Humanized CD19 CAR T-Cell Therapy Shows Early Promise as Treatment of Hematologic Malignancies

An investigator-initiated trial (NCT04008251) of ProMab Biotechnology’s humanized CD19-directed chimeric antigen receptor (CAR) T-cell therapy has been completed, demonstrating the therapy may be a safe and effective treatment for patients with hematologic malignancies.

This study, which was conducted at Union Hospital at the Tongji Medical College in the Huazhong University of Science and Technology, was led by professors Hu Yu and Mei Heng in collaboration with Wuhan Sian Medical Technology with the ProMab humanized CD19 CAR T-cell therapy. Ten patients with relapsed/refractory CD19-positive B-cell malignant hematological tumors, which included acute lymphoblastic leukemia and chronic lymphocytic leukemia, and non-Hodgkin lymphoma.

Seven of the 10 patients were in a continuous remission on the study, and the longest continuous remission was 9 months. Cytokine release syndrome (CRS), which is a common toxicity concern with CAR T cells, was significantly reduced with the humanized CD19 CAR T-cell therapy. Five patients experienced level 1 CRS, and 4 patients did not have CRS at all.

These results show that the humanized CD19-directed CAR T-cell therapy is a safe and effective treatment, and the complete remission rate was greatly improved with this product compared with the mouse version of CD19 CAR T cells.

“In our clinical study of 10 patients with hematological tumors who had experienced other treatment failures, ProMab helped 70% [7 out of 10] of patients achieve complete remission,” said John Wu, president and chief executive officer, ProMab, in a statement. “We are aiming to provide patients with alternative means to treat their hematological tumors and save more lives. ProMab’s CAR-T/natural killer (NK) cell technology platforms can meet that goal.”

The humanized CD19 CAR T-cell therapy has been approved as treatment of adults with relapsed/refractory hematological tumors. CAR T cells can be given to an individual in order to enhance the immune system to recognize and destroy cancer cells. This helps to give the patient a better chance at fighting the cancer when it returns or resists other treatments.

For this study, the primary end point was number of participants with adverse events, and secondary end points included 1-month remission rate, overall survival, event-free survival, relapse-free survival, rate of anti-CD19 CAR T cells in bone marrow and peripheral blood cells, quantity of anti-CD19 CAR T cells in the bone marrow and peripheral blood cells, and quantity of anti-CD19 CAR copies in bone marrow and peripheral blood cells.

To be included in the study, patients had to have a pathologically and histologically confirmed CD19-positive B-cell tumor with no effective alternative treatment options currently available. Patients had to have either a B-cell acute lymphocytic leukemia, indolent B-cell lymphoma, and aggressive B-cell lymphoma, be 14 to 70 years old, and have an expected survival time of > 6 months.

Patients were ineligible to be included in the trial if they had a history of epilepsy or other central nervous system disease, graft-versus-host reaction requiring immunosuppressants, clinically significant cardiovascular disease, an incurable active infection, hepatitis B or C virus, or combined use of systemic steroids within 2 weeks.

The study investigators designed this trial to determine the safety and effectiveness of the humanized CD19 CAR T cells as treatment of patients with relapsed/refractory B cell malignancies. These cells have the capabilities to recognize tumor-associated antigens and kill tumor cells specifically, and they have shown a great effect on this particular patient population in previous studies.

“Our study with humanized CD19 CAR-T cells for the treatment of relapsed and refractory hematological tumors have demonstrated hope for patients and the future of CAR-T technology,” stated Wu.

_Reference

_{ProMab Presents Promising Results in Humanized CD19 CAR-T Cells Trial. News Release. July 27, 2020. Accessed August 18, 2020. https://bwnews.pr/2Yf8iZX}