Oncolytic reovirus in combination with chemotherapy in metastatic or recurrent non-small cell lung cancer patients with KRAS-activated tumors.

BACKGROUND: The type 3 Dearing reovirus (Reolysin) is a naturally occurring virus that preferentially infects and causes oncolysis in tumor cells with a Ras-activated pathway. It induces host immunity and cell cycle arrest and acts synergistically with cytotoxic agents.
METHODS: This study evaluated Reolysin combined with paclitaxel and carboplatin in patients with metastatic/recurrent KRAS-mutated or epidermal growth factor receptor (EGFR)-mutated/amplified non-small cell lung cancer.
RESULTS: Thirty-seven patients were treated. Molecular alterations included 20 KRAS mutations, 10 EGFR amplifications, 3 EGFR mutations, and 4 BRAF-V600E mutations. In total, 242 cycles (median, 4; range, 1-47) were completed. The initial doses were area under the curve (AUC) 6 mg/mL/min for carboplatin, 200 mg/m(2) for paclitaxel on day 1, and 3 × 10(10) 50% tissue culture infective dose for Reolysin on days 1 to 5 of each 21-day cycle. Because of diarrhea and febrile neutropenia (in the first 2 patients), subsequent doses were reduced to 175 mg/m(2) for paclitaxel and AUC 5 mg/mL/min for carboplatin. Toxicities included fatigue, diarrhea, nausea/vomiting, neutropenia, arthralgia/myalgia, anorexia, and electrolyte abnormalities. Response Evaluation Criteria in Solid Tumors 1.0 responses included the following: partial response for 11 patients, stable disease (SD) for 20 patients, progressive disease for 4 patients, and not evaluable for 2 patients (objective response rate, 31%; 90% 1-sided lower confidence interval, 21%). Four SD patients had >40% positron emission tomography standardized uptake value reductions. The median progression-free survival, median overall survival, and 12-month overall survival rate were 4 months, 13.1 months, and 57%, respectively. Seven patients were alive after a median follow-up of 34.2 months; they included 2 patients without disease progression at 37 and 50 months.
CONCLUSIONS: Reolysin in combination with paclitaxel and carboplatin was well tolerated. The observed response rate suggests a benefit of the reovirus for chemotherapy. A follow-up randomized study is recommended. The proportion of patients surviving longer than 2 years (30%) suggests a second/third-line treatment effect or possibly the triggering of an immune response after tumor reovirus infiltration.