Antonia, Scott

Background Our study was designed to determine the safety, efficacy, and immunological effects of perioperative pembrolizumab in early-stage NSCLC. Methods This is a single-arm phase II study of perioperative pembrolizumab in patients with untreated, clinical stage IB to IIIA NSCLC. Patients received two doses of 200 mg pembrolizumab, surgery, standard adjuvant chemotherapy, followed by four doses adjuvant pembrolizumab. The primary objective of this study was to determine surgical feasibility rate, and secondary objectives are pathological response rate, treatment adverse events, efficacy data, and exploratory analysis of biomarkers. Results 30 patients initiated perioperative pembrolizumab, and 25 completed tumor resection. At median follow-up of 59 months after surgical resection, seven patients had disease progression, while six had died representing. A 5-year progression-free survival (PFS) from time of surgery was 72.0% (56.4%–91.9%) and overall survival (OS) from time of surgery was 75.8% (60.7%–94.7%). Major pathological response (MPR) was found in seven tumors (28%) including two complete responses (4%). Across all treated patients, four receiving neoadjuvant and four receiving adjuvant pembrolizumab experienced treatment-related adverse events of grade 3 or higher with no grade 5 events. Plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) levels increased across our patient cohort over time from baseline until postsurgery and remained elevated at the end of treatment. There was a significant difference between mean plasma PCSK9 levels for patients with MPR versus all other patients on study when checked postoperatively. Conclusions Perioperative pembrolizumab was safe and effective with promising MPR rate, PFS, and OS.

Background Availability of checkpoint inhibitors has created a paradigm shift in the management of patients with solid tumors. Despite this, most patients do not respond to immunotherapy, and there is considerable interest in developing combination therapies to improve response rates and outcomes. B7-H3 (CD276) is a member of the B7 family of cell surface molecules and provides an alternative immune checkpoint molecule to therapeutically target alone or in combination with programmed cell death-1 (PD-1)–targeted therapies. Enoblituzumab, an investigational anti-B7-H3 humanized monoclonal antibody, incorporates an immunoglobulin G1 fragment crystallizable (Fc) domain that enhances Fcγ receptor-mediated antibody-dependent cellular cytotoxicity. Coordinated engagement of innate and adaptive immunity by targeting distinct members of the B7 family (B7-H3 and PD-1) is hypothesized to provide greater antitumor activity than either agent alone. Methods In this phase I/II study, patients received intravenous enoblituzumab (3–15 mg/kg) weekly plus intravenous pembrolizumab (2 mg/kg) every 3 weeks during dose-escalation and cohort expansion. Expansion cohorts included non–small cell lung cancer (NSCLC; checkpoint inhibitor [CPI]–naïve and post-CPI, programmed death-ligand 1 [PD-L1] <1%), head and neck squamous cell carcinoma (HNSCC; CPI-naïve), urothelial cancer (post-CPI), and melanoma (post-CPI). Disease was assessed using Response Evaluation Criteria in Solid Tumors version 1.1 after 6 weeks and every 9 weeks thereafter. Safety and pharmacokinetic data were provided for all enrolled patients; efficacy data focused on HNSCC and NSCLC cohorts. Results Overall, 133 patients were enrolled and received ≥1 dose of study treatment. The maximum tolerated dose of enoblituzumab with pembrolizumab at 2 mg/kg was not reached. Intravenous enoblituzumab (15 mg/kg) every 3 weeks plus pembrolizumab (2 mg/kg) every 3 weeks was recommended for phase II evaluation. Treatment-related adverse events occurred in 116 patients (87.2%) and were grade ≥3 in 28.6%. One treatment-related death occurred (pneumonitis). Objective responses occurred in 6 of 18 (33.3% [95% CI 13.3 to 59.0]) patients with CPI-naïve HNSCC and in 5 of 14 (35.7% [95% CI 12.8 to 64.9]) patients with CPI-naïve NSCLC. Conclusions Checkpoint targeting with enoblituzumab and pembrolizumab demonstrated acceptable safety and antitumor activity in patients with CPI-naïve HNSCC and NSCLC. Trial registration number NCT02475213.

