NPS Pharmaceuticals (NASDAQ: NPSP) continued to live up its too hot to handle reputation in the after-hours this evening after the biopharmaceutical company reported robust sales and bottom-line growth with its fourth-quarter results.

For the quarter, NPS' revenue jumped 101% to $54.5 million from $27.2 million in the year-ago period. This jump includes a 44% jump in its royalty revenue to $39.2 million – of which a majority came from the sale of Amgen's (AMGN -0.21%) Sensipar which provided $36.4 million of its $39.2 million in royalty revenue – as well as $15.3 million in product revenue from short bowel syndrome drug, Gattex (known as Revestive in the EU). NPS did not recognize any product revenue during the fourth-quarter last year.

According to its report, 303 patients were taking Gattex as of the end of the quarter, in line with the company's prior guidance of 275 to 325 patients. NPS further states that it anticipates "recognizing meaningful commercial sales from ex-US territories in the second-half of 2014."

In addition to robust top-line growth, NPS reversed a $12.2 million net loss, or an adjusted $0.14 per share from last year, by reporting net income of $7.8 million, or $0.07 per share in the fourth-quarter. The company also finished the year with $180 million in cash and marketable investment securities compared to just $101 million in the year prior.

Looking ahead, NPS is forecasting net Gattex/Revestive sales of $110 million-$120 million in 2014, representing 262% year-over-year growth at the midpoint, with operating expenses of $180 million-$200 million, an increase of 24% from fiscal 2014. NPS notes the increased expenses will go toward building up a pre-launch inventory for experimental hypoparathyroidism drug Natpara, trials related to expanding Gattex/Revestive to pediatric patients, and regulatory activities which include preparations for an FDA advisory committee meeting for Natpara.