Ultra-rare disease fighting biotech BioMarin Pharmaceutical (BMRN -0.93%) proved in its first-quarter results after the bell that there's certainly growth to be had in developing therapies that treat rare diseases. For the quarter, BioMarin reported a revenue jump of 18.5%, to $151.5 million, driven by product sale gains across the board.

The company's launch of Vimizim during the quarter netted $0.9 million in revenue, while Naglazyme (by far BioMarin's best-selling drug), Kuvan, Aldurazye, and Firdapse all delivered revenue gains of 15%, 20%, 8%, and 31%, respectively. Though small, even BioMarin's collaborative and royalty revenue soared to $2.5 million combined versus just $0.6 million in the prior-year period.

Operating expenses for the quarter increased nearly 11%, to $178 million, as selling, general, and administrative expenses rose 18%, tied mainly to the launch of Vimizim. Research and development expenses increased by 3%, as well.

On the heels of higher sales came a significantly smaller adjusted quarterly loss of just $1.7 million, or $0.01 per share, compared to a loss of $8 million, or $0.07 per share, in the year-ago quarter. BioMarin announced that it ended the quarter with $1.14 billion in cash and cash equivalents.

Looking forward, BioMarin left its previous revenue guidance of $650 million to $680 million unchanged; however, it did note that current sales trends would favor the upper end of its current projections. Furthermore, the company now believes that its R&D expensing of $500 million to $530 million, as well as adjusted loss of $100 million to $130 million, are trending toward the lower-end of its prior guidance.