More positive phase III data for tanezumab, this time in chronic lower back pain, could help the drug gain widespread use if approved. However, success at only the high dose tested could raise safety concerns. Pfizer and Lilly did not disclose detailed efficacy data from the back pain trial, other than to say that a 10mg dose showed a statistically significant improvement in the low back pain intensity score when compared with placebo after 16 weeks of treatment, while a 5mg dose missed significance. A 10mg dose of the anti-nerve growth factor (NGF) antibody is double the maximum given to patients in the osteoarthritis trial in which Pfizer and Lilly posted a win last year. And with worries over bone damage resulting from NGF use, that high dose could cause concern among regulators. Pfizer and Lilly did disclose more complete 80-week safety data from the back pain trial: rapidly progressing osteoarthritis (RPOA) was seen in 1.4% of patients taking tanezumab and 0.1% of placebo patients. More patients had the less severe type 1 RPOA versus the more severe type 2, at a ratio of 6:1, although the fact there were any cases of type 2 RPOA could be cause for concern. Total joint replacement was required in 0.7% of tanezumab patients, the companies said. The balancing act for regulators, particularly in the US, will be whether doctors desperate for non-opioid options for pain relief can overcome their concerns over safety. More clues could be provided by the readout of two more pivotal trials in chronic lower back pain and osteoarthritis due to read out later this year.
|Remaining tanezumab trials|
|Hip/knee osteoarthritis long-term study||3,047||NCT02528188|
|Chronic low back pain in Japanese patients||277||NCT02725411|