8036 Background: AUY922 is a synthetic HSP90 inhibitor that degrades client onco-proteins including EGFR. Preclinical studies demonstrate HSP90 inhibitors are effective agents against models of AR in EGFR-mutant lung cancer cell lines and xenografts harboring the “gatekeeper” mutation EGFR T790M. Pts with EGFR mutations who develop AR often continue E with 2nd-line therapies to avoid “disease flare” associated with discontinuing TKI. This phase II study combines AUY922 and E for the treatment of pts with EGFR-mutant lung cancer and RECIST-progression on 1st-line EGFR TKIs. Methods: Eligible pts had EGFR mutations and developed AR (Jackman, JCO 2010) after treatment with EGFR TKIs. Pts underwent tumor biopsies after developing AR and prior to study entry. Pts received AUY922 70 mg/m2 IV weekly and E 150 mg oral daily in 28-day cycles. Response assessment occurred at 4 weeks (wks), 8 wks, and every 8 wks thereafter. The primary objective was overall response rate (ORR, CR+PR) at 8 wks. A Simon mini-max design determined sample size (stage I: 16 pts (≥2 responses needed to proceed to stage II), stage II: 9 pts; α=10%, β=10%, p0=10%, p1=30%). Tumor tissue from re-biopsy at study entry was analyzed for EGFR T790M. Results: Sixteen pts have been treated (10 women, median age 58 [range 47-76]). The median time on EGFR-TKI prior to the development of AR was 12 mo (range 2-42 mo). Seven pts had EGFR T790M confirmed by tumor re-biopsy. ORR was 2/16 (13%, 95% CI 2-37%). Both pts with PR had EGFR T790M. Four other pts had stable disease for at least 8 wks, two remain on study after more than 12 wks. Adverse events reported in ≥20% of pts were diarrhea, fatigue, myalgias, nausea, and transient flashing lights or night blindness. One pt each experienced grade 3 diarrhea and cardiac abnormalities. Conclusions: AUY922 and E is a well-tolerated regimen for pts with EGFR-mutant lung cancer and AR to EGFR TKIs. Two pts remain on study and 9 additional pts will be accrued in stage II; final response rate and survival outcomes will be reported. Supported by Novartis, Inc. Clinical trial information: NCT01259089.
Phase II study of osimertinib in patients with plasma EGFR T790M positive advanced lung cancer (WJOG8815L/LPS)