Chimeric Antigen Receptor T Cell Therapy Redirected to CD4 (CD4CAR)as a Second Line Treatment for Chronic Myelomonocytic Leukemia, CMML.

The study will be performed as a dose-escalation protocol. Due to the relatively low incidence and prevalence of cluster of differentiation 4-positive (CD4+) hematological malignancies and the associated aggressive nature of these diseases and the sequel of treatment failure, the investigators expect to recruit 20 subjects at Indiana University with an expected dropout rate of 25% primarily due to rapid progression or death and screen and or manufacturing failure. Taking this into account, the investigators expect to treat 15 subjects. The study will utilize autologous CD4CAR T-cells that are engineered to express a chimeric antigen receptor (CAR) targeting CD4 that is linked to the cluster of differentiation 28 (CD28), 4-1BB, cluster of differentiation 3-zeta (CD3ζ) signaling chains (third generation CAR).

At entry, disease status will be staged. Qualifying subjects will be leukapheresed to obtain large numbers of peripheral blood mononuclear cells (PBMC) for the manufacturing. Next, participants will receive conditioning chemotherapy. If tumor burden is sufficiently reduced (screening step), participants will receive CD4CAR cells by infusion on Day 0 of treatment.

If the disease progresses during the manufacturing period participants may be excluded from the study. Minimal chemotherapy to keep the disease under control in the meanwhile is allowed if deemed necessary by investigators.

A single dose of CD4CAR transduced T cells will consist of the cell number for the dose level to be infused.

Post-infusion monitoring of CD4CAR T-cells: Subjects will have blood drawn for cytokine levels, CD4CAR Transgene Copy Number (PCR) and flow cytometry in order to evaluate the presence of CD4CAR cells on days 0, 1, 3, 5, 7, 14, and 28 following infusion (or as clinically needed). Cytokines levels will be evaluated per schedule above in addition to and as needed every 8 +/- 2 hours as feasible if/when CRS occurs and until resolution. Active monitoring of fungal and viral infections during treatment while utilizing standard prophylaxis recommended for HIV-positive subjects with T-cell aplasia and those undergoing allogeneic stem cell transplant. Investigators plan to collect data about clinicoradiologic measurements of residual tumor burden starting on day 7 and weekly afterward until Day 28 and then monthly for 6 months. This will be followed by quarterly clinical evaluations for the next two (2) years with a medical history, physical examination, and comprehensive blood testing. After these short- and intermediate-term evaluations are performed, these subjects will enter a rollover study to assess for disease-free survival (DFS), relapse, and the development of other health problems or malignancies where follow-up will be up to twice a year by phone and a questionnaire for an additional thirteen (13) years. The treating physician will decide to proceed with allogeneic or autologous transplant when needed.