Cytomegalovirus (CMV) disease and infection refractory to antiviral treatment after allogeneic stem cell transplantation (allo-SCT) is associated with a high mortality. Adoptive transfer of CMV-specific T cells could reconstitute viral im-munity after SCT and could protect from CMV-related complications. However, logistics of producing virus-specific T-cell grafts limited the clinical application. We treated 18 patients after allo-SCT from human leukocyte antigen–mismatched/haploidentical or human leukocyte antigen–matched unrelated donors with polyclonal CMV-specific T cells generated by ex vivo stimulation with pp65, followed by isolation of interferon-γ–producing cells. Patients with CMV disease or viremia refractory to antiviral chemotherapy or both were eligible for adoptive T-cell transfer and received a mean of 21 × 10³/kg pp65-specific T cells. In 83% of cases CMV infection was cleared or viral burden was significantly reduced, even in cases of CMV encephalitis (n = 2). Viral control was associated with in vivo expansion of CMV-specific T lymphocytes in 12 of 16 evaluable cases, resulting in reconstitution of antiviral T-cell responses, without graft-versus-host disease induction or acute side effects. Our findings indicate that the infusion of low numbers of CMV-specific T cells is safe, feasible, and effective as a treatment on demand for refractory CMV infection and CMV disease after allo-SCT.

The transplantation of stem cells from a matched unrelated donor (MUD) or a haploidentical mismatched related donor (MMRD) is a widely used variant of curative treatment for patients with primary immunodeficiency (PID). Currently, different strategies are used to reduce the risk of post-transplant complications and enhance immune reconstitution. We report the preliminary results of MUD and MMRD transplantation with TCRαβ/CD19 depletion in patients with PID (trial registered at www.clinicaltrials.gov as NCT02327351). Thirty-seven PID patients (median age, 2.6 years; range, .2 to 17) were transplanted from MUDs (n = 27) or haploidentical MMRDs (n = 10) after TCRαβ(+)/CD19(+) graft depletion. The median numbers of CD34(+) and TCRαβ(+) cells in the graft were 11.7 × 10(6)/kg and 10.6 × 10(3)/kg, respectively. Acute graft-versus-host disease (GVHD) was observed in 8 patients (22%), without a statistically significant difference between MUDs and MMRDs; 7 of these patients had grade II acute GVHD and responded to first-line therapy, whereas 1 patient had grade IV acute GVHD with transformation to extensive chronic GVHD. Primary and secondary graft failure (nonengraftment or rejection) was observed in 10 patients (27%), 9 of whom were treated with 1 alkylating agent in the conditioning regimen. All these patients were successfully retransplanted with different rescue protocols. Preliminary data on immune reconstitution were very encouraging. Most patients had significant numbers of T lymphocytes detected on the first assessment (day +30) and more than 500 T cells/μL, on day +120. Based on our preliminary data, no significant difference was seen between MMRD and MUD hematopoietic stem cell transplantation (HSCT). With a median follow-up period of 15 months, the cumulative probabilities of overall patient survival and transplant-related mortality were 96.7% and 3.3%, respectively. Based on the results, the ability to control the main post-transplant complications and the immune reconstitution rates are the main factors leading to successful outcome in patients with PID after TCRαβ(+)-depleted HSCT.

Chimeric antigen receptor (CAR) T cells targeting the CD19 antigen are effective in treating adults and children with B-cell malignancies. Place-of-care manufacturing may improve performance and accessibility by obviating the need to cryopreserve and transport cells to centralized facilities. Here we develop an anti-CD19 CAR (CAR19) comprised of the 4-1BB co-stimulatory and TNFRSF19 transmembrane domains, showing anti-tumor efficacy in an in vivo xenograft lymphoma model. CAR19 T cells are manufactured under current good manufacturing practices (cGMP) at two disparate clinical sites, Moscow (Russia) and Cleveland (USA). The CAR19 T-cells is used to treat patients with relapsed/refractory pediatric B-cell Acute Lymphocytic Leukemia (ALL; n = 31) or adult B-cell Lymphoma (NHL; n = 23) in two independently conducted phase I clinical trials with safety as the primary outcome (NCT03467256 and NCT03434769, respectively). Probability of measurable residual disease-negative remission was also a primary outcome in the ALL study. Secondary outcomes include complete remission (CR) rates, overall survival and median duration of response. CR rates are 89% (ALL) and 73% (NHL). After a median follow-up of 17 months, one-year survival rate of ALL complete responders is 79.2% (95%CI 64.5‒97.2%) and median duration of response is 10.2 months. For NHL complete responders one-year survival is 92.9%, and median duration of response has not been reached. Place-of-care manufacturing produces consistent CAR-T cell products at multiple sites that are effective for the treatment of patients with B-cell malignancies.