FDA official calls UniQure's Huntington's disease treatment a failure

By Michael Erman and Puyaan Singh

March 5 (Reuters) - A senior FDA official called UniQure's UQ1.F experimental treatment for Huntington's disease a "failed product" in a conference call with media members on Thursday, casting further doubt on the prospects of the gene therapy.

The Dutch drugmaker said on Monday that the U.S. Food and Drug Administration had called for a new study to support the approval of its gene therapy for the rare, inherited neurodegenerative disorder, and rejected its most recent trial for not including participants given a placebo.

The FDA official, who spoke on the condition of anonymity, said a trial run by the company several years ago with a placebo design "was stone cold negative. We have a failed product here."

The call followed criticism from UniQure and patient advocacy groups of the FDA's request.

The official also accused UniQure of making a "distorted or manipulated comparison" in how it presented data for the treatment.

UniQure declined to comment on the FDA official's remarks.

The company's U.S.-listed shares were up 19% at $10.75 in late afternoon trading.

UNACCEPTABLE COMPARISON

Huntington's disease is marked by degeneration of nerve cells in certain areas of the brain that causes uncontrolled movements, balance problems, loss of intellectual faculties and emotional disturbance. It eventually can make a person unable to walk, talk or swallow, and typically leads to death 10 to 30 years after symptoms begin.

UniQure in September said its studies showed statistically significant improvement in slowing disease progression after three years by 75%, based on a clinical rating scale when compared with patients from an external dataset of Huntington's patients.

The FDA official said such a comparison was not acceptable and that the agency has "never in 25 years" accepted such a trial design for Huntington’s disease therapies.

"We do not dispute the claim that it is 75% better than those people. What FDA disputes is that those people are a fair comparator," the official said.

Patient advocacy groups, which can be strong voices in favor of treatments for rare diseases, often pushing back against regulators, have weighed in on the debate.

The Huntington's Disease Society of America said a new and prolonged trial could impose significant costs on patients with a rapidly progressive illness.

For Huntington's patients, a two-year period spent in a control arm of a study "is not a 'neutral' observation window, it is a period of active, irreversible neurodegeneration," the group said.

By the time a participant in the control arm of the study eventually receives the therapy, "they may have progressed past the therapeutic window where a treatment could have best preserved their quality of life," the organization added.

It declined to directly address the FDA official's comments.