Series A Biotech companies in San Francisco

Companies applying biology, chemistry, and computation to therapeutics and tooling. Filtered to Series A-stage companies headquartered in San Francisco.

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Built from a search like: “Top Series A Biotech companies in San Francisco”

Ranked by current headcount across Series A Biotech companies in San Francisco. Refreshed daily.

1
Genentech· South San Francisco, California, United States
About GenentechWe're passionate about finding solutions for people facing the world's most difficult-to-treat conditions. That is why we use cutting-edge science to create and deliver innovative medicines around the globe. To us, science is personal.Making a difference in the lives of millions starts when you make a change in yours. If you’d like to join our team, view our openings at gene.com/careers. Our patient resource center is dedicated to getting patients and caregivers to the right resources. You can reach them at 1 (877) GENENTECH (436-3683)Monday-Friday, 6am-5pm PST or patientinfo@gene.com. Community Guidelines:1. We want to foster positive conversation around the issues we are passionate about. To that end, we remove profanity, content that contains threatening language, content that is aimed at private individuals, personal information, and repeated unwanted messages.2. Don’t mention any medicines by name — ours or anyone else’s.Because of the fair balance rules governing our industry, we cannot post any comments that reference any pharmaceutical brand, product, or service. Please do not mention any specific medicines by name, or include any links to third party sites in your comments.3. This isn’t the place to report or discuss side effects.This site is not intended as a forum for reporting side effects experienced while taking a Genentech product. Instead, you should report any side effects to Genentech Drug Safety at 1-888-835-2555. You can also report side effects of any prescription product directly to the FDA at 1-800-FDA-1088 or by visiting www.FDA.gov/medwatch.4. Don’t pitch your product or service.Please don't use our page as a place to promote your product or pitch your services. Please also avoid posting links to external sites. We reserve the right to remove any posts that are deemed promotional.
- Series A
- 18.3k employees
- Founded 1976
2
Xaira Therapeutics· South San Francisco, California, United States
Xaira Therapeutics is an integrated biotechnology company driving advances in artificial intelligence to learn the language of life and transform how we treat disease. We seek to rethink the drug discovery and development process from end-to-end by bringing together leading talent across three core areas: machine learning research to better understand biology, expansive data generation to power new models, and robust therapeutic product development to treat disease. Xaira is headquartered in the San Francisco Bay Area.Please be advised that we will never ask for personal information or any financial commitment from a candidate as a pre-employment requirement. All legitimate Xaira communication regarding our recruitment processes comes from email addresses ending with @xaira.com or through recognized professional networks, such as LinkedIn. To avoid any potential fraudulent activity, please make sure to apply only through Xaira's official Careers page: https://www.xaira.com/work-with-us
- Series A
- 214 employees
- Founded 2023
3
iZumi· South San Francisco, California, United States
iPS cells, cell reprogamming, and cell differentiation for drug discovery
- Series A
- 94 employees
- Founded 2007
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4
BIOMAKERS· San Francisco, California, United States
BIOMAKERS is a global Precision Medicine Company that produces complex & advanced genomic data + RWE to make cancer patients live longer and transform oncology data-driven Drug Development globally. having built an unprecedented platform that enables Diagnosis, Treatment, Drug Development, Target discovery and AI for Cancer and Rare Diseases, having developed genomic products in the 4 Stages of the Biopharmaceutical chain and providing the largest LATAM genomic representation in the global Oncology Drug Development Landscape.BIOMAKERS provides extensive genomic and molecular Testing services for cancer & rare disease patients in +18 countries in Latin America.In just a few years BIOMAKERS has become the leading company in Precision Medicine in the region having built the largest and unique of its kind multinational Advanced Tumor Biobank and Cancer Dataset from LATAM, with HQ in USA and fully owned Sequencing Labs in Mexico, Brazil, and Argentina.
- Series A
- 77 employees
- Founded 2014
5
Addition Therapeutics· South San Francisco, California, United States
Addition Therapeutics is on a mission to fulfill the transformative promise of genomic medicine for people impacted by both chronic and rare diseases. Leveraging our breakthrough all-RNA, non-viral, LNP-based PRINTTM platform, we are overcoming the limitations of existing genetic medicine modalities to develop safer, durable, one-time therapies. Bolstered by our team of top-tier scientists and engineers, we are advancing a robust pipeline of PRINTed therapeutics that have the potential to fundamentally redefine how chronic and rare diseases are treated. Our investor syndicate includes SR One, Pivotal Life Sciences, Abingworth, Osage University Partners, the Gates Foundation, and BEVC.
- Series A
- 68 employees

