News of a big and important regulator's move was the electricity that powered Biohaven (BHVN 11.19%) stock to an 11%-plus gain on the second trading day of the week. Its leading investigational drug is now significantly closer to potential approval, and many are feeling bullish about the company. Its Tuesday pop was quite the outlier, given that the S&P 500 index only traded sideways.

NDA accepted

Before market open, Biohaven announced that the U.S. Food and Drug Administration (FDA) had accepted its New Drug Application (NDA) for troriluzole. This is a once-daily oral treatment for adults with spinocerebellar ataxia (SCA), the name for a clutch of inherited neurodegenerative disorders affecting the cerebellum of the brain and the spinal cord.

The FDA has granted priority review status to troriluzole. This designation is reserved for drugs that either represent a notable improvement over existing treatments on the market or are entirely new for an indication. Biohaven's medication falls into the latter category.

With priority review, it's quite possible the FDA's approval could be handed down in the very near future.

Biohaven quoted its SCA clinical development lead Melissa Beiner as saying the FDA's move "demonstrates the extremely high unmet need in this rare neurodegenerative disease."

"Time is of the essence for patients with SCA, who are suffering relentless and irreversible functional decline including impairments in coordination and balance leading to falls, loss of ambulation, and difficulties with vision, speech and swallowing," Beiner added.

From clinical to commercial

This is an exciting development for Biohaven, which said the NDA acceptance caps eight years of development for troriluzole. If approved, the drug would be the clinical-stage biotech company's first approved product. That alone is worth considering its stock for a buy.