Kleo had received approval from the U.S. Food and Drug Administration (FDA) earlier this year to proceed with an antibody recruiting molecule (ARM)-NK cell combination therapy clinical trial for treatment of newly diagnosed multiple myeloma patients. The ARM in that trial targets the CD38 cell surface protein and uses autologous cytokine-induced memory-like NK cells to kill tumor cells, according to the company.

Meanwhile, GCLC's allogeneic NK cells are in late-stage clinical development in immuno-oncology applications and are projected to advance into the clinic for COVID-19 in the second half of this year, according to Kleo.

Kleo's ARM technology platform can develop fully synthetic bifunctional molecules that redirect a patient's own antibodies for therapeutic effect. The ARM has multiple proposed mechanisms of action in the context of a COVID-19 therapeutic, according to the company.

For example, it acts as a neutralizing antibody to block direct binding on the virus to human cells and also utilizes immune effector cells to eliminate viral particles and infected cells. What's more, the ARM can produce a long-term vaccination effect by activating and expanding immune memory cells, Kleo said.