ABSTRACT
Background: Despite remarkable results with salvage standard-dose or high-dose chemotherapy â¼15% of patients with relapsed germ-cell tumors (GCT) are incurable. Immune checkpoint inhibitors have produced significant remission in multiple tumor types. We report the first study of immunotherapy in patients with GCT. Patients and methods: Single arm phase II trial investigating pembrolizumab 200 mg i.v. Q3weeks until disease progression in patients with relapsed GCT and no curable options. Patients age ≥18 with GCT who progressed after first-line cisplatin-based chemotherapy and after at least one salvage regimen (high-dose or standard-dose chemotherapy) were eligible. Centrally assessed programmed death-ligand 1 (PD-L1) on tumor and infiltrating immune cells was scored. Primary end point was overall response rate using immune-related response criteria. Simon two-stage design with type I error 20% and power 80% was utilized. Results: Twelve male patients were enrolled. Median age was 38 years. All patients had nonseminoma. Primary site was testis (11) or mediastinum (1). Median AFP 615 (range 1-32, 760) and hCG 4 (range 0.6-37, 096). Six patients had late relapse (>2 years). Median number of previous chemotherapy regimens was 3. Six patients received prior high-dose chemotherapy. Two patients had positive PD-L1 staining (H-score 90 and 170). Median number of pembrolizumab doses was 2 (range 1-8). There were six grade 3 adverse events. No immune-related adverse events were reported. No partial or complete responses were observed. Two patients achieved radiographic stable disease for 28 and 19 weeks, respectively; both had continued rising AFP level despite radiographic stability and had negative PD-L1 staining. Conclusion: This is the first reported trial evaluating immune checkpoint inhibitors in GCT. Pembrolizumab is well tolerated but does not appear to have clinically meaningful single-agent activity in refractory GCT. Clinical trial information: NCT02499952.
Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Neoplasms, Germ Cell and Embryonal/drug therapy , Testicular Neoplasms/drug therapy , Adult , Antibodies, Monoclonal, Humanized/adverse effects , Antineoplastic Agents, Immunological/adverse effects , Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor , Cisplatin/administration & dosage , Drug Resistance, Neoplasm , Humans , Male , Middle Aged , Salvage TherapyABSTRACT
BACKGROUND: Based on the risk stratification from the International Germ Cell Cancer Collaborative Group (IGCCCG), only 14% of patients with metastatic germ-cell tumors (GCT) had poor-risk disease with a 5-year progression-free survival (PFS) rate of 41% and a 5-year overall survival (OS) rate of only 48%. This analysis attempts to identify prognostic factors for patients with poor-risk disease. PATIENTS AND METHODS: We conducted a retrospective analysis of all patients with GCT diagnosed and treated at Indiana University from 1990 to 2014. Clinical and pathological characteristics were available for all patients and all of them were treated with cisplatin-etoposide-based chemotherapy. Cox proportional hazards models were used to target significant predictors of disease progression and mortality. A significance level of 5% was used in the analysis. RESULTS: We identified 273 consecutive patients with poor-risk GCT (PRGCT). Median follow-up time was 8 years (range 0.03-24.5). The 5-year PFS and OS rates were 58% [95% confidence interval (CI) 51% to 63%] and 73% (95% CI 67% to 78%), respectively. In multivariate survival analyses, multiple risk factors were associated with disease progression, including liver metastasis, brain metastasis, primary mediastinal nonseminomatous GCT (PMNSGCT), and elevation in logarithmic ß-hCG. Significant predictors of mortality were PMNSGCT [hazard ratio (HR) 4.63, 95% CI 2.25-9.56; P < 0.001], brain metastasis (HR 3.30, 95% CI 1.74-6.23; P < 0.001), and increasing age (HR 1.03, 95% CI 1.01-1.06; P = 0.02). CONCLUSIONS: Patients with PMNSGCT, brain metastasis, or with increasing age are at higher risk of death than their counterparts. This contemporary cohort (1990-2014) of 273 patients with PRGCT had improved PFS and OS outcomes than those from the historical IGCCCG group of patients (1975-1990).
