What Osel does

Osel Inc. is a privately held, clinical-stage biopharmaceutical company headquartered in Mountain View, California, that is pioneering the development of Live Biotherapeutic Products (LBPs) — rigorously selected, single-strain live microorganisms engineered to prevent or treat disease by restoring healthy microbiome communities. The company filed its first IND with the FDA in 2003 for clinical testing of a live biotherapeutic, well before the FDA formally defined the LBP category in 2012, establishing it as a first mover in this regulatory class. Osel differentiates its single-strain products from fecal microbiota transplants and dietary probiotics on the basis of reproducibility, scalability, and biologic-drug-grade regulatory rigor.

Name

Osel

Legal name

Osel Inc.

Website

https://oselinc.com

Company type

Private

Founded year

2003

Operating status

Operating

Headcount range

1–10 employees

Short description

Osel Inc. is a clinical-stage biopharmaceutical company developing Live Biotherapeutic Products — engineered single-strain bacteria that restore healthy microbiome communities. The company targets women's health conditions (bacterial vaginosis, preterm birth) and oncology immunotherapy enhancement, and is headquartered in Mountain View, California.

Ownership category

akta.pro rank

Product category

Microbiome Therapeutics

NAICS

Biological Product (except Diagnostic) Manufacturing (325414), Research and Development in Biotechnology (except Nanobiotechnology) (541714)

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Live Biotherapeutic Products (LBPs) (HLAAAFAA)

akta.pro secondary industry

Microbiome Manufacturing, Formulation & Delivery Technologies (encapsulation, spores, oral delivery) (HLAAAFAJ)

Keywords

• Live biotherapeutic products
• Microbiome therapeutics
• Biologic drug development
• Women's health microbiome
• Immuno-oncology microbiome

Headquarters

HQ city

Mountain View

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales, Supply Chain

Distribution channels1 record

Marketing channels4 records

Core offering

Osel develops and commercializes Live Biotherapeutic Products (LBPs), which are FDA-regulated biologic drugs consisting of rigorously selected, single-strain live bacteria engineered to prevent or treat disease by restoring healthy microbiome communities. Its lead clinical-stage products are LACTIN-V, a vaginally administered Lactobacillus crispatus CTV-05 therapy for recurrent bacterial vaginosis and preterm birth prevention, and CBM588/MO-03, an orally administered Clostridium butyricum strain used to enhance cancer immunotherapy response. The company also advances the MucoCept platform for mucosal viral protection and the Gassericin K7 bacteriocin for cervical cancer, supported by proprietary bacterial strain libraries, screening methods, and formulation/manufacturing technologies.

Product overview

Osel is a clinical-stage biopharma company pioneering Live Biotherapeutic Products (LBPs) to prevent or treat conditions resulting from disruptions of the human microbiome. The company's portfolio includes LACTIN-V for women's health (bacterial vaginosis and preterm birth prevention), CBM588/MO-03 for oncology immunotherapy enhancement, Gassericin K7 for cervical cancer, and the MucoCept platform for mucosal viral protection. Osel focuses on rigorously selected single-strain products that are highly reproducible, scalable, and regulated as biologic drugs by the FDA, differentiating from fecal transplants and dietary probiotics.

Differentiator

Problem solved

Functional benefit

Brands

• LACTIN-V: Live biotherapeutic product containing Lactobacillus crispatus CTV-05 for preventing recurrent bacterial vaginosis and preterm birth
• CBM588
• MO-03
• Gassericin K7B Bacteriocin
• MucoCept Technology Platform

