A phase I/II study of adoptive SARS-CoV-2-specific T cells in immunocompromised hosts with or at risk of severe COVID-19 infection.

BACKGROUND: Post-transplant or hematological cancer patients have a higher risk of mortality after infection with ancestral and early variants of severe acute respiratory syndrome (SARS)-CoV-2. Adoptive cell therapy (ACT) with virus-specific T cells (VSTs) could augment endogenous T cell immunity to avoid disease deterioration before viral clearance. METHODS: We established a third-party SARS-CoV-2-specific T cell (COVID-T) bank in 2020 (NCT04351659) using convalescent and/or vaccinated donors. In a phase I/II study (NCT04457726), 13 adult and pediatric patients, acutely positive for SARS-CoV-2 and predicted to have a high chance of mortality, were recruited from September 2021 to February 2022. Twelve patients received a single dose of COVID-T cells, matched on at least 1 HLA. RESULTS: A dose of either 75,000 or 150,000 IFN-γ+CD3+ cells/m2 SARS-COV-2-specific T cells did not cause cytokine release syndrome, acute respiratory distress syndrome, or graft-versus-host disease. In the 8 patients who had detectable donor SARS-COV-2-specific T cells after ACT, none progressed to severe disease or died with COVID-19. In contrast, among the other four patients without evidence of donor micro-chimerism, two died of COVID-19. CONCLUSIONS: Long-acting third-party VSTs from convalescent or vaccinated donors could be expediently produced and might be clinically useful in future pandemics, particularly before global vaccination is implemented.

An ex vivo platform to guide drug combination treatment in relapsed/refractory lymphoma.

Although combination therapy is the standard of care for relapsed/refractory non-Hodgkin's lymphoma (RR-NHL), combination treatment chosen for an individual patient is empirical, and response rates remain poor in individuals with chemotherapy-resistant disease. Here, we evaluate an experimental-analytic method, quadratic phenotypic optimization platform (QPOP), for prediction of patient-specific drug combination efficacy from a limited quantity of biopsied tumor samples. In this prospective study, we enrolled 71 patients with RR-NHL (39 B cell NHL and 32 NK/T cell NHL) with a median of two prior lines of treatment, at two academic hospitals in Singapore from November 2017 to August 2021. Fresh biopsies underwent ex vivo testing using a panel of 12 drugs with known efficacy against NHL to identify effective single and combination treatments. Individualized QPOP reports were generated for 67 of 75 patient samples, with a median turnaround time of 6 days from sample collection to report generation. Doublet drug combinations containing copanlisib or romidepsin were most effective against B cell NHL and NK/T cell NHL samples, respectively. Off-label QPOP-guided therapy offered at physician discretion in the absence of standard options (n = 17) resulted in five complete responses. Among patients with more than two prior lines of therapy, the rates of progressive disease were lower with QPOP-guided treatments than with conventional chemotherapy. Overall, this study shows that the identification of patient-specific drug combinations through ex vivo analysis was achievable for RR-NHL in a clinically applicable time frame. These data provide the basis for a prospective clinical trial evaluating ex vivo-guided combination therapy in RR-NHL.

Rapid production of clinical-grade SARS-CoV-2 specific T cells.

Objectives: To determine whether the frequencies of SARS-CoV-2-specific T cells are sufficiently high in the blood of convalescent donors and whether it is technically feasible to manufacture clinical-grade products overnight for T-cell therapy and assessment of COVID-19 immunity. Methods: One unit of whole blood or leukapheresis was collected from each donor following standard blood bank practices. The leukocytes were stimulated using overlapping peptides of SARS-CoV-2, covering the immunodominant sequence domains of the S protein and the complete sequence of the N and M proteins. Thereafter, functionally reactive cells were enriched overnight using an automated device capturing IFNγ-secreting cells. Results: From 1 × 109 leukocytes, a median of 0.98 × 106 (range 0.56-2.95) IFNγ + T cells were produced from each of the six donors, suggesting a high frequency of SARS-CoV-2 reactive T cells in their blood, even though only one donor had severe COVID-19 requiring mechanical ventilation whereas the other five donors had minor symptoms. A median of 57% of the enriched T cells were IFNγ+ (range 20%-74%), with preferential enrichment of CD56+ T cells and effector memory T cells. TCRVß-spectratyping confirmed distinctively tall oligoclonal peaks in final products. With just six donors, the probability that a recipient would share at least one HLA allele with one of the donors is >88% among Caucasian, >95% among Chinese, >97% among Malay, and >99% among Indian populations. Conclusions: High frequencies of rapid antigen-reactive T cells were found in convalescent donors, regardless of severity of COVID-19. The feasibility of clinical-grade production of SARS-CoV-2-specific T cells overnight for therapeutics and diagnostics is revealed.

Vinorelbine-Cyclophosphamide compared to cyclophosphamide in peripheral blood stem cell mobilization for multiple myeloma.

