Immuno-oncology company Kleo Pharmaceuticals Inc reported on Friday the receipt of the US Food and Drug Administration (FDA) Investigational New Drug (IND) authorisation to initiate a safety and tolerability clinical study combining KP1237 with patients' own Natural Killer (NK) cells to treat multiple myeloma (MM).

The company said it will proceed with safety and tolerability clinical study combining KP1237, a CD38-targeting antibody recruiting molecule (ARM), with patients' own Natural Killer (NK) cells to treat multiple myeloma (MM) in post-transplant patients. he trial is expected to begin enrollment in the first half of 2020 and topline data are expected in the second half of 2021.

According to the company, the single-arm study will be conducted in 25-30 patients with exploratory endpoints that assess the MRD (minimal residual disease) conversion rate at 90-100 days after transplantation.

As part of the trial, KP1237 is being investigated as a "cell homing" molecule to target the patient's activated NK cells to the CD38-expressing tumor. Current anti-CD38 therapeutic antibodies kill NK cells and are not approved for use in this clinical setting.

Nonclinical efficacy data demonstrated that CD38-ARMs are able to kill multiple myeloma cells by antibody-dependent cellular cytotoxicity without depleting CD38-expressing immune cells as well as demonstrated that the CD38-ARM molecule did not induce complement-dependent cytotoxicity (CDC) suggesting it is not likely to cause CDC in humans, concluded the company.