Abcuro, Inc. - Clinical-Stage Biotechnology Company Developing First-in-Class KLRG1 Immunotherapies

Company Overview (Updated April 2026)

Abcuro, Inc. is a clinical-stage biotechnology company headquartered in Newton, Massachusetts, USA. Founded in 2015, the company is pioneering the development of first-in-class immunotherapies targeting KLRG1 (killer cell lectin-like receptor G1) to treat autoimmune diseases and cancer. Abcuro's lead candidate, ulviprubart (ABC008), is a monoclonal antibody that selectively depletes highly cytotoxic late-differentiated T and NK cells while sparing beneficial immune cell populations required for normal immune homeostasis.

Corporate Status:

- Company Type: Private biotechnology company (clinical-stage)

- Founded: 2015

- Headquarters: Newton, MA, USA

- Employees: 55 (as of 2025)

- Industry: Drug Discovery / Clinical-Stage Biopharmaceuticals

- Total Funding: Over $407 million

Historical Evolution:

- 2015: Founded by Stefano Gullà and Steven A. Greenberg, MD, MS

- Dec 2016: Seed Round $2.25M

- Nov 2018: Series A $8M

- Jan 2021: Series A-1 $42M (co-led by Mass General Brigham Ventures and Sanofi Ventures)

- Aug 2023: Series B $155M oversubscribed (co-led by Redmile Group and Bain Capital Life Sciences)

- Jul 2024: Appointed Sarah Boyce (Avidity Biosciences CEO) to Board of Directors

- Feb 2025: Series C $200M led by New Enterprise Associates

- Jun 2025: Appointed Courtney Cupples as Chief Commercial Officer

- Aug 2025: Appointed George Eldridge as Chief Financial Officer

- Feb 2026: Announced initial MUSCLE study results (Phase 2/3 IBM trial)

- Mar 2026: Presented detailed MUSCLE data at GCOM, Lisbon

Financing & Investors (2016-2025)

Funding History

Total Raised to Date: Over $407 million

- Seed Round (Dec 2016): $2.25 million

- Series A (Nov 2018): $8 million

- Series A-1 (Jan 2021): $42 million (co-led by Mass General Brigham Ventures and Sanofi Ventures)

- Series B (Aug 2023): $155 million oversubscribed

- Series C (Feb 2025): $200 million (led by New Enterprise Associates)

Investor Syndicate:

New Enterprise Associates (NEA), Foresite Capital, RA Capital Management, Bain Capital Life Sciences, Redmile Group, Samsara BioCapital, Sanofi Ventures, Pontifax, Mass General Brigham Ventures, New Leaf Ventures, abrdn Inc., BlackRock, Eurofarma Ventures, Soleus Capital

Product Pipeline & Clinical Development

Lead Candidate: Ulviprubart (ABC008)

Mechanism of Action:

- First-in-class monoclonal antibody targeting KLRG1 (killer cell lectin-like receptor G1)

- Selectively depletes highly cytotoxic late-differentiated effector memory (TEM) and effector (TEMRA) T cells and NK cells

- Spares naïve, regulatory, and central memory T cells required for immune system homeostasis

Regulatory Designations:

- Orphan Drug Designation: Granted by FDA and EMA for IBM treatment

- Fast Track Designation: Granted by FDA for IBM treatment

- Addresses critical unmet need for over 75,000 IBM patients (40,000 in US, 35,000 in Europe/Japan)

Clinical Trials & Results (2026 Update)

MUSCLE Study - Inclusion Body Myositis (IBM):

- Phase: Phase 2/3 registrational trial

- Enrollment: 272 patients randomized (Placebo n=86; Ulviprubart 0.5mg/kg n=94; Ulviprubart 2.0mg/kg n=92)

- Primary Endpoint: Change in Inclusion Body Myositis Functional Rating Scale (IBMFRS) from baseline to Week 52

- Initial Results Announced (Feb 2026):

- Study did not meet primary endpoint in overall population

- Key secondary endpoints also not met in overall population

- Drug was well-tolerated with no significant safety concerns

- GCOM 2026 Detailed Data (Mar 2026):

- In mild-to-moderate disease subgroup (baseline IBMFRS ≥29, n=156):

- 0.5mg/kg dose: 50% slowing of disease progression (p=0.066)

- 2.0mg/kg dose: 50% slowing of disease progression (p=0.075)

- Population PK model shows dose-dependent target engagement

- Results suggest earlier intervention may provide greater clinical benefit

- Next Steps: Exploring regulatory pathways and potential Phase 3 study design focused on early-stage patients

T-LGLL Study - T Cell Large Granular Lymphocytic LeUKemia:

