Vertex Pharmaceuticals’ investigational non-opioid analgesic suzetrigine failed to outperform placebo. Investors voiced their concerns as the company’s share price fell 13% in premarket trading.
Vertex Pharmaceuticals on Thursday released mid-stage data for its investigational non-opioid analgesic suzetrigine, which elicited significant pain relief from baseline—but failed to significantly outperform placebo.
Investors were underwhelmed by the readout, sending the biotech’s stocks falling 13% in premarket trading on Thursday, according to Seeking Alpha.
“We continue to be confused by management’s strong defense of the LSR data as offering evidence of a drug effect,” William Blair analysts wrote in a note to investors following the announcement. The firm added that it’s “unsure about the validity of moving into Phase III in LSR based on today’s data.”
Made to be taken orally, suzetrigine a small molecule drug candidate that binds to the NaV1.8 voltage-gated sodium channel typically found on neurons involved in sensing pain. Through this mechanism of action, suzetrigine helps inhibit pain signals, preventing their transmission from peripheral neurons back to the spine and brain.
Thursday’s data come from nearly 220 patients with lumbosacral radiculopathy (LSR), which causes pain in the lower back and hips, and often radiating down the legs. At 12 weeks, participants on suzetrigine saw a mean reduction of 2.02 points in the numeric pain rating scale (NPRS), indicative of lowered pain. Vertex in its news release said that this effect was statistically significant, with a p-value less than 0.0001.
The biotech also called suzetrigine’s pain relief “clinically meaningful” and claimed that the study met its primary efficacy endpoint.
However, the placebo group also saw a 1.98-point drop in mean NPRS score, which was also a significant improvement from baseline. Vertex did not perform a between-group statistical analysis, noting the Phase II trial “was not designed nor powered for statistical comparison between suzetrigine and placebo.”
A posthoc analysis found that there was high variability in placebo responses across study sites, which is a common issue in pain trials. According to Vertex’s news release, at around 40% of clinical sites that had lower placebo responses, suzetrigine showed greater separation from placebo.
But analysts were unconvinced. “In our view, a post-hoc analysis of 40% of sites doesn’t do much in offering evidence of a real clinical benefit,” the William Blair group wrote.
Truist Securities analysts agreed, writing in a note to investors that the mid-stage results are “worse than anticipated as no numeric separation can be seen between [suzetrigine] and [placebo] arms.”
“Prospects for a Ph3 in LSR looks dim, in our view,” the Truist team said.
Jefferies analysts, meanwhile, appeared to be more optimistic about the drug, writing to investors that they believe suzetrigine “is still an active drug and has promise as a chronic pain drug.” While acknowledging that today’s readout will not be well received, the Jefferies group suggested this might present “a compelling buying opportunity.”
Thursday’s Vertex readout comes a day after pain-focused SiteOne Therapeutics raised $100 million in its Series C funding round. Also developing analgesics targeting the NaV1.8, SiteOne could be a future competitor of Vertex, though the two companies are also collaborating on an asset that targets the NaV1.7 sodium channel.
