Inclusion Criteria:

- Male and female subjects ≥ 18 years of age undergoing HSCT.

- Planning to undergo allogeneic hematopoietic stem cell transplantation from a human
leukocyte antigen matched sibling, haploidentical related donor, HLA-matched unrelated
donor, or HLA 1-antigen mismatched unrelated donor, with either bone marrow or
peripheral blood stem cells as a graft source, and with any conditioning regimen

Exclusion Criteria:

- Severe colitis of any etiology or active/currently-treated inflammatory bowel disease
(IBD) or total colectomy.

- Evidence of relapse or progression of hematologic malignancy (minimal residual disease
is allowed).

- Transplant using umbilical cord blood or ex vivo T-cell-depleted HSCT

- Receipt of chimeric antigen receptor T-cell (CAR-T) therapy.

- Received a fecal microbiota transplant (FMT) or any live microbial therapeutic within
3 months prior to Screening.

- Known allergy or intolerance to oral vancomycin.

- Concomitant participation or participation within 14 days or 5 half-lives of another
investigational unapproved treatment, whichever is longer.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Eligibility last updated12/22/22. Questions regarding updates should be directed to the study team contact.