Treatment with PBI-4050 in patients with Alström syndrome: study protocol for a phase 2, single-Centre, single-arm, open-label trial.

BACKGROUND: Alström syndrome (ALMS) is a very rare autosomal recessive monogenic disorder caused by a mutation in the ALMS1 gene and characterised by childhood onset obesity, dyslipidaemia, advanced non-alcoholic fatty liver disease, diabetes and extreme insulin resistance. There is evidence of multi-organ fibrosis in ALMS and severity of the disease often leads to organ failure with associated morbidities, resulting in reduced life expectancy. There are no specific treatments for this disease, and current management consists of only symptomatic therapies. PBI-4050 is a new molecular entity with demonstrated anti-inflammatory and anti-fibrotic activities in preclinical models, including animal models of human diseases characterized by progressive fibrosis in the kidney, heart, liver and lungs. Moreover, completed Phase 2 studies in type 2 diabetes mellitus with metabolic syndrome and idiopathic pulmonary fibrosis further support the anti-inflammatory and anti-fibrotic activity of PBI-4050. Together, these data suggest that PBI-4050 has the potential to treat the pathological inflammatory and fibrotic features of ALMS. The aim of this study is to evaluate the safety and anti-inflammatory & anti-fibrotic activities of PBI-4050 in subjects with ALMS. METHODS: This is a Phase 2, single-centre, single-arm, open-label trial. A total of 18 patients with ALMS will be enrolled to receive PBI-4050 at a total daily oral dose of 800 mg for an initial 24 weeks with continuation for an additional 36 or 48 weeks. Standard assessments of safety include adverse events, clinical laboratory tests, vital signs, physical examination and electrocardiograms. Efficacy assessments include adipose tissue biopsy, hyperinsulinaemic-euglycaemic glucose clamp, adipose tissue microdialysis, liver transient elastography, liver and cardiac magnetic resonance imaging, and laboratory blood tests. DISCUSSION: This is the first clinical study of PBI-4050 in subjects with ALMS. Given the rarity and complexity of the disease, a single-centre, single-arm, open-label design has been chosen to maximise subject exposure and increase the likelihood of achieving our study endpoints. The results will provide valuable safety and preliminary evidence of the effects of PBI-4050 in ALMS, a rare heterogeneous disease associated with progressive fibrosis and premature mortality. TRIAL REGISTRATION: The trial is registered on ClinicalTrials.gov (Identifier; NCT02739217 , February 2016) and European Union Drug Regulating Authorities Clinical Trials (EudraCT Number 2015-001625-16, Sept 2015).

Comprehensive Endocrine-Metabolic Evaluation of Patients With Alström Syndrome Compared With BMI-Matched Controls.

Background: Alström syndrome (AS), a monogenic form of obesity, is caused by recessive mutations in the centrosome- and basal body-associated gene ALMS1. AS is characterized by retinal dystrophy, sensory hearing loss, cardiomyopathy, childhood obesity, and metabolic derangements. Objective: We sought to characterize the endocrine and metabolic features of AS while accounting for obesity as a confounder by comparing patients with AS to body mass index (BMI)-matched controls. Methods: We evaluated 38 patients with AS (age 2 to 38 years) who were matched with 76 controls (age 2 to 48 years) by age, sex, race, and BMI. Fasting biochemistries, mixed meal test (MMT), indirect calorimetry, dual-energy X-ray absorptiometry, and MRI/magnetic resonance spectroscopy were performed. Results: Frequent abnormalities in AS included 76% obesity, 37% type 2 diabetes mellitus (T2DM), 29% hypothyroidism (one-third central, two-thirds primary), 3% central adrenal insufficiency, 57% adult hypogonadism (one-third central, two-thirds primary), and 25% female hyperandrogenism. Patients with AS and controls had similar BMI z scores, body fat, waist circumference, abdominal visceral fat, muscle fat, resting energy expenditure (adjusted for lean mass), free fatty acids, glucagon, prolactin, ACTH, and cortisol. Compared with controls, patients with AS were shorter and had lower IGF-1 concentrations (Ps ≤ 0.001). Patients with AS had significantly greater fasting and MMT insulin resistance indices, higher MMT glucose, insulin, and C-peptide values, higher HbA1c, and higher prevalence of T2DM (Ps < 0.001). Patients with AS had significantly higher triglycerides, lower high-density lipoprotein cholesterol, and a 10-fold greater prevalence of metabolic syndrome (Ps < 0.001). Patients with AS demonstrated significantly greater liver triglyceride accumulation and higher transaminases (P < 0.001). Conclusion: Severe insulin resistance and T2DM are the hallmarks of AS. However, patients with AS may present with multiple other endocrinopathies affecting growth and development.