What ACELYRIN does

ACELYRIN was a clinical-stage biopharmaceutical company founded in 2020 and headquartered in California, focused on developing differentiated medicines for inflammatory and immune-mediated diseases. The company's lead asset was izokibep, an IL-17A inhibitor advancing through Phase 3 clinical trials for psoriatic arthritis, axial spondyloarthritis, hidradenitis suppurativa, and uveitis. In January 2023, ACELYRIN expanded its pipeline through an all-stock acquisition of ValenzaBio, adding lonigutamab — a clinical-stage IGF-1R monoclonal antibody for thyroid eye disease — and the preclinical VB-517 program for chronic urticaria. The company operated with 101-250 employees and pursued traditional pharmaceutical commercialization pathways with a focus on late-stage clinical development.

ACELYRIN was funded through approximately $558 million in venture capital (2020 seed, 2021 Series B of $250 million, 2022 Series C of $300 million led by Access Biotechnology) and a $540 million IPO in 2022 — the fourth largest biotech IPO in biopharma history. The firm was pre-revenue throughout its independent existence, generating no product sales and relying on capital markets to fund R&D. Following clinical failures of izokibep, ACELYRIN announced a merger with Alumis Inc. in February 2025, which was opposed by major shareholder Trium Capital over valuation concerns. The merger was completed, and ACELYRIN now operates as a subsidiary of Alumis Inc. (NASDAQ: ALMS), with the combined entity advancing a portfolio that includes lonigutamab, the TYK2 inhibitor envudeucitinib (Phase 3 in psoriasis and lupus), and A-005.

The customer base, in the commercial sense, never materialized at ACELYRIN: the company had no approved products, so its only counterparties were clinical trial investigators, regulators (FDA), and capital providers. The intended end-patients — those with chronic inflammatory conditions, thyroid eye disease, and chronic urticaria — were addressed only through clinical trial enrollment rather than commercial channels.

Name

ACELYRIN

Legal name

ACELYRIN, Inc.

Website

https://acelyrin.com

Company type

Private

Founded year

2020

Operating status

Acquired

Headcount range

101–250 employees

Short description

ACELYRIN was a clinical-stage biopharmaceutical company that developed immunology therapies for inflammatory diseases, including the IL-17A inhibitor izokibep and the IGF-1R antibody lonigutamab, before merging into Alumis Inc. in 2025.

Ownership category

akta.pro rank

Product category

Biopharmaceuticals - Immunology Therapeutics

NAICS

Pharmaceutical Preparation Manufacturing (325412), Pharmaceutical and Medicine Manufacturing (3254)

SIC

Pharmaceutical Preparations (2834)

akta.pro primary industry

Immunology & Autoimmune Specialty Pharmaceuticals (HLAIACAB)

akta.pro secondary industries

Rare Immunology, Autoimmune & Autoinflammatory Therapies (HLAIAIAE), Rare Ophthalmology Disorder Therapies (HLAIAIAK)

Keywords

• Immunology drug development
• Inflammatory disease therapies
• Biopharmaceutical products
• Monoclonal antibody therapies
• Clinical stage biotechnology

Headquarters

HQ city

Los Angeles

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, Others

Revenue model

1. Pharmaceutical Product Revenue: ACELYRIN was a pre-revenue biopharma company focused on developing innovative immunology drugs through clinical stages. The company was advancing toward commercialization of its differentiated medicine pipeline, primarily through izokibep for multiple inflammatory disease indications.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Core offering

ACELYRIN is a clinical-stage biopharma company that identifies, acquires, and accelerates the development and commercialization of immunology therapies. Its lead candidate, izokibep, is an IL-17A inhibitor in Phase 3 development for psoriatic arthritis, axial spondyloarthritis, hidradenitis suppurativa, and uveitis. The pipeline was expanded through the all-stock acquisition of ValenzaBio, adding lonigutamab (an IGF-1R inhibitor for thyroid eye disease) and the pre-clinical program VB-517 (for chronic urticaria).

Product overview

ACELYRIN was a biopharma company focused on differentiated medicines for immunology. The company developed izokibep, an IL-17A inhibitor in Phase 3 for multiple inflammatory conditions, and expanded its pipeline through the acquisition of ValenzaBio which added lonigutamab (thyroid eye disease) and VB-517 (chronic urticaria). ACELYRIN merged with Alumis Inc. in 2025, with Alumis continuing to advance the combined pipeline including lonigutamab and envudeucitinib.

