The 2023 American Society of Clinical Oncology (ASCO) Annual Meeting was held on June 2-6, 2023. As one of the largest and most popular events in oncology, ASCO annual meeting will show the latest frontier progress to scholars from all walks of life. The details of three abstracts of clinical and preclinical research results of Chongqing Precision Biotech were published in ASCO official website. Two of them were selected into the conference report and one was included in the online publication.

Abstract #7026

Examining safety and durable disease remission in R/R B-ALL after autologous CD19-directed CAR T cells produced by novel PRIMCAR manufacture platform.

We established a novel PrimeCAR platform (PRIMCAR) and reported the preliminary safety and effectiveness data of MC-1-50 CAR-T cells before (Shiqi Li, et al. J Clin Oncol 2022; 40 [suppl 16]. Abstract 7008). Here, we present updated data. 19 pts with r/r B-ALL were infused. Disease characteristics and outcomes are shown in the table. No DLTs were reported. 18 pts (94.7%) experienced CRS, including 10 (52.6%) at grade 1, 7 (36.8%) at grade 2, 1 (5.3%) at grade 3, and no ≥ 4 CRS were observed. Three pts (15.8%) experienced ICANS, including 2 (10.5%) at grade 1, 1(5.3%) at grade 2, and no ≥ 3 ICANS occurred. All patients achieved CR/CRi (BM MRD-) in the first month. All patients in 4 dose levels had good CAR-T expansion and exhibited long persistence features.Treatment of r/r B-ALL at a very low dose resulted in excellent safety profiles while exhibiting a high and durable efficacy. That makes this PRIMCAR platform potential for outpatient administration in the future.

Link ：https://meetings.asco.org/abstracts-presentations/220541

Abstract #7553

Safety and efficacy profile of a very low dose of MC-1-50 for treatment of r/r NHL.

To improve efficacy, we established a novel PrimeCAR platform (PRIMCAR) that shortens the manufacture time to about 2 days and enriches more stem cell-like memory T (Tscm) cells in the product. The MC-1-50 CAR-T cells produced by the PRIMCAR platform have exhibited a promising efficacy for B-ALL (Shiqi Li, et al. J Clin Oncol 2022; 40 [suppl 16]. Abstract 7008). Here, we report the preliminary safety and efficacy data of MC-1-50 for r/r B-NHL. As of May 2022, thirteen pts with r/r B-NHL were infused with MC-1-50. No DLTs were reported. 3 pts (23.08%) experienced CRS, no≥3 CRS were observed, and no ICANS occurred. At DL2, two patients showed PR response, and 3 of the 5 patients achieved CR response. At DL3, 5 of 5 patients achieved CR response. These patients with CR response did not experience a relapse during the followed-up (ranging from 5-18 months). CAR-T expansion was observed in all dose levels.The PRIMCAR platform could produce CAR T cells quickly with a high percentage of Tscm. Treatment of r/r B-NHL at very low dose resulted in excellent safety profiles while exhibiting a high and durable efficacy. 

Link ：https://meetings.asco.org/abstracts-presentations/220321

Abstract #e14530

"Armed" CEA CAR-T with a SIRPγ-CD28 chimeric co-receptor to exhibit the enhanced antitumor activity in preclinical study of colorectal cancer.

Nowadays, CAR-T cell therapy still faces limited therapeutic efficacy for solid tumors. SIRPγ is known as a ligand for a well-known immune checkpoint molecule CD47. Preliminary data indicated SIRPγ plays a key role in T-cell transendothelial migration and promotes antigen-specific T-cell proliferation. We thus designed a novel SIRPγ-CD28 chimeric receptor comprising the extracellular part of SIRPγ, the transmembrane and intracellular domains of CD28 and used as the co-receptor for a CEA-targeting CAR. Here, we report on the activity of this "armed" CAR-T with the SIRPγ-CD28 co-receptor in colorectal tumor (CRC) and its anti-tumor efficacy in mice xenograft model.CAR-T with the SIRPγ-CD28 co-receptor exhibited specific cytotoxicity only to CEA+ CRC cells, and the efficacies of CAR-T w/wo the co-receptor were comparable (88.6% vs 87.8%, p > 0.05). These preclinical studies demonstrated the potential of SIRPγ-CD28 co-receptor as a novel T cellular activation signals for CAR-T. The "armed" CAR-T exhibits a fabulous anti-tumor efficacy in CRC and has great potential for applications in other solid tumors.

Link ：https://meetings.asco.org/abstracts-presentations/224647

Focus on Chongqing Precision Biotech

PRIMCAR platform is a new generation of cell preparation technology developed by Chongqing Precision Biotech to solve the two major problems of high side effects and high cost of CAR-T cells. This platform can produce CAR-T cells within 48 hours. With strict quality control system, it can complete cell infusion for patients within 7 days. The advent of PRIMCAR platform not only brings more possibilities to patients, but also solves the technical problem of long preparation cycle.

At present, eight CAR-T products have been listed in the world, all of which focus on hematological tumors. The demand for drugs for other tumor patients, especially for patients with a wider range of solid tumors, is far from being satisfied, and the main reason for these dissatisfaction is that innovative technology has not yet broken through the difficulties of tumor microenvironment, heterogeneity or target selection for other indications. In order to solve the above problems, Chongqing Precision Biotech has developed the HYECAR platform for multi-antigen identification and recurrence prevention, the PhiCAR platform for breaking through the tumor physical microenvironment, and the RESCAR platform for specific tumor microenvironment, which has solved the difficult problems of target heterogeneity of solid tumor and the off-target risk of tumor-related antigens, and helped the company to lead and surpass  in the research and development of CAR-T of solid tumor.