By Toni Clarke (Reuters) - An experimental drug to treat a rare genetic disorder that causes skeletal malformation and a host of related lung, eye, ear and heart problems confers "modest" benefit, according to an initial review by the U.S. Food and Drug Administration. The drug, Vimizim, is being developed by BioMarin Pharmaceutical Inc to treat Morquio A Syndrome, also known as MPS IV-A. BioMarin shares rose as much as 8 percent. The FDA review was posted on the regulator's website on Thursday ahead of a meeting of outside advisers to the agency scheduled for November 19. The advisory panel will be asked to give its own opinion on the drug. The FDA is not bound to follow the advice of its advisory panels but typically does so. The FDA review said the main safety concerns on Vimizim relate to anaphylaxis and allergic reactions. It also said further studies might be needed to better understand the role of antibody development on long-term efficacy and safety.