Products and services

• LACTIN-V A live biotherapeutic product (LBP) containing Lactobacillus crispatus CTV-05, a hydrogen peroxide-producing vaginal Lactobacillus strain. Delivered vaginally with a proprietary applicator to restore protective vaginal microbiota in women suffering from recurrent bacterial vaginosis, and under development for prevention of recurrent urinary tract infections, preterm birth, and HPV/cervical dysplasia. A prescription biologic drug candidate.
• CBM588 (Clostridium butyricum MIYAIRI 588) An orally administered live biotherapeutic product containing Clostridium butyricum MIYAIRI 588, which produces butyrate and other short-chain fatty acids with immunomodulatory activity. Originally developed for GI indications in Japan, being evaluated in the U.S. for antibiotic-associated diarrhea, C. difficile infection prevention, and as an immunotherapy enhancer for cancer treatment in combination with immune checkpoint inhibitors.
• MO-03 A high-potency capsule formulation of CBM588 (Clostridium butyricum MIYAIRI 588) developed specifically for oncology applications. Being evaluated in the Phase 3 BIOFRONT pivotal trial for advanced and metastatic renal cell carcinoma in combination with immune checkpoint inhibitors, with favorable safety observed across higher dose levels and no increase in immune-related adverse events.
• Gassericin K7 Bacteriocin A Class IIb two-peptide bacteriocin (GasK7A and GasK7B) under development that selectively inhibits Lactobacillus iners. GasK7B has nanomolar potency against L. iners and is being developed in collaboration with MD Anderson for cervical cancer treatment in conjunction with chemoradiation therapy to address tumor-specific chemoradiation resistance.
• MucoCept Technology Platform A proprietary technology platform that harnesses and enhances the human microbiome by modifying commensal Lactobacillus to express potent inhibitors of viral pathogens at mucosal surfaces. Proof of concept demonstrated for HIV-1 prevention in women (MucoCept-HIV), with an IND filed with FDA for first-in-human clinical study.

Quantifiable outcome

• LACTIN-V reduced BV recurrence to 30% vs 45% for placebo (p=0.01) in Phase 2b trial
• +5 more outcomes

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Ten partnerships are on record, tiered core and minor.

• March of DimescoreStrategic or Co-development Partner · 13 May 2026Partnership for FLIP-2 Phase 2b clinical trial evaluating LACTIN-V in pregnant women at high risk of preterm birth. March of Dimes provides funding support and access to their Prematurity Research Center at Imperial College London.
• Imperial College LondoncoreStrategic or Co-development Partner · 13 May 2026Imperial Clinical Trials Unit conducting FLIP-2 Phase 2b trial of LACTIN-V for preterm birth prevention. Led by Dr. Lynne Sykes, Professor Phillip Bennett, and Dr. Ryan Love. Trial enrolls 360 pregnant patients across four UK maternity units.
• SWOG Cancer Research NetworkcoreStrategic or Co-development Partner · 8 January 2026Clinical trial agreement for pivotal Phase 3 BIOFRONT trial of MO-03 (CBM588) in combination with standard immuno-oncology regimens for advanced and metastatic renal cell carcinoma. Supported by National Cancer Institute. Trial to enroll approximately 700 patients across up to 150 SWOG sites in the US, initiating Q1 2026.
• Aarhus University, Skive Hospital, Statens Serum Institut (Denmark)minorStrategic or Co-development Partner · 3 February 2021Exclusive worldwide license to inventions from investigator-initiated Phase 2 trial of LACTIN-V in women undergoing in-vitro fertilization. Ongoing Phase 2 IVF trial conducted at four Danish fertility clinics led by Professor Peter Humaidan.
• City of Hope Comprehensive Cancer CentercoreStrategic or Co-development PartnerMultiple clinical trials of CBM588 in combination with immune checkpoint inhibitors for metastatic renal cell carcinoma. City of Hope conducted Phase 1 studies demonstrating improved PFS and response rates. Dr. Sumanta Pal leads the kidney cancer program.
• Miyarisan Pharmaceutical Co., Ltd.coreOEM/ Whitelabel/ Licensing PartnerLicensed exclusive rights for pharmaceutical use of CBM588 (Clostridium butyricum MIYAIRI 588) in the United States, Canada, and Europe. Miyarisan manufactures CBM588 under GMP and markets it as prescription product MIYA-BM in Japan. Supplied GMP product for oncology trials.
• MD Anderson Cancer CentercoreStrategic or Co-development PartnerCollaboration on Gassericin K7B bacteriocin research. MD Anderson's Laboratory of Lauren Colbert discovered oncogenic L. iners strains associated with cervical cancer progression and poor survival. Collaborating to synthesize GasK7B and establish it as a potential drug candidate.
• National Cancer InstitutecoreStrategic or Co-development PartnerProvides support for the BIOFRONT Phase 3 trial of MO-03 in metastatic renal cell carcinoma as part of the National Institutes of Health infrastructure.
• UCSF (University of California San Francisco)coreStrategic or Co-development PartnerLong-standing collaboration since 2007 with Dr. Craig Cohen in clinical development of LACTIN-V through Phase 1, 2a, and 2b studies. Dr. Cohen served as principal investigator on NIAID/NIH grants for MucoCept-CVN development.
• NIHR Imperial Biomedical Research CentreminorStrategic or Co-development PartnerFunding support for FLIP-2 preterm birth prevention trial of LACTIN-V, part of the UK National Institute for Health and Care Research infrastructure.

