BioMarin (BMRN 2.87%) shares rose more than 40% in the past year. This week the company announced a new acquisition, denied any buyout desires, and presented its plans at the JPMorgan Healthcare Conference. I outlined three things to watch at BioMarin. Is more growth coming for this orphan drug focused biotech?

New acquisition and buyout denial
BioMarin paid $10 million upfront for the acquisition of Zacharon Pharmaceuticals. Additional milestone payments might pay out in the future. Zacharon has drug discovery projects and a proprietary technology relating to rare genetic mucopolysaccharidosis, or MPS, disorders. The 2013 guidance had already allotted for the acquisition.

Rumors of a possible takeover have long followed BioMarin, with potential buyers including GlaxoSmithKline (GSK 1.60%). CEO Jean-Jacques Bienaime told reporters at the conference this week there's no plans to sell at this time. He specifically stated that the company wouldn't accept offers of even a 25% to 30% premium.

BioMarin likes where it's going. What's taking it there? A few promising lead drugs.

GALNS near the gates
BioMarin shares shot up more than 30% intraday in November upon positive phase 3 results for GALNS, now renamed Vimizim. The drug treats the rare genetic disorder Morquio syndrome, which causes skeletal dysplasia. The potential market opportunity is estimated at $500 million to $800 million worldwide.

The company already had meetings with the Food and Drug Administration and European Medicines Agency, and market authorization applications will begin in the first quarter. If the FDA gives Vimizim priority review and doesn't impose any delays, the approval could come by year's end.

Potential label expansions could come from the additional Vimizim trials wrapping up this year. BioMarin is testing the drug in patients under the age of 5 and in those with limited ambulation.

Promising PEG-PAL
BioMarin's approved drug Kruvan treats the genetic metabolic disorder phenylketonuria, or PKU. But Kruvan's only effective in a small percentage of patients. Pipeline project PEG-PAL offers a treatment alternative that has proven to work better for more people.

BioMarin reported positive phase 2 results for PEG-PAL last fall, and will meet with the FDA to discuss them in the first quarter. Phase 3 trial should initiate in the second quarter. PEG-PAL's success could mean cannibalization for Kruvan, which earned $36.4 million in the third quarter, but it's worth it for the larger market potential.

PARP potential
BMN-673 will report phase 1/2 trial results during the second quarter. The drug belongs to the PARP inhibitor class and treats genetically defined cancers, including acute myeloid leukemia, or AML. Early trial data seems promising and showed that BMN-673 was far more potent than AstraZeneca's (AZN 1.03%) olaparib, which ceased after phase 2 trials.

Foolish bottom line
BioMarin's business revolves around orphan drugs that earn low by nature. Four drugs have reached market, including Kruvan. But the rising batch of treatments deserves a degree of excitement for their expansion potential. It's bound to be a big year for BioMarin.