Targeted failure of the week. Post No 96. Vercirnon

This time we have problems with CCR9 chemokine receptor antagonist.

ChemoCentryx Inc. (NASDAQ:CCXI) fell $3.37 (29%) to $8.32 on Friday after partner GlaxoSmithKline plc (LSE:GSK; NYSE:GSK) said vercirnon (GSK1605786) missed the primary and secondary endpoints in the Phase III SHIELD-1 trial to treat Crohn's disease. Specifically, vercirnon missed the primary endpoint of improving clinical response, defined as a reduction in Crohn's Disease Activity Index (CDAI) score of 100 points or more from baseline, and the secondary endpoint of improving clinical remission, defined as a CDAI score less than 150 points, at week 12 vs. placebo. GSK also said there was a trend for dose-dependent increases in overall adverse event rates with vercirnon.

The trial enrolled 608 patients with moderately to severely active CD who were not adequately controlled with conventional therapy, including tumor necrosis factor (TNF) alpha antagonists. Following the miss, GSK suspended the Phase III program, which comprises the SHIELD-2, SHIELD-3 and SHIELD-4 trials in addition to SHIELD-1. The pharma said it has not yet put a time frame on when it will make a decision on the program.

Vercirnon, a CC chemokine receptor 9 (CCR9) antagonist, is ChemoCentryx's most advanced compound. ChemoCentryx said it does not yet have access to the SHIELD-1 data, but does "not believe there is evidence that CCR9 is anything but a good target." The company also has a small molecule third-generation CCR9 inhibitor, CCX507, in Phase I testing to treat irritable bowel syndrome (IBS). ChemoCentryx's lead unlicensed product is CCX140, a CCR2 antagonist. The biotech expects data from a Phase II trial of CCX140 to treat diabetic nephropathy this quarter. GSK is also developing ChemoCentryx's CCX354, a CCR1 antagonist, which has completed Phase II testing for rheumatoid arthritis.