A first-in-human phase I trial of daily oral zelenirstat, a N-myristoyltransferase inhibitor, in patients with advanced solid tumors and relapsed/refractory B-cell lymphomas.

Myristoylation, the N-terminal addition of the fatty acid myristate to proteins, regulates membrane-bound signal transduction pathways important in cancer cell biology. This modification is catalyzed by two N-myristoyltransferases, NMT1 and NMT2. Zelenirstat is a first-in-class potent oral small molecule inhibitor of both NMT1 and NMT2 proteins. Patients with advanced solid tumors and relapsed/refractory (R/R) B-cell lymphomas were enrolled in an open label, phase I dose escalation trial of oral daily zelenirstat, administered in 28-day cycles until progression or unacceptable toxicity. The endpoints were to evaluate dose-limiting toxicities (DLT) to establish a maximum tolerated dose (MTD), pharmacokinetic parameters, and anticancer activity. Twenty-nine patients were enrolled (25 advanced solid tumor; 4 R/R B-cell lymphoma) and 24 were DLT-evaluable. Dosing ranged from 20 mg once daily (OD) to 210 mg OD without DLT, but gastrointestinal DLTS were seen in the 280 mg cohort. MTD and recommended phase 2 dose were 210 mg OD. Common adverse events were predominantly Gr ≤ 2 nausea, vomiting, diarrhea, and fatigue. Plasma concentrations peaked at 2 h with terminal half-lives averaging 10 h. Steady state was achieved by day 15, and higher doses achieved trough concentrations predicted to be therapeutic. Stable disease as best response was seen in eight (28%) patients. Progression-free survival and overall survival were significantly better in patients receiving 210 mg OD compared to those receiving lower doses. Zelenirstat is well-tolerated, achieves plasma exposures expected for efficacy, and shows early signs of anticancer activity. Further clinical development of zelenirstat is warranted.

Immune-Related Adverse Events and Survival Among Patients With Metastatic NSCLC Treated With Immune Checkpoint Inhibitors.

Importance: Immune-related adverse events (irAEs) secondary to immune checkpoint inhibitor (ICI) therapy reportedly improve overall survival (OS) in patients with non-small cell lung cancer (NSCLC). However, studies have been small and the association between irAE severity and OS remains poorly defined. Objective: To examine the association between irAEs and their severity with OS in patients with locally advanced or metastatic NSCLC receiving ICIs. Design, Setting, and Participants: This retrospective observational cohort study included patients with NSCLC receiving ICIs between March 1, 2014, and November 30, 2021, with follow-up until March 31, 2023. Data analysis was completed April 26, 2023. The Alberta Immunotherapy Database, a provincial, multicenter cohort, was used to capture data from patients receiving ICIs in Alberta, Canada. Participants included 803 patients 18 years or older who received at least 1 cycle of ICI (alone or with chemotherapy), agnostic to treatment line. Exposure: Developing an irAE mandating delay or discontinuation of ICI therapy and/or systematic corticosteroids for management of toxic effects (hereinafter referred to as clinically meaningful irAEs). Main Outcomes and Measures: The primary outcome was association between irAEs and OS according to Kaplan-Meier analysis. Clinically meaningful irAEs were identified. Patients with poor prognosis (survival <3 months) who may have died prior to irAE development were excluded from OS analysis, mitigating immortal time bias. Adjusted Cox proportional hazards regression analyses ascertained variables associated with OS. Results: Among the 803 patients included in the analysis, the median age of patients with irAEs was 69.7 (IQR, 63.1-75.2) years and the median age of those without irAEs was 67.5 (IQR, 60.4-73.3) years, with comparable sex distribution (139 of 295 men [47.1%] and 156 of 295 women [52.9%] with irAEs vs 254 of 505 men [50.3%] and 251 of 505 women [49.7%] without irAEs). Mitigating immortal time bias (n = 611), irAEs were associated with OS (median OS with irAEs, 23.7 [95% CI, 19.3-29.1] months; median OS without irAEs, 9.8 [95% CI, 8.7-11.4] months; P < .001). No OS difference was associated with treatment in hospital vs as outpatients for an irAE (median OS, 20.8 [95% CI, 11.7-30.6] vs 25.6 [95% CI, 20.1-29.8] months; P = .33). Developing irAEs remained associated with OS in the total cohort after Cox proportional hazards regression with known prognostic characteristics (hazard ratio, 0.53 [95% CI, 0.40-0.70]; P < .001). Conclusions and Relevance: In this cohort study of 803 patients with locally advanced or metastatic NSCLC receiving ICIs, developing a clinically meaningful irAE was associated with improved OS. This association was not compromised by hospitalization for severe toxic effects. Whether and how ICI therapy resumption after an irAE is associated with OS warrants further study.