The patient experience of CHAPLE disease: results from interviews conducted as part of a clinical trial for an ultra-rare condition.

backgroundCD55 deficiency with hyper-activation of complement, angiopathic thrombosis, and protein-losing enteropathy (CHAPLE) disease is a newly identified condition with an estimated worldwide prevalence of < 100 patients. Patient interviews can ensure that what is important to patients is assessed in a clinical trial program. Due to the rare and potentially fatal nature of CHAPLE disease, interviews were conducted as part of the pozelimab clinical trial, rather than in a separate study before the trial. The aim of the interviews was to identify the key disease-related signs, symptoms, and health-related quality-of-life (HRQoL) impacts that are important and relevant to patients with CHAPLE disease.

methodsInterviews were conducted with patients and/or caregivers at two timepoints (screening and Week 24) during the pozelimab trial to document the signs/symptoms and HRQoL impacts of CHAPLE disease, and document the most bothersome sign/symptom at screening. At Week 24, interviews gathered additional information on the patient experience from caregivers and patients (note: the impact of pozelimab treatment was also collected, though these results are presented elsewhere).

resultsTen patients, aged 3-19 years, were enrolled in the trial; caregivers contributed to nine interviews. Thirty-one signs‌/symptoms and 65 HRQoL impacts were reported during the interviews. Abdominal pain, diarrhea, facial and peripheral edema/‌swelling, nausea, and vomiting emerged as the core signs/‌symptoms of CHAPLE disease (i.e., experienced by ≥ 90% of patients prior to treatment). The remaining 25 signs/symptoms were experienced by four or fewer (n ≤ 4, ≤ 40.0%) patients, and 15 were only reported by one patient each. Abdominal pain and facial edema were reported as the most bothersome signs/‌symptoms (n = 9, 90.0% and n = 1, 10.0%, respectively). The most frequently reported (i.e., ≥ 80% of interviews) HRQoL impacts were restricted diet (n = 10, 100.0%), sleep disruptions (n = 10, 100.0%), missing school (n = 9, 90.0%), ability to get dressed independently (n = 8, 80.0%), and difficulty engaging in play activities (n = 8, 80.0%).

conclusionsThe main finding from these patient interviews is the identification of six core signs/symptoms of CHAPLE disease: abdominal pain, diarrhea, facial edema/swelling, peripheral edema/swelling, nausea, and vomiting. The severity of the core signs/symptoms leads to substantial impacts on patients' lives.

trial registrationClinicalTrials.gov, NCT04209634. Registered 20 December 2019 https://classic. CLINICALTRIALS: gov/ct2/show/NCT04209634 .