Approximately 1–4% of lung adenocarcinomas harbour a HER2 mutation. No targeted treatment is approved yet for this NSCLC pt subgroup. Initial results for the treatment of HER2m+ NSCLC with the irreversible ErbB family blocker, afatinib, have been encouraging, with some pts showing notable responses or promising disease control. Pts with HER2m+ NSCLC were included in a global NPU program for afatinib, which was initiated in 2010, and their treatment outcomes are presented here.
A global NPU program included patients with advanced NSCLC who had progressed after clinical benefit on prior erlotinib/gefitinib, had an activating EGFR or HER2 mutation, had exhausted all other treatment options; and were ineligible for afatinib trials. Pts received daily oral afatinib (starting dose: 40 or 50 mg). Collection of safety data was mandatory. Time to treatment failure (TTF) was defined as time from start of afatinib treatment to the date of treatment discontinuation.
As of May 2017, data were available for 28 pts with HER2m+ NSCLC (male/female: 12/16 [43/57%]; median age: 55 yrs; starting dose 40/50 mg: 17/11 [61/39%]). Patients were heavily pretreated; 16 (57%) received afatinib as ≥ 4th-line treatment and 7 (25%) had received prior targeted anti-HER2 treatment. Median TTF for afatinib, calculated for all 28 patients was 2.9 months and, notably, 9 (32%) pts had TTF >1 yr. Response assessments were reported for 16 pts; disease control rate was 69% (11/16 pts) and objective response rate was 19% (3/16 pts). No new or unexpected safety findings were observed.
This analysis of a heavily pre-treated pt population with HER2m+ NSCLC from the afatinib NPU program showed a promising 32% of pts with TTF >1 yr, durable disease control and a manageable safety profile. With the limitation of retrospective analysis, and also considering that different HER2 mutations can display different treatment sensitivities, these findings suggest that the evaluation of afatinib in earlier treatment lines in HER2m+ NSCLC pts may be warranted.
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J-Y. Shih: Advisory board: AstraZeneca, Roche, Boehringer Ingelheim, MSD Oncology, Chugai Pharma. Honoraria: AstraZeneca, Roche, Eli Lilly, Boehringer Ingelheim, Pfizer, MSD Oncology, Bristol-Myers Squibb, Novartis. Other substantive relationship: Travel, Accommodations, Expenses: Roche, Boehringer Ingelheim, Bristol-Myers Squibb. V.W-Y. Liao: Honoraria: AstraZeneca, Roche,Pfizer, Boehringer Ingelheim, Norvatis, Eli Lilly, Merck Sharp & Dohme, Sanofi. V. Spataro: Advisory board: Roche, Novartis, Bristol-Myers, MSD. R. Lorence: Employee and consultant for Boehringer Ingelheim Pharmaceuticals, Inc. A. Cseh: Employee of Boehringer Ingelheim. All other authors have declared no conflict of interest.