Antiviral cellular therapy for enhancing T-cell reconstitution before or after hematopoietic stem cell transplantation (ACES): a two-arm, open label phase II interventional trial of pediatric patients with risk factor assessment

Viral infections remain a major risk in immunocompromised pediatric patients, and virus-specific T cell (VST) therapy has been successful for treatment of refractory viral infections in prior studies. We performed a phase II multicenter study (NCT03475212) for the treatment of pediatric patients with inborn errors of immunity and/or post allogeneic hematopoietic stem cell transplant with refractory viral infections using partially-HLA matched VSTs targeting cytomegalovirus, Epstein-Barr virus, or adenovirus. Primary endpoints were feasibility, safety, and clinical responses (>1 log reduction in viremia at 28 days). Secondary endpoints were reconstitution of antiviral immunity and persistence of the infused VSTs. Suitable VST products were identified for 75 of 77 clinical queries. Clinical responses were achieved in 29 of 47 (62%) of patients post-HSCT including 73% of patients evaluable at 1-month post-infusion, meeting the primary efficacy endpoint (>52%). Secondary graft rejection occurred in one child following VST infusion as described in a companion article. Corticosteroids, graft-versus-host disease, transplant-associated thrombotic microangiopathy, and eculizumab treatment correlated with poor response, while uptrending absolute lymphocyte and CD8 T cell counts correlated with good response. This study highlights key clinical factors that impact response to VSTs and demonstrates the feasibility and efficacy of this therapy in pediatric HSCT.

The Effects of Human Immunodeficiency Virus Type 1 (HIV-1) Antigen-Expanded Specific T-Cell Therapy and Vorinostat on Persistent HIV-1 Infection in People With HIV on Antiretroviral Therapy

BACKGROUND

The histone deacetylase inhibitor vorinostat (VOR) can reverse human immunodeficiency virus type 1 (HIV-1) latency in vivo and allow T cells to clear infected cells in vitro. HIV-specific T cells (HXTCs) can be expanded ex vivo and have been safely administered to people with HIV (PWH) on antiretroviral therapy.

METHODS

Six PWH received infusions of 2 × 107 HXTCs/m² with VOR 400 mg, and 3 PWH received infusions of 10 × 107 HXTCs/m² with VOR. The frequency of persistent HIV by multiple assays including quantitative viral outgrowth assay (QVOA) of resting CD4+ T cells was measured before and after study therapy.

RESULTS

VOR and HXTCs were safe, and biomarkers of serial VOR effect were detected, but enhanced antiviral activity in circulating cells was not evident. After 2 × 107 HXTCs/m² with VOR, 1 of 6 PWH exhibited a decrease in QVOA, and all 3 PWH exhibited such declines after 10 × 107 HXTCs/m² and VOR. However, most declines did not exceed the 6-fold threshold needed to definitively attribute decline to the study intervention.

CONCLUSIONS

These modest effects provide support for the strategy of HIV latency reversal and reservoir clearance, but more effective interventions are needed to yield the profound depletion of persistent HIV likely to yield clinical benefit. Clinical Trials Registration. NCT03212989.

IMMU-19. Outcomes of Pediatric Patients with High-Risk CNS Tumors Treated with Multi-tumor associated antigen specific T cell (TAA-T) therapy: the ReMIND trial

BACKGROUND: The ReMIND trial hypothesizes that autologous T-cells specific for three tumor-associated antigens (TAA) -WT1, PRAME, and survivin- will be safe and elicit anti-tumor immunity in pediatric patients with CNS cancer. METHODS: Patients (n=25) received autologous TAA-T for newly-diagnosed DIPG (Stratum A, up to 4x107/m2) or recurrent CNS malignancies (Stratum B, up to 8x107/m2) in this dose-escalation study (NCT03652545) and were monitored for toxicity and response. RESULTS: Autologous TAAT products were successfully manufactured from 28 patients. Using IFN-γ ELISPOT assay, 10/11 evaluable products had specificity for 1-3 TAAs. 25 patients received TAA-T (6 in Stratum A and 19 in Stratum B) and completed the 45-day safety monitoring period. Twenty-four (96%) had no dose limiting toxicities (DLT), but 1 (4%) patient with DIPG experienced a DLT related to potential immune-mediated pseudoprogression. Median overall survival for patients with DIPG (Stratum A) was 14 months (range, 6-32 months). Median progression-free survival (PFS) for Stratum B patients was 8 months (range, 2-26+ months), which exceeded their preceding median duration of disease stability of 2 months (range, 1-5 months). Plasma cytokine profiles demonstrated infusion-related immune cytokine responses. CONCLUSIONS: In summary, TAAT had a favorable toxicity profile (4%) especially compared to CAR-T therapy and may elicit anti-tumor immune responses that contribute to prolonged survival. Immunobiology studies and response assessments are ongoing for both strata. Based on these encouraging preliminary results, we have added a stratum that includes prescribed lymphodepletion pre TAA-T administration at a cell dose of 8x107/m2. Further, we plan to add an additional stratum to allow direct administration of TAA-T into the CNS via an Ommaya reservoir.

