* 3 patients in 900 mg arm had high liver enzyme levels * Independent panel recommends other dosage arms continue
* Says data from 12-week treatment expected in Q1 2010
* Shares drop about 18 pct (Adds analysts’ comments, updates share movement)
By Vidya L Nathan
BANGALORE, Nov 17 (Reuters) - Biotechnology company InterMune Inc ITMN.O said it would discontinue one dosage in a mid-stage study of its experimental therapy to treat hepatitis C, sending its shares down 18 percent.
InterMune said an independent data monitoring committee recommended that the company stop testing the therapy in the 900 milligram dosage given once every 12 hours after three patients had elevated levels of ALT, a liver enzyme.
When ALT, or alanine transaminase, is found in significantly elevated levels, it often indicates problems with the liver such as tissue damage or hepatitis.
Analysts are looking for the full data set from the mid-stage study to determine if the safety issue is mirrored in the two other lower doses.
“I would anticipate that the other doses do not show the toxicity concerns that this dose has showed at this point,” ThinkEquity LLC analyst Brian Skorney said.
InterMune, which focuses on treating liver and lung ailments, was testing the drug ITMN-191 in three different doses — 300 mg given every eight hours, 600 mg and 900 mg both given every 12 hours — as a combination therapy with the current standard-of-care Pegasys and Copegus.
To date, about 175 patients have been enrolled in the study.
InterMune said the company and its partner Roche Holding AG ROG.VX agreed with the committee’s recommendation and would continue with the other two doses.
Both companies expect data after 12 weeks of treatment to be available in the first quarter of 2010.
Vertex Pharmaceuticals Inc (VRTX.O) and Merck & Co Inc (MRK.N) are also developing their hepatitis C drugs and both are in mid-stage studies. Shares of Brisbane, California-based InterMune fell about 16 percent to $11.84 Tuesday afternoon, making them one of the top percentage losers on Nasdaq. They touched a low of $11.56 earlier. (Editing by Anne Pallivathuckal and Deepak Kannan)