Phase II study of temsirolimus and erlotinib in patients (pts) with recurrent/metastatic (R/M), platinum-refractory head and neck squamous cell carcinoma (HNSCC).

5549 Background: The Epidermal Growth Factor Receptor (EGFR) is a validated target in HNSCC. In R/M disease, primary or acquired resistance to anti-EGFR therapy inevitably occurs. Downstream activation of the PI3K/Akt/mTOR pathway is an established resistance mechanism. We hypothesized that concurrent mTOR blockade may improve efficacy of anti-EGFR therapy and conducted this phase II study. Methods: We evaluated the combination of erlotinib 150 mg po daily and temsirolimus 15 mg IV weekly in pts with platinum-refractory R/M HNSCC and ECOG PS 0-2. The exact, single-stage phase II design had 80% power (5% significance level) to detect improvement in progression-free survival (PFS) from 2.3 to 4.4 mos with 35 evaluable pts. Correlatives included determination of PIK3CA mutation (mut) status; p16, EGFR and PTEN expression; and immunomodulatory cytokine levels. Results: From Dec 2009 – Mar 2011, 12 pts enrolled. Six pts withdrew prior to first planned response assessment, due to toxicity (5) or death (1), prom...