NEW YORK (AP) — A potential shortage of Genzyme Corp.’s drug Cerezyme could boost sales of a rival treatment that has yet to be approved, a Lazard Capital Markets analyst said Monday. Analyst William Tanner upgraded shares of Shire PLC to “Buy” from “Hold,” saying that manufacturing problems for Genzyme could boost Shire’s product candidate velaglucerase. Both are intended to treat an enzyme deficiency called Gaucher disease. He said Genzyme may not have enough of the product to meet the needs of patients. Tanner now expects sales of velaglucerase to reach $124 million in 2010, up from a previous estimate of $12 million, and he now forecasts $325 million in revenue in 2011, and $407 million in 2012. The Food and Drug Administration has been inspecting a Genzyme facility to evaluate the company’s progress in cleaning up a viral infection. On Aug. 10, Genzyme said the facility is operating, but it had to discard 80 percent of the material used to make Cerezyme, which could cause a shortage of the drug. Gaucher disease can cause liver and neurological problems. Tanner said he discussed the situation with a physician who believes only about 300 to 400 patients will be able to stay on Cerezyme. Unless new lots of the drug reach the market, he said, about 500 more will need a different treatment, and they might continue using other drugs even after Cerezyme supplies are restored. Also on Monday, Protalix BioTherapeutics Inc. said it the FDA approved a treatment protocol for its Gaucher drug prGCD. The FDA’s decision allows Protalix to provide the drug to clinical trial patients for free until the product receives FDA marketing approval. Tanner pared his price target on Genzyme shares to $64 per share from $71. He said the company put sales of Cerezyme and another drug, Fabrazyme, at risk by making them in the same facility as a newer product, Myozyme. The company may scrutinize the decisions of its executives as a result, Tanner wrote.