ACS Pharmaceuticals

ACS Pharmaceuticals was a United Kingdom-based biotechnology company focused on the development of a novel class of drugs known as hydrogen sulfide (H2S)-releasing derivatives, or "S-drugs." The company's core technology involved chemically modifying established pharmaceutical compounds, such as non-steroidal anti-inflammatory drugs (NSAIDs), by attaching a moiety that releases hydrogen sulfide to enhance therapeutic efficacy and significantly reduce side effects like gastrointestinal toxicity. Its lead clinical candidate, ACS-15 (S-naproxen), was advanced into Phase 2 clinical trials for the treatment of osteoarthritis. The company's pipeline also included H2S-releasing versions of aspirin and latanoprost for cardiovascular and ophthalmic indications. ACS Pharmaceuticals was acquired by Cell Therapeutics, Inc. (later CTI BioPharma) in 2008 to bolster its portfolio of anti-inflammatory and oncology-supportive therapies.