• ≥ 18 years old at the time of informed consent

• Ability to provide written informed consent and HIPAA authorization

• Willingness to comply with all study procedures and be available for the duration of the trial

• Have a performance status of 0 to 2 on the ECOG Performance Scale.

• Life expectancy ≥12 weeks as per investigator discretion

• Patients with histologically proven, relapsed or refractory HL or B-NHL as follows:

∙ HL after failure of at least 1 prior line of systemic therapy

‣ Primary mediastinal large B-cell lymphoma (PMBCL) that is refractory to first-line therapy

‣ Other B-cell NHLs after failure of at least 2 prior lines of systemic therapy. The eligible types of B-cell NHLs are:

• i. Diffuse large B cell lymphoma ii. Follicular lymphoma iii. Marginal Zone lymphoma iv. Mantle Cell Lymphoma d. Indolent lymphoma are only eligible if they require systemic treatment e. Lymphocyte predominant HL are eligible Note: Formalin-fixed, paraffin embedded archival tumor sample from the primary cancer must be available for testing. If not available or sufficient, patients will be asked to undergo an US or CT guided biopsy prior to study entry to satisfy this eligibility criterion.

• Adequate hematologic and end organ function, defined by the following laboratory results obtained within 10 days prior to the first study treatment: Hematological Absolute neutrophil count (ANC) ≥1,500 /mcL Platelets ≥100,000 / mcL Hemoglobin ≥9 g/dL or ≥5.6 mmol/L without transfusion or EPO dependency (within 7 days of assessment) INR and aPTT ≤1.5 x ULN; this applies only to patients who are not receiving therapeutic anticoagulation; patients receiving therapeutic anticoagulation should be on a stable dose. Renal calculated creatinine clearance (GFR can also be used in place of creatinine or CrCl) calculated creatinine clearance ≥ 60 mL/min Hepatic Serum total bilirubin

‣ 1.5 X ULN OR Direct bilirubin ≤ ULN for subjects with total bilirubin levels \> 1.5 ULN (patients with known Gilbert disease who have bilirubin levels ≤ 3 x ULN may be enrolled). Patients must be able to undergo biliary stenting if required before or, if required, during the trial AST (SGOT) and ALT (SGPT) ≤ 2.5 X ULN OR

⁃ 5 X ULN for subjects with liver metastases Albumin \>2.5 mg/dL

• Female subject of childbearing potential should have a negative urine or serum pregnancy within 72 hours prior to receiving the first dose of study medication. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required. Note: Female of childbearing potential definition: (ECOG definition) Any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:

∙ Has not undergone a hysterectomy or bilateral oophorectomy; or

‣ Has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months).

• Female subjects of childbearing potential must be willing to use an adequate method of contraception for the course of the study through 120 days after the last dose of study medication.

• Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject.

• Refer to section 8.4.1 for more information.

⁃ Male subjects of childbearing potential must agree to use an adequate method of contraception of the protocol, starting with the first dose of study therapy through 120 days after the last dose of study therapy. Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject. Refer to section 8.4.1 for more information.

⁃ Acceptable methods of contraception include IUD, oral contraceptive, subdermal implant, and double barrier (condom with a contraceptive sponge or contraceptive pessary). Micro-dosed progesterone preparations (mini-pill) are an inadequate method of contraception during treatment with ATRA. If patients are taking this pill they should be instructed to stop, and another form of contraceptive should be prescribed instead.

⁃ Patients with a history of CAR-T cell therapy are eligible if ≥ 3 months post treatment.