What happened

Shares of Karyopharm Therapeutics (KPTI) were down more than 26% Thursday afternoon after the biotech company released first-quarter earnings and updated its guidance. The stock fell to its lowest point since it was $2.51 a share on Dec. 28, 2022. This year, the stock is down more than 18%.

So what

Karyopharm reported first-quarter revenue of $38.7 million, down 18% year over year, though its net loss was $34.1 million, an improvement over the $41.4 million it lost in the same period ago. President and CEO Richard Paulson explained the lower revenue on the first-quarter earnings call by citing more competition; a greater utilization by patients of the company's Patient Assistance Program, including Medicare patients without sufficient funding; and a higher gross to net ratio from increased Medicare rebates and 340B discounts, year over year. 

The big problem for investors, though, was the revenue drop was combined with downgraded guidance. The company said it now expects annual revenue between $145 million and $160 million, compared to earlier guidance of between $160 million and $175 million.

Now what

Karyopharm is very reliant on its one marketed therapy, Xpovio (selinexor), used as a combination multiple myeloma therapy and as a therapy to treat adults with  dif‌fuse large B-cell lymphoma that has come back or did not respond to previous treatment. The company, facing a lot of competition in the multiple myeloma space, needs another marketed therapy, or more indications for selinexor. It has the drug in multiple late-stage trials against various cancers and has another drug, eltanexor, in trials to treat myelodysplastic syndromes, disorders caused by blood cells that are poorly formed or don't work properly.