Next-generation BCMA-targeted chimeric antigen receptor CARTemis-1: the impact of manufacturing procedure on CAR T-cell features.

PURPOSE: CAR therapy targeting BCMA is under investigation as treatment for multiple myeloma. However, given the lack of plateau in most studies, pursuing more effective alternatives is imperative. We present the preclinical and clinical validation of a new optimized anti-BCMA CAR (CARTemis-1). In addition, we explored how the manufacturing process could impact CAR-T cell product quality and fitness. METHODS: CARTemis-1 optimizations were evaluated at the preclinical level both, in vitro and in vivo. CARTemis-1 generation was validated under GMP conditions, studying the dynamics of the immunophenotype from leukapheresis to final product. Here, we studied the impact of the manufacturing process on CAR-T cells to define optimal cell culture protocol and expansion time to increase product fitness. RESULTS: Two different versions of CARTemis-1 with different spacers were compared. The longer version showed increased cytotoxicity. The incorporation of the safety-gene EGFRt into the CARTemis-1 structure can be used as a monitoring marker. CARTemis-1 showed no inhibition by soluble BCMA and presents potent antitumor effects both in vitro and in vivo. Expansion with IL-2 or IL-7/IL-15 was compared, revealing greater proliferation, less differentiation, and less exhaustion with IL-7/IL-15. Three consecutive batches of CARTemis-1 were produced under GMP guidelines meeting all the required specifications. CARTemis-1 cells manufactured under GMP conditions showed increased memory subpopulations, reduced exhaustion markers and selective antitumor efficacy against MM cell lines and primary myeloma cells. The optimal release time points for obtaining the best fit product were > 6 and < 10 days (days 8-10). CONCLUSIONS: CARTemis-1 has been rationally designed to increase antitumor efficacy, overcome sBCMA inhibition, and incorporate the expression of a safety-gene. The generation of CARTemis-1 was successfully validated under GMP standards. A phase I/II clinical trial for patients with multiple myeloma will be conducted (EuCT number 2022-503063-15-00).

Safety and efficacy of intra-arterial bone marrow mononuclear cell transplantation in patients with acute ischaemic stroke in Spain (IBIS trial): a phase 2, randomised, open-label, standard-of-care controlled, multicentre trial.

BACKGROUND: Pilot clinical trials have shown the safety of intra-arterial bone marrow mononuclear cells (BMMNCs) in stroke. However, the efficacy of different doses of intra-arterial BMMNCs in patients with acute stroke has not been tested in a randomised clinical trial. We aimed to show safety and efficacy of two different doses of autologous intra-arterial BMMNC transplantation in patients with acute stroke. METHODS: The IBIS trial was a multicentre phase 2, randomised, controlled, investigator-initiated, assessor-blinded, clinical trial, in four stroke centres in Spain. We included patients (aged 18-80 years) with a non-lacunar, middle cerebral artery ischaemic stroke within 1-7 days from stroke onset and with a National Institutes of Health Stroke Scale score of 6-20. We randomly assigned patients (2:1:1) with a computer-generated randomisation sequence to standard of care (control group) or intra-arterial injection of autologous BMMNCs at one of two different doses (2 × 106 BMMNCs/kg or 5 × 106 BMMNCs/kg). The primary efficacy outcome was the proportion of patients with modified Rankin Scale scores of 0-2 at 180 days in the intention-to-treat population, comparing each BMMNC dose group and the pooled BMMNC group versus the control group. The primary safety endpoint was the proportion of serious adverse events. This trial was registered at ClinicalTrials.gov, NCT02178657 and is completed. FINDINGS: Between April 1, 2015, and May 20, 2021, we assessed 114 patients for eligibility. We randomly assigned 77 (68%) patients: 38 (49%) to the control group, 20 (26%) to the low-dose BMMNC group, and 19 (25%) the high-dose BMMNC group. The mean age of participants was 62·4 years (SD 12·7), 46 (60%) were men, 31 (40%) were women, all were White, and 63 (82%) received thrombectomy. The median NIHSS score before randomisation was 12 (IQR 9-15), with intra-arterial BMMNC injection done a median of 6 days (4-7) after stroke onset. The primary efficacy outcome occurred in 14 (39%) patients in the control group versus ten (50%) in the low-dose group (adjusted odds ratio 2·08 [95% CI 0·55-7·85]; p=0·28), eight (44%) in the high-dose group (1·89 [0·52-6·96]; p=0·33), and 18 (47%) in the pooled BMMNC group (2·22 [0·72-6·85]; p=0·16). We found no differences in the proportion of patients who had adverse events or dose-related events, but two patients had a groin haematoma after cell injection in the low-dose BMMNC group. INTERPRETATION: Intra-arterial BMMNCs were safe in patients with acute ischaemic stroke, but we found no significant improvement at 180 days on the mRS. Further clinical trials are warranted to investigate whether improvements might be possible at different timepoints. FUNDING: Instituto de Salud Carlos III co-funded by the European Regional Development Fund/European Social Fund, Mutua Madrileña, and the Regional Ministry of Health of Andalusia.

