Heron Therapeutics has reported positive results from two Phase III studies investigating the efficacy of its painkiller agent HTX-011 in relieving pain and reducing opioid use in patients undergoing bunionectomy and hernia repair.

The treatment achieved its primary and key secondary endpoints, showing statistically-significant reductions in both pain intensity and the use of opioid rescue medications in the 72 hours following surgery. According to the company it is the first long-acting painkiller to do so.

HTX-011 contains the anaesthetic bupivacaine in a fixed-dose combination with the anti-inflammatory drug meloxicam. It was trialled in comparison with placebo and bupivacaine solution in two studies, which showed HTX-011 to be well-tolerated and with a promising safety profile.

The trials enrolled over 800 patients in total. The first examined HTX-011 as a pain medication for 412 bunionectomy patients. It was shown to reduce pain by 27% compared with placebo, and 18% compared with bupivacaine. Opioid use decreased by 37% compared with placebo and 25% compared with bupivacaine.

Of the patients given HTX-011, 29% did not require opioids throughout the 72-hour period compared with 2% taking placebo and 11% taking bupivacaine.

The second trial tested HTX-011 as pain relief for hernia repair patients. Subjects showed a 23% reduction in pain intensity compared with placebo, and 21% compared with bupivacaine solution. Over the 72 hours following surgery patients receiving HTX-011 consumed 38% less opioids than placebo patients and 25% less than patients receiving bupivacaine solution.

Of those receiving HTX-011, 51% did not require opioid medication following surgery, compared to 22% of those receiving placebo and 40% of those taking bupivacaine.

Pain intensity was measured using the Area Under the Curve (AUC) score from 0 to 72 hours following surgery as compared with placebo.

“HTX-011 is the only locally administered anaesthetic to demonstrate superior pain relief and a reduction in opioid use as compared to not only placebo, but also the current standard-of-care, bupivacaine solution, in Phase III studies,” Heron Therapeutics CEO Barry D Quart said.

“We look forward to submitting a New Drug Application for HTX-011 to the US Food and Drug Administration in the second half of 2018. If approved, we believe that HTX-011 could have a significant impact on the opioid crisis by reducing the use of opioids after surgery, while at the same time allowing patients to experience less pain.”

According to Heron, HTX-011 is the first and only long-acting anaesthetic that targets both postoperative pain and inflammation in a single administration at the surgical site. Its application via a needle-free syringe allows the affected tissue to be directly coated prior to suturing. As such, the method is easier, faster and potentially safer than current practices, which require numerous injections of local anaesthetics. There is also the hope that it can provide a viable option to opioid medications, which carry the risk of addiction and other adverse side effects.

HTX-011 was granted Fast Track Designation from the FDA in the fourth quarter of 2017, and Heron is anticipated to file an NDA to the FDA in the second half of 2018.

The treatment is also currently being investigated in a Phase II study as a pain-killing treatment for nerve block and total knee arthroplasty.