Unique fusion protein yields stable improvement in VA

Fort Lauderdale, FL-A phase II update study highlighted factors predictive of visual acuity (VA) outcomes in patients with neovascular age-related macular degeneration (AMD) who were treated with repeated intravitreal injections of a unique fusion protein (VEGF Trap-Eye, Regeneron and Bayer HealthCare). Jeffrey S. Heier, MD, a vitreoretinal specialist affiliated with Ophthalmic Consultants of Boston, reported these results on behalf of CLEAR-IT 2 Investigators.

“[The fusion protein] is uniquely suited to treat exudative AMD,” he said. “It has important components of vascular endothelial growth factor (VEGF) receptor 1 and VEGF receptor 2, and it blocks all VEGF isoforms and placental growth factor.”

Inhibition of placental growth factor may ameliorate the pathological angiogenesis, he added.

Patients were randomly selected to the fusion protein 0.5 or 2 mg monthly or to 0.5, 2, or 4 mg quarterly (given at baseline and week 12) with re-assessments on a monthly basis and at 3 months they began follow-up for 1 year with as-needed dosing. Patients had a dramatic increase in VA. After about 8 weeks, the monthly patients had continued increases in VA and the quarterly patients had a slow decrease in VA. After the as-needed dosing regimen, in which both groups received about the same number of injections of drug, the quarterly patients never matched the monthly patients in VA gain, suggesting that a loading dose may be important to maximize vision.

Dr. Heier also included 18-month follow-up data from an open-label extension study of the drug, which patients could enter after 1 year. Patients received 2-mg dosing as needed.

“[The fusion protein] has demonstrated excellent ability to improve VA and has excellent durability over an extended PRN phase in maintaining vision,” he concluded. “Twelve percent received only fixed doses and 75% needed four or fewer injections over a 15-month PRN phase. Treatments were safe and well tolerated.”