Climb Bio

What Climb Bio does

Climb Bio, Inc. (NASDAQ: CLYM; formerly Eliem Therapeutics) is a clinical-stage biotechnology company headquartered in Wellesley Hills, Massachusetts, developing differentiated monoclonal antibody (mAb) therapeutics for B-cell mediated immune-mediated diseases. The company's pipeline is anchored by two core investigational assets: budoprutug, an Fc-enhanced anti-CD19 mAb designed for potent, durable, and complete B-cell depletion with both intravenous (IV) and subcutaneous (SC) formulations, being developed across four indications — primary membranous nephropathy (pMN, Phase 2 PrisMN trial), immune thrombocytopenia (ITP, Phase 1b/2a), systemic lupus erythematosus (SLE, Phase 1b), and an SC formulation study; and CLYM116, a novel anti-APRIL mAb featuring a 'sweeper' mechanism with pH-dependent binding for APRIL blockade and lysosomal degradation plus Fc-engineering for extended half-life, being developed for IgA nephropathy (IgAN) by partner Beijing Mabworks Biotech in Greater China and by Climb Bio worldwide ex-China.

The company's scientific differentiation is grounded in clinically validated B-cell targets (CD19, APRIL) and proprietary antibody engineering, including Fc enhancement for optimal biological activity and the pH-dependent sweeper architecture unique to CLYM116. Budoprutug has demonstrated 100% rapid and complete circulating B-cell depletion and 100% complete or partial remission by week 48 in a Phase 1b pMN study, supported by FDA Fast Track Designation and Orphan Drug Designation for the SC formulation in pMN, an indication with no FDA-approved therapies.

Climb Bio is pre-revenue with no commercial products. The company is funded by equity financing, holding $160.7 million in cash, cash equivalents, and marketable securities as of December 31, 2025, supplemented by a $110 million private placement in April 2026, providing runway into 2028. R&D expenses were $46.7 million in 2025 (versus $14.3 million in 2024), partly driven by the 2025 acquisition of Tenet Medicines. Distribution occurs exclusively through global clinical trial sites registered on ClinicalTrials.gov; commercial revenue is contingent on future FDA approval and likely eventual distribution through specialty pharmacies for rare autoimmune indications.

Name

Climb Bio

Legal name

Climb Bio, Inc.

Website

https://climbbio.com

Company type

Public

Founded year

2018

Operating status

Operating

Headcount range

11–50 employees

Short description

Climb Bio is a clinical-stage biotechnology company developing differentiated monoclonal antibody therapies (budoprutug, anti-CD19; CLYM116, anti-APRIL) for B-cell mediated rare kidney and autoimmune diseases including pMN, ITP, SLE, and IgAN, funded by equity with no commercial revenue.

Ownership category

akta.pro rank

Product category

Clinical-stage Biopharmaceuticals

NAICS

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

SIC

Biological Products, (No Disgnostic Substances) (2836), Pharmaceutical Preparations (2834)

akta.pro industry

PRIMARYHLAAAAAA

Monoclonal Antibody Therapeutics (mAbs)

Healthcare & Life Sciences/Biotechnology & Biologics/Therapeutic Biologics (mAbs, recombinant proteins, cytokines)

SECONDARYHLAIACAJ

Transplant & Immunosuppression Specialty Pharmaceuticals

Healthcare & Life Sciences/Pharmaceuticals/Specialty Pharmaceuticals

Keywords

• Monoclonal antibody therapeutics
• Immune-mediated disease treatments
• B-cell targeted therapies
• Clinical-stage biopharmaceuticals
• Rare autoimmune disease drugs

Headquarters

HQ city

Wellesley

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Others

Revenue model

1. Pre-commercial / Pipeline Development: As a clinical-stage biotechnology company, Climb Bio has no commercial revenue. The company is funded through equity financing, private placements, and cash reserves ($160.7 million as of December 31, 2025). Revenue will depend on successful FDA approval and commercialization of budoprutug and CLYM116.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels5 records

Core offering

Climb Bio is a clinical-stage biotechnology company developing a pipeline of differentiated monoclonal antibody (mAb) therapeutics for B-cell-mediated immune-mediated diseases. Its lead candidate budoprutug is an Fc-enhanced anti-CD19 mAb in clinical development for primary membranous nephropathy, immune thrombocytopenia, and systemic lupus erythematosus, with both intravenous and subcutaneous formulations. Its second candidate CLYM116 is a novel anti-APRIL mAb with a proprietary 'sweeper' mechanism in development for IgA nephropathy.

Product overview

Climb Bio is a clinical-stage biotechnology company developing a differentiated pipeline of monoclonal antibody (mAb) therapeutics targeting B-cell mediated immune-mediated diseases. The company's core portfolio consists of two investigational drug candidates: Budoprutug (anti-CD19 mAb) available in both intravenous (IV) and subcutaneous (SC) formulations, being developed across multiple indications including primary membranous nephropathy (pMN), immune thrombocytopenia (ITP), and systemic lupus erythematosus (SLE); and CLYM116 (anti-APRIL mAb), featuring a novel 'sweeper' mechanism, developed for IgA nephropathy (IgAN). Both programs leverage clinically validated B cell targets with differentiated mechanisms designed to deliver disease-modifying therapies for patients with limited therapeutic options.

