Shares of molecular diagnostics company GenMark Diagnostics (GNMK) are rallying on Tuesday after reporting that its preliminary fourth-quarter revenue rose approximately 21% year over year.

PRELIMINARY RESULTS: The company said in a statement that it expects Q4 revenue of $19.4M, representing an increase of 21% over the fourth quarter of 2017. Analysts were anticipating GenMark's Q4 revenue to be 18.75M. Genmark also provided guidance for the full year 2018, forecasting total revenue of approximately $70.8M, representing an increase of 35% over 2017. Analysts' consensus for 2018 revenue is $70.05M.

EPLEX REVENUE SEEN GROWING 270%: ePlex revenue for the full year 2018 is expected to be approximately $37.9M, an increase of more than 270% over 2017, the company said. GenMark noted that it placed 42 ePlex analyzers in Q4, finishing the year with an installed base of 354 ePlex analyzers in U.S. and European labs.

EXECUTIVE COMMENTARY: "We delivered solid financial and operational results in the fourth quarter, to complete another exciting year for our company. We expect this strong momentum to continue in 2019, driven by the expanding installed base of our ePlex analyzers and the recent FDA clearances of our BCID panels", said Hany Massarany, President and CEO. "With the Gram-Positive and Fungal Pathogen Panels already cleared for marketing in the U.S., and the Gram-Negative Panel currently under review by the FDA, we expect BCID to be a strong driver of ePlex placements and revenue growth in 2019. These will continue to be significant areas of focus for our company in 2019, as will our ongoing efforts to improve ePlex gross margin," added Massarany.

PRICE ACTION: Shares of GenMark are up 13.2% to $5.91 in afternoon trading.