Opthea Meets Primary Endpoint in Phase 2b Study of OPT-302 in Wet AMD

Source: Opthea

Opthea announced positive phase 2b results demonstrating that OPT-302 combination therapy met the primary endpoint of superiority in mean visual acuity gain at 24 weeks compared to Lucentis monotherapy in treatment-naïve patients with wet age-related macular degeneration (AMD).  

The phase 2b, randomized, double-masked, sham-controlled clinical trial recruited 366 wet AMD patients who were allocated to two intravitreal doses of OPT-302 (0.5 mg and 2.0 mg), administered monthly in combination with 0.5 mg Lucentis over 24 weeks, versus a control group that received standard of care 0.5 mg Lucentis administered monthly. 

Patients administered 2.0 mg OPT-302 combination therapy gained a mean of 14.2 letters of vision from baseline on the Early Treatment of Diabetic Retinopathy Study (ETDRS) standardized eye chart at 24 weeks, compared to 10.8 letters in the control group, a statistically significant benefit of 3.4 letters (P=0.0107). The 0.5 mg OPT-302 low dose group had a similar outcome to the control group (+9.4 letters). Compared to Lucentis monotherapy, OPT-302 (2.0 mg) combination treatment showed improvements across multiple secondary endpoints, including a higher proportion of patients with stable vision (defined as ≤ 15 letter loss from baseline), and those gaining ≥10 and ≥15 letters of visual acuity. 

“In testing for superiority against very intensive anti-VEGF-A therapy, the bar was set high. Despite this, OPT-302 (2.0 mg) combination therapy showed statistical superiority for the most accepted and sensitive primary efficacy outcome—mean visual acuity,” Professor Tim Jackson, Chief Investigator of the study, and Consultant Ophthalmic Surgeon at King’s College London, said in a company news release. “Key secondary endpoints were very supportive of the primary outcome, and safety was favorable. Taken together, these results indicate that combined suppression of VEGF A, C and D has considerable potential as a novel treatment for wet AMD. OPT-302 may emerge as a combination treatment that can offer better vision gains than standard of care. Further registrational trials are clearly justified.”

OPT-302 intravitreal injections were well tolerated, with the safety profile similar to the control group. The independent Data and Safety Monitoring Board (DSMB) confirmed that no safety risks were identified. 

Secondary endpoint results were also supportive of the primary outcome. Of those in the 2.0 mg OPT-302 combination group, 45% gained 15 or more letters from baseline to week 24, compared to 40.5% of patients in the Lucentis control group. The proportion of patients gaining 10 or more letters was also greater, at 70% versus 57.8%, respectively. Stable vision was achieved in 99.2% with the 2.0 mg OPT-302 combination treatment, compared to 96.7% of the Lucentis control group.  

Excess retinal thickness measured on spectral domain optical coherence tomography was decreased and normalized consistently across all treatment groups by week 24. In the 2.0 mg OPT-302 combination group, mean central subfield thickness (CST) was reduced by -147 µm, from 414 µm at baseline to 266 µm at week 24. The mean CST was reduced by -134 µm, from 413 µm at baseline to 278 µm at week 24 in the Lucentis control group. 

“To achieve this highly significant result and meaningful additional clinical efficacy with OPT-302 in a trial powered for superiority, against a Lucentis standard of care control arm that outperformed relative to prior published studies, is a great achievement,” Pravin Dugel, MD, Managing Partner of Retinal Consultants of Arizona and clinical professor at the University of Southern California Roski Eye Institute, Keck School of Medicine, and study investigator on the trial, said in the news release.

“OPT-302 has the potential to be a game-changer in the treatment landscape, not just for wet AMD but also for other debilitating retinal vascular diseases where there remains a significant unmet medical need for more efficacious therapies. The phase 2b trial results demonstrate for the first time, that clinically meaningful gains in visual acuity approaching 3 lines of vision (15 letters) may be possible with OPT-302 combination therapy targeting a novel mechanism of action,” added Dr Dugel. 

Opthea is in a strong cash position with ~A$20m cash and an additional ~A$14m from an anticipated Research and Development tax rebate later this year. Furthermore, the phase 2b trial reported 6 months ahead of schedule leading to substantial cost savings for the company. Opthea is fully funded through the remaining phase 2b trial close-out activities and completion of the ongoing phase 2a study in diabetic macular edema. In addition, the company has sufficient capital to prepare for registrational phase 3 trial activities and evaluation of all strategic and corporate options. 

“We are extremely pleased with the significant positive outcomes from this study. They further support our conviction that OPT-302, the first ‘Trap’ inhibitor of vascular endothelial growth factors C and D designed specifically for the eye, can improve patient outcomes in wet AMD and other retinal vascular diseases,” commented Dr Megan Baldwin, CEO and Managing Director, Opthea Limited. 

“We are delighted that the clinical results from this study support advancing OPT-302 into pivotal, registrational Phase 3 development, and firmly believe that OPT-302 will have a significant commercial role in the treatment landscape for wet AMD patients. We express our gratitude to the patients, investigators and site staff who participated in the study.  Additional analyses of the Phase 2b study are ongoing, and we look forward to presenting detailed data at future ophthalmology conferences, as well as reporting topline data from our ongoing Phase 2a clinical trial of OPT-302 in patients with persistent diabetic macular edema, anticipated in early 2020.”   


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