Healthy-donor Microbiome MTP-101-C in Steroid Relapse/Refractory Immune-related Cutaneous Adverse Events (irCAEs) and Immune-mediated Colitis (IMC)

Eligibility Criteria

• * Able to swallow oral medication.
• * The participant provides written informed consent for the trial.
• * Willingness to use contraception for duration of trial participation. Male participants: A male participant must agree to use a contraception per protocol during the treatment period and for at least 120 days after the last dose of study treatment and refrain from donating sperm during this period.
• * Receipt of high-dose systemic corticosteroids defined as 1-2mg/kg prednisone equivalent daily (either oral or intravenous) with a taper over 4-6 weeks as defined by society consensus guidelines102-105; AND
• * No receipt of biologic such as but not limited to (dupilumab, rituximab) prior to enrollment.
• * NOTE: Patients must have received steroids to be eligible.
• * NOTE: Steroid "resistant" disease: patients whose symptoms responded (reduction in a CTCAE grade) initially but who developed recurrence upon steroid taper or discontinuation.
• * NOTE: Steroid "refractory" disease: patients whose symptoms have not clinically improved by a CTCAE grade in ≥48 hours or maximum of 14 days.
• * Receipt of high-dose systemic corticosteroids defined as 1-2mg/kg prednisone equivalent daily (either oral or intravenous) with a taper over 4-6 weeks as defined by society consensus guidelines102-105; AND
• * No receipt of biologic such as but not limited to (TNFα inhibitor infliximab OR α₄β₇ integrin inhibitor vedolizumab) prior to enrollment.
• * Patients must have received steroids to be eligible.
• * Steroid "resistant" disease: patients whose symptoms responded (reduction in a CTCAE grade) initially but who developed recurrence upon steroid taper or discontinuation.
• * Steroid "refractory" disease: patients whose symptoms have not clinically improved by a CTCAE grade in ≥48 hours or maximum of 14 days.
• * Patient may have received any number of lines of prior systemic therapy.
• * Patient with any solid tumor or hematologic malignancy are eligible.
• * Patient must not be receiving concurrent radiation therapy.
• * Willingness to undergo cohort-specific evaluation.
• * Cohort 1: Dermatologic evaluation, and skin biopsy evaluation prior to and after MTP-101-C administration.
• * Cohort 2: GI evaluation, and endoscopic evaluation including colonoscopies prior to and after MTP-101-C administration.
• * Willingness to undergo correlative blood and stool sampling.
• * Have an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2.
• * Patients with ECOG PS 2 wherein the decline in PS from baseline is deemed secondary to IMC may be enrolled at the discretion of Sponsor-Investigator.
• * Patients with ECOG PS 2 wherein PS is at baseline and deemed secondary to disease are excluded.
• * Have adequate organ function per specimens must be collected within 7 days prior to the start of study treatment.
• * Multiple irAEs besides irCAE or IMC.
• * Patients with concurrent ≥Grade 3 irAEs besides irCAE or IMC that necessitate systemic immune suppression are not candidates for this trial.
• * Patients with irCAE and/or IMC that are not otherwise clarified in Section 5.1.5 (irCAE including alopecia etc.) are not candidates for this trial.
• * Patients with concomitant irAEs that are well controlled (≤Grade 1 or Grade 2 on repletion medication) may be enrolled at the discretion of Sponsor-Investigator.
• * Diagnosis of immunodeficiency, immunosuppression or any other form of immunosuppressive therapy besides steroids/biologics within 7 days prior to the first dose of MTP-101-C treatment.
• * Patients at high risk of MDRO colonization including: nursing home residence, age \>85, underlying diseases (dementia, poorly controlled diabetes, chronic wounds), in-dwelling medical devices (urinary catheters, feeding tubes, PEG tubes) and a prior history of MDRO colonization.
• * Contraindication to endoscopy (cohort 2 only).
• * Contraindication to MTP-101-C administration.
• * Any prior head/neck and/or abdominal surgery resulting in potentially altered absorption of orally administered FMT pills.
• * Active bacterial infection requiring systemic antibiotic therapy.
• * Received live vaccines within 30 days prior to the first dose of study treatment and while participating in the study