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leaptherapeutics Leap Therapeutics Presents DKN - 01 Clinical Data at the Society of Gynecologic Oncology 2021 Annual Meeting on Women's Cancer March 22 , 2021 - DKN - 01 Monotherapy Demonstrated Clinical Activity in Patients with Endometrial Cancer · Tumoral DKK1 Expression Biomarker Predicts Strongest Outcomes - Conference Call to Discuss Results Today at 8:30 a.m. Eastern Time CAMBRIDGE , Mass . , March 22 , 2021 / PRNewswire / -- Leap Therapeutics , Inc. ( Nasdaq : LPTX ) , a biotechnology company focused on developing targeted and immuno - oncology therapeutics , today announced the presentation of clinical data from its Phase 2 clinical trial of DKN - 01 as a monotherapy and in combination with paclitaxel in patients with advanced gynecological malignancies at the Society of Gynecologic Oncology 2021 Annual Meeting on Women's Cancer , being held as a virtual meeting from March 19-25 , 2021. DKN - 01 is a humanized monoclonal antibody that binds to and blocks the activity of the Dickkopf - 1 ( DKK1 ) protein , leading to the activation of the innate immune system in the tumor microenvironment and anti - tumor activity . " DKN - 01 demonstrated objective responses , including a monotherapy complete response continuing now for over 2 and a half years , and durable tumor reductions as a single agent and in combination with paclitaxel in the advanced gynecologic cancer patients treated in the study , " said Rebecca Arend , M.D. , MSPH , Associate Professor , University of Alabama at Birmingham O'Neal Comprehensive Cancer Center . " The disease control rate and progression - free survival were strongest in patients whose tumors express high levels of DKK1 ( DKK1 - high ) , which is a group that real world evidence has shown to have poorer outcomes on other therapies . " " The activity of DKN - 01 in this study was comparable to the monotherapy data from other widely - used immuno - oncology or targeted therapies , " Dr. Arend continued . " As DKN - 01 was extremely well tolerated , additional studies of DKN - 01 as a monotherapy and in combination with anti - PD - 1 antibody therapy are warranted in endometrial cancer patients with DKK1 - high tumors . " The P204 Study in Advanced Gynecologic Cancers The P204 study was a Phase 2 basket study evaluating DKN - 01 as a monotherapy or in combination with paclitaxel in groups composed of epithelial endometrial cancer ( EEC ) , epithelial ovarian cancer ( EOC ) , or carcinosarcoma ( MMMT ) patients . The primary endpoint of the P204 study was overall response rate ( ORR ) , and secondary endpoints include disease control rate ( DCR ) and progression - free survival ( PFS ) . In each group , at least fifty percent ( 50 % ) of patients were required to have specified Wnt signaling pathway alterations , a subgroup of which ( Wnt activating mutations ) are known to drive high tumoral DKK1 expression . Tumoral DKK1 expression was determined retrospectively by RNAscope® chromogenic in situ hybridization and correlated with clinical outcomes . Key Findings from the P204 Study One hundred - eleven patients were enrolled in the study , including 29 EEC patients in a DKN - 01 monotherapy group , 24 EEC patients in a DKN - 01 plus paclitaxel group , 14 EOC patients in a DKN - 01 monotherapy group , 19 EOC patients in a DKN - 01 plus paclitaxel group , 9 MMMT patients in a DKN - 01 monotherapy group , and 16 MMMT patients in a DKN - 01 plus paclitaxel group . The key findings from the study were : • EEC patients and patients with Wnt activating mutations express higher levels of DKK1 : EEC patients expressed higher levels of DKK1 and had a higher frequency of Wnt activating mutations than patients with EOC . Within EEC , patients with endometrioid histology had higher DKK1 expression than those with non - endometrioid histology . Patients whose tumors had Wnt activating mutations expressed 14.4 times higher levels of DKK1 . • DKN - 01 has enhanced activity in patients whose tumors express high levels of DKK1 : In the group of 22 EEC patients treated with DKN - 01 monotherapy for whom DKK1 expression data was available , patients with DKK1 - high tumors ( n = 7 ) had greater ORR ( 14 % vs. 0 % ) , DCR ( 57 % vs. 7 % ) , and median PFS ( 3.0 months vs. 1.8 months [ HR 0.39 ; 95 % CI : 0.14 , 1.1 ] ) compared to patients with DKK1 - low tumors ( n = 15 ) . Additionally , seven patients did not have DKK1 expression results available , of whom one had a complete response ( 14 % ) and five ( 72 % ) had a best response of stable disease , including three patients with Wnt activating mutations . In the group of 24 EEC patients treated with DKN - 01 plus paclitaxel , 72 % of whom had received three or more prior systemic therapies , DKK1 - high patients ( n = 11 ) had improved median PFS ( 5.4 months vs. 1.8 months [ HR 0.34 ; 95 % CI : 0.12 , 0.97 ] ) compared to DKK1 - low patients ( n = 9 ) . Four patients did not have DKK1 expression data available . • Within EEC , DKN - 01 activity strongest in endometrioid histology : In the pooled group of 27 patients with endometrioid histology for whom DKK1 expression data was available , patients with DKK1 - high tumors ( n = 14 ) had greater DCR ( 57 % vs. 15 % ) and median PFS ( 4.1 months vs. 1.8 months [ HR 0.34 ; 95 % CI : 0.14 , 0.81 ] ) than patients with DKK1 - low tumors ( n = 13 ) . Additionally , seven patients with endometrioid histology did not have DKK1 expression results available , of whom one ( 14 % ) had a complete response and five ( 72 % ) had a best response of stable disease , including two patients with Wnt activating mutations .