IM862 is a synthetic thymic dipeptide consisting of L-glutamic acid and L-tryptophan (L-Glu-L-Trp, MW ~333.3 g/mol). It was originally investigated by Imutec/Shire Pharmaceuticals as an anti-angiogenic and immunomodulatory agent for AIDS-related Kaposi sarcoma (KS). Early open-label studies showed promising tumor regression, but a subsequent Phase II placebo-controlled trial failed to demonstrate efficacy, and development was discontinued.
Category: Immune Modulator. Evidence rating: D (animal/preclinical only).
Clinical status: Development discontinued. Phase II for AIDS-related Kaposi sarcoma failed to show efficacy (2002). No further clinical development.
IM862 was proposed to exert anti-angiogenic effects by inhibiting VEGF and bFGF-driven neovascularization, along with immunomodulatory activity through stimulation of natural killer cell function and modulation of T-cell responses. The peptide was administered intranasally, and the exact mechanism…
Safety considerations: Intranasal administration was well-tolerated in clinical trials; Mild nasal irritation and rhinorrhea reported as most common side effects; No serious treatment-related adverse events in Phase I/II studies.
Reviewed by the PeptideAtlas Editorial Team. Last reviewed: 2026-08-12.
Related peptides: Thymosin Alpha-1, Thymulin.
Compare: IM862 vs Thymosin Alpha-1, IM862 vs Thymulin.
A randomized, placebo-controlled Phase II trial in AIDS-related Kaposi sarcoma failed to demonstrate efficacy. The earlier promising open-label results likely reflected improvements in HIV treatment (HAART) rather than IM862 activity. Shire Pharmaceuticals discontinued the program.
No. IM862 is not manufactured or marketed by any pharmaceutical company. Any products claiming to be IM862 are grey-market products without clinical evidence supporting their use.
No. IM862 is a specific synthetic dipeptide (L-Glu-L-Trp), not to be confused with thymalin (a thymic extract preparation used in Russia) or thymulin (FTS, a 9-amino-acid thymic hormone). They are distinct molecules with different origins and mechanisms.