Combined treatment of graft versus host disease using donor regulatory T cells and ruxolitinib.

Donor derived regulatory T lymphocytes and the JAK1/2 kinase inhibitor ruxolitinib are currently being evaluated as therapeutic options in the treatment of chronic graft versus host disease (cGvHD). In this work, we aimed to determine if the combined use of both agents can exert a synergistic effect in the treatment of GvHD. For this purpose, we studied the effect of this combination both in vitro and in a GvHD mouse model. Our results show that ruxolitinib favors the ratio of thymic regulatory T cells to conventional T cells in culture, without affecting the suppressive capacity of these Treg. The combination of ruxolitinib with Treg showed a higher efficacy as compared to each single treatment alone in our GvHD mouse model in terms of GvHD incidence, severity and survival without hampering graft versus leukemia effect. This beneficial effect correlated with the detection in the bone marrow of recipient mice of the infused donor allogeneic Treg after the adoptive transfer.

Ruxolitinib in refractory acute and chronic graft-versus-host disease: a multicenter survey study.

Graft-versus-host disease is the main cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. First-line treatment is based on the use of high doses of corticosteroids. Unfortunately, second-line treatment for both acute and chronic graft-versus-host disease, remains a challenge. Ruxolitinib has been shown as an effective and safe treatment option for these patients. Seventy-nine patients received ruxolitinib and were evaluated in this retrospective and multicenter study. Twenty-three patients received ruxolitinib for refractory acute graft-versus-host disease after a median of 3 (range 1-5) previous lines of therapy. Overall response rate was 69.5% (16/23) which was obtained after a median of 2 weeks of treatment, and 21.7% (5/23) reached complete remission. Fifty-six patients were evaluated for refractory chronic graft-versus-host disease. The median number of previous lines of therapy was 3 (range 1-10). Overall response rate was 57.1% (32/56) with 3.5% (2/56) obtaining complete remission after a median of 4 weeks. Tapering of corticosteroids was possible in both acute (17/23, 73%) and chronic graft-versus-host disease (32/56, 57.1%) groups. Overall survival was 47% (CI: 23-67%) at 6 months for patients with aGVHD (62 vs 28% in responders vs non-responders) and 81% (CI: 63-89%) at 1 year for patients with cGVHD (83 vs 76% in responders vs non-responders). Ruxolitinib in the real life setting is an effective and safe treatment option for GVHD, with an ORR of 69.5% and 57.1% for refractory acute and chronic graft-versus-host disease, respectively, in heavily pretreated patients.

Allocation to Matched Related or Unrelated Donor Results in Similar Clinical Outcomes without Increased Risk of Failure to Proceed to Transplant among Patients with Acute Myeloid Leukemia: A Retrospective Analysis from the Time of Transplant Approval.

Clinical outcomes after allogeneic hematopoietic stem cell transplantation (allo-SCT) from unrelated donors (URDs) approach those of matched related donor (MRD) transplants in patients with acute myeloid leukemia (AML). Yet, available data fail to account for differences in pretransplantation outcomes between these donor selection strategies. In this regard, URD allo-HSCT is associated with longer waiting times to transplantation, potentially resulting in higher probabilities of failure to reach transplant. We retrospectively analyzed 108 AML patients accepted for first allo-HSCT from the time of approval to proceed to transplant. Fifty-eight (54%) patients were initially allocated to MRD, while URD search was initiated in 50 (46%) patients. Time to transplant was longer in patients allocated to a URD when compared with patients assigned to an MRD (median 142 days versus 100 days; p < .001). Forty-three of 58 (74%) patients in the MRD group and 35 of 50 (70%) patients in the URD group underwent transplantation (odds ratio [OR], 1.22; p = .63). Advanced disease status at the time of allo-HSCT approval was the only predictor of failure to reach transplantation in the multivariate analysis (OR, 4.78; p = .001). Disease progression was the most common cause of failure to reach allo-HSCT (66.7%) in both the MRD and URD groups. With a median follow-up from transplantation of 14.5 (interquartile range, 5 to 29) months, the 2-year estimate of overall survival (OS) from allo-HSCT was 46% in the MRD group and 57% in the URD group (p = .54). There were no differences in OS according to donor type allocation in the multivariate analysis (hazard ratio, 1.01; p = .83). When including patients from the time of transplant approval, 2-year OS was 39% in the MRD group versus 42% in the URD group. Our study suggests that allocation of AML patients to URDs may result in comparable clinical outcomes to MRD assignment without a significant increase in the risk of failure to reach transplant.