Karyopharm Therapeutics Inc (NASDAQ:KPTI) stock plunged after an update on its supplemental New Drug Application submission based on the Phase 3 SIENDO study data of selinexor as front-line maintenance therapy following chemotherapy in advanced or recurrent endometrial cancer.

• The cmpany received feedback that the current SIENDO study topline results would not support an sNDA approval. 
• Karyopharm and the FDA participants had differing views on the study significance and overall clinical benefit for the whole population.
• They discussed further exploring patients with advanced or recurrent endometrial cancer with p53 wild-type is warranted. 
• Related: Karyopharm Shares Fall After Selinexor Data In Endometrial Cancer Patients.
• The company will continue collecting and analyzing the SIENDO study data.
• In addition, Karyopharm plans to initiate a new study of selinexor in patients with p53 wild-type endometrial cancer and believes topline data will be available in 1H of 2024. 
• SVB Leerink maintains Market Perform on Karyopharm Therapeutics, but it lowered the price target to $6 from $8.
• Price Action: KPTI shares traded 27.3% lower at $7.55 in pre-market on the last check Wednesday.