This study is designed as a single arm open label traditional Phase I, 3+3, study of CD4-directed chimeric antigen receptor engineered T-cells (CD4CAR) in subjects with relapsed or refractory CMML. Specifically, the study will evaluate the safety and feasibility of CD4CAR T-cells.

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.

Dose of CD4CAR description: the main objective of this study is to establish a recommended dose and/or schedule of CD4CAR. The guiding principle for dose escalation in phase I is to avoid unnecessary exposure of subjects to sub-therapeutic doses (i.e., to treat as many subjects as possible within the therapeutic dose range) while preserving safety and maintaining rapid accrual. Investigators will use the rule-based traditional Phase I "3+3" design for the evaluation of safety. Based on lab experience in mice the starting dose (dose level 1) for the first cohort of three subjects in phase I portion of the study will be 8x10^5 cells. The dose escalation or de-escalation will follow a modified Fibonacci sequence as below.

If more than one subject out of the first cohort of three subjects in dose level 1 experience dose limiting toxicity (DLT), the trial will be placed on hold. If zero or one out of three subjects in the first cohort of dose level 1 experience DLT, three more subjects will be enrolled at dose level 1; the dose escalation continues until at least two subjects among a cohort of six subjects experience DLT (i.e., ≥33% of subjects with a DLT at this dose level)

If one of the first three subjects in dose level 1 experiences a DLT, three more subjects will be treated at dose level 1.

If none of the three subjects or only one of the 6 subjects in the dose level 1 experiences a DLT, the dose escalation continues to the dose level 2 If one of the first three subjects in dose level 2 experience a DLT, three more subjects will be treated at dose level 2 If none of the three subjects or only one of the 6 subjects in the dose level2 experiences a DLT, the dose escalation continues to the dose level 3 If one of the first three subjects in dose level 3 experiences a DLT, three more subjects will be treated at dose level 3 If none of the three subjects or only one of the 6 subjects in the dose level 3 experiences a DLT, dose level 3 will be declared the maximum tolerated dose (MTD) and will be used as the recommended phase II dose (RP2D) for the phase II portion of the study.

In summary, the dose escalation continues until at least two subjects among a cohort of six subjects experience DLT (i.e., ≥33% of subjects with a DLT at that dose level). The recommended dose for phase II trials is defined as one dose level below this toxic dose level. Since some grade 3 and possibly 4 toxicities are highly likely to be reversible, grade 3 infectious, hematological and vascular toxicities will not be considered DLTs mandating dose reduction. Also allergic or infusion-related reactions ≤ grade 3 will not be counted as DLTs. There will be no intra-subject dose escalation or reduction.

To allow for full spectrum toxicity duration evaluation and reporting, no subjects within the same or a different cohort will be initiated on lymphodepleting chemotherapy sooner than 28 days from the initiation date of the preceding subject.

Inclusion Criteria:

1. ≥ 18 years old at the time of informed consent
2. Ability to provide written informed consent and HIPAA authorization
3. Diagnosis of CMML that is CD4+ and is recurrent or refractory to first line standard of care treatment.
4. Creatinine clearance of ≥ 60 ml/min (or otherwise non clinically significant, per study investigator)
5. ALT/AST < 3 x ULN
6. Bilirubin < 2 x ULN
7. No supplemental oxygen at rest Note: Pulmonary Function Test (PFT) only required per treating physician discretion.
8. Adequate cardiac function with EF of ≥50%. This will not have to be repeated if within 45 days of initial assessment
9. Adequate venous access for apheresis and no other contraindications for leukapheresis

Exclusion Criteria:

1. CD4 negative CMML

2. Pregnant or lactating women. The safety of this therapy on unborn children is not known. Female study participants of reproductive potential (see definition below) must have a negative serum or urine pregnancy test prior to initiation of conditioning chemotherapy, per research sites' clinical policy

3. Uncontrolled active infection necessitating systemic therapy

4. Active hepatitis B or hepatitis C infection. Active hepatitis C is defined as the hepatitis C antibody is positive while quantitative HCV RNA results exceed the lower detection limit

   Note the following subjects will be eligible:

   • Subjects with a history of hepatitis B but have received antiviral therapy and have non-detectable viral DNA for 6 months prior to enrollment are eligible
   • Subjects seropositive for HBS antibodies due to hepatitis B virus vaccine with no signs or active infection (Negative HBs Ag, HBc and HBe Ags) are eligible
   • Subjects who had hepatitis C but have received antiviral therapy and show no detectable hepatitis C virus (HCV) viral RNA for 6 months are eligible
   • If hepatitis C antibody test is positive, then patients must be tested for the presence of antigen by reverse transcription-polymerase chain reaction (RT-PCR) and be hepatitis C virus ribonucleic acid (HCV RNA) negative

5. Concurrent use of systemic glucocorticoids in greater than replacement doses or steroid dependency defined in rheumatological and pulmonary diseases as uninterrupted corticosteroid intake for more than a year at a dosage of 0.3 mg/kg/day or greater, and where the underlying disease worsens on temporary stoppage of steroid therapy, with symptoms of steroids withdrawal (eg, lethargy, headache, weakness, pseudo rheumatism, emotional disturbances, etc) precipitated by the temporary stoppage unless tapering can occur safely without compromising the underlying disease, the withdrawal tolerance and can happen in a timeframe appropriate to enroll in this trial without safety concerns

