{
  "abstract": "Cyclin-dependent kinase 4/6 inhibitors (CDK4/6Is), including ribociclib, are used alongside endocrine therapy for hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative metastatic breast cancer. Ribociclib-induced colitis is a rare drug reaction with unknown incidence, lack of discovery in clinical trials, and only one other published case. We describe a case of ribociclib-induced colitis and subsequent management. A female with metastatic HR+ breast cancer in her 60s was prescribed letrozole and ribociclib. She developed acute diarrhea, and a surveillance CT demonstrated pan-colitis. After discontinuing ribociclib and completing steroids, the diarrhea resolved. Palbociclib, an alternative CDK4/6I, was initiated as replacement. The patient tolerated palbociclib for up to 5 months at the time of publication without recurrence of colitis. Postmarket drug surveillance is crucial to prevent diagnostic delays. An investigation into CDK4/6-induced colitis, relative risks between agents, and potential risk factors is needed.",
  "authors": [
    {
      "affiliations": [
        "Internal Medicine, Banner - University Medical Center Phoenix, Phoenix, Arizona, USA"
      ],
      "name": "Ishitha Jagadish"
    },
    {
      "affiliations": [
        "Internal Medicine, Banner - University Medical Center Phoenix, Phoenix, Arizona, USA"
      ],
      "name": "Phoebe Newell"
    },
    {
      "affiliations": [
        "Breast Cancer Program, Banner MD Anderson Cancer Center, Gilbert, Arizona, USA"
      ],
      "name": "Hung Thieu Khong"
    }
  ],
  "title": "Cyclin-dependent kinase 4/6 inhibitor ribociclib-induced colitis with a successful transition to palbociclib",
  "uid": "aaac1fff-b8f3-5956-9b03-e45f6cdab1e9"
}