Differentiator

Problem solved

Functional benefit

Products and services

• Izokibep IL-17A inhibitor drug candidate in Phase 3 development for inflammatory diseases including psoriatic arthritis, axial spondyloarthritis, hidradenitis suppurativa, and uveitis. Intended for adult patients with chronic immune-mediated inflammatory conditions.
• Lonigutamab Clinical-stage monoclonal antibody IGF-1R inhibitor for active and chronic thyroid eye disease (TED), acquired from ValenzaBio. Targets proptosis, eye pain, inflammation, and potential vision impairment in TED patients.
• VB-517 Pre-clinical drug candidate acquired from ValenzaBio, being developed for chronic urticaria (persistent hives). Targets persistent skin rash, itching, and inflammation.

Segments3 records

Ideal customer profiles1 record

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Two partnerships are on record, tiered core.

• AlumiscoreStrategic or Co-development Partner · 1 February 2025ACELYRIN merged with Alumis, another immune-mediated disease focused biotech company. The merger was announced in February 2025 but faced opposition from major shareholders including Trium Capital who contended the offer undervalued ACELYRIN and preferred alternative strategic options or liquidation. Following clinical trial failures of izokibep, the merger proceeded and combined the two companies' pipelines.
• ValenzaBiocoreStrategic or Co-development Partner · 5 January 2023ACELYRIN acquired ValenzaBio, a privately held biotech developing therapies for inflammatory diseases, in an all-stock deal. The acquisition added several clinical and pre-clinical programs including lonigutamab (for thyroid eye disease) and VB-517 (for chronic urticaria) to ACELYRIN's immunology pipeline, supporting its strategic focus on differentiated medicines.

Scale indicators4 records

Recent moves8 records

Expansion highlights4 records

Broad incumbents

• AbbVie: AbbVie markets Skyrizi (risankizumab, IL-23) and Rinvoq (upadacitinib, JAK) across psoriatic arthritis and other immune-mediated conditions, anchoring the competitive landscape ACELYRIN sought to enter.
• UCB: UCB markets Cimzia (certolizumab), an anti-TNF biologic used across psoriatic arthritis and axial spondyloarthritis—direct overlap with ACELYRIN's lead izokibep indications. As a specialty immunology biopharma, UCB is a benchmark comparator for the commercial profile ACELYRIN pursued.
• Eli Lilly: Eli Lilly markets Taltz (ixekizumab), a leading IL-17A inhibitor approved for psoriatic arthritis, axial spondyloarthritis, and other inflammatory conditions—directly competing with izokibep in the same mechanism and indications ACELYRIN pursued.
• Novartis: Novartis markets Cosentyx (secukinumab), the first and largest-selling IL-17A inhibitor with indications spanning psoriatic arthritis, axial spondyloarthritis, and hidradenitis suppurativa—directly competitive with ACELYRIN's izokibep across the same diseases.
• Amgen: Through its acquisition of Horizon Therapeutics, Amgen markets Tepezza (teprotumumab), the only approved IGF-1R inhibitor for thyroid eye disease. Tepezza is the dominant incumbent ACELYRIN's lonigutamab would have to displace or differentiate against.
• Bristol Myers Squibb: BMS markets Sotyktu (deucravacitinib), an oral TYK2 inhibitor for plaque psoriasis, and Zeposia (ozanimod) in immune-mediated disease—making BMS a key competitor in the same immunology/autoimmune space ACELYRIN targeted.

Direct peers

• Alumis: Alumis is the merged entity that absorbed ACELYRIN, advancing envudeucitinib (TYK2) and lonigutamab (IGF-1R) across immune-mediated diseases including psoriasis, SLE, and TED—the direct continuation and successor of ACELYRIN's pipeline.
• Argenx: Argenx is a clinical-to-commercial immunology biopharma with Vyvgart (efgartigimod) in autoimmune disease, representing the type of late-stage immunology-focused biotech comparable to ACELYRIN's commercial trajectory and market positioning.

Emerging players

• Dice Therapeutics (acquired by Eli Lilly): Dice was a clinical-stage immunology biotech developing oral IL-17 small molecules for psoriasis and related inflammatory diseases—an emerging modality competitor to ACELYRIN's biologic IL-17A approach with overlapping indications.
• Kymera Therapeutics: Kymera is a clinical-stage immunology biotech developing targeted protein degraders (e.g., IRAK4) for immune-mediated diseases, representing an emerging modality competitor with overlapping therapeutic focus on inflammatory conditions.

Market position

Strengths4 records

Weaknesses5 records

Competitive moat3 records

Key risks6 records

Key highlights5 records

Customer concentration

• Xx.com/acelyrin

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Subsidiaries1 record

Funding overview

Funding rounds3 records

Investors12 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 ACELYRIN