Sponsor business decision to terminate the study early

This is a Phase 2a, open-label, multicenter study to evaluate the safety and efficacy of HMO (PBCLN-010) and B. infantis (PBCLN-014) on the gut microbiome and GI domination by pathobionts in participants receiving allo-HCT.

Approximately 60 participants will be enrolled in this study, and all participants will undergo screening assessments up to 28 days before the first study drug dose (D 7). Participants meeting all the eligibility criteria based on the screening assessments will be enrolled and randomly assigned to 1 of the 3 cohorts:

• Cohort A (HMO 9.0 g and B. infantis) BID
• Cohort B (HMO 4.5 g and B. infantis) BID
• Cohort C (Control Cohort): Participants in this cohort will not receive any study drug.

Inclusion Criteria:

1. Signed informed consent prior to initiation of any study-specific procedure or treatment.
2. Male and female participants 18 to 75 years of age at the time of informed consent.
3. Planning to receive a first allo-HCT.
4. Able to comply with protocol requirements.

Exclusion Criteria:

1. Participants with prior bowel resection resulting in colostomy
2. Serious medical or psychiatric illness likely to interfere with participation in study.
3. History or presence, upon clinical evaluation, of any illness that, in the opinion of the Investigator, would interfere with the ability to provide informed consent or comply with study instructions.
4. Female participants who are pregnant, breastfeeding, lactating, or planning to become pregnant during the study.

To be determined

To be determined

To be determined

Unblinded