High-Specificity CRISPR-Mediated Genome Engineering in Anti-BCMA Allogeneic CAR T Cells Suppresses Allograft Rejection in Preclinical Models.

Allogeneic chimeric antigen receptor (CAR) T cell therapies hold the potential to overcome many of the challenges associated with patient-derived (autologous) CAR T cells. Key considerations in the development of allogeneic CAR T cell therapies include prevention of graft-vs-host disease (GvHD) and suppression of allograft rejection. Here, we describe preclinical data supporting the ongoing first-in-human clinical study, the CaMMouflage trial (NCT05722418), evaluating CB-011 in patients with relapsed/refractory multiple myeloma. CB-011 is a hypoimmunogenic, allogeneic anti-B-cell maturation antigen (BCMA) CAR T cell therapy candidate. CB-011 cells feature 4 genomic alterations and were engineered from healthy donor-derived T cells using a Cas12a CRISPR hybrid RNA-DNA (chRDNA) genome-editing technology platform. To address allograft rejection, CAR T cells were engineered to prevent endogenous HLA class I complex expression and overexpress a single-chain polyprotein complex composed of beta-2 microglobulin (B2M) tethered to HLA-E. In addition, T-cell receptor (TCR) expression was disrupted at the TCR alpha constant locus in combination with the site-specific insertion of a humanized BCMA-specific CAR. CB-011 cells exhibited robust plasmablast cytotoxicity in vitro in a mixed lymphocyte reaction in cell cocultures derived from patients with multiple myeloma. In addition, CB-011 cells demonstrated suppressed recognition by and cytotoxicity from HLA-mismatched T cells. CB-011 cells were protected from natural killer cell-mediated cytotoxicity in vitro and in vivo due to endogenous promoter-driven expression of B2M-HLA-E. Potent antitumor efficacy, when combined with an immune-cloaking armoring strategy to dampen allograft rejection, offers optimized therapeutic potential in multiple myeloma. See related Spotlight by Caimi and Melenhorst, p. 385.

Comparison of Urinary and Serum CA 19-9 as Markers of Early Stage Urothelial Carcinoma

Objectives Although the glycoprotein group tumor marker CA 19-9 has been detected in both serum and urine of bladder cancer patients, information about their comparative role in screening of low grade transitional cell carcinoma (LGTCC) and high grade transitional cell carcinoma (HGTCC) is rare. Materials and Methods In this study we measured both the urinary and serum levels of CA 19-9 in 35 LGTCC and 20 HGTCC patients by ELISA and determined the cut off value of both urinary and serum CA 19-9 levels by receiver operator characteristic curve (ROC) for both patient groups. Odds ratio (OR) for CA 19-9 was analyzed with its range at 95% confidence interval to analyze the role of this tumor marker as a screening parameter for both of these cancer types. Results For urinary CA 19-9 the OR was 20.16 with an interval of 4.91-82.71 whereas for the serum CA 19-9 it was 7.5 with an interval of 2.28-24.62. Conclusions From these data we suggest that urinary CA 19-9 is a better screening parameter with optimum sensitivity and specificity than its serum counterpart for diagnosis of low grade and early stages of transitional cell carcinoma of urinary bladder. Furthermore, it can be suggested that urinary CA 19-9 can be used as better prognostic marker for LGTCC than its serum counterpart. .