With rapid advances in our understanding of cancer, there is an expanding number of potential novel combination therapies, including novel–novel combinations. Identifying which combinations are appropriate and in which subpopulations are among the most difficult questions in medical research. We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review of trials of novel–novel combination therapies involving immunotherapies or molecular targeted therapies in advanced solid tumors. A MEDLINE search was conducted using a modified Cochrane Highly Sensitive Search Strategy for published clinical trials between July 1, 2017, and June 30, 2020, in the top-ranked medical and oncology journals. Trials were evaluated according to a criterion adapted from previously published Food and Drug Administration guidance and other key considerations in designing trials of combinations. This included the presence of a strong biological rationale, the use of a new established or emerging predictive biomarker prospectively incorporated into the clinical trial design, appropriate comparator arms of monotherapy or supportive external data sources and a primary endpoint demonstrating a clinically meaningful benefit. Of 32 identified trials, there were 11 (34%) trials of the novel–novel combination of anti-programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) and anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) therapy, and 10 (31%) trials of anti-PD-1/PD-L1 and anti-vascular endothelial growth factor (VEGF) combination therapy. 20 (62.5%) trials were phase II trials, while 12 (37.5%) were phase III trials. Most (72%) trials lacked significant preclinical evidence supporting the development of the combination in the given indication. A majority of trials (69%) were conducted in biomarker unselected populations or used pre-existing biomarkers within the given indication for patient selection. Most studies (66%) were considered to have appropriate comparator arms or had supportive external data sources such as prior studies of monotherapy. All studies were evaluated as selecting a clinically meaningful primary endpoint. In conclusion, designing trials to evaluate novel–novel combination therapies presents numerous challenges to demonstrate efficacy in a comprehensive manner. A greater understanding of biological rationale for combinations and incorporating predictive biomarkers may improve effective evaluation of combination therapies. Innovative statistical methods and increasing use of external data to support combination approaches are potential strategies that may improve the efficiency of trial design. Designing trials to evaluate novel–novel combination therapies presents numerous challenges to demonstrate efficacy in a comprehensive manner. A greater understanding of biological rationale for combinations and incorporating predictive biomarkers may improve effective evaluation of combination therapies. Innovative statistical methods and increasing use of external data to support combination approaches are potential strategies that may improve the efficiency of trial design.

Abstract Background: This is an update of the safety and efficacy of durvalumab monotherapy in pts with locally advanced/metastatic urothelial carcinoma (UC) from an ongoing, phase 1/2 open-label study (NCT01693562). Methods: Pts received 10 mg/kg every 2 weeks up to 12 months or until unacceptable toxicity, progression, or starting another anticancer therapy. Pts were stratified by tumor PD-L1 expression (Ventana PD-L1 [SP263] Assay [PD-L1 cutoff: ≥25% of tumor cells and/or immune cells with membrane staining]) and treatment line. Results: As of the data cutoff (16Oct2017), 201 UC pts with Stage IV disease received treatment, with a median follow-up of 16.9 months (range, 0.4-37.7). Across treatment lines, objective response rate (ORR) by blinded independent central review was 17.4% (95% CI, 12.4, 23.4) in all pts; 27.5% in the PD-L1 ≥25% group vs 5.8% in the PD-L1 &lt;25% group. The responses have been durable regardless of PD-L1 status, with the median duration of response not yet reached in the PD-L1 ≥25% group and 12.2 months in the PD-L1 &lt;25% group. Responses lasted ≥12 mo in 62.9% of responders (max 25.7+ mo). Overall, median OS was 10.5 months (95% CI, 6.9, 15.7); 19.8 months in the PD-L1 ≥25% group vs 4.8 months in the PD-L1 &lt;25% group (Table). Pts previously treated with platinum based chemotherapy also reported similar durable responses. At least one treatment-related AE was reported in 120 pts (59.7%), including fatigue (39 [19.4%]), decreased appetite and rash (18 [9.0%] each), and diarrhea (16 [8.0%]). Grade 3/4 treatment-related AEs occurred in 19 (9.5%) pts; 6 (3.0%) treatment discontinuations and 2 (1.0%) deaths were attributed to treatment-related AEs. Conclusions: With extended follow-up, durvalumab continues to show durable clinical activity in UC pts, especially in the PD-L1 ≥25% group with an acceptable toxicity profile. PD-L1 ≥25%PD-L1 &lt;25%PD-L1 unknownTotalAll UCn=102n=86n=13N=201Confirmed ORR, %27.55.815.417.4(95% CI)(19.1, 37.2)(1.9, 13.0)(1.9, 45.4)(12.4, 23.4)CR, %7.83.57.76.0PR, %19.62.37.711.4Median DoR, monthsNR12.2NRNR(min, max)(2.7, 25.7+)(8.6, 21.7+)(14.5+, 14.6+)(2.7, 25.7+)Median PFS, months (95% CI)1.9 (1.4, 2.7)1.4 (1.3, 1.5)2.8 (1.4, NE)1.5 (1.4, 1.8)6-month PFS rate, %28.68.625.220.412-month PFS rate, %22.37.125.216.2Median OS, months (95% CI)19.8 (9.3, NE)19.8 (9.3, NE)4.8 (3.3, 8.1)NR (4.9, NE)10.5 (6.9, 15.7)6-month OS rate, %67.645.869.258.912-month OS rate, %57.629.561.546.6 Citation Format: Peter O'Donnell, Christophe Massard, Bhumsuk Keam, Sang-We Kim, Terry Friedlander, Myung-Ju Ahn, Michael Ong, Michael Gordon, Marcus Butler, Scott Antonia, Gerardo Colon-Otero, Martin Gutierrez, Sumati Gupta, Alexander Spira, Alexandra Drakaki, Michele Maio, Feng Xiao, Natasha Angra, Shaad Abdullah, Thomas Powles. Updated efficacy and safety profile of durvalumab monotherapy in urothelial carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT031.