FDA regulatory update on selinexor in advanced or recurrent endometrial cancer.- Karyopharm.

During a productive meeting with the FDA, the Company received feedback that the current SIENDO study top-line results are unlikely to support an sNDA approval. Karyopharm and the FDA participants had differing views on the study significance and overall clinical benefit for the whole population and discussed that further exploration of patients with advanced or recurrent endometrial cancer with p53 wild-type is warranted. The Company will continue to collect and analyze the SIENDO study data and work with the FDA to explore all regulatory pathways for patients with p53 wild-type. In addition, considering the FDA's feedback, the Company intends to initiate a new placebo-controlled, randomized clinical study of selinexor in patients with p53 wild-type endometrial cancer and believes top-line data will be available in the first half of 2024.

Karyopharm plans to rapidly initiate this study of selinexor in patients with p53 wild-type this year, working with the FDA as well as established networks and partners, including the European Network of Gynaecological Oncological Trial groups (ENGOT) and the Gynecologic Oncology Group Foundation, Inc. (GOG-F).

The majority of endometrial cancers are diagnosed at an early stage and are typically curable with surgery, however, women with advanced and recurrent endometrial cancer have very limited therapeutic options following front-line treatments and prognosis is typically poor," said Professor Ignace Vergote, principal investigator and gynecologist oncologist, ENGOT and the Belgium and Luxembourg Gynaecological Oncology Group (BGOG), University of Leuven, Leuven Cancer Institute, Leuven, Belgium. "Selinexor has the potential to transform the way advanced or recurrent endometrial cancer is treated in patients with p53 wild-type and I look forward to learning more from a new study."