Ado-trastuzumab emtansine (T-DM1) in patients (pts) with HER2 amplified (amp) tumors excluding breast and gastric/gastro-esophageal junction (GEJ) adenocarcinomas: Results from the National Cancer Institute (NCI) Molecular Analysis for Therapy Choice (MATCH) trial.

100Background: The NCI-MATCH is the largest national signal-finding trial incorporating centralized genomic testing to direct pts to molecularly targeted phase 2 treatment arms. HER2 gene amp is observed in many different tumor types. Methods: HER2 amp was defined as copy number (CN) ≥7 based on tumor sequencing on an adapted Oncomine AmpliSeq™ panel under FDA investigational device exemption. Pts with prior trastuzumab, pertuzumab or T-DM1 treatment were excluded. Pts received T-DM1 at 3.6 mg/kg IV Q3 weeks until toxicity or disease progression. Tumor assessments occurred Q3 cycles for 33 cycles and Q4 cycles thereafter. Primary endpoint was objective response. Correlative studies included correlating HER2 CN, HER2 protein levels by IHC, HER2:CEP17 ratio (by FISH), PTEN loss, MYC amplification and PIK3CA mutation status with response. Results: 37 eligible pts were treated between 11/15-3/17. Median age was 65 (range 39-80). 33% had received > 3 lines of prior therapy. Median HER2 CN was 17 (7-139). Vario...