Cell Pathways, Inc. (CPI) was a development-stage pharmaceutical company headquartered at 702 Electronic Drive, Horsham, Pennsylvania, focused on the research and development of products to treat and prevent cancer. Incorporated in Delaware in July 1998 (as Cell Pathways Holdings, Inc., renamed Cell Pathways, Inc. in February 2001), it developed a class of compounds it called selective apoptotic anti-neoplastic drugs (SAANDs), designed to induce selective apoptosis — programmed cell death — in precancerous and cancerous cells without affecting normal cells. Its lead candidate was Aptosyn (exisulind), studied in precancerous lesions such as colonic polyps and cervical dysplasia and later in prostate, lung, and breast cancer; the company also imported, promoted, and sold Gelclair Concentrated Oral Gel into oncology and dental markets, and had previously marketed Nilandron. It traded on the Nasdaq National Market (Commission File No. 000-24889) and employed approximately 34 people full-time as of March 1, 2003. In February 2003 Cell Pathways signed an Agreement and Plan of Merger to be acquired by OSI Pharmaceuticals, Inc. in a stock-for-stock exchange; stockholders approved the merger on June 10, 2003, and the company filed a Form 15-12G on June 12, 2003 terminating its Exchange Act registration with one holder of record. OSI Pharmaceuticals was itself acquired by Astellas Pharma and deregistered on June 18, 2010. Cell Pathways predates the API economy entirely, never operated a developer program or public API surface, and no longer exists as an operating entity. This profile is retained as an acquired-company lead with no API surface to enrich.
Cell Pathways is profiled on the APIs.io network. Tagged areas include Company, Pharmaceuticals, Biotechnology, Oncology, and Cancer Research.
aid: cell-pathways
name: Cell Pathways
description: Cell Pathways, Inc. (CPI) was a development-stage pharmaceutical company headquartered at 702 Electronic Drive,
Horsham, Pennsylvania, focused on the research and development of products to treat and prevent cancer. Incorporated in
Delaware in July 1998 (as Cell Pathways Holdings, Inc., renamed Cell Pathways, Inc. in February 2001), it developed a class
of compounds it called selective apoptotic anti-neoplastic drugs (SAANDs), designed to induce selective apoptosis — programmed
cell death — in precancerous and cancerous cells without affecting normal cells. Its lead candidate was Aptosyn (exisulind),
studied in precancerous lesions such as colonic polyps and cervical dysplasia and later in prostate, lung, and breast cancer;
the company also imported, promoted, and sold Gelclair Concentrated Oral Gel into oncology and dental markets, and had previously
marketed Nilandron. It traded on the Nasdaq National Market (Commission File No. 000-24889) and employed approximately 34
people full-time as of March 1, 2003. In February 2003 Cell Pathways signed an Agreement and Plan of Merger to be acquired
by OSI Pharmaceuticals, Inc. in a stock-for-stock exchange; stockholders approved the merger on June 10, 2003, and the company
filed a Form 15-12G on June 12, 2003 terminating its Exchange Act registration with one holder of record. OSI Pharmaceuticals
was itself acquired by Astellas Pharma and deregistered on June 18, 2010. Cell Pathways predates the API economy entirely,
never operated a developer program or public API surface, and no longer exists as an operating entity. This profile is retained
as an acquired-company lead with no API surface to enrich.