Differentiator

Problem solved

Functional benefit

Products and services

• Budoprutug
• Budoprutug SC (subcutaneous formulation)
• CLYM116

Quantifiable outcome

• 100% (5/5) rapid and complete circulating B cell depletion at doses of 100-200 mg IV in Phase 1b pMN study
• +4 more outcomes

Named customers3 records

Segments4 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature2 records

Partnerships

Two partnerships are on record, tiered core.

• Professor David Jayne, University of CambridgecoreStrategic or Co-development Partner · 7 April 2026Professor David Jayne from the University of Cambridge is featured in Climb Bio's R&D Spotlight webcast covering the scientific rationale, clinical trial design, and development strategy for budoprutug.
• Beijing Mabworks BiotechcoreStrategic or Co-development Partner · 1 January 2025Beijing Mabworks Biotech is Climb Bio's partner for CLYM116, an anti-APRIL monoclonal antibody. Mabworks initiated a Phase 1/2 study of CLYM116 and expects to initiate dosing in IgAN patients in Q3 2026. Climb Bio holds worldwide rights outside of Greater China.

Scale indicators12 records

Recent moves7 records

Expansion highlights6 records

Broad incumbents

• Vertex Pharmaceuticals: Large-cap biotech with growing immunology/rare disease franchise. While much larger and more diversified, Vertex shares Climb Bio's model of targeting well-validated mechanisms in rare diseases with high unmet need, and has overlapping commercial leadership recruited to Climb Bio (e.g., Bo Cumbo's prior VP role). Comparable as a successful rare-disease specialty biotech.
• Apellis Pharmaceuticals: Commercial-stage biotech with approved complement-based therapies for rare diseases including renal indications. Comparable as a small-cap immunology/rare-disease biotech with a similar go-to-market specialty model in high-unmet-need conditions overlapping Climb Bio's nephrology focus.
• Biogen: Large biotech with deep expertise in autoimmune neurology and rare disease biologics (previously approved SPINRAZA, ALPROLIX, ELOCTATE). Not a direct competitor today, but multiple Climb Bio senior leaders (CEO Aoife Brennan, Chairman Doug Williams, prior Biogen executives) come from Biogen, making it a comparable organizational DNA peer.
• Bristol Myers Squibb: Large pharma with deep autoimmune franchise (deucravacitinib, abatacept, rituximab biosimilars) and active clinical pipeline in lupus nephritis and related indications. Relevant as the broad incumbent against which Climb Bio's budoprutug must differentiate commercially, and as the employer of Climb Bio's CMO Edgar Charles who led development of deucravacitinib.

Direct peers

• argenx: Clinical/commercial-stage immunology biotech built around differentiated antibody engineering (FcRn antagonist efgartigimod) for autoimmune diseases including ITP, pMN, and other IgG-mediated diseases. Closest direct peer — same therapeutic axis (targeted antibodies for autoimmune disease), same lead indications (ITP, pMN), and same growth-stage trajectory Climb Bio aspires to follow.
• Travere Therapeutics: Commercial-stage rare disease company with approved therapies in IgA nephropathy (FILSPARI) and other rare kidney/autoimmune conditions. Direct competitor in IgAN and adjacent to Climb Bio's budoprutug pMN development, making it a relevant therapeutic-area peer at a more advanced commercial stage.
• Vera Therapeutics: Late clinical-stage biotech developing atacicept for IgA nephropathy and other B-cell mediated autoimmune diseases. Directly comparable to Climb Bio's CLYM116 program in IgAN, with both targeting APRIL/B-cell biology pathways in autoimmune nephrology at similar clinical stages.
• ACELYRIN: Clinical-stage immunology biotech developing monoclonal antibodies for autoimmune diseases (lonigutamab for thyroid eye disease, izokibep for hidradenitis suppurativa/pMN). Similar size and stage to Climb Bio, recently acquired ValenzaBio (whose former CSO Stephen Thomas is now on Climb Bio's board), giving it overlapping competitive and personnel ties.
• Chinook Therapeutics: Was a clinical-stage biotech focused on rare kidney diseases including IgAN (atrasentan) and pMN before being acquired by Novartis in 2023. Direct comparable as a developer of targeted therapies for the same nephrology indications Climb Bio is pursuing, illustrating both the strategic value of the space and the M&A exit pathway.
• Kezar Life Sciences: Small clinical-stage immunology biotech developing novel small molecules for autoimmune diseases (lupus nephritis, pMN). Comparable in size, stage, and autoimmune nephrology focus to Climb Bio, though using small-molecule rather than antibody approaches.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/climbbio
• LinkedInlinkedin.com/company/climbbio
• Facebookfacebook.com/ClimbBio

Revenue estimate

Valuation estimate

Number of profiles

Profiles17 records

Funding overview

Funding rounds7 records

Investors21 records

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

M&A1 record

Investments

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

Frequently asked questions about Climb Bio