Image source: Relypsa Inc.

What: After reporting prescription data for its newly commercialized medicine Veltassa, shares in Relypsa (NASDAQ:RLYP) fell by as much as 10% earlier today before recovering to close down 6.65%.

So what: Last quarter, Relypsa's sales totaled $12 million, and based on the company's updated prescription data, sales should continue to trend higher in the first quarter.

According to a filing with the SEC, 812 new patients began taking Veltassa with a free starter supply, up from 409 patients in January. Also, 350 outpatient prescriptions were filled and reimbursed last month, up from 99 in January. The company also notes that units sold in the hospital setting improved to 117 units from 56 units last month.

That's progress, but investors are obviously hoping for a more rapid roll-out of the drug, which is used to treat extraordinarily high levels of potassium in the blood, or hyperkalemia.

Now what: Investor concern may be warranted given that Relypsa is spending money at a torrid pace. Operating expenses hit $70.5 million last year, up from $27 million in 2014, and its guidance is for spending between $275 million and $300 million this year, which is about what it had in cash on the books heading into 2016.

That spending pace means the company needs a rapid uptake of Veltassa to avoid a dilutive stock offering.

Overall, demand for Veltassa could be big enough for risk-averse investors to step in and buy some shares, but until there's more insight into the company's cash-raising plans, most investors might want to take a wait-and-see approach to the company.