Extended follow-up of a phase 2 trial of xevinapant plus chemoradiotherapy in high-risk locally advanced squamous cell carcinoma of the head and neck: a randomised clinical trial.

INTRODUCTION: We report long-term efficacy and overall survival (OS) results from a randomised, double-blind, phase 2 study (NCT02022098) investigating xevinapant plus standard-of-care chemoradiotherapy (CRT) vs. placebo plus CRT in 96 patients with unresected locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). METHODS: Patients were randomised 1:1 to xevinapant 200 mg/day (days 1-14 of a 21-day cycle for 3 cycles), or matched placebo, plus CRT (cisplatin 100 mg/m2 every 3 weeks for 3 cycles plus conventional fractionated high-dose intensity-modulated radiotherapy [70 Gy/35 F, 2 Gy/F, 5 days/week for 7 weeks]). Locoregional control, progression-free survival, and duration of response after 3 years, long-term safety, and 5-year OS were assessed. RESULTS: The risk of locoregional failure was reduced by 54% for xevinapant plus CRT vs. placebo plus CRT but did not reach statistical significance (adjusted hazard ratio [HR] 0.46; 95% CI, 0.19-1.13; P = .0893). The risk of death or disease progression was reduced by 67% for xevinapant plus CRT (adjusted HR 0.33; 95% CI, 0.17-0.67; P = .0019). The risk of death was approximately halved in the xevinapant arm compared with placebo (adjusted HR 0.47; 95% CI, 0.27-0.84; P = .0101). OS was prolonged with xevinapant plus CRT vs. placebo plus CRT; median OS not reached (95% CI, 40.3-not evaluable) vs. 36.1 months (95% CI, 21.8-46.7). Incidence of late-onset grade ≥3 toxicities was similar across arms. CONCLUSIONS: In this randomised phase 2 study of 96 patients, xevinapant plus CRT demonstrated superior efficacy benefits, including markedly improved 5-year survival in patients with unresected LA SCCHN.

Xevinapant or placebo plus chemoradiotherapy in locally advanced squamous cell carcinoma of the head and neck: TrilynX phase III study design.

Xevinapant is a first-in-class antagonist of inhibitor of apoptosis proteins, which enhances cancer cell sensitivity to chemotherapy and radiotherapy. In a phase II randomized study in patients with unresected locally advanced squamous cell carcinoma of the head and neck (LA SCCHN), xevinapant plus standard-of-care cisplatin-based chemoradiotherapy (CRT) showed superior efficacy versus placebo plus CRT. Here, we describe the design of TrilynX (NCT04459715), a randomized, double-blind, phase III study. In total, 700 patients with unresected LA SCCHN will be randomized 1:1 to receive xevinapant or placebo plus standard-of-care CRT followed by xevinapant monotherapy or placebo. The primary end point is event-free survival by blinded independent review committee. Secondary end points include progression-free survival, locoregional control, overall survival and safety.

Xevinapant is being developed as a new type of cancer treatment. Xevinapant works by enhancing the effects of chemotherapy and radiotherapy (chemoradiotherapy), which are standard anticancer treatments. Researchers are studying whether adding xevinapant to these treatments could be helpful for people with head and neck cancers that have not spread to other parts of the body and cannot be removed by surgery. In a study of 96 people with this disease, those treated with chemoradiotherapy plus xevinapant on average lived longer than people treated with chemoradiotherapy plus placebo (liquid that looked the same but did not contain any medicine). To confirm the results, researchers have started a larger study, called TrilynX, that will compare the same treatments in around 700 people worldwide. This study will show if adding xevinapant to chemoradiotherapy can help to keep the cancer from progressing, control symptoms better and help people live longer. Clinical trial registration: NCT04459715 (ClinicalTrials.gov).

Biomarker results from a phase II study of MEK1/2 inhibitor binimetinib (MEK162) in patients with advanced NRAS- or BRAF-mutated melanoma.

