2 abstracts on Crizotinib

Please see glossary for definitions of acronyms.

Abstract 19135 is a survival comparison study of 3 ways of detecting the ALK fusion gene. This study was done in China and involved 75 (and possibly 98 patients). The abstract refers to two groups of patients but it is not clear if they are two separate groups or if one is a subset of the other. So I will just focus on the 75 patient group.

The trial looked at progression free survival (PFS) and overall survival. All patients were treated with Crizotinib.

Of the group of 75 patients, 23 were identified by break apart fluorescence in situ hybridization (FISH). This is the standard test used in the U.S. to determine ALK status. 35 patients were identified by Ventana immunohistochemistry (IHC).  17 patients were identified by reverse transcriptase polymerase chain reaction (RT-PCR).

The median PFS for IHC was 16 months, for FISH it was 14 months, for RT-PCR it was 8 months. There was apparently minimal effect on overall survival between detection methods.

The abstract concluded that IHC is a valuable and efficient tool and that RT-PCR needs to be further evaluated. No conclusions about FISH.

Abstract 19139 is a retrospective study from China that compares Crizotinib in the first line, second line, and subsequent lines effect on PFS and 2 year survival. As of 1-29-2015 there were 68 patients.

For the 22 patients who received Crizotinib first line, their median PFS was 13.8 months, ORR was 81.8%, and 2 year survival rate was 65%.

For the 29 patients who received Crizotinib second line, their median PFS was 6.8 months, ORR was 72.4%, and 2 year survival rate was 47%.

For the 18 patients who received Crizotinib third line or later, their median PFS was 7 months, ORR was 69.6%, and 2 year survival rate was 50%.

The abstract concluded that “First-line was significantly superior…with respect to PFS.”

http://abstracts.asco.org/156/AbstView_156_150033.html     Comparison of ALK detection methods

http://abstracts.asco.org/156/AbstView_156_152068.html     First, second, or third line

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