Placebo response is one of the most significant challenges faced by drug developers who are investigating new pain medications. According to a review of published chronic neuropathic pain trials, placebo responses have increased in magnitude over time, making it even more difficult to definitively demonstrate treatment advantage.1 Research has also shown that up to 60 percent of study participants may experience placebo-related analgesic responses and that these responses may be persistent.2
As we know from our own work and the research of others, the placebo response is a recognized psychobiological phenomenon that must be factored into any chronic pain clinical trial with a symptom-based approach. Generally, chronic pain studies are designed under the assumption that the placebo effect accounts for approximately 30 percent of the analgesic response.3In this article, we provide an introduction to the latest placebo considerations for sponsors of chronic pain studies, including strategies for developing robust placebo-controlled analgesia clinical trials and tips for reducing response bias and variability.