Interim Results from EXPLORE Natural History Study for Acute Hepatic Porphyrias

We reported interim results from our ongoing EXPLORE study, a multinational, prospective, observational study aimed at characterizing the natural history and clinical management of patients with acute hepatic porphyrias (AHP) who experience recurrent attacks or receive prophylactic treatment to prevent attacks.  Results from 112 patients, of which 104 have acute intermittent porphyria (AIP), showed a mean of 9.5 acute attacks reported in the prior year with severe neuropathic pain as the cardinal feature in 100% of attacks, along with other symptoms including nausea or vomiting (>80%), fatigue (77%), and weakness (79%).  Approximately 64% of patients reported experiencing porphyria symptoms between attacks, with about 46% experiencing symptoms daily.  Patients also reported a diminished quality of life and significant healthcare utilization, with a mean of 4.6 overnight hospitalizations per year (range 0-70) and a mean hospital stay duration of 6.6 days (range 1-60).  Of the attacks reported on study, approximately 76% of them required treatment with heme or at a healthcare facility.

We continue to strive to bring a safe and effective therapy to this patient population with devastating disease burden and enormous unmet medical need. We look forward to the continued advancement of ALN-AS1, as we believe it represents a potentially transformative treatment option for patients with AHP.