Yet another failure in Biogen's gene therapy program leaves no dent in stock price in wake of Aduhelm approval

While basking in the glow of the controversial approval for its Alzheimer’s disease treatment, Biogen has slipped in other news, announcing that a gene therapy candidate failed a late-stage clinical trial—yet again.

The news marks Biogen's second gene therapy to fail in an eye disorder. The Cambridge, Massachusetts-based company said in an after-market release Monday that timrepigene emparvovec did not correct vision at Month 12 and also did not meet the trial’s secondary goals. The safety results were consistent with previous studies. The phase 3 involved 169 men with a confirmed diagnosis of the rare genetic retinal disease choroideremia, which causes progressive vision loss and eventually blindness.

A month to the day, it was cotoretigene toliparvovec in X-linked retinitis pigmentosa. Both therapies came out of Biogen’s $877 million deal for British biotech Nightstar Therapeutics, adding another question mark to the value of the acquisition.

RELATED: Biogen reveals gene therapy trial failure as investors remain laser-focused on aducanumab drama

Biogen will evaluate the full data set from timrepigene’s STAR study as it considers next steps for the program. Full results will be presented at a future scientific forum, the company added.

“While we are disappointed by the results of the STAR study, we are hopeful that the clinical insights gleaned from this study may help to shape therapeutic innovation for inherited retinal diseases including choroideremia, so that in the future there may be treatment options for the community affected by these debilitating disorders,” said Biogen’s Katherine Dawson, M.D., head of the Therapeutics Development unit.

Biogen had slightly more success in the cotoretigene toliparvovec phase 2/3 trial, which failed on the main endpoint but did seem to improve vision in low light conditions. The company was similarly noncommittal about the future of that program.

RELATED: FDA's 'intellectually insulting' aducanumab decision opens up a regulatory foothold for leading competitors

But the addition of another failure is no matter for Biogen, which is still riding high from the controversial approval of Aduhelm in Alzheimer’s. The stock price skyrocketed 52% after the June 7 approval, reaching $434 apiece, and has been sitting pretty since then. While the company's shares were trending down slightly about a half-percent following the after-market news, the price hovered around the new $400-range plateau.