Background: The standard treatment of patients with metastatic germ-cell tumor (GCT) relapsing after first-line chemotherapy is based on a cisplatin and ifosfamide-containing three-drug regimen, which usually yields a complete response (CR) rate <50%. As gemcitabine consistently displayed activity in patients with advanced GCT and as synergy with cisplatin was reported, we integrated this drug into the salvage triplet regimen and assessed its activity in this phase II study.
Patients and methods: The GIP regimen consisted in gemcitabine 1000 mg/m(2) day 1 and 5, ifosfamide 1200 mg/m(2)/day day 1-5, cisplatin 20 mg/m(2)/day day 1-5, and granulocyte colony-stimulating factor 263 μg/day day 7-15, repeated every 3 weeks for four cycles. Eligibility criteria were that patients had favorable prognostic factors to conventional-dose salvage chemotherapy including a testis primary tumor and a previous CR to first-line chemotherapy for metastatic disease. The primary end point was the CR rate and a two-stage Simon design was used.
Results: Thirty-seven patients were accrued and 29 (78%) achieved a favorable response, including a CR in 20 (54%) and a partial response with normalization of tumor markers (PRm-) in 9 (24%). With a median follow-up of 53 months (13-81), the 2-year overall survival rate is 73% (57%-84%) and the continuous progression-free survival rate is 51% (35%-66%). Myelosuppression was the main toxicity including febrile neutropenia in 8 (22%) patients and 18 (50%) cases required platelet infusion. No grade 3 and 4 peripheral neurotoxicity or renal toxicity occurred. Two patients died of treatment-related toxicity, one of them with cancer progression.
Conclusion: In a multicenter context, four cycles of the GIP regimen achieved a high CR rate in patients with relapsed testicular GCT. The GIP regimen avoided severe neurotoxicity and yielded a high survival rate.
Clinical trial number: NCT00127049.
Keywords: chemotherapy; gemcitabine; germ-cell tumor; salvage.