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Company<\/strong><\/p>\n Karyopharm Therapeutics<\/p>\n Event Type<\/strong><\/p>\n Clinical Trial Results (Phase 3, Missed Primary Endpoint)<\/p>\n Modality<\/strong><\/p>\n Oral exportin-1 (XPO1) inhibitor<\/p>\n Asset<\/strong><\/p>\n Selinexor<\/p>\n Target<\/strong><\/p>\n XPO1 (exportin-1)<\/p>\n Disease Area<\/strong><\/p>\n TP53-wild-type advanced or recurrent endometrial cancer (maintenance)<\/p>\n Phase 3 XPORT-EC-042 did not meet its primary progression-free-survival endpoint for selinexor maintenance in TP53-wild-type advanced or recurrent endometrial cancer. In the modified intent-to-treat population, median PFS was 12.75 months with selinexor and 7.43 months with placebo, but the hazard ratio was 0.76 with a 95% confidence interval of 0.51-1.12 and one-sided p=0.0791. The numerical median difference is descriptive and does not override the failed primary analysis.<\/p>\n Karyopharm plans longer-term follow-up but will reduce planned endometrial-cancer investment and prioritize myelofibrosis and multiple myeloma. The result materially weakens selinexor’s near-term path in this indication while leaving open narrower biomarker or survival hypotheses that require prespecified, statistically robust confirmation.<\/p>\n The randomized, double-blind, placebo-controlled maintenance trial enrolled patients with TP53-wild-type advanced or recurrent endometrial cancer after response to systemic therapy. The sponsor reported no new safety signal and said safety was consistent with the known selinexor profile.<\/p>\n The company’s resource decision is an operational consequence of the trial outcome, not proof that the molecule lacks activity in every molecular or clinical subgroup. No regulatory filing based on this study was announced. Full subgroup, censoring, subsequent-treatment, quality-of-life, discontinuation, and overall-survival data were not available in the topline disclosure.<\/p>\n The primary endpoint failed, and the confidence interval crosses 1.0. The 5.32-month separation between medians can appear clinically attractive, but medians summarize one point on time-to-event curves and may diverge even when the overall hazard comparison is inconclusive. The result cannot be described as demonstrating benefit. Modified intent-to-treat handling also warrants scrutiny because exclusions after randomization can alter balance and estimand interpretation.<\/p>\n TP53-wild-type status was intended to enrich for tumors more likely to retain nuclear-export-dependent tumor-suppressor biology. Selinexor blocks exportin-1 and can increase nuclear retention of p53 and other regulatory proteins. Yet TP53 wild type is a broad marker, not a direct measurement of exportin dependence. Endometrial cancers remain heterogeneous in mismatch repair, POLE, copy-number state, hormone signaling, immune context, and prior checkpoint exposure.<\/p>\n One interpretation is that selinexor has a modest real maintenance effect that the study was underpowered to establish because of event timing, heterogeneity, or treatment patterns; the hazard ratio below 1.0 and longer median PFS support this possibility, while the wide confidence interval and failed primary threshold contradict a definitive claim. A second interpretation is that the apparent median separation reflects chance, nonproportional hazards, informative censoring, or benefit confined to a small post hoc subgroup; the statistical failure and broad interval support caution, though the direction and magnitude of the descriptive median difference justify examining prespecified molecular and treatment-interaction analyses.<\/p>\n This is a high-confidence negative\/mixed signal. The proper headline is that the pivotal trial missed its primary endpoint. The numerical PFS separation is hypothesis-generating, not a positive trial. Karyopharm’s resource reprioritization is consistent with a materially impaired development case, but the disclosed facts do not establish why the trial failed or whether a narrower biologically defined population could benefit.<\/p>\n Advanced or recurrent endometrial cancer comprises molecularly distinct diseases. Maintenance therapy aims to prolong disease control after response to chemotherapy, with or without immunotherapy, while preserving function and tolerability. Current development increasingly relies on molecular classification, including mismatch-repair deficiency, POLE mutation, p53 abnormality, and copy-number patterns.<\/p>\n Selinexor is an oral exportin-1 inhibitor. Inhibition of nuclear export can retain tumor suppressors and regulatory proteins in the nucleus and disrupt oncogenic stress adaptation. XPORT-EC-042 tested oral selinexor against placebo as maintenance in TP53-wild-type disease after systemic therapy.<\/p>\n Signal Importance is rated 4\/5 with a Negative\/mixed direction. Confidence in the underlying facts is High; confidence in the interpretation is High, with the main uncertainty being mechanistic and subgroup-level rather than whether the primary endpoint was missed.<\/p>\n","protected":false},"excerpt":{"rendered":" Phase 3 XPORT-EC-042 did not meet its primary progression-free-survival endpoint for selinexor maintenance in TP53-wild-type advanced or recurrent endometrial cancer. In the modified intent-to-treat population, median PFS was 12.75 months with selinexor and 7.43…<\/p>\n","protected":false},"author":1,"featured_media":2354,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,11,3],"tags":[244,94],"class_list":["post-2343","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-all-categories","category-clinical","category-therapeutic-indication","tag-endometrial-cancer","tag-karyopharm-therapeutics"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2343","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2343"}],"version-history":[{"count":2,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2343\/revisions"}],"predecessor-version":[{"id":2357,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2343\/revisions\/2357"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/media\/2354"}],"wp:attachment":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2343"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2343"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2343"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Summary<\/h4>\n
Statistical interpretation<\/h4>\n
Biological interpretation<\/h4>\n
Alternative interpretations and validation gate<\/h4>\n
Signal Extraction<\/h4>\n
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InSilens Take<\/h4>\n
Company and Product Background<\/h4>\n
Signal Assessment<\/h4>\n