No abstract

HER2-targeted therapy is not standard of care for HER2-positive non-small cell lung cancer (NSCLC). This phase II study investigated efficacy and safety of the HER2-targeted antibody-drug conjugate trastuzumab emtansine (T-DM1) in patients with previously treated advanced HER2-overexpressing NSCLC. Eligible patients had HER2-overexpressing NSCLC (centrally tested IHC) and received previous platinum-based chemotherapy and targeted therapy in the case of mutation or gene rearrangement. Patients were divided into cohorts based on HER2 IHC (2+, 3+). All patients received T-DM1 3.6 mg/kg intravenously every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was investigator-determined overall response rate (ORR) using RECIST v1.1. Forty-nine patients received T-DM1 (29 IHC 2+, 20 IHC 3+). No treatment responses were observed in the IHC 2+ cohort. Four partial responses were observed in the IHC 3+ cohort (ORR, 20%; 95% confidence interval, 5.7%-43.7%). Clinical benefit rates were 7% and 30% in the IHC 2+ and 3+ cohorts, respectively. Response duration for the responders was 2.9, 7.3, 8.3, and 10.8 months. Median progression-free survival and overall survival were similar between cohorts. Three of 4 responders had gene amplification. No new safety signals were observed. T-DM1 showed a signal of activity in patients with HER2-overexpressing (IHC 3+) advanced NSCLC. Additional investigation into HER2 pathway alterations is needed to refine the target population for T-DM1 in NSCLC; however, HER2 IHC as a single parameter was an insufficient predictive biomarker.

Background: In the KATHERINE study (NCT01772472), patients with residual invasive early breast cancer (EBC) after neoadjuvant chemotherapy (NACT) plus human epidermal growth factor receptor 2 (HER2)-targeted therapy had a 50% reduction in risk of recurrence or death with adjuvant trastuzumab emtansine (T-DM1) versus trastuzumab. Here, we present additional exploratory safety and efficacy analyses. Patients and methods: KATHERINE enrolled HER2-positive EBC patients with residual invasive disease in the breast/ axilla at surgery after NACT containing a taxane (AE anthracycline, AE platinum) and trastuzumab (AE pertuzumab). Patients were randomized to adjuvant T-DM1 (n ¼ 743) or trastuzumab (n ¼ 743) for 14 cycles. The primary endpoint was invasive disease-free survival (IDFS). Results: The incidence of peripheral neuropathy (PN) was similar regardless of neoadjuvant taxane type. Irrespective of treatment arm, baseline PN was associated with longer PN duration (median, 105-109 days longer) and lower resolution rate (w65% versus w82%). Prior platinum therapy was associated with more grade 3-4 thrombocytopenia in the T-DM1 arm (13.5% versus 3.8%), but there was no grade !3 hemorrhage in these patients. Risk of recurrence or death was decreased with T-DM1 versus trastuzumab in patients who received anthracycline-based NACT [hazard ratio (HR) ¼ 0.51; 95% confidence interval (CI): 0.38-0.67], non-anthracycline-based NACT (HR ¼ 0.43; 95% CI: 0.22-0.82), presented with cT1, cN0 tumors (0 versus 6 IDFS events), or had particularly high-risk tumors (HRs ranged from 0.43 to 0.72). The central nervous system (CNS) was more often the site of first recurrence in the T-DM1 arm (5.9% versus 4.3%), but T-DM1 was not associated with a difference in overall risk of CNS recurrence. Conclusions: T-DM1 provides clinical benefit across patient subgroups, including small tumors and particularly high-risk tumors and does not increase the overall risk of CNS recurrence. NACT type had a minimal impact on safety.

The maleate salt-based tablet formulations were bioequivalent to the diHCl tablet formulation. The extent of the observed effect of a high-fat, high-calorie meal or concurrent rabeprazole treatment on glasdegib exposure is not considered clinically meaningful.