url: https://raw.githubusercontent.com/api-evangelist/cell-pathways/refs/heads/main/apis.yml
accessModel:
pricing: unknown
onboarding: unknown
trial: false
try_now: false
public: false
label: Unknown
confidence: low
source: []
generated: '2026-07-22'
method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/cell-pathways.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- canaan-partners
x-tier: stub
x-tier-reason: portfolio-lead
x-status: acquired
x-acquired-by: osi-pharmaceuticals
x-acquired-date: 2003-06
x-successor: OSI Pharmaceuticals (subsequently acquired by Astellas Pharma, 2010)
x-no-api-surface: true
x-domain-reassigned: true
x-evidence:
- probe: SEC EDGAR company record (CIK 0001066284)
result: CELL PATHWAYS INC /DE, SIC 2834 Pharmaceutical Preparations, Horsham PA; former name CELL PATHWAYS HOLDINGS INC
(until 2001-02-14); 74 filings spanning 1998-07-22 (S-4) through 2003-06-12
url: https://data.sec.gov/submissions/CIK0001066284.json
- probe: SEC Form 15-12G (termination of registration), filed 2003-06-12
result: 'Certification and Notice of Termination of Registration under Section 12(g); Commission File No. 000-24889; approximate
number of holders of record: One — consistent with the company becoming a wholly owned subsidiary'
url: https://www.sec.gov/Archives/edgar/data/1066284/000095012303006981/y87358e15v12g.txt
- probe: SEC Form 425 merger communication, filed 2003-05-30
result: 'Filed by OSI Pharmaceuticals, Inc.; Subject Company: Cell Pathways, Inc. — confirms the proposed merger of OSI
Pharmaceuticals and Cell Pathways and the June 10, 2003 stockholder meeting'
url: https://www.sec.gov/Archives/edgar/data/1066284/000095012303006696/y87196e425.htm
- probe: SEC Form 10-K for FY2002, filed 2003-03-27
result: business description, SAANDs technology, Aptosyn (exisulind) and Gelclair product detail, ~34 full-time employees
as of 2003-03-01, and disclosure of the February 2003 OSI merger agreement
url: https://www.sec.gov/Archives/edgar/data/1066284/000089322003000434/w84292e10vk.txt
- probe: SEC EDGAR successor lookup — OSI PHARMACEUTICALS INC (CIK 0000729922)
result: filed Form 15-12G on 2010-06-18, deregistering after its own acquisition (Astellas Pharma); the successor developer
surface, if any, is not Cell Pathways
- probe: whois cellpathways.com
result: Creation Date 2020-02-15 — 17 years AFTER Cell Pathways deregistered in 2003. Registrar GoDaddy.com, LLC; name servers
NS*.DURABLEDNS.COM. This is a re-registration by an unrelated third party, NOT continuity of the company domain.
- probe: https://cellpathways.com/ (HTTP 200)
result: unrelated WordPress site titled "Cell Pathways - Index of Biotech and Genetics", a generic biotech/genetics content
blog. NOT the pharmaceutical company. Deliberately NOT wired as a Website pointer to avoid attributing third-party content
to this company.
- probe: /.well-known/security.txt, /openid-configuration, /oauth-authorization-server, /api-catalog, /ai-plugin.json, /llms.txt,
/openapi.json, /api on cellpathways.com
result: all 404 — no discovery, developer, or API surface (and the host is not the company's in any case)
- probe: GitHub organization search for "cellpathways" / "cell-pathways"
result: 0 results — no GitHub organization
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Pharmaceuticals
- Biotechnology
- Oncology
- Cancer Research
- Drug Development
- Life Sciences
- Acquired
- Defunct
apis: []
maintainers:
- FN: Kin Lane
email: kin@apievangelist.com
- FN: APIs.json
email: info@apis.io
common:
- type: Successor
name: OSI Pharmaceuticals, Inc.
url: https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000729922&type=&dateb=&owner=include&count=40
- type: SECFilings
name: SEC EDGAR — CELL PATHWAYS INC /DE (CIK 0001066284)
url: https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001066284&type=&dateb=&owner=include&count=40
x-enrichment:
date: '2026-07-20'
status: minimal
artifacts_added: 0
pass: local-v1
note: completed pass — no API surface exists to enrich. Company deregistered 2003-06-12 after the OSI Pharmaceuticals merger;
identity verified against SEC EDGAR primary filings. cellpathways.com is an unrelated 2020 re-registration and was deliberately
not wired as a company property.
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