Isis trading halts as FDA reviews key drug's risks

Drug developer Isis Pharmaceuticals Inc. and partner Genzyme said Thursday a panel of advisers to the Food and Drug Administration had voted 9 to 6 to recommend approval of Kynamro, for treating patients genetically predisposed to have sky-high LDL, or bad cholesterol.

Approval had looked far from certain, given recent questions about the experimental drug's links to cancer. But the companies said that the advisory panel decided there was sufficient data on the drug's safety and effectiveness to allow sales of Kynamro. If approved, Kynamro will be the first Isis drug to reach market.

The FDA is not bound to follow recommendations of its advisers, but usually does so.

Just Tuesday, the advisers had posted information on the FDA's website noting that in recent patient studies, 23 patients getting Kynamro developed tumors and three of them died, while only two patients getting a placebo developed tumors. The advisory panel on endocrinology and metabolic drugs also noted liver and blood vessel cancers were seen in earlier tests of the drug conducted on mice.

The company's share price plunged on that news and is down more than 35 percent since a 52-week high of $15.61 on Sept. 21. Trading in the stock was halted at $9.62.

Kynamro is the most advanced of about 25 experimental drugs the company is developing for cancer, heart disease, metabolic conditions and rare diseases.

Isis has a deal with Genzyme, a unit of French drugmaker Sanofi that bought the rights to Kynamro in 2008, to market the drug if it is approved.

The FDA has set a target deadline of Jan. 29 to decide whether to approve sale of Kynamro for homozygous familial hypercholesterolemia in patients not adequately treated by standard cholesterol drugs such as Lipitor and Zocor.

The European Union also is considering approval of the drug. Regulators there are expected to make a decision by year-end.

About 40,000 people in the U.S. and Europe are estimated to have homozygous familial hypercholesterolemia or a related high cholesterol problem, Isis said. Meanwhile, Genzyme is preparing to apply for approval to sell Kynamro in other regions.

The Carlsbad, Calif.-based company planned to host a webcast at 7:30 p.m. Eastern time Thursday to discuss the outcome of the advisory panel meeting.