A phase 1, first-in-human study of autologous monocytes engineered to express an anti-HER2 chimeric antigen receptor (CAR) in participants with HER2-overexpressing solid tumors.

Yara Abdou The University of North Carolina at Chapel Hill, Chapel Hill, NC info_outline Yara Abdou, Paula R Pohlmann, Richard T. Maziarz, Hemant S. Murthy, Yuan Yuan, Anuradha Krishnamurthy, Kim Anna Reiss, James Isaacs, Daniel Blumenthal, Linara Gabitova, Brett Menchel, Kenneth Locke, Jeanette Wetzel, Michael Klichinsky, Daniel Cushing, Thomas Condamine, Davendra Sohal

Authors Yara Abdou The University of North Carolina at Chapel Hill, Chapel Hill, NC info_outline Yara Abdou, Paula R Pohlmann, Richard T. Maziarz, Hemant S. Murthy, Yuan Yuan, Anuradha Krishnamurthy, Kim Anna Reiss, James Isaacs, Daniel Blumenthal, Linara Gabitova, Brett Menchel, Kenneth Locke, Jeanette Wetzel, Michael Klichinsky, Daniel Cushing, Thomas Condamine, Davendra Sohal Organizations The University of North Carolina at Chapel Hill, Chapel Hill, NC, The University of Texas MD Anderson Cancer Center, Houston, TX, Oregon Health & Science University, Portland, OR, Mayo Clinic Florida, Jacksonville, FL, Cedars-Sinai Medical Center, Los Angeles, CA, Roswell Park Comprehensive Cancer Center, Buffalo, NY, University of Pennsylvania, Philadelphia, PA, Cleveland Clinic, Cleveland, OH, Carisma Therapeutics, Philadelphia, PA, Division of Hematology/Oncology, University of Cincinnati Cancer Center, Cincinnati, OH Abstract Disclosures Research Funding No funding sources reported Background: Myeloid cells are actively recruited to the solid tumor microenvironment (TME) and have the potential to mediate tumor control via phagocytosis, TME remodeling, and T cell activation. We previously developed human chimeric antigen receptor macrophages (CAR-M) and have shown potent anti-tumor activity in pre-clinical solid tumor models. The anti-HER2 CAR-M cell therapy product, CT-0508, is currently being evaluated in a Phase I trial as a monotherapy and in combination with pembrolizumab. Early clinical data have shown feasibility, safety, and validated the mechanism of action. We have developed a next-generation CAR monocyte (CAR-Mono) platform to increase the dose, improve tumor trafficking and engraftment, and shorten the manufacturing and vein-to-vein time as compared to CAR-M therapy. CT-0525 is an autologous anti-HER2 CAR-Mono cell therapy based on CD14+ monocytes engineered with an Ad5f35 adenoviral vector to express an anti-HER2 CAR. Pre-clinical studies have demonstrated the feasibility, phenotype, pharmacokinetics, durable CAR expression, cellular fate, antigen specificity, and anti-tumor activity of CT-0525. Pre-clinical studies have shown that CT-0525 differentiated into pro-inflammatory CAR-M in vivo and controlled tumor growth. The CT-0525 manufacturing process takes one day and enables the production of up to 10 billion cells from a single apheresis. CT-0525 is being investigated in a first-in-human, open-label, multi-center, Phase I study in patients with HER2 overexpressing solid tumors. Methods: This Phase 1, first-in-human study evaluates the feasibility, safety, tolerability, trafficking, TME activation, and preliminary evidence of efficacy of the investigational CAR-Mono product CT-0525 in 6 participants (pts) with locally advanced unresectable/metastatic solid tumors overexpressing HER2. Pts previously treated with anti-HER2 therapies are eligible. Filgrastim mobilized autologous CD14+ monocytes are collected by apheresis, followed by manufacturing and cryopreservation. The 1 st cohort of pts (n=3) will receive 3 x 10 9 CT-0525 CAR positive monocytes administered IV in one infusion. If tolerated as per the modified toxicity probability interval algorithm (mTPI), the 2 nd cohort of pts (n=3) will receive up to 10 x 10 9 CT-0525 CAR positive monocytes in one infusion. CT-0525 will be administered without conditioning chemotherapy. Primary endpoints include assessment of safety and tolerability, as well as manufacture feasibility. Correlative assessments include pre- and post-treatment biopsies and blood samples for safety, immunogenicity, pharmacokinetics, tumor trafficking, TME modulation, epitope spreading, and other translational biomarkers. Clinical trial information: NCT06254807.

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