A Phase II trial of 17-allylamino, 17-demethoxygeldanamycin (17-AAG, tanespimycin) in patients with metastatic melanoma.

PURPOSE

A Phase II study to screen for anti-melanoma activity of the heat shock protein 90 (HSP90) inhibitor, 17-AAG (17-allylamino-17-demethoxygeldanamycin) was performed. The primary endpoint was the rate of disease stabilisation in patients with progressive, metastatic melanoma treated with 17-AAG. Secondary endpoints were to determine: the toxicity of 17-AAG, the duration of response(s), median survival and further study the pharmacokinetics and pharmacodynamics of 17-AAG.

PATIENTS AND METHODS

Patients with metastatic melanoma (progressive disease documented ≤6 months of entering study) were treated with weekly, intravenous 17-AAG. A Simon one sample two stage minimax design was used. A stable disease rate of ≥25% at 6 months was considered compatible with 17-AAG having activity.

RESULTS

Fourteen patients (8 male: 6 female) were entered, eleven received 17-AAG (performance status 0 or 1). Median age was 60 (range 29-81) years. The majority (93%) received prior chemotherapy and had stage M1c disease (71%). Toxicity was rarely ≥ Grade 2 in severity and commonly included fatigue, headache and gastrointestinal disturbances. One of eleven patients treated with 17-AAG had stable disease for 6 months and median survival for all patients was 173 days. The study was closed prematurely prior to completion of the first stage of recruitment and limited planned pharmacokinetic and pharmacodynamic analyses.

CONCLUSION

Some evidence of 17-AAG activity was observed although early study termination meant study endpoints were not reached. Stable disease rates can be incorporated into trials screening for anti-melanoma activity and further study of HSP90 inhibitors in melanoma should be considered.