7236 Long Term Extension of Osilodrostat Therapy in Canadian Patients with Cushing’s Disease Benefiting from the LINC 3 and LINC 4 Studies
Authors: Martel Luciana Maria , Houde Ghislaine , Chik Constance , Imran Syed Ali , Paron Emilia , Lebel France , Lacroix André 
Published: October 2024

Disclosure: L.M. Martel: Other; Self; LMD receives partial fellowship salary support though educational grants from Recordati Rare Disease Canada Inc and Pfizer Canada. G. Houde: Other; Self; GH served as a consultant for Novartis. C. Chik: Other; Self; grants and/or consulting fees from Pfizer, Ipsen, Novartis and Novo Nordisk Canada. S.A. Imran: Other; Self; consulting fees from Pfizer, Recordati and Novartis. E. Paron: Other; Self; employees of Recordati Rare Disease Canada Inc. F. Lebel: Other; Self; employees of Recordati Rare Disease Canada Inc. A. Lacroix: Other; Self; reports grants and personal consulting fees from Novartis, Recordati and Pfizer.

Introduction: Osilodrostat, a potent oral 11β-hydroxylase inhibitor, provided rapid, sustained cortisol normalization in Cushing’s disease (CD) patients in two Phase III trials (LINC 3, NCT02180217; LINC 4, NCT02697734); persistent biochemical and clinical improvement of CD were reported after 72 and 96 weeks of therapy, respectively (10.1530/EJE-22-0317; 10.3389/fendo.2023.1236465). After study completion and continued clinical benefit with osilodrostat, patients could transition in a roll-over study (CLCI699C2X01B , NCT03606408). As osilodrostat is now approved for therapy of CS in Europe and CD in USA, but not in Canada, seven Canadian patients who had benefited from osilodrostat were transitioned to an investigator initiated study ((ISS-CA-2023, NCT06131580). Objective: To analyze the course of therapy with osilodrostat which allowed long-term biochemical and clinical control of CD since initiation of LINC 3 and LINC 4 core studies for up to 105 months. Methods: Retrospective review of clinical, biochemical and imaging data were collected through chart review of 11patients enrolled in four Canadian centers in LINC 3 and 4 in LINC 4 parent studies. Seven patients remained in the roll-over study until termination and initiation of the Canadian study on October 24 2023. Data from initiation of therapy until October 24 2023 were analyzed. Results: Of the eleven enrolled patients, four discontinued treatment due to muscle cramps, repeat transsphenoidal surgery (TSS) for corticotroph adenoma progression in 2 cases, and hyperandrogenism and opting for bilateral adrenalectomy in one case. Seven cases (5 LINC 3 and 2 LINC 4) pursued therapy in the extension study: 2 men and 5 women, mean age 46 y.o. (range 28-72). All but one had previous TSS, one Gamma Knife and 4 received previous medical therapy. The median 24 hour urinary free cortisol (UFC) before starting osilodrostat was 334 nnmol/d (2.4 x ULN; range 133-414). The median treatment duration was 82 months (range 67-105) and median time to normalize UFC was 36 days. The median maximal dose required to normalize UFC was 10 mg/day (4-60); dose was frequently reduced because of symptoms of relative cortisol withdrawal or adrenal insufficiency (n: 5) to 6.5 mg/day (range: 1 mg every 6 days to 30 mg/d) currently. Last median UFC was 60 nmol/d (range 22-154; 6/7 in normal range &lt; 138nmol/d). Tumor growth occurred in 1 patient (2mm). All patients presented partial to complete improvement of CD features, whereas one patient developed moderate clinical hyperandrogenism, hypertension and borderline prolongation of QTc that normalized after a dose reduction. Conclusions: Osilodrostat can provide sustained biochemical and clinical control of hypercortisolism in patients with CD for up to 9 years; however drug efficacy and dose requirement varies greatly between patients and must be adjusted carefully and regularly during course of therapy.

Presentation: 6/3/2024