Spine BioPharma's Phase 3 Trial for Chronic Low Back Pain Treatment Misses Primary Endpoint

Spine BioPharma, a biotechnology company focused on developing treatments for chronic low back pain, has announced that its phase 3 trial for the investigational drug SB-01 has failed to meet its primary endpoint. The company attributes this outcome to an unexpectedly high response rate in the sham control group.

Trial Design and Results

The phase 3 trial enrolled 417 patients suffering from chronic low back pain associated with degenerative disc disease. Participants were randomized into two groups: one receiving a single injection of SB-01, a TGF-β antagonist, directly into the affected intervertebral disc, and the other receiving a sham control treatment.

After six months, researchers evaluated changes in patients' scores on both a disability index and pain scale. According to Spine BioPharma, 67% of patients in the SB-01 arm met the primary endpoint response criteria, which the company described as clinically meaningful and consistent with earlier phase 2 findings.

However, the trial failed to achieve statistical significance due to an unexpectedly high response rate in the sham control group. Fran Magee, Spine BioPharma's chief technology officer, stated, "The sham control response was statistically significantly higher than observed in the phase 2 study. The statistical design of this phase 3 study anticipated a high sham control success, as observed in the phase 2 study and typically seen in [chronic low back pain] studies. We are surprised by the very high sham control response in this study that kept us from achieving statistical significance."

Subset Analysis and Future Plans

In response to the unexpected results, Spine BioPharma conducted a subset analysis focusing on 227 patients from sites with an anticipated sham response rate consistent with their phase 2 study. This analysis showed that 70% of patients in the SB-01 arm and 59% in the control arm met the primary endpoint response criteria.

The company now plans to complete its data analysis and meet with the FDA to explore potential pathways for the approval of SB-01. Spine BioPharma intends to present the phase 3 results alongside data from phase 1 and 2 studies during these discussions.

As the biotechnology industry continues to grapple with the challenges of developing effective treatments for chronic pain conditions, the outcome of Spine BioPharma's phase 3 trial underscores the complexities involved in clinical research and the impact of placebo effects in pain management studies.