics
    Y Combinator LogoW2025
    Active • 2 employees • San Francisco
    Our founder Noah, an experienced tech entrepreneur, was directly impacted by a severe genetic disease when his daughter was diagnosed with Rett Syndrome, a disease that afflicts 1 in 10,000 girls. Using an innovative polytherapy strategy, we’ve successfully improved her quality of life, and have designed new therapeutics that each could be worth billions and together could deliver a cure.
    gene-therapy
    biotechnology
    crispr
  • Exin Therapeutics
    Exin Therapeutics
    Y Combinator LogoW2025
    Active • 9 employees • San Francisco
    We use AI and high-throughput mouse studies to discover therapeutics that modify neural activity in the brain. The initial focus is on epilepsies associated with autism and Parkinson’s disease with the potential to expand to any neurological disorder underlined by a dysfunction in neural activity. Our R&D is guided by AI models trained on high-density multimodal mouse data generated in-house. We are 3 Oxford-trained neuroscientists supported by an experienced SAB from Harvard, Science Corp (ex-Neuralink), EPFL, Meta, and UCL. In 1.5 months since landing in SF, we went from nothing to (1) opening and operating an animal lab in South SF, (2) obtaining a proof-of-concept in mice, (3) building a multimodal AI model that directs our screening approach and (4) submitting two provisional patents; all while utilizing less than 50% of our YC funding. 
    biotech
    therapeutics
    neurotechnology
  • Kopra Bio
    Kopra Bio
    Y Combinator LogoS2024
    Active • 2 employees • San Francisco
    Kopra Bio makes genetically engineered viruses that teach your immune system to kill cancer using tech we developed at UCSF. We’re making the next Keytruda ($25B/yr cancer drug blockbuster) starting with the most aggressive form of brain cancer, glioblastoma. In the most challenging brain cancer model, we improve survival from 0% with the current FDA approved treatment to 90% with our treatment.
    biotech
    gene-therapy
    oncology
    therapeutics
    synthetic-biology
  • Granza Bio
    Granza Bio
    Y Combinator LogoW2024
    Active • 7 employees • San Francisco
    Granza Bio is developing programmable therapeutics for the immune system. Our platform is built on the foundational discovery of immune “superkiller” attack particles — the natural ammunition used by cytotoxic immune cells to deliver potent, localized killing. By re-arming exhausted immune cells with newly programmed ammunition, Granza restores and enhances immune function. This approach enables a new class of treatments with the potential to transform diseases ranging from cancer to autoimmunity.
    oncology
    therapeutics
    biotech
    synthetic-biology
    healthcare
  • ParcelBio
    ParcelBio
    Y Combinator LogoW2024
    Active • 6 employees • San Francisco
    ParcelBio is engineering a new class of mRNA medicines designed to deliver unprecedented potency and durability. Its proprietary APEXm™ platform uses novel RNA domains to enhance protein expression and extend activity, enabling therapies that reach the thresholds required for meaningful, and potentially curative, clinical outcomes. The company is advancing programs in autoimmune disease, oncology, and encoded protein therapeutics.
    synthetic-biology
    drug-discovery
    therapeutics
    biotech
    gene-therapy
  • Velorum Therapeutics
    Velorum Therapeutics
    Y Combinator LogoW2024
    Active • 5 employees • San Francisco
    Velorum Therapeutics is developing breakthrough medicines by unlocking the biology of heme.
    therapeutics
    biotech
    healthcare
    drug-discovery
    oncology
  • Keylika
    Keylika
    Y Combinator LogoS2022
    Active • 1 employees • San Francisco
    Keylika is an early stage biopharma startup developing metal-based drugs using a platform synthesis technology to treat unmet medical needs. We then administer these drugs using proven delivery technologies to effect the best clinical outcomes. Our first product is a small molecule iron drug (new molecular entity) delivered by a wearable skin patch to treat Iron Deficiency Anemia (IDA), with significantly higher safety, efficacy and tolerability over existing treatments. This is poised to be a best-in-class, potentially breakthrough therapy for treating iron deficiency without any GI side-effects (eg. nausea, constipation, diarrhea, etc.) typically associated with oral iron supplements, and without the risks, costs and side-effects associated with IV iron infusions. When approved, Keylika’s proprietary transdermal iron will be the world's first prescription iron patch. Iron deficiency is a hugely understated problem affecting about 1.6 billion people worldwide and more than 30 million in the US alone, translating to a $17B US market.
