Heron soars with phase II pain success

Getting a pain drug approved is a tricky business, but Heron Therapeutics is looking increasingly capable of pulling this off, with its HTX-011 showing a benefit in phase II. The company's stock flew up 22% in morning trading today.

With a potential duration of 72 hours, HTX-011 could make an attractive alternative in post-operative pain, both to opioids and current long-acting non-opioid analgesics. But now Heron has the more difficult task of proving its worth in phase III.

Extended duration

The phase II results in bunionectomy support Heron’s claims of an extended duration of pain relief with HTX-011, a reformulation of bupivacaine/meloxicam, at least with the higher 400mg dose. The project met the primary endpoint, reducing pain intensity in the first 24 hours post-surgery by 69% versus placebo.

There was also a significant decrease in pain at 48 and 72 hours, which were secondary endpoints.

In addition, the need for rescue opioids was significantly delayed and reduced with the 400mg dose of HTX-011. The time to first use of rescue opioids was 48.2 hours with the project compared with 8.2 hours with placebo, while 32% of patients receiving it did not need rescue opioids at all, versus 5% in the placebo group.

The 200mg dose showed a more modest benefit after 24 hours, but did not lead to pain reduction at later time points – and it did not significantly delay rescue opioid use.

Heron will now move the 400mg dose into phase III, where it will likely need to prove that it is superior to bupivacaine solution. If this is positive, the company could submit HTX-011 for approval in early 2017 and get a green light later that year.

Versus Exparel

This would set HTX-011 up for a showdown with other long-acting local anaesthetics such as Pacira’s Exparel, which lasts for approximately 24 hours. Exparel is expected to hit $900m in sales in 2020, but could find turnover hit by competition from HTX-011, which is expected to be similarly priced.

The consensus forecast for HTX-011 sits at $174m in 2020, and could therefore be due an upgrade after these results. Leerink analysts, who predict sales of $700m by 2025, had previously given it a 40% chance of success, which they have now raised to 65%.

HTX-011 is also in a phase II study in hernia, which is “much more exploratory” according to Heron's chief executive, Barry Quart – topline results are expected in the fourth quarter. In addition the company is working on a second formulation, HTX-011b, designed to provide higher bupivacaine levels and a slightly faster onset, which could be used in procedures such as abdominoplasty, which involve larger incisions. The new formulation is also in phase II in bunionectomy.

HTX-011 is not Heron’s main focus – the chemotherapy-induced nausea candidate Sustol is due to reach the market first, in 2016, and to be its best seller with $428m of revenue by 2020. Even so, if HTX-011 continues to show good results in pain, it will be a welcome distraction.

To contact the writer of this story email Madeleine Armstrong in London at [email protected] or follow  @medtech_ma on Twitter