Anti-angiogenic therapy for aggressive posterior retinopathy of prematurity (ROP) may be a feasible therapy for these children with this form of ROP, which develops in profoundly immature neonates. The BLOCK-ROP study, which is slated to begin soon, will add to the limited knowledge of the safety and efficacy of an anti-vascular endothelial growth factor (VEGF) drug in treating posterior ROP, Anthony Capone Jr., MD, reported during Retina Subspecialty Day at the annual meeting of the American Academy of Ophthalmology.

"With the advent of FDA-approved drugs for anti-VEGF treatment, the possibility of treating eyes off-label with an anti-VEGF drug has become possible," he said. The rationale for this treatment approach is that VEGF promotes retinal vascularization. The current standard of care is laser treatment to the peripheral retina, which is not universally effective in fostering regression of ROP.

The largest experience to date with anti-VEGF therapy for ROP was carried out in Mexico, Portugal, and New York, in which 53 eyes were treated with one injection of bevacizumab (Avastin, Genentech) and followed for a mean of 6 months. The study included patients who received the standard of care for ROP, eyes that were untreated because of poor visualization, and eyes with high-risk pre-threshold ROP in an institution where laser was unavailable, Dr. Capone recounted. He is clinical associate professor of ophthalmology, Oakland University, Royal Oak, MI.

"All eyes responded favorably to treatment regarding neovascularization; five eyes worsened. There were no serious systemic adverse events. The authors concluded that further studies were needed to determine the safety and long-term efficacy of the treatment," Dr. Capone said.

The BLOCK-ROP study, a phase I trial will be carried out in the United States and Canada beginning in the fourth quarter of 2007, picks up the challenge and will evaluate the safety of one injection of bevacizumab (0.75 mg) into the vitreous cavity in 22 patients.

"The scientific rationale for using anti-VEGF therapy for ROP is compelling. This is an exciting time in ROP therapy. Approval of standard phase I and II data is appropriate considering the vulnerability of the target population. In the interim, caution is warranted with use of anti-VEGF drugs outside of a clinical trial in premature neonates," Dr. Capone concluded.