    nanotechnology
    therapeutics
    medical-devices
    ai-powered-drug-discovery
    drug-delivery
  • Eugit Therapeutics
    Eugit Therapeutics
    Y Combinator LogoS2022
    Active • 2 employees • San Francisco
    Eugit Therapeutics targets the issue of non-specific drugs that cause toxicity and clinical trial failures, affecting millions with tissue-specific inflammatory diseases. TAGHOME delivers drugs with precision to diseased tissues using T cell receptors, enhancing safety and improving efficacy. Our initial focus is on the 3.1 million U.S. individuals with Inflammatory Bowel Disease, aiming to initiate clinical trials within two years. Cofounded by George Church (Harvard) and funded by Y Combinator (S22).
    therapeutics
    cell-therapy
    biotechnology
    oncology
    synthetic-biology
  • GEn1E Lifesciences
    Y Combinator LogoS2019
    Active • San Francisco
    GEn1E Lifesciences is a Clinical-stage, multi-target company with a unique AI platform. We develop novel, next-generation, immunomodulatory therapies for rare & inflammatory diseases with no effective treatments. Our team is supercharging the drug development cycle by applying AI to multiple-mechanism-of-action protein targets and their natural platform capabilities—creating novel therapeutics at an unprecedented pace. Our AI platform has enabled us to develop a purpose-built therapy for ARDS to reduce its $20 billion cost on society (just in the USA). GEn1E has built a rich pipeline of 21+ novel and selective immunomodulators and has plans to accelerate 2 additional devastating diseases (beyond their lead indication) to IND in the next 12 months. Our AI platform enables tremendous pace and capital efficiency as demonstrated by our progress in ~2 years with seed capital—a stark contrast to the typical spend of $100M+ and 7+ years exhibited in the pharmaceuticals / biotech industry. With ~90% of rare diseases having no therapeutic treatment at all, GEn1E is taking a giant swing that will hopefully bring life-saving therapies to the lives of patients in need. The team at GEn1E has decades of experience in drug development and machine learning. We graduated from YCombinator and Stanford-StartX in late 2019. We are based in Palo Alto, CA.
    healthcare
    biotech
    drug-discovery
    artificial-intelligence
  • Alixia
    Alixia
    Y Combinator LogoW2022
    Active • 2 employees • San Francisco
    Our compounds disrupt the metabolic and inflammatory triggers in both cancer and quasi-cancerous cells in the tumor microenvironment. By impacting multiple cell types, we are enabling effective, lasting cancer treatments.
    drug-discovery
    oncology
    therapeutics
    biotech
    biotechnology
  • Catena Biosciences
    Catena Biosciences
    Y Combinator LogoS2021
    Active • 7 employees • San Francisco
    Catena’s technology lets us attach any two proteins together using an enzyme and the native amino acids tyrosine and cysteine within target proteins. It is a true platform technology because it enables the joining of any two soluble proteins together with minimal engineering and without restrictions due to protein size or complexity. Our work has already been used to modify cancer specific antibodies, CRISPR proteins and even cell surfaces. Our ability to produce modular protein therapeutics in a fraction of the time allows for true library creation across the therapeutics spectrum from oncology, vaccines, inflammatory disease and beyond.
    biotech
    therapeutics
  • Equator Therapeutics
    Equator Therapeutics
    Y Combinator LogoW2020
    Active • 2 employees • San Francisco
    We are developing a drug to increase metabolism and burn calories without exercise. Obesity and type 2 diabetes have reached epidemic proportions. There are 2.2B overweight people and 500M people with type 2 diabetes worldwide, and these numbers increase drastically every year. Existing drugs are not effective enough to reverse the trend. Our drug can solve this problem, because it addresses the root cause of metabolic disorders – the imbalance between caloric intake and expenditure. Our drug will target mitochondria – the powerhouse of the cell – to generate heat. This approach has been proven to fully reverse obesity and type 2 diabetes in animals. However, therapeutic application for humans was impossible, because mitochondrial heat production could only be induced by highly artificial methods with side effects. This changed after our recent breakthrough discovery of the protein that mitochondria naturally use to generate heat. We have developed a unique high-throughput drug discovery platform to identify compounds that selectively activate this target protein, without side effects. For decades people have wanted a drug that burns calories like exercise does. We are realizing this dream at Equator Therapeutics.
    biotech
    therapeutics
  • Altay Therapeutics
    Y Combinator LogoW2020
    Active • 6 employees • San Francisco
    Altay develops small molecule drugs to treat chronic liver diseases like liver fibrosis and liver cancer. Our co-founder Dr. Osman Ozes, led the first drug development program for Esbriet (Pirfenidone), resulting in the first FDA approved therapy for lung fibrosis. Esbriet is now a $1 billion/year drug and has already made over $6 billion in revenue. With a team that has over 70+ years of small molecule drug development experience, we intend to do the same with chronic liver diseases, which affects over 20 million Americans and represents a market size of over $30 billion. We know we are well positioned for success because we have shown excellent pre-clinical mouse data in several liver fibrosis models using our novel small molecule. We demonstrate a reduction in fibrosis with our drug, but more significantly, we show a reversal in fibrotic tissue back to normal tissue. With our current developmental strategy, we hope to have a clinic-ready compound by the end of 2021 and be in phase I clinical trials by mid of 2022.
