Doxorubicin, paclitaxel, and cisplatin (ATP) for refractory germ cell tumors

e17028 Background: Patients with refractory germ cell tumor (GCT) have limited treatment options and poor prognosis. We describe our institutional experience with doxorubicin, paclitaxel, and cisplatin (ATP) as an outpatient chemotherapy regimen for patients with refractory GCT. Methods: We performed a retrospective chart review of all patients who received ATP at our institution between August 2017 and August 2022. ATP consisted of doxorubicin 30 mg/m2, paclitaxel 100 mg/m2 over one hour, and cisplatin 30 mg/m2 every 2-3 weeks. We reviewed patient and disease characteristics including staging, histology, prior therapies, tumor marker and imaging responses. Progression free survival (PFS) and overall survival (OS) were respectively calculated from the first ATP dose date to disease progression/death and to death/last follow up. Results: A total of 39 patients with refractory GCT received ATP. Patients were 95% male, 54% white, with a mean age of 30 years (range 18-63). Prior to ATP administration, 92% of GCTs had elevated tumor markers, including 54% with elevated AFP, 56% with elevated HCG, and 18% with elevated both tumor markers. 8% of GCTs did not have elevated tumor markers at baseline. Further disease characteristics are described in table 1. Patients received a median of 2 lines of prior systemic therapies (range 1-6), including 97% with prior cisplatin-based regimens and 21% with prior high dose chemotherapy with stem cell rescue transplant. Patients received a median of 3 doses of ATP (range 1-8) with 31% for palliative intent and the rest as a bridge to transplant or other therapies. After ATP administration, 77% patients had decreased tumor markers, including 18% with tumor marker normalization. Of the 19 patients with imaging post-ATP, 53% had complete or partial response, 16% had stable disease, and 32% had disease progression. By December 2022, 79% patients had progression or death, with a median PFS of 3.8 months (95% CI: 1.94, 7.16) and median OS of 10.7 months (95% CI: 6.37, 32.69). 18% of patients experienced toxicities requiring admissions. Conclusions: Based on our retrospective single institution experience, ATP has clinical activity in refractory GCT and is associated with decreased tumor markers and imaging response in most patients. ATP is a convenient and feasible outpatient regimen and can be used in the salvage setting and as a bridge to other therapies. [Table: see text]