NEW YORK ( TheStreet) -- Biomarin Pharmaceuticals ( BMRN) has four major clinical trial catalysts before the end of the year -- one of which could possibly be the most important event in the company's history. I've been an investor in Biomarin since 2006. In fact, the company is the longest-tenured stock in my SharkBiotech portfolio. As with most biotech stocks, investing in Biomarin requires patience because, at times, the periods between stock-moving events can be long. But the pace of news coming out of Biomarin is going to accelerate over the next three months. Here's a breakdown of what's in store: 1. The announcement of top-line results from a phase III study of GALNs in Morquio syndrome, also known as MPS IV. I have confidence that the GALNS data will be positive. Results from phase II studies were strong, showing improvements in walking ability and a sustained decrease in keratin sulfate levels. Morquio syndrome patients lack an enzyme that breaks down keratin sulftate in cells, leading to progressive skeletal and spinal cord malformation. GALNS is a replacement enzyme that reduces the harmful levels of keratin sulfate. Morquio syndrome is an ultra-orphan disease closely related to two other diseases, MPS I and MPS VI, that are treated with Biomarin's currently approved Aldurazyme and Naglazyme, respectively. The company's proven expertise in developing effective enzyme replacement therapies in this area bolsters the odds that GALNS will also succeed. The body language from Biomarin management regarding GALNS has been excellent. GALNS is Biomarin's most important growth driver because the identified population of Morquio patients exceeds those of MPS 1 and MPS VI. The company has already identified more than 1,200 Morquio patients to target for the GALNS launch. By comparison, Aldurazyme and Naglazyme launched with 200 and 300 patients, respectively. Peak annual sales of GALNS could exceed more than $500 million. 2. Data from phase II trials of Peg-Pal in phenylketonuria (PKU) is expected within the next several weeks. If positive, Biomarin will move the drug into a pivotal phase III program. PKU is a genetic disease that causes the inability to break down the amino acid phenylalanine (PHE). Peg-Pal significantly lowers PHE levels but some patients have experienced tolerability issues that forced Biomarin to tweak the drug's formulation and dosing schedule. It's very important Biomarin gets this right because PHE levels can be maintained at an acceptable level with a strict non-protein diet. Lingering safety/tolerability issues could hurt the drug's acceptance within the PKU patient community.