Philadelphia chromosome positive chronic myeloid leukemia in blast crisis

The goal of this clinical trial is to test the ability to restore gut microbiota to healthier levels in patients with blood cancers scheduled to have stem cell transplant.
The main questions it aims to answer are:
* Tolerability and acceptability of intestinal microbiota transplantation (IMT) versus placebo (as assessed via patient perspective questionnaires
* Changes in gut microbiome diversity across all timepoints
* Markers of general health, infective/microbiological and haematological outcomes including, days of fever, admission to intensive care unit, survival, non-relapsed mortality, and incidence of graft-versus-host disease across all time points measured.
Participants will be asked at their routine follow up visits to,
* Provide stool, urine and blood samples at the scheduled study visits
* Complete questionnaires at selected visits
* Swallow either Placebo or IMT capsules once at the second study visit which will occur 2 weeks prior to the stem cell transplant (+/-3 days)
Researchers will compare IMT capsules and Placebo to investigate the change in gut microbiota diversity.

This phase II trial investigates two strategies and how well they work for the reduction of graft versus host disease in patients with acute leukemia or MDS in remission. Giving chemotherapy and total-body irradiation before a donor peripheral blood stem cell transplant helps stop the growth of cells in the bone marrow, including normal blood-forming cells (stem cells) and cancer cells. It may also stop the patient's immune system from rejecting the donor's stem cells. When the healthy stem cells from a donor are infused into the patient, they may help the patient's bone marrow make stem cells, red blood cells, white blood cells, and platelets. The donated stem cells may also replace the patient's immune cells and help destroy any remaining cancer cells.

This study evaluates the use of ETC-1907206 in combination with dasatinib in certain types of blood cancers. The first phase of the study (1A) is designed to find the highest tolerated dose of ETC-1907206, while the second phase (1B) will assess the safety and tolerability of the recommended dose of ETC-1907206. ETC-1907206 has been designed to block the activity of an enzyme of the body known as Mnk kinase, which is thought to be involved in the development of a variety of cancers.