Patients with recurrent gynecologic cancers and Wnt activating mutations demonstrated greater clinical benefit when treated with DKN-01 therapy

Objectives: Dickkopf-1 (DKK1) modulates Wnt signaling, promotes tumor growth through a CKAP4-AKT signaling pathway and contributes to an immune suppressive tumor microenvironment. DKN-01 (D), a neutralizing DKK1 antibody has demonstrated safety and clinical activity in advanced gynecologic malignancies. Prior literature has reported an association of CTNNB1 mutations and an aggressive biology and shorter survival in endometrioid endometrial cancer. We previously demonstrated Wnt activating mutations were associated with higher DKK1 tumoral expression in advanced gynecologic malignancies. Methods: Pts with recurrent gynecologic cancers [endometrial (EEC), ovarian (EOC) and carcinosarcoma (MMMT)] were treated with D as monotherapy (mono) or in combination with paclitaxel (pac) in a phase 2 basket trial (NCT03395080) whereby ≥50% must have had a Wnt signaling alteration. Here we report on the subgroup of pts with Wnt activating mutations (CTNNB1, RNF43, APC). Clopper-Pearson confidence intervals were used to study the association of Wnt activating mutations with clinical benefit (CR, PR or SD); Kaplan-Meier estimates/Cox-PH models were used for analyses of progression free survival (PFS) and overall survival (OS). Results: Conclusions: D has single agent activity in a subgroup of pts with Wnt activating mutations, historically identified as a poor prognostic group, whereby they experienced greater clinical benefit and longer survival compared with pts without Wnt activating mutations. A notable finding was that all responding pts had PIK3CA mutations. This study is ongoing and updated results will be presented. Dickkopf-1 (DKK1) modulates Wnt signaling, promotes tumor growth through a CKAP4-AKT signaling pathway and contributes to an immune suppressive tumor microenvironment. DKN-01 (D), a neutralizing DKK1 antibody has demonstrated safety and clinical activity in advanced gynecologic malignancies. Prior literature has reported an association of CTNNB1 mutations and an aggressive biology and shorter survival in endometrioid endometrial cancer. We previously demonstrated Wnt activating mutations were associated with higher DKK1 tumoral expression in advanced gynecologic malignancies. Pts with recurrent gynecologic cancers [endometrial (EEC), ovarian (EOC) and carcinosarcoma (MMMT)] were treated with D as monotherapy (mono) or in combination with paclitaxel (pac) in a phase 2 basket trial (NCT03395080) whereby ≥50% must have had a Wnt signaling alteration. Here we report on the subgroup of pts with Wnt activating mutations (CTNNB1, RNF43, APC). Clopper-Pearson confidence intervals were used to study the association of Wnt activating mutations with clinical benefit (CR, PR or SD); Kaplan-Meier estimates/Cox-PH models were used for analyses of progression free survival (PFS) and overall survival (OS). D has single agent activity in a subgroup of pts with Wnt activating mutations, historically identified as a poor prognostic group, whereby they experienced greater clinical benefit and longer survival compared with pts without Wnt activating mutations. A notable finding was that all responding pts had PIK3CA mutations. This study is ongoing and updated results will be presented.