National Cancer Institute and Merck KGaA.

Purpose: M7824 (MSB0011359C) is an innovative first-in-class bifunctional fusion protein composed of a monoclonal antibody against programmed death ligand 1 (PD-L1) fused to a transforming growth factor-β (TGF-β) "trap."Experimental Design: In the 3+3 dose-escalation component of this phase 1 study (NCT02517398), eligible patients with advanced solid tumors received M7824 at 1, 3, 10, or 20 mg/kg once-every-2-weeks until confirmed progression, unacceptable toxicity, or trial withdrawal; additionally, a cohort received an initial 0.3 mg/kg dose to evaluate pharmacokinetics/pharmacodynamics (PK/PD), followed by 10 mg/kg dosing. The primary objective is to determine the safety and maximum tolerated dose (MTD); secondary objectives include PK, immunogenicity, and best overall response. Results:Nineteen heavily pretreated patients with ECOG 0-1 have received M7824. Grade ≥3 treatment-related adverse events occurred in 4 patients (skin infection secondary to localized bullous pemphigoid, asymptomatic lipase increase, colitis with associated anemia, and gastroparesis with hypokalemia). The MTD was not reached. M7824 saturated peripheral PD-L1 and sequestered any released plasma TGF-β1, -β2, and -β3 throughout the dosing period at >1 mg/kg. There were signs of efficacy across all dose levels, including 1 ongoing confirmed complete response (cervical cancer), 2 durable confirmed partial responses (PRs; pancreatic cancer; anal cancer), 1 near-PR (cervical cancer), and 2 cases of prolonged stable disease in patients with growing disease at study entry (pancreatic cancer; carcinoid). Conclusions STATEMENT OF TRANSLATIONAL RELEVANCEExcitement surrounding the durable benefits associated with PD-1/PD-L1-targeted therapy has been tempered somewhat by responses being confined to only a subset of patients.To increase the rate of response, many ongoing trials are evaluating anti-PD-1/PD-L1 agents in combination with other immunotherapies; however, these combination strategies have limitations and novel approaches are required. M7824 (MSB0011359C) is an innovative first-in-class bifunctional fusion protein composed of a monoclonal antibody against PD-L1 fused to a TGF-β "trap." We report the first clinical data for M7824 -including pharmacokinetics, safety, and efficacy findings -which derive from a phase 1 dose-escalation study in patients with advanced solid tumors. M7824 saturated peripheral PD-L1 and sequestered any released plasma TGF-β throughout the dosing period at a dose >1 mg/kg. M7824 appeared to have a manageable safety profile and early evidence of clinical efficacy -including 1 ongoing confirmed complete response and 2 durable confirmed partial responses -was demonstrated.

BackgroundCheckpoint inhibitors have not been effective for prostate cancer as single agents. Durvalumab is a human IgG1-K monoclonal antibody that targets programmed death ligand 1 and is approved by the U.S. Food and Drug Administration for locally advanced or metastatic urothelial cancer and locally advanced, unresectable stage 3 non-small cell lung cancer. Olaparib, a poly (ADP-ribose) polymerase inhibitor, has demonstrated an improvement in median progression-free survival (PFS) in select patients with metastatic castration-resistant prostate cancer (mCRPC). Data from other trials suggest there may be improved activity in men with DNA damage repair (DDR) mutations treated with checkpoint inhibitors. This trial evaluated durvalumab and olaparib in patients with mCRPC with and without somatic or germline DDR mutations.MethodsEligible patients had received prior enzalutamide and/or abiraterone. Patients received durvalumab 1500 mg i.v. every 28 days and olaparib 300 mg tablets p.o. every 12 h until disease progression or unacceptable toxicity. All patients had biopsies of metastatic lesions with an evaluation for both germline and somatic mutations.ResultsSeventeen patients received durvalumab and olaparib. Nausea was the only nonhematologic grade 3 or 4 toxicity occurring in > 1 patient (2/17). No patients were taken off trial for toxicity. Median radiographic progression-free survival (rPFS) for all patients is 16.1 months (95% CI: 4.5–16.1 months) with a 12-month rPFS of 51.5% (95% CI: 25.7–72.3%). Activity is seen in patients with alterations in DDR genes, with a median rPFS of 16.1 months (95% CI: 7.8–18.1 months). Nine of 17 (53%) patients had a radiographic and/or PSA response. Patients with fewer peripheral myeloid-derived suppressor cells and with alterations in DDR genes were more likely to respond. Early changes in circulating tumor cell counts and in both innate and adaptive immune characteristics were associated with response.ConclusionsDurvalumab plus olaparib has acceptable toxicity, and the combination demonstrates efficacy, particularly in men with DDR abnormalities.Trial registrationClinicalTrials.gov identifier: NCT02484404.Electronic supplementary materialThe online version of this article (10.1186/s40425-018-0463-2) contains supplementary material, which is available to authorized users.