BRAF and RAS are the most frequently mutated mitogen-activated protein kinase (MAPK) genes in melanoma. Binimetinib is a highly selective MAPK kinase (MEK) 1/2 inhibitor with clinical antitumor activity in NRAS- and BRAF V600-mutant melanoma. We performed a nonrandomized, open-label phase II study, where 183 metastatic melanoma patients received binimetinib 45 mg / 60 mg twice-daily (BRAF arms), or binimetinib 45 mg twice-daily (NRAS arm). Biomarker analyses were prespecified as secondary and exploratory objectives. Here we report the extent of MAPK pathway inhibition by binimetinib, genetic pathway alterations of interest, and potential predictive markers for binimetinib efficacy. Twenty-five fresh pre- and post-dose tumor sample pairs were collected for biomarker analyses, which included assessment of binimetinib on MEK/MAPK signaling by pharmacodynamic analysis of pERK and DUSP6 expression in pre- vs post-dose tumor biopsies; identification of pERK and DUSP6 expression/efficacy correlations; assessment of baseline tumor molecular status; and exploration of potential predictive biomarkers of efficacy of binimetinib. The postbaseline pERK and DUSP6 expression decreased across all arms; no association between reduced pERK or DUSP6 levels with clinical efficacy was observed. Genetic aberrations were similar to previously reported data on clinical melanoma samples. Genetic pathway alterations occurred predominantly within CDKN2A/B, PTEN, and TRRAP (BRAF-mutation) and CDKN2A/B, TP53, and NOTCH2 (NRAS-mutation). Several patients with BRAF mutations had amplification of genes on chromosome 7q; these patients tended to have shorter progression-free survival than other patients with BRAF-mutant melanoma. Further analysis of genetic alterations, including amplifications of growth factor genes, will determine utility as biomarkers for efficacy.

A phase Ib dose-escalation study of the oral pan-PI3K inhibitor buparlisib (BKM120) in combination with the oral MEK1/2 inhibitor trametinib (GSK1120212) in patients with selected advanced solid tumors.

PURPOSE: MAPK and PI3K/AKT/mTOR pathways play important roles in many tumors. In this study, safety, antitumor activity, and pharmacokinetics of buparlisib (pan class PI3K inhibitor) and trametinib (MEK inhibitor) were evaluated. EXPERIMENTAL DESIGN: This open-label, dose-finding, phase Ib study comprised dose escalation, followed by expansion part in patients with RAS- or BRAF-mutant non-small cell lung, ovarian, or pancreatic cancer. RESULTS: Of note, 113 patients were enrolled, 66 and 47 in dose-escalation and -expansion parts, respectively. MTD was established as buparlisib 70 mg + trametinib 1.5 mg daily [5/15, 33% patients with dose-limiting toxicities (DLT)] and recommended phase II dose (RP2D) buparlisib 60 mg + trametinib 1.5 mg daily (1/10, 10% patients with DLTs). DLTs included stomatitis (8/103, 8%), diarrhea, dysphagia, and creatine kinase (CK) increase (2/103, 2% each). Treatment-related grade 3/4 adverse events (AEs) occurred in 73 patients (65%); mainly CK increase, stomatitis, AST/ALT (aspartate aminotransferase/alanine aminotransferase) increase, and rash. For all (21) patients with ovarian cancer, overall response rate was 29% [1 complete response, 5 partial responses (PR)], disease control rate 76%, and median progression-free survival was 7 months. Minimal activity was observed in patients with non-small cell lung cancer (1/17 PR) and pancreatic cancer (best overall response was SD). Relative to historical data, buparlisib exposure increased and trametinib exposure slightly increased with the combination. CONCLUSIONS: At RP2D, buparlisib 60 mg + trametinib 1.5 mg daily shows promising antitumor activity for patients with KRAS-mutant ovarian cancer. Long-term tolerability of the combination at RP2D is challenging, due to frequent dose interruptions and reductions for toxicity.