The GETUG SEMITEP Trial: De-Escalating Chemotherapy in Good-Risk Metastatic Seminoma Based on Early FDG-PET/CT

Background: Negative positron emission tomography/computed tomography (FDG-PET/CT) predicts the absence of viable seminoma cells in residual disease after chemotherapy in men with metastatic seminoma. In this study, we assessed whether men with good-prognosis metastatic seminoma could be treated with 2 cycles of etoposide-cisplatin (EP) followed by only one cycle of carboplatin (CARBO) based on a negative interim FDG-PET/CT, thereby limiting the burden of treatment and toxicity. Methods: In this non-randomised, multicentre, phase 2 trial (NCT01887340), we enrolled patients with good-prognosis metastatic seminoma (stage IIB, IIC and III with a good prognosis according to the Medical Research Council classification). All patients with baseline-positive FDG-PET/CT received EP for two cycles. After completing the first two cycles, the patients underwent a second FDG-PET/CT scan to assess the response between days 17 and 20. Patients with persistent positive FDG-PET/CT (based on local review) proceeded directly to two additional EP cycles (for a total of 4 cycles); those who achieved FDG-PET/CT negativity received only one cycle of CARBO AUC=7. The primary outcome was the proportion of patients with a negative FDG-PET/CT on interim assessment who received de-escalating chemotherapy. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Findings: Between June 2013 and July 2017, 102 patients were enrolled in the study. Three patients were deemed ineligible or not evaluable; thus, 99 patients received treatment. After the first 2 EP cycles, FDG-PET/CT was available in 98 pts. Overall, 67 patients (68.4%; 95% CI: 58.2-77.4) had a negative FDG-PET/CT and proceeded to a single CARBO cycle. Twenty-seven patients (27.6%; 95% CI: 19.0-37.5) still had a positive FDG-PET/CT after 2 EP cycles; overall, 31 patients received two additional cycles of EP. After a median follow-up of 39.4 months, only 9 patients relapsed (3/31 in the EP group and 6/67 in the CARBO group). The 3-year PFS rate was 90.0% (95% CI: 74.4-96.5) in the EP group and 90.2% (95% CI: 80.2-95.5) in the CARBO group. One patient died from sepsis during the first two cycles. Interpretation: De-escalating treatment based on a negative FDG-PET/CT after 2 cycles of chemotherapy appears to be safe and feasible in most men with good-prognosis metastatic seminoma. Trial Registration: The trial was registered at ClinicalTrials.gov (NCT01887340). Funding Statement: Programme Hospitalier de Recherche Clinique (PHRC) from the Institut National du Cancer (INCA), France. Declaration of Interests: Yohann Loriot: Dr Loriot reports grants from CELSIUS, grants from SANOFI, grants and personal fees from JANSSEN, personal fees from ASTELLAS, grants and personal fees from MSD, personal fees from ASTRA ZENECA, personal fees from BMS, personal fees from SEATTLE GENETICS, personal fees from PFIZER, personal fees from ROCHE, personal fees from IMMUNOMEDICS outside the submitted work; Matthieu Texier: Dr Texier has nothing to disclose; Stephane Culine: Dr Culine has nothing to disclose; Aude Flechon: Dr Flechon has nothing to disclose; Antoine Thierry-Vuillemin: Dr Thierry-Vuillemin reports personal fees from Pfizer, Astra Zeneca, Sanofi, Janssen, Novartis, Ipsen, Roche, Bristol-Myers Squibb, MSD, Astellas; Gwenaelle Gravis: Dr Gravis has nothing to disclose; Lionel Geoffrois: Dr Geoffrois reports personal fees from BMS, personal fees from NOVARTIS, personal fees and other from IPSEN, personal fees from PFIZER, personal fees from A-Z, personal fees from MSD, outside the submitted work; Christine Chevreau: Dr Chevreau has nothing to disclose; Marine Gross-Goupil: Dr Gross-Goupil has nothing to disclose; Philippe Barthelemy: Dr Barthelemy reports advisory board and travels from BMS, advisory board from MSD, advisory board and travels from IPSEN, advisory board from EUSAPHARMA, advisory board from NOVARTIS, advisory board and travels from ROCHE, advisory board and travels from PFIZER, advisory board and travels from JANSSEN, advisory board from ASTELLAS, outside the submitted work; Emmanuelle Bompas: Dr Bompas has nothing to disclose; Hakim Mahammedi : Dr Mahammedi reports personal fees from Bayer, personal fees from BMS , personal fees from Roche , personal fees from MSD , personal fees from Astra Zeneca , personal fees from Sanofi , personal fees and other from Janssen , personal fees and other from Astellas , outside the submitted work; Brigitte Laguerre: Dr Laguerre has nothing to disclose; Sophie Abadie Lacourtoisie : Dr Abadie Lacourtoisie has nothing to disclose; Carole Helissey: Dr Helissey reports personal fees from Sanofi, Janssen, Astellas and Roche; Sylvain Ladoire : Dr Ladoire reports grants from Pfizer, grants from Astellas, grants from Roche , grants from Novartis , grants from BMS, grants from Ipsen, grants from Janssen, grants from Sanofi, outside the submitted work; Christine Abraham: Dr Abraham has nothing to disclose; Christophe Massard: Dr Massard reports Consultant/Advisory fees from Amgen, Astellas, Astra Zeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion; Serena Grimaldi: Dr Grimaldi has nothing to disclose; Karim Fizazi: Dr Fizazi reports Consultant/Advisory fees from Amgen, Astellas, Bayer, Jansen, Takeda, Sanofi, Orion, Essa, Genentech, Astra Zeneca, Clovis. Ethics Approval Statement: Written informed consent was obtained from all the patients. The study was approved by the ethics committee of Ile de France II (N°2013-02-12 MS1) and the French Healthcare Agency (N°130253B-12).