NOVATO --  Ultragenyx Pharmaceutical, Inc. (Nasdaq: RARE), on Monday reported a net loss for the fourth quarter that was nearly three times larger than a year before and for the year that was two and a half times bigger.

Ultragenyx, which makes treatments for rare diseases, reported a net loss of $18.7 million, or $4.98 per share, in the fourth quarter, ended Dec. 31, compared with a net loss of $6.8 million at the end of 2012.

"Ultragenyx completed a landmark year in 2013, during which we achieved multiple milestones in our vision to build a next generation rare disease company," Dr. Emil D. Kakkis CEO and president of Ultragenyx, said in a statement.  "We have expanded our pipeline to five clinical programs in phase 1/2 or phase 2 studies, and with the completion of our initial public offering in early 2014, we believe we are well-positioned to advance multiple programs in parallel to address the significant unmet medical needs of these patients."

For the year, the net loss attributable to common stockholders was $50.3 million, or $14.87 per share, compared with a 2012 net loss of $19.6 million, or $14.20 per share.

The increase in total operating expenses was attributed to the addition of several drugs in the company's pipeline, including triheptanoin and KRN23, as well as the development of sialic acid extended release (SA-ER) and recombinant human beta-glucuronidase (rhGUS), and increased headcount to support the company's growth.

Total operating expenses for 2013 were $32.3 million, compared with $16.0 million for 2012. For the fourth quarter, they were $9.5 million, up from $4.7 million a year before.

Cash, cash equivalents, and short-term investments were $53.4 million as of Dec. 31, 2013. Based on current operating levels, the company expects that existing cash, cash equivalents and short-term investments, including approximately $121.7 million in net proceeds received from the initial public offering in February, will be sufficient to fund operations into 2016.

Shares of Ultragenyx were $51.41 at the end of trading Monday, down more than 6.6 percent from Friday. Pharmaceutical stocks overall took a just more than 1 percent hit to pricing Monday.