Uncertainty is growing regarding drug reviews by the FDA as the US government shutdown continues, Xconomy reported Friday.

Earlier this week, FDA Commissioner Scott Gottlieb said that the agency will be diverting funds from pre-market drug reviews to post-market safety surveillance.

The FDA has been unable to accept new user fees from life sciences companies since the shutdown begin, while Gottlieb revealed earlier this month that funding for drug reviews will likely be exhausted within a month.

The Commissioner also explained that user-fee funding for medical device reviews should last another two to three months, while that for generic drug reviews will likely run out in about a month.

"For everyone, it's a tenuous situation," commented Todd Bazemore, chief operating officer of Kala Pharmaceuticals, whose filing for a dry eye disease drug was accepted by the FDA last month.

Meanwhile, furloughs at the Securities and Exchange Commission could delay initial public offerings for firms including Gossamer Bio, Poseida Therapeutics and Alector.