BACKGROUND: High dose Cyclophosphamide (Cy) and Vinorelbine Cyclophosphamide (Vino-Cy) are stem cell (SC) mobilisation options for patients with multiple myeloma (MM). We present a comparison of mobilisation outcomes using these regimens. PATIENTS AND METHODS: Vino-Cy patients received Vinorelbine 25 mg/m2 on day 1, cyclophosphamide 1500 mg/m2 on day 2, and pegylated GCSF on day 4 or GCSF 10 mcg/kg/day from day 4 onwards. Cy patients were given cyclophosphamide 4000 mg/m2 on day 1 and GCSF10 mcg/kg/day from day 5 onwards. The target CD34 + SC collection was 5 × 106 per kg/BW. RESULTS: 149 patients were included. SC collection was lower in the Vino-Cy group (8.20 × 106/Kg BW) compared to the Cy group (11.43 × 106/Kg BW), with adjusted geometric mean ratio of 0.59 (95% CI 0.41 to 0.86, p = 0.006). Time taken to achieve an adequate PB SC count was shorter for Vino-Cy (9 ±â€¯1 day compared to 12 ±â€¯2 days for Cy, adjusted absolute mean difference -3.95, 95% CI -4.85 to -3.06, P < .001). Mobilisation related toxicities (in particular, neutropaenic fever) were greater for Cy. CONCLUSION: Vino-Cy is a potential alternative to Cy given the need for effective mobilisation protocols with acceptable toxicity.

Storage time affects umbilical cord blood viability.

BACKGROUND: Cryopreserved umbilical cord blood (CB) is increasingly used as a cell source to reconstitute marrow in hematopoietic stem cell transplant patients. Delays in cryopreservation may adversely affect cell viability, thereby reducing their potential for engraftment after transplantation. STUDY DESIGN AND METHODS: The impact of delayed cryopreservation for up to 3 days on the viability of both CD45+ and CD34+ cell populations in 28 CB donations with volumes of 58.40 ± 15.4 mL (range, 39.4-107.4 mL) was investigated to establish whether precryopreservation storage time could be extended from our current time of 24 to 48 hours in line with other CB banks. Viability was assessed on 3 consecutive days, both before and after cryopreservation, by flow cytometry using 7-aminoactinomycin D (7-AAD) and annexin V methods. RESULTS: The results using 7-AAD and annexin V indicated the viability of CD34+ cells before cryopreservation remained high (>92.33 ± 4.11%) over 3 days, whereas the viability of CD45+ cells decreased from 86.36 ± 4.97% to 66.24 ± 7.78% (p < 0.0001) by Day 3. Storage time significantly affected the viability of CD34+ cells after cryopreservation. Using 7-AAD, the mean CD34+ cell viability decreased by approximately 5% per extra day in storage from 84.30 ± 6.27% on Day 1 to 79.01 ± 7.44% (p < 0.0057) on Day 2 and to 73.95 ± 7.54% (p < 0.0001) on Day 3. With annexin V staining CD34+ cell viability fell by approximately 7% per extra day in storage from 77.17 ± 8.47% on Day 1 to 69.56 ± 13.30% (p < 0.0194) on Day 2 and to 62.89 ± 15.22% (p < 0.0002) on Day 3. CONCLUSION: This study demonstrates that extended precryopreservation storage adversely affects viability and should be avoided.

Comparing peripheral blood stem cell collection using the COBE Spectra, Haemonetics MCS+, and Baxter Amicus.

Peripheral blood stem cells (PBSC) have become the most common source of hematopoietic cells for allogeneic or autologous blood and marrow transplantation (BMT). We performed an evaluation of PBSC collections using three different apheresis systems in two major transplantation centers in Singapore. Patients undergoing autologous BMT and donors collecting for allogeneic BMT were harvested using the COBE Spectra, Haemonetics MCS+, or Baxter Amicus. There were 99 Spectra collections (61 were autologous), 81 MCS+ collections (35 were autologous) and 38 Amicus collections (33 were autologous). Our data shows that the Amicus not only processed larger peripheral blood volumes but also yielded larger PBSC volume (P-value<0.05). In terms of PBSC products, the Spectra produced more WBC, WBC/liter blood processed, and WBC/kg (P-value<0.05). The Spectra and MCS+ produced comparable amount of CD34+ cells. Amicus collected 50% less platelets compared to Spectra and MCS+. The total CD34+ cells in the PBSC products was linearly correlated to the circulating CD34+ cells using Spectra, MCS+, and Amicus. Our results suggest that, compared to MCS+ and Amicus, collecting PBSC using the COBE Spectra can produce more WBC with a similar number of CD34+ cells. With a linear correlation of circulating CD34+ cells to the total CD34+ cells in the products, the availability of an automated procedure, no rotating seal, and a small extracorporeal volume, the Spectra appears to be the preferred machine for PBSC collection.