First Patient Dosed in Phase 1 Trial of MCY-M11 in Ovarian Cancer, Peritoneal Mesothelioma

First Patient Dosed in Phase 1 Trial of MCY-M11 in Ovarian Cancer, Peritoneal Mesothelioma

MaxCyte has begun dosing participants in a Phase 1 trial to assess its lead CAR T-cell therapy, MCY-M11, for the treatment of advanced ovarian cancer and peritoneal mesothelioma patients who failed prior chemotherapy.

Taking place at the National Cancer Institute at the National Institutes of Health and Washington University in St. Louis, the open-label study (NCT03608618is expected to include 15 participants. It is still recruiting patients. 

“The initiation of patient dosing in our first clinical trial with our lead CAR therapeutic candidate is a significant milestone for MaxCyte, validating our streamlined manufacturing process for clinical use,” Doug Doerfler, MaxCyte’s CEO, said in a press release. “We are extremely pleased to have very experienced investigators at two leading clinical centers conducting this study in solid tumors.”

CAR T-cell immunotherapy — an approach that consists of collecting a patient’s own T-cells and modifying them in the lab to recognize cancer cells when injected back into the patient — has been successful in treating some leukemias and lymphomas.

Current CAR T-cell approaches, however, require a great deal of time to be expanded in the lab and are often associated with marked toxicity, caused by an overactive immune system. This has limited their development.

Aiming to address these issues, MaxCyte has been developing a kind of transient CAR T-cell approach. The company uses their proprietary CARMA platform, which allows the modification of immune cells with a messenger RNA molecule instead of using the standard virus-based approaches.

Messenger RNAs (mRNAs) are molecules that translate DNA into proteins, but are not inserted in the cell’s genome. In this way, once the mRNA molecule is degraded, CAR T-cells are no longer able to recognize their targets, minimizing potential side effects.

Additionally, CARMA uses both T-cells and other immune cells with killing ability, eliminating the need for expanding cells in the lab. This is expected to bring the therapy to patients much faster and at lower costs than current CAR T-cell approaches.

MaxCyte’s lead candidate, MCY-M11, is a therapy where immune cells are modified to target mesothelin, a protein widely produced by mesothelioma, pancreatic, ovarian, and lung cancer cells.

The ongoing Phase 1 trial is testing the treatment in patients with high-grade cancers of the ovary, peritoneum, or fallopian tube, who stopped responding to platinum-based chemotherapy, and in peritoneal mesothelioma patients whose cancer returned after prior chemotherapy.

Patients receive one of four ascending doses of MCY-M11 — injected into the peritoneum once weekly for three weeks — to determine the treatment’s safety, which is the primary goal of the trial. Secondary measures include the proportion of patients responding MCY-M11 and immune responses.

“In recent years we have seen tremendous progress in the treatment of some types of cancer, but there remains a significant need to explore novel treatments that may benefit patients,” said Claudio Dansky Ullmann, MD, MaxCyte’s chief medical officer. “Individuals with advanced and relapsed ovarian cancer or peritoneal mesothelioma have limited effective therapeutic options today. MCY-M11 is an exciting new approach with the potential to improve outcomes for these patients. We look forward to the continued progress of this first clinical study.”