Phase 2 trial of combination thalidomide plus temozolomide in patients with metastatic malignant melanoma: Southwest Oncology Group S0508.

BACKGROUND

In limited institution phase 2 studies, thalidomide and temozolomide has yielded response rates (RRs) up to 32% for advanced melanoma, leading to the use of this combination as "standard" by some. We conducted a multicenter phase 2 trial to better define the clinical efficacy of thalidomide and temozolomide and the immune modulatory effects of thalidomide, when combined with temozolomide, in patients with metastatic melanoma.

METHODS

Patients must have had stage IV cutaneous melanoma, no active brain metastases, Zubrod PS 0-1, up to 1 prior systemic therapy excluding thalidomide, temozolomide, or dacarbazine, adequate organ function, and given informed consent. The primary endpoint was 6-month progression-free survival (PFS). Secondary endpoints included overall survival (OS), RR, toxicities, and assessment of relationships between biomarkers and clinical outcomes. Patients received thalidomide (200 mg/d escalated to 400 mg/d for patients <70, or 100 mg/d escalated to 250 mg/d for patients > or =70) plus temozolomide (75 mg/m(2)/d x 6 weeks, and then 2 weeks rest).

RESULTS

Sixty-four patients were enrolled; 2 refused treatment. The 6-month PFS was 15% (95% confidence interval [CI], 6%-23%), the 1-year OS was 35% (95% CI, 24%-47%), and the RR was 13% (95% CI, 5%-25%), all partial. One treatment-related death occurred from myocardial infarction; 3 other grade 4 events occurred, including pulmonary embolism, neutropenia, and central nervous system (CNS) ischemia. There was no significant correlation between biomarkers and PFS or OS.

CONCLUSIONS

This combination of thalidomide and temozolomide does not appear to have a clinical benefit that exceeds dacarbazine alone. We would not recommend it further for phase 3 trials or for standard community use.