Kiadis to buy CytoSen, adding June to advisory board

Carl June (Penn Medicine)

Kiadis is set to buy CytoSen Therapeutics to expand into anti-cancer natural killer (NK) cell therapies. The all-stock transaction will give Kiadis control of a preclinical NK cell therapy and see it add CAR-T pioneer Carl June to its scientific advisory board.

Dutch biotech Kiadis has focused its efforts to date on T cell therapies, specifically a drug designed to improve outcomes in cancer patients who undergo partially matched, haploidentical hematopoietic stem cell transplants (HSCT). That drug, ATIR101, could come to market in Europe later this year and is on the road to the phase 3 data needed to win global approvals. 

With ATIR101 potentially closing in on the end of clinical development, Kiadis is set to add another asset to its pipeline by acquiring CytoSen for 1.94 million shares upfront. Kiadis trades at around €10 ($11) a share. 

CytoSen has spent the past few years working on NK cell technology licensed from the University of Central Florida. Using a nanoparticle processing technology, CytoSen thinks it can improve the expansion and activation of NK cells, thereby facilitating multiple high-dose infusions with potent anti-cancer effects. The goal is to augment a patient’s innate immunity to wipe out cancer cells, either as a monotherapy or in combination with T cells that dial up the adaptive immune response.

“I believe the fields of NK cells and T cells are enormously synergistic and the combination could potentially help patients with devastating diseases,” the University of Pennsylvania’s Carl June said in a statement. June, a scientific adviser to CytoSen, will join Kiadis’ scientific advisory board when the deal closes. 

Stefan Ciurea and Dean Lee, co-founders of CytoSen, demonstrated the potential of NK cell therapy in proof-of-concept work performed with their colleagues at MD Anderson Cancer Center. NK cells were given in conjunction with haploidentical HSCT to 13 leukemia patients. One of the patients relapsed, resulting in a relapse rate the authors called “remarkably low.”

CytoSen set out to build on the findings by holding a pre-IND meeting with the FDA last year ahead of a planned phase 2 trial of its lead NK program, CSDT002-NK, in high-risk acute myeloid leukemia or myelodysplastic syndrome patients undergoing haploidentical HSCT.

At one point, that trial was due to get underway in the first half of this year, but Kiadis is aiming toward a 2020 start date. By then, Kiadis may have won approval for ATIR101 in Europe and could be about a year away from generating the phase 3 data it needs to support filings in the U.S. and other regions.

The CytoSen deal provides Kiadis with a fairly low-risk way to gain a backup to ATIR101 and set the stage for possible combinations of NK and T cell therapies. Kiadis will absorb the $6 million in cash held by CytoSen when it closes the deal, partly offsetting the upfront stock costs. And it will pay milestones tied to six clinical development and regulatory events using 5.82 million shares, at most.   

Editor's note: A previous version of this article erroneously said CtyoSen licensed its technology from the University of Florida. The technology is from the University of Central Florida.