Safety and efficacy of pralsetinib in RET fusion-positive non-small-cell lung cancer including as first-line therapy: update from the ARROW trial.

BACKGROUND: RET fusions are present in 1%-2% of non-small-cell lung cancer (NSCLC). Pralsetinib, a highly potent, oral, central nervous system-penetrant, selective RET inhibitor, previously demonstrated clinical activity in patients with RET fusion-positive NSCLC in the phase I/II ARROW study, including among treatment-naive patients. We report an updated analysis from the ARROW study. PATIENTS AND METHODS: ARROW is a multi-cohort, open-label, phase I/II study. Eligible patients were ≥18 years of age with locally advanced or metastatic solid tumours and an Eastern Cooperative Oncology Group performance status of 0-2 (later 0-1). Patients initiated pralsetinib at the recommended phase II dose of 400 mg once daily until disease progression, intolerance, consent withdrawal, or investigator's decision. The co-primary endpoints (phase II) were overall response rate (ORR) by blinded independent central review and safety. RESULTS: Between 17 March 2017 and 6 November 2020 (data cut-off), 281 patients with RET fusion-positive NSCLC were enrolled. The ORR was 72% [54/75; 95% confidence interval (CI) 60% to 82%] for treatment-naive patients and 59% (80/136; 95% CI 50% to 67%) for patients with prior platinum-based chemotherapy (enrolment cut-off for efficacy analysis: 22 May 2020); median duration of response was not reached for treatment-naive patients and 22.3 months for prior platinum-based chemotherapy patients. Tumour shrinkage was observed in all treatment-naive patients and in 97% of patients with prior platinum-based chemotherapy; median progression-free survival was 13.0 and 16.5 months, respectively. In patients with measurable intracranial metastases, the intracranial response rate was 70% (7/10; 95% CI 35% to 93%); all had received prior systemic treatment. In treatment-naive patients with RET fusion-positive NSCLC who initiated pralsetinib by the data cut-off (n = 116), the most common grade 3-4 treatment-related adverse events (TRAEs) were neutropenia (18%), hypertension (10%), increased blood creatine phosphokinase (9%), and lymphopenia (9%). Overall, 7% (20/281) discontinued due to TRAEs. CONCLUSIONS: Pralsetinib treatment produced robust efficacy and was generally well tolerated in treatment-naive patients with advanced RET fusion-positive NSCLC. Results from the confirmatory phase III AcceleRET Lung study (NCT04222972) of pralsetinib versus standard of care in the first-line setting are pending.

Updated overall survival and final progression-free survival data for patients with treatment-naive advanced ALK-positive non-small-cell lung cancer in the ALEX study.

BACKGROUND: The ALEX study demonstrated significantly improved progression-free survival (PFS) with alectinib versus crizotinib in treatment-naive ALK-positive non-small-cell lung cancer (NSCLC) at the primary data cut-off (9 February 2017). We report mature PFS (cut-off: 30 November 2018) and overall survival (OS) data up to 5 years (cut-off: 29 November 2019). PATIENTS AND METHODS: Patients with stage III/IV ALK-positive NSCLC were randomized to receive twice-daily alectinib 600 mg (n = 152) or crizotinib 250 mg (n = 151) until disease progression, toxicity, withdrawal or death. Primary end point: investigator-assessed PFS. Secondary end points included objective response rate, OS and safety. RESULTS: Mature PFS data showed significantly prolonged investigator-assessed PFS with alectinib [hazard ratio (HR) 0.43, 95% confidence interval (CI) 0.32-0.58; median PFS 34.8 versus 10.9 months crizotinib]. Median duration of OS follow-up: 48.2 months alectinib, 23.3 months crizotinib. OS data remain immature (37% of events). Median OS was not reached with alectinib versus 57.4 months with crizotinib (stratified HR 0.67, 95% CI 0.46-0.98). The 5-year OS rate was 62.5% (95% CI 54.3-70.8) with alectinib and 45.5% (95% CI 33.6-57.4) with crizotinib, with 34.9% and 8.6% of patients still on study treatment, respectively. The OS benefit of alectinib was seen in patients with central nervous system metastases at baseline [HR 0.58 (95% CI 0.34-1.00)] and those without [HR 0.76 (95% CI 0.45-1.26)]. Median treatment duration was longer with alectinib (28.1 versus 10.8 months), and no new safety signals were observed. CONCLUSIONS: Mature PFS data from ALEX confirmed significant improvement in PFS for alectinib over crizotinib in ALK-positive NSCLC. OS data remain immature, with a higher 5-year OS rate with alectinib versus crizotinib. This is the first global randomized study to show clinically meaningful improvement in OS for a next-generation tyrosine kinase inhibitor versus crizotinib in treatment-naive ALK-positive NSCLC. CLINICAL TRIALS NUMBER: NCT02075840.

