Doxorubicin, Paclitaxel, and Cisplatin (ATP) for Relapsed/Refractory Germ Cell Tumors

Abstract

Patients with relapsed/refractory germ cell tumors (GCT) have limited treatment options and poor survival outcomes. We describe our institutional experience with doxorubicin, paclitaxel, and cisplatin (ATP) as an outpatient regimen for 35 patients with relapsed/refractory GCT between 2017 and 2022. Twenty-four patients received non-palliative intent ATP, with a median of 2 lines of prior therapy, 23 (96%) having received at least one cisplatin-based regimen and one (4%) with a prior stem cell transplant. The objective response rate for the non-palliative intent cohort was 37.5% (one complete response and eight partial responses). Post-ATP, 12 patients underwent stem cell transplant, 7 patients had surgical resections, and 4 patients received radiation. The median PFS was 4.3 months (95% CI: 3.8, 32.7) and median OS of 13.1 months (95% CI: 10.7, NA) for the non-palliative intent cohort. Eleven patients received palliative intent ATP, with a median of 4 lines of prior therapy, all having received at least one cisplatin-based regimen, and 7 (64%) having received prior stem cell transplants. Within the palliative intent cohort, the objective response rate was 9% (one partial response). Patients who received palliative intent ATP had a median PFS of 0.92 months (95% CI 0.46, NA) and median OS of 5.2 months (95% CI 3.3, NA). Treatment toxicities occurred in five (14%) patients who required dose reductions and five (14%) patients who were admitted for treatment related toxicities, most commonly for myelosuppression. Our results support the use of ATP in a primarily anthracycline naïve patient population and show the safety of continued cisplatin use in patients who have previously received cisplatin-based regimens. Therefore, ATP is a feasible and well tolerated chemotherapy regimen in the salvage setting and can serve as a bridge to other treatments for patients with relapsed/refractory GCT. Micro-abstractWe report our institutional experience with doxorubicin, paclitaxel, and cisplatin (ATP) in patients with relapsed/refractory germ cell tumors (GCT). A total of 35 patients received ATP. In the non-palliative intent cohort (24 patients), the objective response rate was 37.5%, with a median progression free survival (PFS) of 4.3 months and a median overall survival (OS) of 13.1 months. For the palliative intent cohort (11 patients), the objective response rate was 9%, with a median PFS of 0.92 months and a median OS of 5.2 months. Treatment-related toxicities were observed in 14% of patients, with five requiring dose reductions and five requiring hospital admission, primarily due to myelosuppression. Overall, ATP is a feasible and well-tolerated outpatient chemotherapy regimen that may serve as a bridge to other therapies.