Tomivosertib in Relapsed or Refractory Acute Myeloid Leukemia (AML)

Inclusion Criteria:

* Patients age \>= 18 years
* Patients with relapsed/refractory AML (based on the International Consensus Classification of Myeloid Neoplasms and Acute Leukemias

Previous treatment must consist of:

1. At least 1 cycle of therapy with an anthracycline and standard dose cytarabine containing regimen; OR
2. At least one cycle of a high- or intermediate-dose cytarabine containing regimen; OR
3. At least 4 cycles of hypomethylating agent (HMA) as single agent or 2 cycles of HMA and venetoclax; OR
4. Allogeneic stem cell transplant (SCT) for either AML or high-risk MDS and have recovered from all transplant-related toxicities, are off all immunosuppression for at least 6 weeks, and have no evidence of acute or chronic graft-versus-host disease GvHD); OR
5. Relapsed or refractory disease without established alternative therapy.

   * For patients with a known history of human immunodeficiency virus (HIV), infected patients on effective anti-retroviral therapy must have a viral load undetectable for 6 months prior to registration.
   * For patients with a known history of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated.
   * Patients with a known history of hepatitis C virus (HCV) infection must have been treated and cured. For patients with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load.
   * Patients must agree to serial bone marrow aspirate/biopsies
   * The effects of tomivosertib on the developing human fetus are unknown. For these reasons, patients of child-bearing potential (POCBP) must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) and refrain from donating eggs from the time of informed consent, for the duration of study treatment, and for 30 days following completion of study therapy. Should a patient become pregnant or suspect they are pregnant while they or their partner are participating in this study, they should inform their treating physician immediately.

People with sperm-producing reproductive capacity treated or enrolled on this protocol must also agree to use adequate contraception (or abstinence or vasectomy) and refrain from donating sperm from the time of informed consent, for the duration of study therapy, and 30 days after completion of study therapy.

NOTE: A POCBP is any person with an egg-producing reproductive tract (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
* Has had menses at any time in the preceding 12 consecutive months (and therefore has not been naturally postmenopausal for \> 12 months)
* POCBP (defined in 3.1.7) must have a negative serum β-subunit of human chorionic gonadotropin (β-hCG) pregnancy test (sensitivity of at least 25 mIU/mL) within 14 days prior to registration on study and have a negative serum β-hCG pregnancy test (sensitivity of at least 25 mIU/mL) within 72 hours prior to the start of study treatment.

NOTE: The screening serum pregnancy test can be used as the test prior to the start of study treatment if it is performed within the 72-hour timeframe.

\- Patients must provide written, signed, and dated informed consent prior to study registration. Patient must have the ability to understand and the willingness to sign a written informed consent document. The patient must be willing and able to comply with the protocol for the duration of the study. NOTE: No study-specific screening procedures may be performed until written consent has been obtained

Exclusion Criteria:

* Patients who are receiving any other investigational agents
* Previous chemotherapy including biologic/targeted therapy or immunological agents for AML within 14 days prior to start of tomivosertib..
* Patients who have a prior or concurrent malignancy that may interfere with study treatment or safety. NOTE: Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen (i.e., cancers under observation that do not require treatment, resectable skin cancer, low risk prostate cancer, DCIS, LCIS, etc.) are eligible per lead PI discretion. Patients with prior MDS or MPN are eligible.
* Patients who have conditions that would interfere with drug absorption
* Patients who have conditions that would interfere with their ability to swallow oral medications
* Patients who have a history of allergic reactions attributed to compounds of similar chemical or biologic composition to tomivosertib, azacitidine, and/or venetoclax
* Patients who have an uncontrolled intercurrent illness including, but not limited to any of the following, are not eligible:

  * Uncontrolled systemic infection (defined as ongoing signs/symptoms related to the infection without improvement despite appropriate antibiotics, antiviral therapy, antifungal therapy and/or other treatment)
  * Unstable angina pectoris
  * Cardiac ventricular arrhythmia, except for patients that can be successfully treated with rate control or anti-arrhythmic agents
  * Psychiatric illness/social situations that would limit compliance with study requirements
  * Any other illness or condition that the treating investigator feels would interfere with study compliance or would compromise the patient's safety or study endpoints
* Patients who are pregnant or nursing.