(Reuters) - A panel of advisers to the U.S. health regulator unanimously recommended against approving Delcath Systems Inc's cancer therapy for a rare form of eye cancer that spreads to the liver, saying it was too risky.
Concerns that the treatment may not win U.S. Food & Drug Administration (FDA) approval have driven New York-based Delcath's shares down by three-quarters from a year high of $2.94 in May.
The shares fell heavily on Tuesday when FDA staff documents were released that showed serious concerns about the risks of the therapy, the only product Delcath has in development. (r.reuters.com/qew77t)
Trading in the shares was halted around 1300 ET when the panel meeting convened.
There is currently no approved therapy for patients suffering from this type of cancer but the FDA staff said there was no indication the treatment improved overall survival or delayed disease progression.
One of the advisers, Aman Buzdar, vice president of clinical research at Texas-based MD Anderson Cancer Center said during the panel discussion Thursday that though the condition has no cure, by any yardstick the quality of life would be worse after the therapy.
The panel of independent experts voted 16-0 against recommending the therapy.
"While we were disappointed in today's outcome, we will continue to work closely with the FDA throughout its ongoing evaluation of Melblez Kit," Delcath Chief Executive Eamonn Hobbs said in a statement.
The drug-device combination product consists of a chemotherapy drug, melphalan hydrochloride, and a device known as the Delcath Hepatic Delivery System. The two are combined in a single package known as the Melblez Kit.
The therapy targets ocular melanoma, a rare form of eye cancer which has spread and given rise to a malignant liver tumor and cannot be removed surgically.
In the FDA staff briefing released on Tuesday, reviewers noted that "substantial and severe toxicity" was identified in the clinical trials.
Seven percent of the 122 patients treated by the drug-device combination died as a result of treatment related side effects, the FDA staff said.
Delcath outlined a specific risk management strategy to reduce the risks including the presence of a 7-member multi-disciplinary procedural team during the procedure.
However, reviewers said the risk management strategy designed by the company could not be expected to eliminate inherent toxicities.
The FDA staff said that despite careful selection of patients and rigorous training of those who performed the procedure "there was a high treatment related mortality rate that in the best-case scenario would be replicated in the post-marketing setting."
The American Cancer Society said about 2,800 adults a year in the United States develop ocular melanoma.
Delcath said up to 70 percent of ocular melanoma patients will develop liver cancer within 2 to 5 years of the onset of the disease.
The last trade prior to the stock's halt showed shares up 4.7 percent at $0.79 on the Nasdaq.
(Reporting by Pallavi Ail in Bangalore, additional reporting by Toni Clarke in Washington; Editing by Sriraj Kalluvila and Anil D'Silva)