What happened

Shares of the rare disease specialist BioCryst Pharmaceuticals (BCRX 0.79%) were up by a noteworthy 20% on heavy volume at 9:38 a.m. ET Thursday morning. Although the biotech reported encouraging 2022 second-quarter results prior to today's opening bell, the real needle mover here appears to be the news that the Food and Drug Administration (FDA) has lifted the partial clinical hold on BCX9930.

The company will thus be allowed to resume enrollment in the drug's global clinical trials under a revised dosing regimen. BCX9930 is an oral Factor D inhibitor indicated for a rare blood disease known as paroxysmal nocturnal hemoglobinuria (PNH). The FDA put the drug on partial hold earlier this year following reports that after treatment, some patients experienced elevated serum creatinine levels, a condition that can lead to serious kidney damage. 

So what

Investors have clearly placed a heavy premium on BCX9930's clinical program. Even though PNH is a high-value indication, the drug's real value to the biotech -- at least from Wall Street's perspective -- is its ability to diversify BioCryst's revenue stream. At present, the company is heavily dependent on its oral hereditary angioedema drug, Orladeyo, for growth.

The single-drug growth story, however, has grown exceedingly unpopular among investors in light of the numerous clinical, regulatory, and legal setbacks for such companies across the space. BCX9930, in effect, would provide a nice cushion in the event something unexpected happens to BioCryst's main growth driver.  

Now what

Is BioCryst's stock still a buy? I think so. I don't particularly buy into the bear thesis surrounding Orladeyo based on the drug's exceptionally strong commercial launch to date. In fact, I think this stock could nearly double from current levels within a few short years.