Karyopharm Shares Fall After Selinexor Data In Endometrial Cancer Patients

Karyopharm Therapeutics Inc's KPTI Phase 3 SIENDO selinexor study has met the primary endpoint of improved progression-free survival (PFS) as front-line maintenance therapy in advanced or recurrent endometrial cancer. 

• Selinexor-treated patients had a median PFS of 5.7 months compared to 3.8 months for patients on placebo, representing an improvement of 50%, with a hazard ratio of 0.70 (p=0.0486), representing a 30% reduction in the risk of disease progression or death. 
• Selinexor demonstrated a sustained and long-term improvement with a 37% increase in the probability that selinexor-treated patients will be in remission compared to patients on no treatment or today's standard of "watch and wait." 
• In the pre-specified subgroup (wild-type p53), selinexor-treated patients had a median PFS of 13.7 months compared to 3.7 months, representing a 62% reduction in disease progression or death risk.
• The Company plans to submit a supplemental marketing application with the FDA in 1H 2022.
• Q4 Earnings: Karyopharm reported Q4 EPS of $0.46, a turnaround from EPS loss of $(0.59) a year ago. Net product revenue reached $29.8 million, up 47% Y/Y.
• Guidance: Karyopharm expects FY22 Xpovio net product revenue of $135 million - $145 million.
• The Company held cash, cash equivalents, restricted cash, and investments of $235.6 million, sufficient to fund its planned operations into early 2024.
• Price Action: KPTI shares are trading 22% lower at $7.99 during the market session on the last check Tuesday.