BioMarin Pharmaceuticals (BMRN -1.10%), a biopharmaceutical company that specializes in finding therapies for rare genetic diseases, saw its shares drop 6.9% on Thursday after falling as much as 9.8% earlier in the day. The stock closed on Wednesday at $92.10, then opened on Thursday at $89.63. It fell to its daily low at $83.10 shortly after noon before rising a bit to the close at $89.73. The stock has a 52-week low of $70.73 and a 52-week high of $97.76.

What happened

The company reported third-quarter earnings after the market closed on Wednesday, and investors were not that impressed.

BioMarin reported nine-month revenue of $1.56 billion, up 12% year over year, and third-quarter revenue of $505 million, again up 24% over the same period last year. Earnings per share (EPS) for nine months came in at a loss of $0.04, compared to an EPS loss of $0.20 in the first nine months of 2021. In the quarter, the company posted EPS of $0.77 compared to an EPS loss of $0.03 in the same quarter in 2021. The reason the stock slumped a bit is analysts had predicted quarterly revenue to fall between $513 million and $515.5 million.

Now what

While investors may have been unimpressed, the report was mostly positive for BioMarin. Dwarfism therapy Voxzogo, which was approved by the Food and Drug Administration late last year, has done $102.3 million in sales in its first year, while Brineura, used to slow the loss of ambulation in pediatric patients 3 or older with late infantile neuronal ceroid lipofuscinosis type 2, a rare neurodegenerative disorder, did $111.7 million in nine-month sales, up 23% year over year.

The biotech company kept its guidance intact, except that it increased estimated sales this year for Voxzogo from a range of $130 million to $160 million to instead fall between $140 million and $170 million. The drug increases linear growth in children with achondroplasia ages 5 and up whose growth plates are still open. Achondroplasia, caused by a genetic mutation, results in dwarfism because it impairs the growth of bone in the limbs and causes abnormal growth in the spine and skull. It affects less than 50,000 people in the U.S., according to the National Institutes of Health.

The company said it is also looking forward to the possible launch next year of Roctavian (valoctocogene roxaparvovec), the first gene therapy that treats severe hemophilia A. The FDA just approved the company's biologics license application on Oct. 12 and has set a Prescription Drug User Fee Act (PDUFA) target action date of March 31.