Scale indicators5 records

Expansion highlights5 records

Direct peers

• Evelo Biosciences: Developed orally delivered, single-strain microbial medicines (SINTAX platform) for immune-mediated diseases including oncology and inflammatory indications. Direct peer to Osel in the microbe-based immunomodulation therapeutic approach.
• Seres Therapeutics: Pioneer microbiome therapeutics company that developed VOWST (SER-109), the first FDA-approved oral LBP for prevention of recurrent C. difficile infection in adults. Direct precedent for LBP regulatory pathway, manufacturing, and commercial playbooks relevant to Osel.
• MaaT Pharma: European clinical-stage microbiome biotherapeutics company developing standardized, full-ecosystem LBPs (e.g., MaaT013 for GvHD) with oncology overlap. Comparable to Osel in developing rigorous, GMP-manufactured bacterial therapies with regulatory-grade data.
• Finch Therapeutics: Was a clinical-stage microbiome therapeutics company developing Full-Spectrum Microbiota (FMP) products for recurrent C. difficile and other dysbiosis indications. Direct peer in the live biotherapeutic / microbiome drug category with overlapping clinical trial and regulatory considerations.
• Vedanta Biosciences: Clinical-stage developer of defined Live Biotherapeutic Products (VE303, VE202) for C. difficile and IBD. Closely comparable to Osel as a Boston/Cambridge-based LBP company advancing single-strain and consortia bacterial drugs through FDA-regulated trials.
• Assembly Biosciences: Clinical-stage microbiome-focused company developing engineered microbial therapies, including work with gamma-delta T cells and oral microbiome candidates. Comparable to Osel as a clinical-stage developer advancing engineered/consortium bacterial candidates into FDA-regulated trials.
• 4D Pharma (AbbVie): UK-based clinical-stage microbiome therapeutics company (acquired by AbbVie in 2023) developing Live Biotherapeutic Products including Blautix for IBS and oncology candidates. Comparable to Osel in clinical-stage LBP development, including regulatory engagement and bacterial strain selection.
• Ferring Pharmaceuticals (Rebiotix): Ferring's Rebiotix unit developed Rebyota (RBX2660), an FDA-approved live biotherapeutic for prevention of recurrent C. difficile. Comparable to Osel as a developer of FDA-regulated live biotherapeutic products with a similar clinical development and scale-up profile.
• Axial Therapeutics: Clinical-stage biopharmaceutical company developing gut-brain-axis targeted microbiome-based therapeutics for neurological and neurodevelopmental disorders. Comparable to Osel in being a clinical-stage venture-backed microbiome therapeutics developer with a strain-specific, FDA-regulated drug approach.
• Kaleido Biosciences: Was a clinical-stage microbiome metabolic therapies company developing novel chemistries derived from the microbiome. Comparable to Osel as a clinical-stage microbiome drug developer pursuing FDA-regulated live biotherapeutic and metabolite therapeutic approaches across multiple indications.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/osel-inc-

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Osel