6
OneSkin· San Francisco, California, United States
OneSkin is a longevity company on a mission to transform the way we think about skin and aging. Founded by a team of four female PhDs, OneSkin’s products focus on skin longevity. OneSkin’s proprietary peptide, OS-01, is the first ingredient designed to reduce skin's biological age by improving skin barrier, supporting DNA damage repair, and preventing the accumulation of aged cells.
- Series A
- 62 employees
- Founded 2016
7
Until· San Francisco, California, United States
We are building reversible cryopreservation technology to solve the organ procurement and matching problem.Cryopreservation is already essential to modern medicine — powering IVF and life-saving stem cell therapies. Now, we’re extending this technology to whole human organs — transforming hours of viability into weeks, or months, however long is necessary — so that no donated organ is lost to logistics, and no patient dies waiting. By solving this immediate need, we de-risk and build the foundation for what comes next: whole-body reversible cryopreservation. We're pausing molecular motion to give patients a bridge to future cures.
- Series A
- 56 employees
- Founded 2021
8
Vilya· South San Francisco, California, United States
Vilya is a cutting-edge computational biotechnology company, co-founded a team of scientists from from the Institute of Protein Design (IPD) led by David Baker, Ph.D. and by ARCH Venture Partners.At Vilya, we are creating a novel class of medicines to precisely target disease biology. Our platform is built on ground-breaking research in advanced computational approaches and taps into uncharted chemical space within cyclic peptides to design new molecular structures not found in nature. We aim to boldly leverage cutting edge computing to change how we design new medicines, and to ultimately cure diseases.Who will love working with us? We are a group of machine learning scientists, computational chemists, medicinal chemists, biologists and scientific enthusiasts that are driven to design and create life-altering medicines that will make a big impact on the world. Learn more about our job openings and join us! join@vilyatx.com
- Series A
- 49 employees
- Founded 2022
9
LatchBio· San Francisco, California, United States
Agent infrastructure for biology. Bundled with kits + machines to serve 300+ pharma, biotech and academic teams around the world.
- Series A
- 46 employees
- Founded 2021
10
Rezo Therapeutics· San Francisco, California, United States
Rezo is a different kind of biopharma company. Our mission is to dramatically increase the success rate of drug development by building a disease-agnostic, fully-integrated, network biology platform that will redefine our understanding of human disease and ability to treat it. Our Founders and members of the Board are a group of esteemed, world-class scientists from the University of California, San Francisco: Nevan Krogan, Kevan Shokat, Sourav Bandyopadhyay, Natalia Jura, as well as renowned biotech executives George Scangos and Norbert Bischofberger. These leaders bring with them a strong track record of amazing discoveries and scientific breakthroughs, leading to very successful companies and many FDA approved drugs.
- Series A
- 45 employees
- Founded 2021

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Find engineers at Series A Biotech companies in San Francisco

Searching for “engineers at top Series A Biotech companies in San Francisco” surfaces this slice of the market. The list above ranks Biotech companies headquartered in San Francisco whose latest disclosed round is Series A, by current headcount, drawn from public LinkedIn and Crunchbase records. With 51 matching companies in Refolk’s index, this is a tight read on where the Biotech talent in San Francisco is heating up.

Three filters at once narrows the field hard. The companies that survive all three - Series A, Biotech, in San Francisco - are usually the most targeted recruiting pool a hiring manager can ask for. Senior engineers, founding designers, and product leads here are about to become Biotech’s next operators and angel investors.

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Refolk pulled Biotech companies headquartered in San Francisco whose latest disclosed funding round is Series A from public LinkedIn and Crunchbase records, ranked them by current employee count, and kept those with at least 3 employees. The list refreshes once a day.

Last refreshed: Wed, 05 Aug 2026 16:58:09 GMT

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