PHILADELPHIA -(Dow Jones)- Cigna Corp. (CI) said Tuesday it was adjusting its coverage policy for the cholesterol drug Vytorin in the wake of a negative study of the drug.

The Philadelphia health insurer said it was immediately suspending part of a program that notified members using certain other cholesterol drugs that Vytorin was an effective and less costly alternative. The program, known as "step therapy," is an effort to help health plans control drug costs.

Cigna said the suspension of Vytorin's role in the step therapy program would last until a committee of experts could review the latest study to decide if permanent coverage changes were needed. Spokeswoman Lindsay Shearer declined to say when the committee would make a decision.

Vytorin is co-marketed by a joint venture of Merck & Co. (MRK), Whitehouse Station, N.J., and Schering-Plough Corp. (SGP) of Kenilworth, N.J.

Cigna will continue to pay for Vytorin prescriptions, and the insurer stressed that no one should discontinue any therapy without first talking to a doctor.

Cigna's move follows Sunday's release of the full results of the so-called " Enhance" study, showing that Vytorin - which is a combination of the drugs Zetia and simvastatin - was no better than simvastatin alone at slowing artery thickening despite producing a greater drop in bad cholesterol. The study prompted some cardiologists to recommend limiting use of the drugs.

"In light of the questions raised by the results of the Enhance trial about Vytorin, Cigna Pharmacy Management is taking immediate action to suspend a specific component of our step-therapy program that advised that Vytorin could be considered an effective and less-costly alternative to more costly non- preferred medications members may have been taking," Cigna spokeswoman Shearer said in a written statement to Dow Jones Newswires.

Under Cigna's step-therapy program, members can take "non-preferred" cholesterol drugs such as Pfizer Inc.'s (PFE) Lipitor and AstraZeneca PLC's ( AZN) Crestor, but they have higher copays than "preferred" brands and generic drugs.

Until now, Cigna would notify people taking Lipitor, Crestor and other non- preferred drugs that Vytorin was an effective and less costly alternative. Such notifications are being suspended.

Cigna has more than 10 million medical members but not all are affected by the change in the step-therapy program.

Spokespeople for Merck and Schering-Plough couldn't immediately be reached for comment.

-By Peter Loftus, Dow Jones Newswires; 215-656-8289; peter.loftus@dowjones.com

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  04-01-08 1724ET
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