The Patient Odyssey to Confirmed Acute Hepatic Porphyria Diagnosis: Neurological Symptoms and Use of Drugs Known to Provoke Porphyria Attacks Prior to Diagnosis (P3.9-070)

Objective: This study’s objective was to follow AHP/AIP patients’ healthcare journeys from first suspected symptom to diagnosis. Background: Acute hepatic porphyrias (AHPs) are caused by genetic defects in hepatic heme biosynthesis; accumulation of neurotoxic intermediates causes potentially life-threatening, neurovisceral attacks. Acute intermittent porphyria (AIP) is the most common subtype. Patients commonly undergo prolonged periods of missed or incorrect diagnosis and inadvertently receive drugs known to provoke porphyria attacks. Design/Methods: The IBM MarketScan Databases were used to identify patients between 1 Jan 2010–30 Jun 2017 using a previously defined AHP/AIP algorithm: 1) ICD-9-CM(277.1) porphyria diagnosis claim with either a) symptoms and AHP lab test or b) hemin use, or 2) ICD-10-CM(E80.21) AIP claim. At least 5 years continuous enrollment prior to the index date (date of first AHP claim) was required. The time between first identified AHP symptom(s) and index date was defined as the observation period (ObP). Symptoms, AHP-like attacks, healthcare resource utilization (HCRU), unsafe drug prescriptions, and diagnoses were analyzed during the ObP. Results: 126 patients were identified (63% female, mean age:47 years, and mean ObP:3.9 years). The most common symptom was abdominal pain (79.4%). Neurological symptoms preceding diagnosis included leg/arm pain (45.2%), seizures (12.7%), neuropathy (11.1%), and muscle weakness (10.3%). Patients had a mean of 1.1 AHP-like attacks/year requiring an inpatient (IP) admission or emergency department (ED) visit. Prescriptions drugs known to trigger attacks were observed in the week prior to ER visit and IP admissions in 38.0% and 23.4%, respectively. During the ObP, 34.1% saw a neurologist. Claims for neurological conditions included fibromyalgia (27.0%), neuropathy (24.6%), and epilepsy (11.9%). Conclusions: Prior to diagnosis, patients exhibited symptoms commonly associated with AHP/AIP and high HCRU, including IP admissions and ED visits. Unsafe drug prescription claims often preceded these visits. Opportunity exists to improve recognition and treatment of AHP based on patient history of neurovisceral and other common symptoms. Disclosure: Dr. Pedro has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Alexion Pharmaceuticals, Shire, and Sanofi Genzyme. Dr. Pedro has received research support from Shire, Sanofi Genzyme, Horizon Pharma, and Amicus Therapeutics. Dr. Rudnick has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Alnylam Pharmaceuticals. Dr. Rudnick has received research support from High Tide Pharmaceuticals. Dr. Merkel has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Alnylam Pharmaceuticals . Dr. Ko has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Alnylam Pharmaceuticals. Dr. Ko holds stock and/or stock options in Alnylam which sponsored research in which Dr. Ko was involved as an investigator. Dr. Johnson has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with IBM Watson Health. Dr. Noxon has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with IBM Watson Health. Dr. Cole has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with IBM Watson Health. Dr. Agarwal has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Alnylam Pharmaceuticals. Dr. Agarwal has received compensation for serving on the Board of Directors of Alnylam Pharmaceuticals.