Clinical experience and management of adverse events in patients with advanced ALK-positive non-small-cell lung cancer receiving alectinib.

Alectinib is a preferred first-line therapy for patients with advanced anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) in several national clinical practice guidelines. The randomized, global, phase III ALEX study has demonstrated significant improvement in progression-free survival for alectinib over crizotinib in treatment-naive ALK-positive NSCLC. It was also the first study to show clinically meaningful improvement in overall survival for a next-generation ALK tyrosine kinase inhibitor relative to crizotinib. The J-ALEX and ALESIA phase III studies confirmed the clinical benefit of alectinib relative to crizotinib in the first-line ALK-positive NSCLC treatment setting in Japanese and Asian patients, respectively. Across these pivotal phase III trials, alectinib had a manageable, well-characterized safety profile. Here, we review the safety and tolerability of long-term alectinib treatment in patients with advanced ALK-positive NSCLC and provide guidance for physicians, based on clinical experience, on the management of the most frequently reported adverse events (AEs). Most AEs associated with alectinib can be managed by dose reduction. Some alectinib-related AEs are not yet fully characterized, including myalgia and peripheral oedema and deciphering their underlying mechanism of action could enhance their management. With longer-term follow-up, the safety profile of alectinib continues to remain consistent in the ALEX study, with no new safety signals observed. Safety and tolerability data from the first-line phase III alectinib trials are also consistent with those observed in clinical trials of alectinib in later-line settings. These results add to the weight of evidence recommending alectinib as a preferred therapy for treatment-naive advanced ALK-positive NSCLC.

Final efficacy and safety data, and exploratory molecular profiling from the phase III ALUR study of alectinib versus chemotherapy in crizotinib-pretreated ALK-positive non-small-cell lung cancer.

BACKGROUND: At the primary data cut-off, the ALUR study demonstrated significantly improved progression-free survival (PFS) and central nervous system (CNS) objective response rate (ORR) with alectinib versus chemotherapy in pretreated, advanced anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer. We report final efficacy and safety data, and exploratory molecular profiling. PATIENTS AND METHODS: Patients who received prior platinum-doublet chemotherapy and crizotinib were randomized 2 : 1 to receive alectinib 600 mg twice daily (n = 79) or chemotherapy (pemetrexed 500 mg/m2 or docetaxel 75 mg/m2, every 3 weeks; n = 40) until progressive disease, death or withdrawal. The primary endpoint was investigator-assessed PFS. Secondary endpoints included ORR, CNS ORR and safety. Plasma samples were collected at baseline, then every 6 weeks until progressive disease; molecular factors detected by next-generation sequencing were correlated with outcomes. RESULTS: Investigator-assessed PFS was significantly longer with alectinib than chemotherapy (median 10.9 versus 1.4 months; hazard ratio 0.20, 95% confidence interval 0.12-0.33; P < 0.001). ORR was 50.6% with alectinib versus 2.5% with chemotherapy (P < 0.001). In patients with measurable CNS metastases at baseline, CNS ORR was 66.7% with alectinib versus 0% with chemotherapy (P < 0.001). No new safety signals were seen. ALK rearrangement was identified in 69.5% (n = 41/59) of baseline plasma samples. Confirmed partial responses were observed with alectinib in 6/11 patients with a secondary ALK mutation and 4/6 patients with a non-EML4-ALK (where EML4 is echinoderm microtubule-associated protein-like 4) fusion. Detection of mutant TP53 in baseline plasma resulted in numerically shorter PFS with alectinib (hazard ratio 1.88, 95% confidence interval 0.9-3.93). CONCLUSIONS: Final efficacy data from ALUR confirmed the superior PFS, ORR and CNS ORR of alectinib versus chemotherapy in pretreated, advanced ALK-positive non-small-cell lung cancer. Alectinib prolonged PFS versus chemotherapy in patients with wild-type or mutant TP53; however, alectinib activity was considerably decreased in patients with mutant TP53.