Biogen Fails to Meet Primary or Secondary Endpoints in Phase 3 Gene Therapy Study in Choroideremia
Biogen announced topline results from the phase 3 STAR study of timrepigene emparvovec (BIIB111/AAV2-REP1), an investigational gene therapy for the potential treatment of choroideremia. The STAR study did not meet its primary endpoint of proportion of participants with a ≥15 letter improvement from baseline in best corrected visual acuity (BCVA) at Month 12 in the interventional group in comparison to the non-interventional control group, as measured by the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. In addition, the study did not demonstrate efficacy on key secondary endpoints. Safety results from the Phase 3 STAR study were consistent with previous studies.
Biogen obtains rights to the investigational gene therapy after acquiring Nightstar Therapeutics in 2019 for approximately $800 million.
“We extend our deepest gratitude to all those who contributed to the STAR study, including the participants, investigators, site staff and the broader choroideremia community,” Katherine Dawson, MD, head of the Therapeutics Development Unit at Biogen, said in a company news release. “While we are disappointed by the results of the STAR study, we are hopeful that the clinical insights gleaned from this study may help to shape therapeutic innovation for inherited retinal diseases including choroideremia, so that in the future there may be treatment options for the community affected by these debilitating disorders.”
Biogen will evaluate the complete data set before confirming next steps for the timrepigene emparvovec clinical development program. Detailed results of this study will be made available at a future scientific forum.
About timrepigene emparvovec (BIIB111/AAV2-REP1)
Timrepigene emparvovec is an investigational recombinant AAV2 vector designed to deliver a functional version of the human choroideremia gene into the retinal pigment epithelium and photoreceptor cells that aims to address the underlying genetic cause of choroideremia.
About the STAR Phase 3 Study (NCT03496012)
STAR was a phase 3, multicenter, randomized, three-arm, parallel-controlled group study that enrolled 169 adult males with a genetically confirmed diagnosis of choroideremia. The study evaluated the safety and efficacy of a single subretinal injection of investigational timrepigene emparvovec. The primary endpoint was the proportion of patients with an improvement of at least 15 letters from baseline in best corrected visual acuity (BCVA) at 12 months post-treatment as measured by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. While the Phase 3 STAR study did not meet its primary endpoint, more information about the study is available here: www.clinicaltrials.gov.