Arena Pharmaceuticals
Arena Pharmaceuticals was a clinical-stage biopharmaceutical company that developed etrasimod, an S1P receptor modulator for autoimmune diseases including inflammatory bowel disease. Acquired by Pfizer in 2021, its pipeline was integrated into Pfizer's Inflammation & Immunology portfolio.
- Company typePrivate
- Founded1977
- HeadquartersSan Diego, United States
- Headcount251–500
- GTM typeB2B
- OfferingHardware or Manufacturing
What Arena Pharmaceuticals does
Arena Pharmaceuticals was a clinical-stage biopharmaceutical company founded in 1977 and headquartered in San Diego, California. The company specialized in developing novel small-molecule therapeutics targeting cardiovascular, central nervous system, inflammatory, and metabolic diseases, with its strategic focus narrowing over time toward immunology and inflammation. Arena's lead pipeline asset was etrasimod, an investigational sphingosine-1-phosphate (S1P) receptor modulator designed as an S1P1/S1P5 dual receptor agonist for targeted immunomodulation, with clinical programs in inflammatory bowel disease and alopecia areata. The technology was pursued as a domain-specialized approach aimed at reducing systemic immunosuppression relative to traditional autoimmune therapies.
The company operated as a publicly traded entity on NASDAQ under the ticker ARNA and funded its development through capital markets rather than commercial product sales. Cumulative disclosed funding activity across 2003–2020 exceeded $1 billion across multiple rounds, with notable 2018 ($352.8M) and May 2020 ($316.3M) financings, plus a $56M raise in October 2020 led by Farallon Capital Management. Revenue mechanics were non-existent on a commercial basis because etrasimod and other programs remained investigational throughout Arena's independent existence; pricing was not publicly disclosed.
In 2021, Pfizer Inc. completed the acquisition of Arena Pharmaceuticals, absorbing Arena's pipeline—including etrasimod—into Pfizer's Inflammation & Immunology therapeutic area. Post-acquisition, Arena ceased to operate as an independent publicly traded company and became a wholly-owned subsidiary of Pfizer. The acquisition was framed within Pfizer's broader R&D pipeline expansion strategy alongside other transactions (e.g., Seagen, Biohaven).
Arena Pharmaceuticals firmographics
Firmographics- Name
- Arena Pharmaceuticals
- Legal name
- Arena Pharmaceuticals, Inc.
- Website
- https://arenapharm.com
- Company type
- Private
- Founded year
- 1977
- Operating status
- Acquired
- Headcount range
- 251–500 employees
- Short description
- Arena Pharmaceuticals was a clinical-stage biopharmaceutical company that developed etrasimod, an S1P receptor modulator for autoimmune diseases including inflammatory bowel disease. Acquired by Pfizer in 2021, its pipeline was integrated into Pfizer's Inflammation & Immunology portfolio.
- Ownership category
- akta.pro rank
Arena Pharmaceuticals industry classification
Industry- Product category
- Immunology & Inflammation Therapeutics
- NAICS
- Pharmaceutical Preparation Manufacturing (325412)
- SIC
- Pharmaceutical Preparations (2834)
- akta.pro primary industry
- Immunology & Autoimmune Specialty Pharmaceuticals (HLAIACAB)
- akta.pro secondary industry
- Immunology & Inflammation Pharmaceuticals (HLAIAAAD)
Keywords
Where Arena Pharmaceuticals is headquartered
LocationHeadquarters
- HQ city
- San Diego
- HQ country
- United States
- HQ region
- North America
Markets served
Arena Pharmaceuticals business model
Business model- GTM type
- B2B
- Offering type
- Hardware or Manufacturing
- Cost components
- Technology or R&D, Personnel, Operations, Marketing or Sales, Supply Chain
Arena Pharmaceuticals product offering
Product offeringCore offering
Arena Pharmaceuticals was a clinical-stage biopharmaceutical company that developed novel small-molecule therapeutics for autoimmune and inflammatory diseases. Its lead pipeline asset was etrasimod, an investigational S1P1/S1P5 dual receptor agonist designed to provide targeted immunomodulation for conditions such as inflammatory bowel disease, alopecia areata, and other immunological disorders. The company was acquired by Pfizer in 2021.
