Image source: Ionis Pharmaceuticals.

What: Shares of Ionis Pharmaceuticals (NASDAQ:IONS) (previously Isis Pharmaceuticals), a predominantly clinical-stage drug developer utilizing its antisense technology platform to create therapies for a variety of diseases, lost 12% of its value in February, based on data from S&P Global Market Intelligence. Look no further than Ionis' fourth-quarter earnings report as the reason why its share price tanked.

So what: Ionis Pharmaceuticals reported its fourth-quarter results on Feb. 25, delivering $51.6 million in revenue, 98.7% of which came from research and development agreements (i.e., milestone payments). Net loss for the quarter ballooned to $71.4 million, mainly as a result of a near doubling in general and administrative expenses and a more than 50% increase in research and development expenses to $101.3 million. In the prior-year period, Ionis Pharmaceuticals earned $31.1 million in net income, albeit with a $15.4 million tax benefit. On an adjusted basis, it reported a loss of $0.59 per share compared to a $0.25 profit per share in Q4 2014.

Comparatively, Wall Street was looking for Ionis to lose just $0.49 per share, although its total revenue of $51.6 million topped the Street's projections by $2.5 million. Considering that investors remain somewhat jittery, Ionis' wider-than-expected loss didn't sit well.

Image source: Ionis Pharmaceuticals.

Now what: Loss aside, Ionis has a number of things working in its favor, the first of which might be its $804 million in cash, cash equivalents, and short-term investments. When taking into account that Ionis has roughly two dozen partnered compounds and these partnerships provide development, regulatory, and potentially sales-based milestones, the implication is that Ionis has a pretty long cash runway. The company anticipates finishing fiscal 2016 with more than $600 million in cash and cash equivalents, and it has a history of being conservative with its cash burn estimates.

The next point is that Ionis' antisense platform has allowed it to research close to three dozen compounds across a wide swath of disease indications. Since antisense technology tends to be predictive, Ionis often has a good idea of what compounds have a decent chance of success. It also helps the company bring what seems like five new compounds into its pipeline every year.

In the near term, 2016 is going to be a pivotal year for Ionis to complete a trio of late-stage clinical studies. The expectation is for a data readout for nusinersen, a spinal muscular atrophy therapy for children and infants, volanesorsen, a cholesterol-lowering drug for select genetic indications, and IONIS-TTRrx for familial amyloid neuropathy and TTR amyloid cardiomyopathy, in the first half of 2017.

In the meantime, all I can suggest is patience. Ionis appears to have one of the best-developing pipelines in the biotech industry, but it's going to take time before it has any shot at steady profits and recurring revenue.