NEW YORK – Dragonfly Therapeutics said on Wednesday that it dosed the first patients in a Phase II trial of its HER2-targeting NK-cell engager DF1001 for patients with advanced solid tumors.
The Phase II portion of the trial follows successful completion of the Phase I dose escalation study. In that study, patients with solid tumors expressing HER2 received DF1001 plus Bristol Myers Squibb's Opdivo (nivolumab) or DF1001 plus nab-paclitaxel. In Phase II, Dragonfly is opening multiple expansion cohorts using the best dose selected from Phase I. Those cohorts include patients with urothelial, metastatic breast, non-small cell lung, gastric, and esophageal cancer with low or high HER2 expression or EERBB2 amplification. Some cohorts will also comprise patients without biomarkers.
Trial participants will receive DF1001 monotherapy, DF1001 with Opdivo, or DF1001 with nab-paclitaxel, and the trial's primary endpoints will include safety, pharmacokinetics, immunogenicity, overall response, duration of response, and progression-free survival, among others. The trial is recruiting patients at 34 sites in the US and Europe.
In Phase I, DF1001 was well tolerated with no dose-limiting toxicities. Investigators observed infiltration of NK cells and T cells into tumors and a clinical response in patients in the monotherapy group as well as the two combination groups, including tumor burden reductions in HER2-low and HER-2-high cancers.
Waltham, Massachusetts-based Dragonfly partnered with Gilead Sciences in May to advance a set of Dragonfly's NK-cell engagers for oncology and inflammation indications. The deal gave Gilead an option to license exclusive, worldwide rights to develop and commercialize certain NK cell engager programs developed using Dragonfly's Tri-specific NK Engager (TriNKET) platform.