Product overview
Arena Pharmaceuticals was a biopharmaceutical company focused on developing innovative therapies for immunological and inflammatory diseases. The company's key asset was etrasimod, a late-stage therapy candidate for conditions such as alopecia areata. Arena was acquired by Pfizer in 2021, integrating its pipeline into Pfizer's therapeutic portfolio.
Differentiator
Problem solved
Functional benefit
Products and services
- Etrasimod Investigational small-molecule S1P receptor modulator (S1P1/S1P5 dual receptor agonist) being developed for the treatment of autoimmune and inflammatory diseases, including inflammatory bowel disease, alopecia areata, and other immunological conditions. Designed to provide targeted immunomodulation with the goal of reducing systemic immunosuppression compared to traditional therapies. Targeted at regulators, healthcare providers, and patients with high-unmet-need autoimmune conditions.
Companies that use Arena Pharmaceuticals
Customer profileIdeal customer profiles1 record
Arena Pharmaceuticals technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature1 record
Arena Pharmaceuticals partnerships and signals
Strategic signalPartnerships
Two partnerships are on record, tiered core.
- PfizercorePfizer completed its acquisition of Arena Pharmaceuticals in 2021. The acquisition strengthened Pfizer's pipeline with Arena's lead asset etrasimod, an S1P receptor modulator for autoimmune diseases. Arena Pharmaceuticals operated as a separate clinical-stage biopharmaceutical company focused on developing innovative medicines for immunology and inflammation before becoming part of Pfizer's portfolio.
- PfizercoreArena Pharmaceuticals was acquired by Pfizer as part of the company's strategy to expand its R&D pipeline and therapeutic areas. The acquisition brought etrasimod (an S1P receptor modulator) into Pfizer's portfolio, supporting their Oncology and Vaccines growth drivers alongside other acquisitions including Seagen and Biohaven.
Scale indicators2 records
Recent moves6 records
Expansion highlights3 records
Arena Pharmaceuticals competitors and assessment
Company assessmentMarket position
Weaknesses4 records
Competitive moat3 records
Key risks4 records
Key highlights5 records
Customer concentration
Arena Pharmaceuticals social profiles
Digital presenceArena Pharmaceuticals financial estimates
Financial estimateRevenue estimate
Valuation estimate
Arena Pharmaceuticals leadership team
Management profileNumber of profiles
Profiles8 records
Arena Pharmaceuticals funding detail
Funding detailFunding overview
Funding rounds8 records
Investors3 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Arena Pharmaceuticals M&A and investment
M&A and investmentM&A
Investments1 record
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Arena Pharmaceuticals
What does Arena Pharmaceuticals do?
Arena Pharmaceuticals was a clinical-stage biopharmaceutical company that developed novel small-molecule therapeutics for autoimmune and inflammatory diseases. Its lead pipeline asset was etrasimod, an investigational S1P1/S1P5 dual receptor agonist designed to provide targeted immunomodulation for conditions such as inflammatory bowel disease, alopecia areata, and other immunological disorders. The company was acquired by Pfizer in 2021.
Is Arena Pharmaceuticals a public or private company?
Arena Pharmaceuticals is a private company. It is classified as corporate owned and is currently acquired.
When was Arena Pharmaceuticals founded?
Arena Pharmaceuticals was founded in 1977. It employs 251 to 500 people.
Where is Arena Pharmaceuticals based?
Arena Pharmaceuticals is headquartered in San Diego, United States, in the North America region.
Does Arena Pharmaceuticals have an API?
No public API is recorded for Arena Pharmaceuticals.
What industry is Arena Pharmaceuticals in?
Arena Pharmaceuticals's product category is Immunology & Inflammation Therapeutics. Its primary akta.pro industry code is HLAIACAB, Immunology & Autoimmune Specialty Pharmaceuticals, with a secondary code of HLAIAAAD, Immunology & Inflammation Pharmaceuticals. Its NAICS code is 325412 and its SIC code is 2834.