A Study of MK-6194 (PT101) in Participants With Active Ulcerative Colitis (UC) (MK-6194-002)

The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of MK-6194 in participants with active UC.


Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of UC at least 3 months prior to screening.
* Mildly to severely active UC.
* Inadequate response, loss of response, or intolerance to at least 1 prior conventional therapy, and no more than 2 prior advanced therapies.
* Participants at risk for colorectal cancer must have a colonoscopy prior to or at screening as follows:

  * Participants \> 50 years of age must have documentation of a colonoscopy within 3 years of the screening visit to exclude adenomatous polyps. Participants whose adenomas have been completely excised at screening are eligible.
  * Participants with extensive colitis for ≥ 8 years, or disease limited to the left side of the colon for ≥ 10 years, must either have had a full colonoscopy to assess for the presence of dysplasia within 1 year before first administration of study drug or a full colonoscopy to assess for the presence of malignancy at the screening visit.
* No evidence of active tuberculosis (TB), latent TB, or inadequately treated TB.
* Women of childbearing potential (WOCBP) and males with female partners of childbearing potential must utilize highly effective contraceptive methods beginning 4 weeks prior to first dose of study drug and continue for 30 days after the last dose of study drug.
* Body mass index (BMI) 18 to 35 kg/m\^2 inclusive and weight ≥ 50 kg.

Exclusion Criteria:

* Prior treatment with recombinant IL-2 or modified IL-2 therapy, including MK-6194 (PT101).
* Known sensitivity to MK-6194 (PT101) or its excipients.
* Known history of hypersensitivity to interleukin-2 (IL-2).
* Disease limited to the rectum (i.e., within 15 cm of the anal verge).
* Diagnosis of toxic megacolon.
* Suspected or known colon stricture or stenosis.
* Diagnosis of Crohn's disease, or indeterminant colitis.
* Has severe colitis as evidenced by:

  * Current hospitalization for the treatment of UC
  * Likely to require a colectomy within 12 weeks of baseline in the opinion of the Investigator
  * At least 4 symptoms of severe colitis as identified at screening or baseline visits.
* Previously had surgery for UC, or likely to require surgery for UC during the study period in the opinion of the Investigator.
* History of abnormal thallium stress test or functional cardiac function test.
* History of significant cardiac, pulmonary, renal, hepatic, or central nervous system (CNS) impairment.
* Active clinically significant infection, or any infection requiring hospitalization or treatment with intravenous anti-infectives within 8 weeks of randomization, or any infection requiring oral anti-infective therapy within 6 weeks of randomization.
* History of opportunistic infection.
* History of symptomatic herpes zoster within 16 weeks of randomization, or any history of disseminated herpes simplex, disseminated herpes zoster, ophthalmic zoster, or central nervous system (CNS) zoster.
* Currently on any chronic systemic (oral or IV) anti-infective therapy for chronic infection (such as pneumocystis, cytomegalovirus, herpes zoster, or atypical mycobacteria).
* Currently receiving lymphocyte depleting therapy.
* History of abnormal pulmonary function tests.
* Participants with organ or tissue allograft.
* Malignancy within 5 years of screening, with the exception of adequately treated or excised non-metastatic basal cell or squamous cell cancer of the skin.
* Exposure to advanced therapy within 5 half-lives of the Day 1 visit, or documentation of detectable drug during screening.
* Received a live attenuated vaccine \< 1 month prior to screening or is planning to receive a live attenuated vaccine during the study period or within 12 weeks of the end of participation in the study.
* Is pregnant or nursing or is planning to become pregnant during the study.
* Any uncontrolled or clinically significant concurrent systemic disease other than UC.