The study will evaluate the safety and early efficacy of administering the combination of a commercially available potato-based resistant starch along with iron chelation therapy to subjects undergoing alloHCT.

The deferasirox intervention will begin one week prior to the RPS (Resistant Potato Starch) conditioning phase and both will continue through day +100. The study hypothesis is that a short-term administration of a resistant starch and iron chelation therapy will be capable of both increasing levels of butyrate within the intestine and restoring physiological hypoxia in the intestines, which together will reduce rates of acute GVHD (Graft versus Host Disease) and improve the clinically meaningful outcome of GRFS (Graft versus Host Disease / Relapse-Free Survival) at 12 months post-transplant.

21NOV2025- The grant previously listed on this trial is associated with the conduct of a preliminary study NCT02763033. Therefore, it was removed from this clinical trial as it is not being used for the conduct of this study.

Inclusion Criteria:

• Patients with hematologic disorders undergoing allo-HCT from fully HLA-matched unrelated or related donors after full-intensity conditioning regimen
• Age ≥18 years
• Karnofsky performance status >70%, see Appendix A
• Patients must be able to swallow capsules/tablets
• Ability to understand and the willingness to sign a written informed consent
• Availability of a full-HLA matched related or unrelated donor who is medically eligible to donate cells according to the National Marrow Donor Program criteria

Exclusion Criteria:

• Patients with active inflammatory bowel disease requiring treatment per treating investigator
• Patients with a history of gastric bypass surgery
• Patients with active Clostridium difficile infection at the time of study enrollment. Active infection is defined as a stool sample positive for Clostridium difficile toxin via enzyme immunoassay (EIA) and either symptoms (frequent loose stools) OR imaging findings consistent with toxic megacolon
• Patients with active iron deficiency anemia requiring treatment
• Patients with iron overload receiving active treatment with deferasirox
• Known hypersensitivity to deferasirox or any component of Jadenu or Exjade
• Patients actively enrolled on treatment or in follow up phase on any other GVHD prevention trial
• Any physical or psychological condition that, in the opinion of the investigator, would pose an unacceptable risk to the patient or raise concern that the patient would not comply with protocol procedures