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The US Food and Drug Administration signed off Thursday on the first new type of pain reliever to be approved in more than two decades.
The drug, suzetrigine, is a 50-milligram prescription pill that’s taken every 12 hours after a larger starter dose. It will be sold under the brand name Journavx.
“A new non-opioid analgesic therapeutic class for acute pain offers an opportunity to mitigate certain risks associated with using an opioid for pain and provides patients with another treatment option,” Dr. Jacqueline Corrigan-Curay, acting director of the FDA’s Center for Drug Evaluation and Research, said in a news release. “This action and the agency’s designations to expedite the drug’s development and review underscore FDA’s commitment to approving safe and effective alternatives to opioids for pain management.”
Government surveys show that analgesics, or medications that control pain, are the most commonly prescribed type of drug in hospitals.
About 80 million Americans fill prescriptions each year for medications to treat new instances of moderate to severe pain, according to a study by Vertex Pharmaceuticals, the company that developed the new drug; about half those prescriptions are written for opioid medications, which can lead to dependence and addiction.
Suzetrigine is the first new painkiller approved in the US since Celebrex, a type of nonsteroidal anti-inflammatory drug called a Cox-2 inhibitor, which was approved in 1998.
Multiple parts of the body are involved in the sensation of pain, explains Dr. Sergio Bergese, an anesthesiologist at Stony Brook University’s Renaissance School of Medicine. Nerve cells carry an electrical signal from the site of tissue damage up to the brain, which perceives the signal as pain.
Unlike opioid medications, which dull the sensation of pain in the brain, suzetrigine works by preventing pain-signaling nerves around the body from firing in the first place.
“This drug, what it is doing is interrupting that path, so even though the tissue injury exists, the brain doesn’t know,” Bergese said.
And crucially, suzetrigine creates no euphoria or high like opioids sometimes can, so doctors believe there’s no potential for it to create addiction or dependence in people who use it.
The medication was discovered after researchers learned about a family of fire walkers in Pakistan and discovered that they lacked a gene allowing pain signals to fire in their skin. Members of this family could walk over hot coals without flinching.
“They knew that they were on something hot; they knew they could feel the coals. So it’s not impacting the nerves that do heat and touch and stuff like that. It is just these pain-conducting nerves,” said Stuart Arbuckle, chief operating officer of Vertex Pharmaceuticals. “They were, in every other way, normal.”
Still, it took scientists 25 years to figure out how to exploit that pain-conducting mechanism to develop a medication.
“Neurons talk to each other by producing series of nerve impulses, like a Morse code,” said Dr. Stephen Waxman, who directs the Center for Neuroscience and Regeneration Research at the Yale School of Medicine. “And nerve impulses are produced by tiny molecular batteries within the membranes of neurons. The molecular batteries are called sodium channels.”
Suzetrigine works by closing one sodium channel that conducts only pain signals.
There have been many false starts along the way to finding a drug that could block one specific sodium channel. Suzetrigine’s approval means other drugs that could work even better are likely to follow, Waxman said.
“It is an important step forward, because it provides proof of concept that a [sodium-channel blocker] can reduce pain in humans,” said Waxman, who has no financial ties to the new drug. “That opens up the door to a second generation of even more effective [medications].”
Suzetrigine is a pill that’s given in two dosages. In studies, participants got an initial dose of 100 milligrams, followed by 50 milligrams every 12 hours.
Doctors stress that it may not be the right drug for everyone or for every type of pain.
In two clinical trials that included almost 600 participants, suzetrigine controlled pain after abdominal and foot surgeries better than an inactive placebo pill. About as many people said suzetrigine reduced their pain by at least half after surgery as those who took Vicodin, which is a combination of acetaminophen and the opioid hydrocodone. The research wasn’t designed to directly compare suzetrigine to Vicodin, however, so it’s hard to know whether one worked better than the other.
On a well-known rating scale that runs from 0 to 10, the study participants started with pain of about seven, on average, and suzetrigine reduced it roughly 3.5 points.
“It’s not like eliminating all pain,” Arbuckle said. “It’s reducing pain by about 50%.”
In a third study, of people who had back pain caused by sciatica, suzetrigine reduced pain by about 2 points, the same amount reported by people taking a placebo, suggesting that this drug might not be a standout for chronic pain.
Vertex disagrees, saying that it has tested the drug in different types of chronic pain and that it seems to work for long-term pain, too. The company is continuing to test it in people who have diabetic neuropathy, in which high blood sugar levels damage nerves over time, leading to symptoms such as numbness, tingling, pain and muscle weakness.
The sciatica study was smaller than the others, with about 100 people in the suzetrigine arm and in the placebo group, so there may not have been enough participants to show clear differences between the groups. Placebos tend to have large effects in pain studies too, which complicates their interpretation.
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“In our opinion, the drug did what we expected to do in terms of the amount of pain relief,” Arbuckle said. “But unfortunately, as often happens in studies in pain, there is quite a large placebo response.”
Doctors who help people manage pain said they were excited to have a new option.
“The more options we have, the better we’re able to treat each and every patient,” said Dr. Kimberley Mauer, an anesthesiologist at Oregon Health and Science University.
Mauer said cost might be a big factor in how the drug is used. Vertex said that it has set a wholesale cost of $15.50 per 50-mg pill but that patient assistance programs would be available.
Mauer said doctors and patients would have to wait to learn what insurance companies might do in terms of coverage.
“It might limit some patients getting it. So we just have to kind of see, and it’s hard to tell until it kind of gets out on the market,” she said.
