Real-world annualized healthcare utilization and expenditures among insured US patients with acute intermittent porphyria (AIP) treated with hemin.

Background and aims: Patients with acute intermittent porphyria (AIP) may suffer from acute non-specific attacks that often result in hospitalizations or emergency room (ER) visits. Prior to the recent approval of givosiran (November 2019), hemin was the only FDA-approved therapy for AIP attacks in the US. Our aim was to estimate the annual healthcare utilization and expenditures for AIP patients treated with hemin using real-world data.Methods: Patients with ≥1 hemin claim and confirmed AIP diagnosis - 1 inpatient claim or 2 outpatient claims ≥30 d apart for AIP (2015-2017) or acute porphyria (prior to 2015) - were identified in MarketScan administrative claims dataset between 2007 and 2017. Continuous enrolment for ≥6 months from confirmed diagnosis was required. A secondary analysis ("active disease population") limited the sample to adult patients with ≥3 attacks or 10 months of prophylactic use of hemin within a 12-month pre-index period. AIP-related care was defined by hemin use during an attack (daily glucose and/or hemin use) or prophylaxis (non-attack hemin use). Outcomes were annualized and expenditures were inflated to 2017.Results: Across 10 years, patients with a confirmed AIP diagnosis (N = 8,877) and ≥1 hemin claim (N = 164) were restricted by ≥6 months continuous follow-up (N = 139). AIP patients were mostly female (N = 112; 81%), had median age of 40 and 3 years average follow-up. Annualized average total expenditures for AIP-related care were $113,477. Annualized average all-cause (any diagnosis) hospitalizations were statistically significantly lower for patients treated with hemin prophylaxis vs. acute treatment (1.0 vs. 2.1; p < .001). In the secondary analysis (N = 27), annualized average total expenditures for AIP-related care were higher ($187,480).Conclusions: For AIP patients treated with hemin, patients treated for acute attacks may use a greater number of resources compared to patients treated prophylactically.

Cimetidine in the treatment of acute intermittent porphyria.

Treatment options for AIP remain limited. Although no single therapy has been proven superior in clinical trials, intravenous hemin appears to be more effective than increased carbohydrate intake, and remains the treatment of choice. At usual dosages the average wholesale price of hemin is $120-475 per day (for a patient weighing 70 kg), compared with $2.50 per day for cimetidine. Cimetidine may offer a more cost-effective and easily administered alternative to hemin therapy. The optimal dosage and duration of treatment with cimetidine have not been established and are likely to be patient-specific. Oral doses of 800 mg/d have been used. In addition to its potential for treatment, cimetidine may also have a role in prophylaxis of acute episodes by maintaining a baseline suppression of ALA synthase activity. Until well-designed, controlled clinical trials demonstrate its efficacy and compare it with other treatment options, cimetidine should be reserved for use only after standard treatment modalities have failed.