Interleukin-21 Phase 2 Clinical Trial in Advanced Melanoma Set to Begin

Implications: Interleukin-21, or IL-21, is a protein that regulates immunomodulatory cell function. It appears to stimulate the activity of NK cells and cytotoxic T cells, which may be particularly relevant in targeting cancers that more responsive to the immune system, such as melanoma and renal cell carcinoma. This current trial is built upon Phase I results in melanoma and renal cell carcinoma presented over a year ago, at ASCO 2006. In that study, there was one melanoma patient with a complete response and several (not sure from abstract) with stable disease, out of a treatment cohort of 18. The current trial is a Phase 2 trial investigating single agent IL-21 in metastatic melanoma patients. The endpoints are response rate and lack of disease progression.

Analysis: It is interesting that this trial was just announced as initiating because other documents on the Zymogenetics website give the start date as July 2006, which would be more consistent with a June 2006 ASCO presentation. In the interim, they appear to have more aggressively pursued combination therapy with IL-21 and Nexavar in renal cell carcinoma, with some apparently impressive results.