Genentech has completed enrollment in two large phase 3 clinical trials, Chroma and Spectri, investigating the efficacy and safety of lampalizumab in reducing the progression of geographic atrophy (GA) lesions secondary to AMD, according to a company statement. This is the largest interventional clinical development program ever conducted for GA and these phase 3 studies are the largest ophthalmology clinical trials Genentech/Roche has run to date. Lampalizumab is a monoclonal antibody fragment designed to inhibit complement factor D, a rate-limiting enzyme of the alternative complement pathway. This complement pathway is implicated in the development of age-related macular degeneration including GA.
“Geographic atrophy affects approximately 5 million people worldwide and over 1 million people in the US. It is responsible for 20 percent of legal blindness in developed countries,” said Erin Henry, PhD, Senior Medical Science Director, Genentech Ophthalmology. “There are currently no efficacious or FDA-approved treatments for geographic atrophy. In the Chroma and Spectri studies, we hope to demonstrate the potential of lampalizumab to help people with this vision-threatening disease.”
The two identical, double-masked, sham-controlled studies have enrolled 1,881 patients at nearly 300 study locations in more than 20 countries. The primary endpoint of both studies is the mean change in GA lesion area at 1 year, comparing treatment to sham, with a planned overall treatment duration of 2 years. Secondary endpoints assess visual function changes. Importantly, GA patients often report visual dysfunction that is not always reflected in standard best-corrected visual acuity (BCVA) measurements until late in the course of their disease. To provide a more comprehensive measurement of visual function outcomes, Chroma and Spectri use assessments such as low-luminance visual acuity (LLVA), microperimtery, reading speed, and patient-reported outcomes (PROs) in addition to BCVA. One PRO questionnaire, the Functional Reading Independence Index (FRI Index), was developed specifically by Genentech to assess functional reading independence in GA patients. The use of FRI Index has been encouraged by the European Medicines Agency as an endpoint in GA clinical trials and it is available to the ophthalmology research community to utilize.
Lampalizumab is the first potential therapeutic to show evidence of efficacy in slowing the progression of GA in a phase 2 clinical trial, called MAHALO. By reducing the progression of GA, vision loss could be slowed and visual function could be preserved for longer.