(Reuters) - Alnylam Pharmaceuticals Inc's experimental drug to treat a type of respiratory infection in lung transplant patients missed the main goal of a mid-stage trial.
The drug, codenamed ALN-RSV01, is being developed to treat respiratory syncytial virus (RSV) infection that causes respiratory illness in young children.
"We have questioned the investment in this trial since before it even began and removed all value for the RSV program from our target in January 2011," analyst Edward Tenthoff said.
In January, Alnylam cut one-third of its workforce to focus on the development of a hemophilia drug and a treatment for transthyretin-mediated amyloidosis -- a hereditary disease that leads to an abnormal buildup of the protein amyloid in the body, affecting sensory cells.
"We are more interested in ALN-TTR02 for orphan disease transthyretin amyloidosis with early-stage data due in the third quarter," analyst Tenthoff said.
The drug, ALN-RSV01, targets a specific gene that is required for the replication of the RSV. ALN-RSV01 silences that gene, thereby reducing the ability of the virus to reproduce.
The main goal of the study, conducted on 87 patients, was to reduce bronchiolitis obliterans syndrome -- a condition in which the airway is blocked by an inflammation -- 180 days after an RSV infection.
The company said it plans to discuss the results of the trial with U.S. and European regulators later this year to determine the appropriate next steps, "if any."
Severe cases of RSV infection are usually treated with a class of medicines known as bronchodilators, which relax the muscles of the airways and allow for easier breathing.
Bronchodilators include drugs such as Merck & Co Inc's Proventil and GlaxoSmithKline's Ventolin.
The company is also developing drugs for the treatment of lung cancer and cholesterol.
Alnylam's shares, which have lost 24 percent of their value over the past 3 months, were down 2 percent at $9.90 before the bell. They closed at $10.13 on Tuesday on the Nasdaq.
Reporting by Adithya Venkatesan in Bangalore; Editing by Roshni Menon