June 19 (UPI) -- Tanezumab appears to reduce chronic back pain, according to a study published Friday in the journal Pain.
The drug is a monoclonal antibody and doesn't have the same potentially serious side effects of other drugs used in chronic back pain, including opioids and non-steroidal anti-inflammatory drugs, or NSAIDs, researchers said.
"This demonstration of efficacy is a major breakthrough in the global search to develop non-opioid treatments for chronic pain," study co-author Dr. John Markman, said in a statement.
"There were also improvements in function linked to the reduction in pain severity," said Markman, director of the Translational Pain Research Program at the University of Rochester Medical Center.
Some 13 percent of all adults aged 20 to 69 years in the United States have chronic low back pain, according to recent research. The condition is among the leading causes of emergency room visits and hospital admissions -- as well as disability -- nationwide, studies suggest.
Tanezumab is already being evaluated by the U.S. Food and Drug Administration for the treatment of moderate-to-severe osteoarthritis pain. Results from a Phase III clinical trial, which were released by the manufacturers in early 2019, found that the 10-milligram dose was effective at reducing chronic low back pain.
Markman and colleagues from 191 clinics in eight countries worldwide found that a single 10 milligram dose of tanezumab, administered via subcutaneous -- or under the skin -- injection once every two months, provided long-term relief for adults with chronic low back pain.
Study participants given the drug saw a 50 percent reduction in pain after roughly four months of treatment, the researchers found.
The drug works by inhibiting a protein called nerve growth factor, which circulates in the human bloodstream. Nerve growth factor is believed to heighten the sensitivity of cells in the nervous system to pain, the researchers said.
Study participants with chronic low back pain all had a history of treatment with at least three different types of pain medications, including opioids, and were considered "difficult-to-treat," they said.
Those with symptoms, signs and x-ray evidence of moderate-to-severe osteoarthritis, a disorder commonly found in older patients with chronic low back pain, were excluded from the study.
Because tanezumab is a monoclonal antibody -- a synthetic clone of a human immune cell -- the drug has not been associated with the often serious side effects experienced by those taking opioids, which can be addictive, or NSAIDs, according to the researchers.
However, monoclonal antibodies have been linked to joint problems, which are sometimes serious enough to require joint replacement surgery, they said. Because of this, researchers in the new study followed participants for an extended period of time.
In all, 2.6 percent of patients on the drug experienced "joint safety events, and 1.4 percent ultimately required joint replacement, the researchers said.
"In the future, clinicians may have to weigh the different risks of lumbar fusion surgery, chronic opioid use or NSAIDs against the unique risks of a rare but rapidly progressive form of joint problem associated with blocking nerve growth factor," Markman said. "I expect that that the trade-offs between benefit and risk will be different for osteoarthritis than for chronic low back pain."