Inclusion Criteria: 

• Is able to understand and voluntarily sign a written informed consent and is willing and able to comply with the protocol requirements including scheduled visits, treatment plan, laboratory tests and other study procedures.
• Is aged ≥ 18 years.
• Has documented diagnosis of symptomatic primary MF, PPV-MF or PET-MF as defined by the World Health Organization classification.
• Is ineligible or unwilling to undergo stem cell transplantation at time of study entry.
• Is refusing, ineligible for, intolerant of, or not adequately responding to approved therapies for myelofibrosis.
• Has laboratory function within specified parameters per local laboratory (may be repeated):
  • Absolute neutrophil count (ANC) ≥ 100/μL;
  • Platelets ≥ 20,000/mL;
  • Hemoglobin ≥ 8.0 g/dL;
  • Transaminases (AST/ALT) and alkaline phosphatase ≤ 3 x ULN;
  • Bilirubin ≤ 1.5 x ULN (unless patient has Gilbert’s Syndrome);
  • Serum amylase and lipase ≤ 1.5 x ULN.
• Has adequate performance status (PS):
  • Eastern Co-operative Oncology Group (ECOG) PS 0-3.
• Has received the final dose of any of the following treatments/procedures with the specified minimum intervals before first dose of 9-ING-41 (unless in the opinion of the investigator and the study medical coordinator the treatments/procedures will not compromise patient safety or interfere with study conduct:
  • Chemotherapy, immunotherapy, or systemic radiation therapy - 14 days maximum, or ≥ 5 half-lives (whichever is shorter);
  • Surgery with general anesthesia – 7 days.
• Patients who are to receive 9-ING-41 plus Ruxolitinib must have attempted ≥18 weeks of Ruxolitinib therapy and required dose reductions/interruptions and/or had an inadequate response.
• Women of childbearing potential must have a negative baseline blood or urine pregnancy test within 72 hours of first study therapy. Women may be neither breastfeeding nor intending to become pregnant during study participation and must agree to use effective contraceptive methods (hormonal or barrier method of birth control, or true abstinence) for the duration of study participation and in the following 100 days after discontinuation of study treatment.
• Male patients with partners of childbearing potential must take appropriate precautions to avoid fathering a child from screening until 100 days after discontinuation of study treatment and use appropriate barrier contraception or true abstinence.
• Must not be receiving any other investigational product.

Exclusion Criteria: 

• Is pregnant or lactating.
• Is known to be hypersensitive to any of the components of 9-ING-41 or to the excipients used in its formulation.
• Has had a myocardial infarction within 12 weeks of the first dose of 9-ING-41.
• Has any medical and/or social condition which, in the opinion of the investigator or study medical coordinator would preclude study participation.
• Is considered to be a member of a vulnerable population (for example, prisoners).
• Herbal preparations / medications are prohibited throughout the study. These herbal medications include, but are not limited to St. John’s wort, Kava, ephedra (ma huang), Gingko biloba, dehydroepiandrosterone (DHEA), yohimbe, saw palmetto, and Ginseng. Patients should stop using cannabinoids or herbal preparations/medications at least 7 days prior to first dose of study treatment.