Medco digs deeper into diagnostics for drugs

Medco Health Solutions, the big pharmacy benefits manager, is expanding its genetic-testing program, linking the use of more prescription drugs to diagnostic tests. Aimed at identifying patients who most benefit from certain meds--and those who don't--the program ultimately could save money on prescription drugs and help patients avoid unnecessary side effects.

Already offering tests for patients prescribed the blood thinner warfarin and the breast-cancer med tamoxifen, Medco plans to introduce tests for clot-buster Plavix (Sanofi-Aventis and Bristol-Myers Squibb) and the AIDS meds abacavir and Selzentry (Pfizer). Next up: A test to monitor the leukemia drugs Gleevec (Novartis), Sprycel (BMS) and Tasigna (Novartis).

Some drugs work best in patients with particular genetic characteristics. Take Plavix--the FDA recently added a warning to the drug's label advising doctors that patients with a genetic variation of the cytochrome CYP2C19 may not metabolize Plavix properly, so the drug may not be effective in those folks. Doctors can try boosting the dosage of Plavix for those patients or might try the new, competing clotbuster Effient.

Medco's push into diagnostics isn't without its detractors. Some point out that the company will be making money on these diagnostic tests (though they are voluntary). Others wonder whether there's enough clarity about what happens once the results are in.

- see the Wall Street Journal story (sub. req.)