A randomized phase III trial data was presented at ASCO 2010 by Dr. Socinski and colleagues, involving chemonaïve patients with stage IIIb and stage IV non small cell lung cancer patients. Five hundred and twenty five (525) patients received Nab-Paclitaxel (Abraxane) without any pre medications at 100 mg/m2 on days 1, 8 and 15 along with Carboplatin given on day 1 at an AUC of 6. The control group of 525 patients received standard Paclitaxel 200mg/m2 and Carboplatin at an AUC of 6 on day 1. The major end point was response rate. The Nab-Paclitaxel group had a response rate of 33% compared to 25% for the standard Paclitaxel group. When broken down by histology, the response rates in those with squamous cell carcinoma was 41% in the Nab-Paclitaxel group versus 24% in the standard Paclitaxel arm whereas the non squamous subtypes had a response rate of 26% versus 25% in the Nab-Paclitaxel and Paclitaxel group respectively. It is hypothesized that the superior response rates in squamous cell histology may be due to the overexpression by this sub type of Caveolin–1, which is a protein which may facilitate a higher intratumoral drug concentration.
So, here is something for squamous cell histology. Choosing therapy based on histology is here to stay.