Outcome of donor-derived TAA-T cell therapy in patients with high-risk or relapsed acute leukemia post allogeneic BMT

Patients with hematologic malignancies relapsing after allogeneic blood or marrow transplantation (BMT) have limited response to conventional salvage therapies, with an expected 1-year overall survival (OS) of <20%. We evaluated the safety and clinical outcomes following administration of a novel T-cell therapeutic targeting 3 tumor-associated antigens (TAA-T) in patients with acute leukemia who relapsed or were at high risk of relapse after allogeneic BMT. Lymphocytes obtained from the BMT donor were manufactured to target TAAs WT1, PRAME, and survivin, which are over-expressed and immunogenic in most hematologic malignancies. Patients received TAA-T infusions at doses of 0.5 to 4 × 107/m2. Twenty-three BMT recipients with relapsed/refractory (n = 11) and/or high-risk (n = 12) acute myeloid leukemia (n = 20) and acute lymphoblastic leukemia (n = 3) were infused posttransplant. No patient developed cytokine-release syndrome or neurotoxicity, and only 1 patient developed grade 3 graft-versus-host disease. Of the patients who relapsed post-BMT and received bridging therapy, the majority (n = 9/11) achieved complete hematologic remission before receiving TAA-T. Relapsed patients exhibited a 1-year OS of 36% and 1-year leukemia-free survival of 27.3% post-TAA-T. The poorest prognosis patients (relapsed <6 months after transplant) exhibited a 1-year OS of 42.8% postrelapse (n = 7). Median survival was not reached for high-risk patients who received preemptive TAA-T posttransplant (n = 12). Although as a phase 1 study, concomitant antileukemic therapy was allowed, TAA-T were safe and well tolerated, and sustained remissions in high-risk and relapsed patients were observed. Moreover, adoptively transferred TAA-T detected by T-cell receptor V-β sequencing persisted up to at least 1 year postinfusion. This trial was registered at clinicaltrials.gov as #NCT02203903.

Tumor-associated antigen-specific T cells with nivolumab are safe and persist in vivo in relapsed/refractory Hodgkin lymphoma

Hodgkin lymphoma (HL) Reed Sternberg cells express tumor-associated antigens (TAA) that are potential targets for cellular therapies. We recently demonstrated that TAA-specific T cells (TAA-Ts) targeting WT1, PRAME, and Survivin were safe and associated with prolonged time to progression in solid tumors. Hence, we evaluated whether TAA-Ts when given alone or with nivolumab were safe and could elicit antitumor effects in vivo in patients with relapsed/refractory (r/r) HL. Ten patients were infused with TAA-Ts (8 autologous and 2 allogeneic) for active HL (n = 8) or as adjuvant therapy after hematopoietic stem cell transplant (n = 2). Six patients received nivolumab priming before TAA-Ts and continued until disease progression or unacceptable toxicity. All 10 products recognized 1 or more TAAs and were polyfunctional. Patients were monitored for safety for 6 weeks after the TAA-Ts and for response until disease progression. The infusions were safe with no clear dose-limiting toxicities. Patients receiving TAA-Ts as adjuvant therapy remain in continued remission at 3+ years. Of the 8 patients with active disease, 1 patient had a complete response and 7 had stable disease at 3 months, 3 of whom remain with stable disease at 1 year. Antigen spreading and long-term persistence of TAA-Ts in vivo were observed in responding patients. Nivolumab priming impacted TAA-T recognition and persistence. In conclusion, treatment of patients with r/r HL with TAA-Ts alone or in combination with nivolumab was safe and produced promising results. This trial was registered at www.clinicaltrials.gov as #NCT022039303 and #NCT03843294.

Early furosemide therapy in premature infants (less than or equal to 2000 gm) with respiratory distress syndrome: a randomized controlled trial

Pulmonary edema has been demonstrated in the early stages of respiratory distress syndrome in premature infants. To evaluate whether early furosemide therapy (0 to 8 hours after birth) would affect the electrolyte balance, pulmonary status, and outcome, 57 infants (less than or equal to 2000 gm) with respiratory distress syndrome who required mechanical ventilation shortly after birth were randomized into two groups: 29 given furosemide (1 mg/kg/day intravenously for three doses) and 27 control. The clinical, biochemical, and laboratory characteristics of the groups were comparable before entry into the study. Administration of furosemide significantly enhanced the urinary excretion of Na and Cl at 0 to 24, 24 to 48 and 48 to 72 hours and of Ca at 24 to 48 and 48 to 72 hours after drug administration. There was no significant difference between the groups in urinary excretion of K and in serum Na, Cl, K, and Ca values. A spontaneous increase in urine output occurred in the control group at 48 to 72 hours after the initiation of the study (mean +/- SD 7.0 +/- 3.5 hours postnatal age), along with a decrease in mean airway pressure for mechanical ventilation. The use of furosemide (7.3 +/- 3.5 hours postnatal age) enhanced urine output at 24 to 48 and 48 to 72 hours after medication, resulting in further decrease in mean airway pressure and facilitating extubation. There was, however, no significant difference between the groups with respect to incidence of patent ductus arteriosus, morbidity from bronchopulmonary dysplasia, and mortality.