Olaparib as Salvage Treatment for Cisplatin-resistant Germ Cell Tumor

This is a proof-of principle open-label, single-arm, two-stage phase II trial of olaparib 300 mg twice daily in patients with relapsed/refractory metastatic germ cell cancer. The study will recruit 10 patients, if no response is seen the study is terminated. If one or more responses are observed, further 19 patients (for a total of 29 patients) will be enrolled. If 4 or more of the first 29 evaluable patients have achieved objective response, further studies in patients with metastatic germ cell cancer are warranted.

The main inclusion criteria are:

• Patient with metastatic gonadal GCT or extragonadal GCT originating from retroperitoneum or mediastinum.
• Disease progression during cisplatin-based chemotherapy or disease progression or relapse after high-dose chemotherapy or disease progression or relapse after at least 2 different cisplatin-based regimens
• At least one measurable lesion that can be accurately assessed by CT/MRI/plain x-ray) at baseline and follow up visits.

The study will be analyzed on an intent-to-treat basis. Secondary parameters will be analyzed exploratively for the intent-to-treat population.

Correlations between with biomarkers (PAR, poly adenosine diphosphate-ribose polymerase (PARP-1), PTEN, XPA, ERCC1-3, XPF, FanD2, γ-H2AX) expression in paraffin-embedded tumor samples and clinical outcome will be performed in an exploratory intent. Plasma samples will be collected at baseline and at response/progression for possible retrospective biomarkers study.