ASCO '12 Abstract Dump: Cancer Stocks in Focus
What's new in the ASCO abstract: The response data are little changed from the December update because the ASCO abstract (No. 6053) was submitted in January, reflecting a median 6.6 months of follow up. The overall major cytogenic response for CML patients is 49% (higher than in December.) In the T315I subgroup, the response rate is 62% (lower than in December.)
A significant update of results from the PACE study will be presented at ASCO, with six-month follow-up data on all patients available.
What we know already: Top-line data from a phase II study of tivantinib in second-line liver cancer were released in January. Liver cancer patients who progressed after first-line therapy were randomized 2:1 to receive tivantinib or a placebo. The study met its primary endpoint with tivantinib demonstrating a 56% improvement in time to tumor regrowth (time to progression, or TTP) compared to the placebo.
What's new in the ASCO abstract: In the overall patient population, tivantinib-treated patients reported a median time to progression of 1.6 months compared to 1.4 months for placebo patients. The small difference was statistically significant with a p value of 0.04. (Abstract No. 6503)
In a subset of patients who over-expressed c-Met, the molecular target of tivantinib, median TTP was 2.9 months for drug versus 1.5 months for placebo -- a statistically significant benefit. In this same patient subgroup, progression-free survival was 2.4 months for tivantinib compared to 1.5 months for placebo -- statistically significant.
A preliminary overall survival analysis trends in tivantinib's favor but is not yet statistically significant.
Tivantinib dose was reduced mid-study due to reports of low blood cell counts in some patients. This helped reduce the rate of neutropenia from 21% to 6%. The most frequent drug-related serious adverse event was neutropenic sepsis (4.2%).
Other notes: Arqule and partner Daiichi Sankyo are conducting a phase III study of tivantinib in non-small cell lung cancer, with an interim analysis expected in the fourth quarter. A phase II study of tivantinib in colon cancer is also ongoing with results possible by year-end or in early 2013.