- Phase: Phase 1/2 trial

- ASH 2025 Presentation (Dec 2025):

- Cohort A (reduced CD4+ counts): 86% (6/7) patients responded after 3 doses

- 71% ACHieved complete resolution of severe neutropenia

- 100% (4/4) achieved >50% reduction in lymphocytosis

- Cohort B (normal CD4+ counts): 100% (2/2) achieved normalization of neutropenia

- All patients showed reduction or normalization of ANC and ALC

- No significant safety issues reported

- Status: Ongoing; evaluating ABC008 in autoimmune disorder characterized by cytotoxic T lymphocytes attacking neutrophils and red blood cell precursors

Scientific Platform & Technology

Target Discovery Approach

Bioinformatics-Driven Target Validation:

- Systematic use of patient clinical data and tissue transcriptome analyses

- Focus on discrete, pathological immune cell subpopulations

- Identified KLRG1 as compelling target with relevance to both autoimmune disease biology and cancer immunology

Differentiation:

- Precise targeting of clinically relevant cytotoxic T and NK cells

- Preservation of beneficial immune cell populations

- Potential broad applicability across multiple autoimmune diseases and oncology indications

Leadership Team (2025-2026)

Executive Management

Chief Executive Officer: Alex Martin, MBA (appointed Oct 2022)

- Over 30 years experience building biopharmaceutical companies

- Former CEO of Palladio Biosciences and Realm Therapeutics

Chief Financial Officer: George Eldridge (appointed Aug 2025)

- Over 30 years finance experience in biotechnology

- Former CFO at Aerovate Therapeutics and Proteon Therapeutics

Chief Commercial Officer: Courtney Cupples (appointed Jun 2025)

- Over 25 years global commercial leadership and rare disease launch experience

- Former CCO at Priovant Therapeutics; previously at Genzyme, Alexion (led $1B Soliris franchise), Biohaven

Chief Operating Officer: Karen Tubridy

- Over 30 years drug development strategy and operations experience

Chief Medical Officer: H. Jeffrey Wilkins, M.D. (appointed Jun 2022)

- Extensive clinical development experience in immunology, immuno-oncology, and rare diseases

Founders:

- Stefano Gullà, Ph.D.: Founder and former CEO/CSO; over 15 years biotherapeutic drug discovery experience (Pfizer, Agenus, Flagship, RVAC); MIT postdoctoral training

- Steven A. Greenberg, MD, MS: Founder and Chief Scientific Advisor; background in neurology and translational medicine

Board of Directors

Chairman: Mark Pruzanski, M.D.

Director: Sarah Boyce (appointed Jul 2024) - President and CEO of Avidity Biosciences; former President of Akcea Therapeutics; 25+ years global commercial leadership

Market Context & Competitive Landscape

Disease Areas & Unmet Needs

Inclusion Body Myositis (IBM):

- Most common acquired myopathy in patients over 50 years of age

- Progressive and debilitating muscle disease with no approved disease-modifying therapies

- Affects approximately 40,000 patients in the US and 35,000 in Europe and Japan

- Characterized by highly cytotoxic T cells expressing KLRG1 driving chronic tissue damage

T-LGLL:

- Rare autoimmune leukemia with limited treatment options

- Cytotoxic T lymphocytes attack neutrophils and red blood cell precursors

Strategic Outlook & 2026-2027 Milestones

Recent Achievements:

- MUSCLE study readout completed (Feb 2026)

- GCOM 2026 detailed data presentation (Mar 2026)

- Identification of responsive patient population (mild-to-moderate disease)

Next Steps:

- Regulatory strategy discussions with FDA/EMA regarding potential path forward for IBM

- Potential Phase 3 study design focused on early-stage IBM patients

- Continued development in T-LGLL and exploration of broader autoimmune indications

- Commercial launch preparation contingent on positive regulatory pathway resolution

Contact Information

Headquarters

Address: Abcuro, Inc., Newton, Massachusetts, USA
   Website: www.abcuro.com
   Investor/Media Contact: Matt DeYoung, Argot Partners, abcuro@argotpartners.com, 212-600-1902
   Media Contact: David Rosen, Argot Partners, david.rosen@argotpartners.com, 212-600-1902

Keywords: Abcuro, ulviprubart, ABC008, KLRG1, inclusion body myositis, IBM, MUSCLE study, GCOM 2026, T-LGLL, autoimmune disease, cancer immunotherapy, orphan drug, fast track designation, Alex Martin, Newton, Massachusetts, Series C, clinical stage, biotech, 2015, Stefano Gullà, 50% disease slowing, mild-moderate IBM