MaxCyte Regulatory News (MXCT)

CARMA Cell Therapies™ to Share Results of In-vitro Characterization

of MCY-M11 at SITC 2020 Annual Meeting

Gaithersburg, Maryland - 9 November 2020: MaxCyte, Inc. (LSE: MXCT, MXCL), a global cell-based therapies and life sciences company, announces that its subsidiary CARMA Cell Therapies will share results of a detailed phenotypic and functional characterization of MCY-M11, its lead anti-mesothelin CAR-PBMC cell therapy candidate, at the Society for Immunotherapy of Cancer's (SITC) 35th anniversary meeting. The Virtual Scientific Program begins today and runs through to November 14, 2020.

The ePoster (Abstract# 108) entitled, "MCY-M11, a CAR-PBMC cell product transiently expressing a mesothelin targeted mRNA CAR, exhibits desirable functional and immune phenotype attributed to sustained antitumor immunity in vitro," will be presented during SITC's Poster Symposium with a live Q&A on Thursday, November 12 from 4:50-5:20 p.m. EST and on Saturday, November 14 from 1:00-1:30 p.m. EST.

MCY-M11 is a wholly-owned, non-viral, mRNA-based cell therapy candidate manufactured using unstimulated peripheral blood mononuclear cells (PBMCs). MCY-M11 is under Phase I clinical evaluation for the treatment of advanced ovarian cancer and malignant peritoneal mesothelioma.

"We are encouraged by these in vitro findings, which demonstrate MCY-M11's potential to enable a long-term antitumor response. This work brings us one step closer to understanding the mechanism of action of MCY-M11 and provides strong non-clinical rationale for its use as a cancer cell therapy," said Dhana Chinnasamy, VP of Non-Clinical and Translational Studies at CARMA.

For more information about the SITC Virtual Scientific Program and to access the abstract, please visit: https://www.sitcancer.org.

About MCY-M11

MCY-M11 is a non-viral, mRNA-based anti-mesothelin CAR-PBMC cell therapy manufactured using un-manipulated peripheral blood mononuclear cells (PBMC). It is being evaluated in the clinic as treatment for high mesothelin expressing solid tumors. It is under ongoing development in a first-in human multi-center, non-randomized, open label, dose-escalation Phase I clinical trial evaluating the safety and preliminary efficacy of intraperitoneal infusions of MCY-M11 in individuals with platinum-resistant, high-grade, serous adenocarcinoma of the ovary, primary peritoneum or fallopian tube, or individuals with advanced peritoneal mesothelioma, with recurrence after prior chemotherapy.

Interim results presented at the ASCO 2020 meeting show that intraperitoneal infusion of MCY-M11 is feasible, safe, and well tolerated. There have been no dose-limiting toxicities and no treatment related discontinuations or deaths and most reported treatment related adverse events have been Grades 1-2 per NCI CTCAE in three completed dose levels as a single agent in the existing cohort.

Enrollment in the fourth dose level of the existing cohort is in progress and will run alongside with enrollment in the new parallel cohort that includes a preconditioning regimen. Multiple cycles of treatment will be allowed in both the fourth dose level of the existing cohort and at all dose levels in the new parallel preconditioning cohort.

More information about the study can be found at ClinicalTrials.gov (Identifier: NCT03608618).

About CARMA Cell Therapies

Through its wholly owned subsidiary, CARMA Cell Therapies, MaxCyte is facilitating advancement of novel mRNA-based cell therapies for cancer and other diseases with serious unmet needs. MaxCyte has developed CARMA™, a novel and proprietary platform for the development of non-viral, human messenger RNA (mRNA)-based, chimeric antigen receptor (CAR) or T-cell receptor (TCR) redirected immune cell therapies. CARMA [derived from CAR mRNA] utilizes MaxCyte's Flow Electroporation® technology for highly efficient, non-viral, delivery of one or more mRNA(s) into un-manipulated peripheral blood mononuclear cells (PBMCs) or isolated immune cells such as T- or NK-cells. CARMA offers the potential for a safer cell therapy, as a result of transient expression of receptor(s) and a non-viral delivery approach. Together, CARMA and MaxCyte's ExPERT® family of instruments also offer the potential for a significantly streamlined, scalable, and cost-effective GMP manufacturing process without the complexity of virus-based products. At the start of 2020, MaxCyte established CARMA Cell Therapies as a wholly owned subsidiary to facilitate independent investment and new partnerships to advance the CARMA platform. MaxCyte has retained Locust Walk, a global life science strategic advisory and transaction firm. For more information, visit /carma-cell-therapies/.

About MaxCyte

MaxCyte is a clinical-stage global cell-based therapies and life sciences company. As the inventors of the premier cell-engineering enabling technology, the Company helps bring the promise of next-generation cell and gene-editing therapies to life. The Company's technology is currently being deployed by leading drug developers worldwide, including all of the top ten global biopharmaceutical companies. MaxCyte licences have been granted for more than 120 cell therapy programmes, with more than 90 licensed for clinical use, and the Company has now entered into eleven clinical/commercial license partnerships with leading cell therapy and gene editing developers. MaxCyte was founded in 1998, is listed on the London Stock Exchange (LSE: MXCT, MXCL) and is headquartered in Gaithersburg, Maryland, US. For more information, visit www.maxcyte.com.

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