Combining AFM13, a Bispecific CD30/CD16 Antibody, with Cytokine-Activated Blood and Cord Blood–Derived NK Cells Facilitates CAR-like Responses Against CD30+ Malignancies

Abstract

Purpose: Natural killer (NK)-cell recognition and function against NK-resistant cancers remain substantial barriers to the broad application of NK-cell immunotherapy. Potential solutions include bispecific engagers that target NK-cell activity via an NK-activating receptor when simultaneously targeting a tumor-specific antigen, as well as enhancing functionality using IL12/15/18 cytokine pre-activation. Experimental Design: We assessed single-cell NK-cell responses stimulated by the tetravalent bispecific antibody AFM13 that binds CD30 on leukemia/lymphoma targets and CD16A on various types of NK cells using mass cytometry and cytotoxicity assays. The combination of AFM13 and IL12/15/18 pre-activation of blood and cord blood–derived NK cells was investigated in vitro and in vivo. Results: We found heterogeneity within AFM13-directed conventional blood NK cell (cNK) responses, as well as consistent AFM13-directed polyfunctional activation of mature NK cells across donors. NK-cell source also impacted the AFM13 response, with cNK cells from healthy donors exhibiting superior responses to those from patients with Hodgkin lymphoma. IL12/15/18-induced memory-like NK cells from peripheral blood exhibited enhanced killing of CD30+ lymphoma targets directed by AFM13, compared with cNK cells. Cord-blood NK cells preactivated with IL12/15/18 and ex vivo expanded with K562-based feeders also exhibited enhanced killing with AFM13 stimulation via upregulation of signaling pathways related to NK-cell effector function. AFM13–NK complex cells exhibited enhanced responses to CD30+ lymphomas in vitro and in vivo. Conclusions: We identify AFM13 as a promising combination with cytokine-activated adult blood or cord-blood NK cells to treat CD30+ hematologic malignancies, warranting clinical trials with these novel combinations.

Engineering the next generation of CAR-NK immunotherapies

“…Pursuing this approach, we were able to demonstrate increases in the cytotoxic potential of AFM13-loaded NK cells in vitro . When tested in lymphoma-bearing mice, AFM13-complexed NK cells elicited markedly improved anti-tumor responses and significantly prolonged survival, while no significant adverse toxicities were observed [ 34 ]. This approach is currently being tested in the clinic (NCT04101331).…”

“…Several groups are now investigating and analyzing the immunometabolic signatures underpinning this distinct memory-like NK phenotype [ 73 ]. Mitochondrial fitness, in particular, has come to the center of attention with growing evidence linking mitochondrial dysfunction to impaired NK cell immune responses, and strategies to promote mitochondrial health to improve NK cell function are already under way [ 34 , 86 , 87 ].…”

A Hot Topic: Cancer Immunotherapy and Natural Killer Cells

“…It is currently in clinical phase II development against certain hematologic malignancies. Other comparable constructs are likewise tested in phases I or II [ 103 , 105 ]. They function according to the principle of redirected killing.…”

Natural Killer Cell Responses during Human γ-Herpesvirus Infections

“…In a phase I clinical trial, four of six patients with lymphoma experience completed remission without any signs of cytokine release syndrome (CRS) which is often common to CAR therapies [118]. Beyond CD19, CD22 and CD30 are now also explored for similar treatments [115,119]. Therefore, KIR mismatching might allow one to diminish inhibitory signaling, and CAR expression could enable NK cell-mediated targeting of EBV-infected B cells beyond lytic replication, in order to harness NK cell responses against EBV-associated malignancies.…”