Leap Therapeutics, Inc. announced that the first patient has been enrolled in the randomized controlled Part C of the ongoing DisTinGuish study to evaluate DKN-01, Leap's anti-Dickkopf-1 (DKK1) antibody, in combination with tislelizumab, BeiGene's anti-PD-1 antibody, and chemotherapy compared to a tislelizumab and chemotherapy control arm, in patients with gastric or gastroesophageal junction cancer (G/GEJ). The data to date from the DisTinGuish study show the DKN-01 plus tislelizumab combination therapy to be a compelling potential treatment for patients with G/GEJ cancer with response rates and survival outcomes that exceeded the benchmarks. This first randomized controlled study for DKN-01 will characterize the treatment effect in first-line patients, with a particular emphasis on those in the aggressive DKK1-high population.

The DisTinGuish study (NCT04363801) is a Phase 2 study of DKN-01 in combination with tislelizumab and standard of care (SOC) chemotherapy in patients with inoperable, locally advanced, G/GEJ adenocarcinoma. Part C of the DisTinGuish study will enroll approximately 160 first-line, HER2-negative patients. Patients will be randomized 1:1 to evaluate DKN-01 in combination with tislelizumab and standard of care (SOC) chemotherapy, compared to tislelizumab and SOC chemotherapy.

The primary objective is progression-free survival (PFS) in DKK1-high patients. Secondary objectives of Part C include PFS in all patients regardless of DKK1 expression, as well as overall survival and objective response rate as measured by RECIST v1.1 in DKK1-high and all patients.