Familial adenomatous polyposis (FAP) is the most common polyposis syndrome. It is an autosomal dominant inherited disorder characterized by the early onset of hundreds to thousands of adenomatous polyps throughout the colon. JNJ-64251330 (lorpucitinib) is an oral, small molecule, potent pan-janus kinase (JAK) inhibitor that blocks phosphorylation of Signal Transducer and Activator of Transcription (STAT) proteins. pSTAT induces transcription of multiple genes involved in the progression of inflammatory disease. JNJ-64251330 has chemical properties that limits the amount of drug in the blood while delivering the drug to the tissues of the gut. Local inhibition of JAK in the gut may present a promising method to treat inflammatory diseases of the intestinal tract, such as FAP. The study consists of 3 phases: screening phase (30 days) a treatment phase (24 weeks), and follow-up visit (up to 30 days after last dose of study drug). The total duration of the study will be up to 32 weeks. Study evaluations will include efficacy via endoscopies, safety (monitoring of adverse events (AE), serious adverse events (SAEs), events of infections including tuberculosis (TB), clinical laboratory blood tests (complete blood count and serum chemistries), vital signs, and concomitant medication review), pharmacokinetics, pharmacodynamic and biomarkers evaluations.
The purpose of this study is to determine the effect of JNJ-64251330 in participants with Familial Adenomatous Polyposis (FAP) on colorectal polyp burden (sum of the polyp diameters).