Karyopharm jumps as blood cancer drug meets one of two main goals in study

Shares of drugmaker Karyopharm Therapeutics KPTI.O rise 22% to $8.15 premarket

Co says its selinexor-plus-ruxolitinib combo met one of two main goals in a late-stage trial in myelofibrosis, a rare blood cancer that causes bone marrow scarring and an enlarged spleen

*Selinexor is already approved under the brand name Xpovio for other blood cancers, including multiple myeloma and lymphoma, but not for myelofibrosis

Trial compared Xpovio plus Incyte’s INCY.O Jakafi with Jakafi alone, with 50% of combo patients achieving meaningful spleen shrinkage versus 28% on Jakafi

Trial met the spleen size reduction goal but did not show a clear difference on symptom improvement versus ruxolitinib alone, co says

Co also flagged a possible survival benefit signal and said it plans to meet the FDA to discuss next steps

Separately, Karyopharm agreed to a $30 million private placement with RA Capital, with up to $44 million more if accompanying warrants are fully exercised

Shares fell ~27% in 2025