UC Irvine

BACKGROUND

In the setting of allogeneic stem cell transplantation (alloSCT), infusing natural killer (NK) cells from a major histocompatibility complex (MHC) mismatched donor can mediate an anti-leukemic effect. Graft versus tumor (GvT) effect following autologous stem cell transplantation (ASCT) may result in less disease relapse.

We performed a phase I clinical trial to assess the safety and feasibility of infusing distantly processed donor NK enriched mononuclear cell (NK-MC) infusions from a MHC haplotype mismatched (haploidentical) donor to patients who recently underwent ASCT for a hematologic malignancy. On day 1, peripheral blood mononuclear cells (MC) were obtained by steady-state leukapheresis and sent from Boston to the Production Assistance for Cellular Therapies (PACT) facility at the University of Minnesota, where immunomagnetic depletion of CD3 cells was performed on day 2. NK-MC product were then returned to Boston on day 2 for infusion on day 3. Toxicity, cellular product characteristics and logistic events were monitored.

At a median of 90 days (range, 49–191) following ASCT, thirteen patients were treated with escalating doses of NK-MC per kg from 10⁵ to 2 ×10⁷. Adverse effects included grade 2 rigors and muscle aches, but no grade 3 or 4 events, and no GvHD or marrow suppression. One air courier delay occurred. NK-MC products were viable with cytotoxic activity after transport.

CD3-depleted, MHC mismatched allogeneic NK-MC infusions can be safely and feasibly administered to patients after ASCT following distant processing and transport, justifying further development of this approach.