Phase II study of fosaprepitant + 5HT3 receptor antagonist + dexamethasone in patients with germ cell tumors undergoing 5-day cisplatin-based chemotherapy: a Hoosier Cancer Research Network study.

PURPOSE: A phase III study adding aprepitant to a 5HT3 receptor antagonist (5HT3-RA) plus dexamethasone in germ cell tumor (GCT) patients treated with 5-day cisplatin combination chemotherapy demonstrated a significant improvement in complete response (CR) (J Clin Onc 30:3998-4003, 2012). Fosaprepitant has demonstrated non-inferiority compared to aprepitant in single-day cisplatin chemotherapy and is approved as a single-dose alternative. This single-arm phase II study is the first clinical trial evaluating fosaprepitant in patients receiving multi-day cisplatin regimen.

METHODS: GCT patients receiving a 5-day cisplatin combination chemotherapy were enrolled. Fosaprepitant 150 mg was given IV on days 3 and 5. A 5HT3-RA days 1-5 (days 1, 3, and 5, if palonosetron) plus dexamethasone 20 mg days 1 and 2 and 4 mg po bid days 6, 7, and 8 was administered. Rescue antiemetics were allowed. The primary objective was to determine the CR rate-no emetic episodes or use of rescue medications. Accrual of 64 patients was planned with expected CR > 27 %.

RESULTS: Sixty-five patients were enrolled of whom 54 were eligible for analysis. Median age was 33. Fifty-one patients received bleomycin, etoposide, and cisplatin (BEP) chemotherapy. CR was observed in 13 (24.1 %) patients (95 % Agresti-Coull binomial C.I. 14.5 %, 37.1 %).

CONCLUSION: The data in this phase II study, in contrast to our prior phase III study, appears to indicate a lower CR rate with the substitution of fosaprepitant for aprepitant. It is unknown whether the substitution of fosaprepitant for aprepitant provides the same benefit in multi-day cisplatin that was achieved with single-day cisplatin. Trial registration Clinical trial information NCT01736917.