   Subjects who receive daily corticosteroids in replacement doses can be included in the study. The replacement doses are defined as following:

   1. Hydrocortisone 25mg/day or less
   2. Prednisone 10mg/day or less
   3. Dexamethasone 4mg or less - Note: Recent or current use of inhaled glucocorticoids is not exclusionary, as this route pertains extremely minimal systemic penetration

6. Any uncontrolled active medical disorder that would preclude participation as outlined in the opinion of the treating investigator and/or Principal Investigator

7. HIV infection

8. Subjects who have received or will receive live vaccines within 30 days before the first experimental cell treatment. Inactivated seasonal flu vaccination is allowed

9. Subjects with active autoimmune diseases who need systematic treatments (such as disease modifying agents, corticosteroids and immunosuppressive drugs) during the last year Note: Replacement therapy (thyroxine, insulin or physiological corticosteroid replacement therapy (up to10 mg of oral daily prednisone or equivalent in hydrocortisone and dexamethasone) to treat adrenal dysfunction or pituitary dysfunction) is not considered as systematic therapy. Subjects who need inhalation corticosteroid therapy can be included in this trial. Subjects with vitiligo or in long-term remission of pediatric asthma or allergic diseases can be included in this trial

10. Subjects with a history of mental disorders or drug abuse that may influence treatment compliance

11. Active malignancy not related to CMML that has required therapy in the last 3 years or is not in complete remission. Exceptions to this criterion include successfully treated non-metastatic basal cell or squamous cell skin carcinoma, or prostate cancer that does not require therapy. Other similar malignant conditions may be discussed with and permitted by the Principal Investigator CMML patients who transformed into AML and who were treated back into CMML status are eligible. CMML patients who transformed into AML and appropriate AML treatment was unsuccessful in reverting their disease back to CMML status will be treated as AML patients and are not eligible for the CMML study.

12. Treatment with any investigational cell/gene therapy within the past 6 months

13. Treatment with any investigational anticancer agent within the last 14 days of study entry or 5 half-lives (whichever is shorter)

Eligibility for Conditioning Chemotherapy:

1. Specific organ function criteria for cardiac, renal, and liver function must be similar to initial inclusion values
2. Review of co-morbidities to confirm no major changes in health status (examples of major changes include heart attack, stroke, and any major trauma)
3. Planned infusion dose was successfully manufactured and met release criteria
4. Negative pregnancy testing (if applicable)

Eligibility for cd4CAR Infusion Inclusion

1. Afebrile and not receiving antipyretics, and no evidence of active infection. If fever is attributed to underlying disease, it will not disqualify.
2. Specific organ function criteria for cardiac, renal, and liver function must be similar to initial inclusion values. The following test does not need repeated: EF if within 6 weeks of initial assessment.
3. If previous history of corticosteroid chemotherapy, subject must be off all but adrenal replacement doses 3 days before the CD4CAR infusion

Exclusion

Note: A subject may still receive the CD4CAR infusion up to 10 days post conditioning chemotherapy as long as they do not meet any of the following at time of infusion:

1. Requirement for supplemental oxygen to keep saturation greater than 95% or presence of radiographic abnormalities on a clinically indicated chest x-ray that are progressive.
2. New cardiac arrhythmia not controlled with medical management.
3. Hypotension requiring pressor support.
4. Positive blood cultures for bacteria, fungus, or virus within 48-hours of T cell infusion.

Contraception and Reproductive Potential Guidelines

Female subjects of reproductive potential (women who have reached menarche or women who have not been post-menopausal for at least 24 consecutive months, i.e., who have had menses within the preceding 24 months, or have not undergone a sterilization procedure [hysterectomy or bilateral oophorectomy]) must have a negative serum or urine pregnancy test prior to conditioning chemotherapy.

Due to the high-risk level of this study, while enrolled, all subjects must agree not to participate in a conception process (e.g., active attempt to become pregnant or to impregnate, sperm donation, in vitro fertilization). Additionally, if participating in sexual activity that could lead to pregnancy, the study subject must agree to use reliable and double barrier methods of contraception from time of consent through at least 90 days after CD4CAR infusion.

Acceptable birth control includes a combination of two of the following methods:

• Condoms (male or female) with or without a spermicidal agent.
• Diaphragm or cervical cap with spermicide
• Intrauterine device (IUD)
• Hormonal-based contraception

Subjects who are not of reproductive potential (women who have been post-menopausal for at least 24 consecutive months or have undergone hysterectomy, salpingotomy, and/or bilateral oophorectomy or men who have documented azoospermia) are eligible without requiring the use of contraception. Acceptable documentation of sterilization, azoospermia, and menopause is specified next:

Written or oral documentation communicated by clinician or clinician's staff of one of the following:

• Physician report/letter
• Operative report or other source documentation in the subject record (a laboratory report of azoospermia is required to document successful vasectomy)
• Discharge summary
• Laboratory report of azoospermia
• Follicle stimulating hormone measurement elevated into the menopausal range