Eli Lilly & Co. and Pfizer’s nonopioid nerve growth factor inhibitor tanezumab beat out placebo in a phase 3 study of patients with chronic lower back pain who had previously seen inadequate relief from at least three different classes of painkillers.
Additionally, tanezumab was well tolerated during a yearlong treatment regimen, with no events of osteonecrosis, a previous concern related to this class of drugs. On average, the more than 1,800 patients who enrolled had dealt with moderate-to-severe chronic back pain for about 10 years, or at least three consecutive months before entering the study.
Administered subcutaneously every eight weeks, top-line results showed that a 10-mg dose of the nerve-blocking tanezumab met its primary endpoint of improving pain after 16 weeks. While a 5-mg dose also showed improvements, it did not reach statistical significance at week 16, the companies said.
"This is one of the longest studies conducted to date in chronic low back pain,” said Ken Verburg, Pfizer’s tanezumab development team leader.
“We look forward to further analyzing these results, and believe the data from this study will support our planned future global regulatory submissions in chronic low back pain,” Verburg added. The two companies expect to present the full results in a future scientific publication.
Pfizer had suspended some tanezumab pain studies in 2010—as part of an FDA hold on all nerve-growth factor inhibitor studies—following reports of adverse events and the worsening of disease in some osteoarthritis patients.
In the latest study, rapidly progressive osteoarthritis was seen in 1.4% of tanezumab-treated patients, compared to 0.1% in others. Overall, 0.7% of treated patients underwent total joint replacements, with none reported in the placebo arm.
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The anti-inflammatory antibody was recently touted by new Pfizer CEO Albert Bourla as a main prospect for the Big Pharma’s pipeline, and a key recipient of R&D dollars as it tries to move it through the clinic.
Tanezumab is also being studied in osteoarthritis pain, with a new phase 3 trial due to read out in 2019, as well as in cancer pain due to bone metastases. A second phase 3 study in chronic lower back pain is also expected to deliver results this year.
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In 2018, Lilly and Pfizer showcased phase 3 data showing the potential opioid alternative met all its primary objectives in patients with osteoarthritis of the knee or hip, including those who struggle to control pain with opioids or nonsteroidal anti-inflammatory drugs.
That study also showed higher levels of joint replacement surgeries than placebo, though there were there were no radiographic differences between treatment groups.
Elsewhere, Regeneron and Teva’s anti-NGF antibody fasinumab met a pair of primary endpoints in a phase 3 trial last year. At 1 mg, the drug significantly improved osteoarthritic knee and hip pain and physical function at 16 weeks, after Regeneron had halted higher doses in 2016. However, some risks remain. The study’s placebo-adjusted rate of arthropathies reaching 2%, with many cases involving rapid progressive osteoarthritis.