Idenix Cancels Hepatitis C Drug On Toxicity Worries

UPDATE 2-FDA removes full clinical hold on Idenix's HCV drug
Wed Feb 9, 2011 6:12pm EST

* Says to stop development of IDX320
* Says FDA places partial clinical hold on IDX184
* Says HIV drug licensed to Glaxo also put on hold (Adds details)
.Feb 9 (Reuters) -
Idenix Pharmaceuticals Inc (IDIX.O) said U.S. health regulators have removed the full clinical hold on one of its two experimental hepatitis C drugs, and it ceased the development of the other drug because of a toxicity issue.

In September, the U.S. Food and Drug Administration halted all trials of the experimental drugs after detecting liver function abnormalities in three healthy volunteers during an early-stage study of a combination of the compounds IDX184 and IDX320. [ID:nSGE6860G7]
The company said the observed toxicity in the drug-drug interaction study was likely caused by IDX320.

Idenix, which focuses on treating viral diseases, said the FDA has placed the IDX184 program on partial clinical hold.

It said it expects to initiate a Phase IIb trial of IDX184 in combination with pegylated interferon and antiviral pill ribavirin in the second half of 2011.

The company also said its HIV drug -- licensed to GlaxoSmithKline's (GSK.L) unit ViiV Healthcare -- was placed on a clinical hold by the FDA.

http://www.reuters.com/article/2011/02/09/idenixpharmaceuticals-idUSSGE6BK0AQ20110209

Idenix Pharmaceuticals Inc. (IDIX) said it will discontinue development on one of its hepatitis-C drug candidates because of toxicity worries, although another drug for the disease is expected to move forward in trials soon.

Additionally, the biopharmaceutical company also reported that a GlaxoSmithKline PLC (GSK, GSK.LN) unit told it their developmental HIV drug is also on clinical hold.

In September, Idenix said the U.S. Food and Drug Administration put full clinical holds on all its drug programs that treat the virus that causes hepatitis C. Instances of elevated liver function in patients who were taking both of the company's hepatitis-C treatment candidates caused the hold order.

On Wednesday, the company said it has determined the toxicity was caused by its drug IDX320, which it will no longer develop as a result. The company said the other hepatitis-C drug candidate, IDX184, is now on a partial hold. Idenix expected a midstage trial of IDX184 would begin in the second half of the year.

Hepatitis C is an infection that attacks the liver. Though it frequently lacks any noticeable symptoms, it can cause liver damage to the point of the organ's failure, and sometimes liver cancer, if untreated.

Also Wednesday, Idenix said an HIV drug it is developing in collaboration with a unit of Glaxo is on clinical hold by the FDA. However, the Glaxo unit has full responsibility for the further development of the drug, including regulatory interactions.

http://online.wsj.com/article/BT-CO-20110209-720136.html

-By Joan E. Solsman, Dow Jones Newswires; 212-416-2291; joan.solsman@dowjones.com