Roche's Genentech triggers its PhIII program for blockbuster AMD contender

Following up on a successful mid-stage study for the AMD eye drug lampalizumab, Genentech has triggered a pair of Phase III studies to see if it can extend its blockbuster-making R&D rep beyond the cancer drug sphere.

The big Roche ($RHHBY) subsidiary says it launched Chroma (GX29176) and Spectri (GX29185) with more than 900 AMD patients in each study. And investigators plan to explore whether a specific genetic biomarker, a mutation in complement factor I, indicates a more likely chance of a positive response to the drug.

A little more than a year ago Genentech said that its Phase II MAHALO study demonstrated that lampalizumab slowed progression of dry, age-related macular degeneration in patients with advanced disease, shrinking the area of geographic atrophy--or GA--by 20.4%. AMD is a leading cause of blindness and major market opportunity for the drug giant. Analysts have concluded that this is one of the top drugs in late-stage development, capable of earning more than $1 billion a year. And Jefferies has ball-parked peak sales of about $2 billion for lampalizumab.

Success is key for Genentech. While best known for its cancer treatments, Genentech made a splash in ophthalmology with Lucentis, which is now losing market share to Regeneron's ($REGN) Eylea.

This new drug is the subject of a global program with sites selected in some 24 countries. According to a spokesperson for Genentech, the studies will each run close to two years, with the primary endpoint being evaluated at 48 weeks.

Sandra Horning, Roche's chief medical officer and head of global product development

Lampalizumab is an antigen-binding fragment (or Fab) of an antibody which is targeted at complement factor D. Complement factor D is a rate-limiting enzyme, says Genentech, "which is involved in the activation of the alternative complement pathway, a component of the immune system. Genetic polymorphisms as well as hyperactivity of the ACP have been implicated in the development of AMD including GA."

 "Lampalizumab has the potential to represent a significant breakthrough for this disease and could provide real hope for GA patients," said Sandra Horning, Roche's chief medical officer. "It is the first complement targeted therapy for GA to enter phase III, and the only ophthalmic drug in clinical development that specifically targets complement factor D."