AcelRx rally quickly fizzles after FDA offers a guarded warning about its latest pain drug pitch
A little less than a year after the FDA kicked back AcelRx’s sublingual jolt of the pain med sufentanil, Dsuvia (ARX-04), in search of more safety data, in-house reviewers at the FDA are ready to hand it over to an outside panel to get their opinion on its potential.
In a cover memo, the FDA’s Sharon Hertz said last year’s CRL was prompted by two key concerns: “the safety of sufentanil sublingual tablets 30 mcg in patients requiring the maximum dosing proposed for labeling and the risk of misplaced tablets.”
On the safety question, the company came back and proposed a reduction in the maximum number of tablets from 24 to 12 a day. But a vigilant FDA — sensitive to the controversy over opioid abuse — still has some worries about the small pills required, worried that they could be easily lost and abused, or expose anyone who comes across them — including children — to a deadly risk.
The concern regarding misplaced tablets, with associated risks of abuse, misuse, and accidental exposure, will be a significant discussion point at this meeting. The risks associated with sufentanil sublingual tablets 30 mcg include respiratory depression, particularly resulting from accidental exposure, inability to account for the drug due to its small tablet size. In particular, patients and providers may not be aware of a dropped tablet, and when aware, may not be able to recover it. The discussion will include consideration of potential risk mitigation proposals. In addition, a point of discussion for this Advisory Committee Meeting is whether the overall benefit/risk profile is favorable.
The overall tone supporting the efficacy of the drug and the work on safety initially satisfied investors, who drove the stock $ACRX up 30% on first review. But it didn’t hold. By mid-morning the stock was up only a few points.
Not surprisingly, investigators reported in early 2016 that ARX-04 cut baseline pain scores by an average of 2.7 on a 10-point scale. In the second cohort, the drop was 3.1 points from a baseline score of 8.1, hitting the primary endpoint. Most of the patients, 75%, got the pain relief they were looking for from a single dose under the tongue, while seven required two doses and two got a third. Three were also dosed with morphine.