Marker Therapeutics announces presentation on Phase 1 APOLLO study

Marker Therapeutics reported that Geoffrey Shouse, D.O., Ph.D., the Principal Investigator at City of Hope National Medical Center in Duarte, CA, was invited to present his clinical experience from the APOLLO study at the 11th Global Summit on Hematologic Malignancies in Whistler, BC, Canada. Dr. Shouse provided an overview on the clinical observations obtained at City of Hope on Saturday, April 6, 2024. The Phase 1 APOLLO study is investigating MT-601, a multi-tumor associated antigen-specific T cell product, for the treatment of patients with lymphoma who have failed or are ineligible to receive anti-CD19 chimeric antigen receptor T cell therapy. Marker previously reported that the first study participant tolerated the treatment well and achieved a complete response eight weeks after the second infusion of MT-601, which was maintained at the six months follow-up visit. During the presentation, Dr. Shouse showed that this study participant remains in CR nine months following initial treatment with MT-601. This APOLLO participant had diffuse large B cell lymphoma and failed four prior lines of therapy, including anti-CD19 CAR T cell therapy. The participant relapsed within 90 days of CAR T cell therapy yet maintained a CR for at least nine months after treatment with MT-601, suggesting that response to MT-601 was more durable compared to CAR T cells in this study participant. Dr. Shouse’s presentation included data from two additional study participants that have been treated at City of Hope. One of the study participants had transformed follicular NHL and failed a total of 12 lines of therapy including mosunetuzumab for follicular NHL, and Yescarta after transformation into DLBCL. At the time of MT-601 administration, only follicular NHL persisted after the last treatment. Eight weeks after initial infusion with MT-601, this study participant achieved a CR and remains in CR three months following treatment with MT-601. The third patient treated at City of Hope as part of the APOLLO trial presented with DLBCL with cutaneous involvement only and was not eligible for CAR T cell therapy. When evaluated at eight weeks post-treatment, the study participant was in partial response with all lesions decreasing in size including one that has completely resolved. Dr. Shouse also reported that treatment was well tolerated among all patients with no significant treatment-related adverse events including no reports of cytokine release syndrome or immune-effector cell associated neurotoxicity syndrome, and that all patients will continue to be monitored closely for long-term treatment effects and durability of response. The therapeutic potential of MT-601 is further reinforced by non-clinical data demonstrating that MT-601 is able to eradicate lymphoma cells resistant to anti-CD19 CAR T cells.