S1154 Clinical Outcomes in Patients With Acute Hepatic Porphyria Treated With Givosiran Who Stopped Hemin Prophylaxis at Study Entry: A Post Hoc Analysis of Data From the Phase 3 ENVISION Study Through Month 12. (October 2020) - Bonkovsky, Herbert L.; Balwani, Manisha; Sardh, Eliane; Gouya, Laurent; Rees, David C.; Stein, Penelope; Stölzel, Ulrich; Peiro, Paula Aguilera; Bissell, D. Montgomery; Keel, Sioban; Parker, Charles; Silver, Samuel; et al.