Dragonfly Therapeutics said today it has doubled to eight the number of its natural killer (NK) cell engager cancer immunotherapy candidates available for in-licensing by Celgene, in a $50 million-plus expansion of the companies’ 17-month-old collaboration.

The four new candidates, as with the four original candidates, are cancer immunotherapies developed through Dragonfly’s Tri-specific, NK cell Engager Therapies (TriNKET™) technology, and designed to attack new solid and hematological tumor targets, Dragonfly said.

The expanded collaboration will give Celgene the option to license exclusive worldwide intellectual property rights to the eight total cancer immunotherapies.

In return, Celgene has agreed to pay Dragonfly $50 million upfront, an undisclosed amount in payments tied to achieving milestones, and unspecified royalties.

Under the companies’ original collaboration, which focused entirely on blood cancer targets, Celgene agreed to pay Dragonfly $33 million upfront plus unspecified milestone and royalty payments.

“Based on the evidence we’ve seen to date, we believe that Dragonfly’s novel TriNKET technology provides a unique platform to support the discovery and development of immunotherapy drug candidates that may help cancer patients, with potential both as monotherapy and in combination with existing therapeutics,” Rupert Vessey, FRCP DPhil, Celgene’s president of research and early development, said in a statement.

The expanded partnership with Celgene marks Dragonfly’s second collaboration announcement in as many months. On October 1, Merck & Co. agreed to develop new solid tumor cancer immunotherapies using the TriNKET™ platform, through an alliance that could generate up to $695 million per program, plus royalties, for Dragonfly. Neither the number of programs, nor the types of solid tumor malignancies, have been disclosed.

Binding Cancer Proteins

Dragonfly’s proprietary TriNKETs are designed to bind to the proteins expressed on both cancer cells and tumor cell-killing NK cells. Through that binding, Dragonfly says, the TriNKETs are intended to stimulate NK cells, making them aware of the cancer and allowing them to both directly kill the cancer cells, and activate T cells and B cells to attack the cancer, helping B cells produce antitumor antibodies and activating more T cells to kill tumor cells.

According to Dragonfly, TriNKETs amplify the effectiveness of T cells by acting as a sentinel that calls other immune system cells to attack the cancer, as well as broadening the therapeutic window by using their special characteristics of distinguishing cancer to more specifically target tumor cells.

Dragonfly’s pipeline consists of six preclinical candidates: a solid tumor targeting candidate, DF1001, four blood tumor targeting candidates (DF2001, DF3001, DF4001, and DF5001), and a TriNKET Enhancer, DF6000.

“Celgene is a leader in innovation in immunotherapy and we are very pleased to double the number of targets within our collaboration, and to move as partners into solid tumor targets,” added Dragonfly CEO Bill Haney. “The Celgene team have been fantastic collaboration partners over the past 18 months, and we look forward to continuing our efforts to bring potential new immuno-oncology treatment options to patients with cancer.”

Haney—a filmmaker, inventor, and technology entrepreneur—co-founded Dragonfly in 2015 with Tyler Jacks, Ph.D., head of the Koch Institute for Integrative Cancer Research at MIT, and chair of the company’s Scientific Advisory Board; and David Raulet, Ph.D., the Esther and Wendy Schekman Chair in Cancer Biology at University of California, Berkeley.