Allogeneic Hematopoietic Cell Transplantation From HLA-matched Donor After Flu-Mel-PTCy Versus Flu-Mel-ATG Reduced-intensity Conditioning

This study is testing a type of bone marrow transplant from a matched donor using a reduced-intensity (gentler) pre-transplant conditioning approach, for older patients or those who are too sick for a full-strength transplant — to treat a range of blood cancers and bone marrow disorders. **You may be eligible if...** - You have been diagnosed with a blood cancer or bone marrow disorder such as leukemia (AML, ALL, CML), MDS, lymphoma (Hodgkin's or non-Hodgkin's), multiple myeloma, CLL, or a related condition - You need a bone marrow transplant but are not a candidate for a full-strength (standard) transplant because of your age (over 50), organ function, or your doctor's assessment - You are between 18 and 75 years old - You have a suitable matched donor available - You have given informed consent **You may NOT be eligible if...** - You are under 18 years old - You do not have a suitable matched donor - Your disease is rapidly progressing and requires urgent treatment not compatible with the transplant protocol - You have significant health conditions that prevent safe participation Talk to your doctor to see if this trial is right for you.