GTB-3550 tri-specific killer cell engager (TriKE™) is a tri-specific scFv recombinant fusion protein conjugate, containing variable regions of the H and L chains of the anti-CD16 and anti-CD33 antibodies along with modified IL-15. The drug is used as a monotherapy treatment and acts on CD33+ leukemias such as acute myeloid leukemia (AML), and myelodysplastic syndrome (MDS) by activating the apoptotic action of natural killer (NK) cells on malignant cells, which contributes to tumor-induced immunosuppression.
Recently, an update on the first-in-human phase I/II clinical trial (NCT03214666) for GTB-3550 TriKE™ to treat relapsed/refractory (R/R) MDS/AML patients was published.1
Major outcomes obtained from treating the first nine patients in the trial are as follows:
- Three out of the last five patients treated responded to the therapeutic dose range (25 mcg/kg/day to 100 mcg/kg/day).
- Reduction (63.7%) in the bone marrow blast level was observed.
- Restoration of endogenous NK cell function, proliferation, and immune surveillance was also detected.
- None of the patients showed cytokine release syndrome.
GTB-3550 TriKE™ would be a cost-effective option as no preconditioning (progenitor-derived or autologous/allogenic cell therapy) of patients is required. Also, it was observed to be well tolerated with reduced toxicity and, therefore, offers the advantage to be used at an early stage of the disease.