    biotech
    therapeutics
    ai-powered-drug-discovery
    drug-discovery
  • Asher Bio
    Asher Bio
    Y Combinator LogoS2019
    Active • 3 employees • San Francisco
    Asher Bio is a biotechnology company developing precisely targeted immunotherapies for cancer and other diseases. Our cis-targeting platform aims to enable selective activation of specific immune cell types, addressing the inherent limitations of otherwise pleiotropic immunotherapies that act on multiple cell types. Our approach has the potential to precisely direct different immune mediators against a range of target immune cell-types and create best-in-class immunotherapies in cancer, autoimmune and infectious diseases. Asher Bio is backed by Third Rock Ventures and is located in South San Francisco.
    biotech
  • YourChoice Therapeutics
    YourChoice Therapeutics
    Y Combinator LogoW2019
    Active • 3 employees • San Francisco
    YourChoice Therapeutics is revolutionizing the global contraceptive market. Our vision is to develop non-hormonal contraceptives to provide both women and men with birth control options that lack the associated risks of hormone-based options but are equally effective. Traditionally, it has been the women’s financial and health burden to have a contraceptive in place. Our first goal is therefore to bring a novel non-hormonal, on-demand and low cost female contraceptive to the market that will substantially improve their quality of life and well-being. Our second goal is to develop the first ever non-surgical and highly effective non-hormonal contraceptive for men. Currently, male contraception is limited to two main options – vasectomy or condoms. Having such options available to both women and men will globally allow for much better family planning, reduce the number of unwanted pregnancies including abortions and therefore reduce costs and ensure contraceptive health and well-being.
    biotech
    health-tech
  • Intact Therapeutics
    Intact Therapeutics
    Y Combinator LogoW2019
    Active • 4 employees • San Francisco
    Intatct is developing an advanced materials platform to improve the way drugs are delivered and absorbed in the digestive tract. Our vision is to improve the treatment of a wide range of gastrointestinal disorders that are currently underserved.
    drug-delivery
    therapeutics
  • Rejuvenation Technologies Inc.
    Rejuvenation Technologies Inc.
    Y Combinator LogoS2018
    Active • 2 employees • San Francisco
    Stanford-patented essential drug platform unlocks the healthspan, which is limited by short telomeres. Extends mouse lifespan by equivalent of 10 years in humans. Reverses 5-10 years of telomere shortening with one dose in one day. Preclinical efficacy in 4 organ systems including immune system. Entering clinical stage. CEO is Subject #1 in longevity trial. 50+ granted patents, 7 patent families. FDA INTERACT cleared. Raising $10M seed extension ($2M+ wired) to fund 3 investigator-initiated trials. Readouts in Q3 2027. $6.8B in comparable mRNA-LNP M&A in last 12 months.
    anti-aging
    nanomedicine
    gene-therapy
  • Hepatx
    Hepatx
    Y Combinator LogoS2018
    Active • 4 employees • San Francisco
    Our vision is to provide regenerative medicine treatments that free patients from chronic liver disease and help usher in an era where diseased and damaged tissues can be repaired.
    biotech
  • Tradewind BioScience
    Tradewind BioScience
    Y Combinator LogoW2018
    Active • 2 employees • San Francisco
    Our lead candidate is a multifaceted attack antibody for ovarian cancer. Our approach enables targeting primary cancer cells directly, alongside enabling the immune system's natural anti-cancer function, all with one therapeutic antibody.
  • Nectome
    Y Combinator LogoW2018
    Active • 5 employees • San Francisco
    Nectome is a neuroscience startup that aims to preserve the brain and keep all its memories intact. The company is building the next generation of tools to preserve the connectome. The connectome is all the connections called synapses between neurons in the brain. Researchers from the company is now learning to manipulate individual memories, building advanced brain prosthetics, and reverse-engineering the brain.
    neurotechnology
  • Engage Bio
    Engage Bio
    Y Combinator LogoW2022
    Acquired • 10 employees • San Francisco
    Engage Bio has developed Tethosomes, a new class of non-viral DNA which finally unleashes potent, durable, redosable, and scalable genetic medicine. In 2026 Engage was acquired by Eli Lilly.
    biotech
    synthetic-biology
    therapeutics
    drug-discovery
    healthcare