The study was withdrawn due to not being able to recruit subjects.

The purpose of the study is to evaluate the PK, safety and tolerability of PF-06687234 and [124I]IB-PF-06687234 (simultaneously given) in subjects with moderate to severe Ulcerative Colitis or Crohn's Disease. The study used PET-CT scan imaging to assess the distribution of PF-06687234 and [124I]IB-PF-06687234 over 24 and 72 hours in colon (inflamed and non-inflamed), plasma, colon, liver, spleen, kidney and small intestine.

Inclusion Criteria:

• Male and/or female subjects of non-child bearing potential, 18 years to 75 years of age inclusive at the time of informed consent
• Only women of non-child bearing potential
• Diagnosis of active UC (histologic) or CD prior to study entry for a minimum of 4 months
• Subjects with moderate to severe, active UC as defined by Mayo endoscopic index of at least 2; or subjects with moderate to severe, active CD as defined by SES-CD score of at least 7.

Exclusion Criteria:

• Clinically significant/unstable clinical conditions (eg. cancer hematological, endocrine etc)
• Active enteric infections
• Other forms of colitis such as infectious colitis etc

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.