Cell Therapy Not Superior to Corticosteroid Injections for Knee Osteoarthritis

New research from Emory University found that at 1 year post injection, there was no superior orthobiologic as compared to corticosteroid injections (CSI) for knee osteoarthritis. The findings, from the phase 2/3 MILES study (NCT03818737), were published in Nature Medicine.¹

“The study demonstrated no superiority of any cell therapy over corticosteroids in reducing pain intensity over the course of a year,” senior author Scott D. Boden, MD, director, Emory Orthopaedics and Spine Center, said in a statement.² “While there is much enthusiasm about the regenerative capacity of stem cells, the findings call into question the comparative effectiveness of various injections for knee osteoarthritis and underscores the importance of a personalized approach in selecting the right treatment for each patient's unique needs.”

The multicenter, single-blind, randomized, controlled MILES study enrolled 480 patients with knee osteoarthritis in 3 different arms: autologous bone marrow aspirate concentrate (BMAC; n = 120) and CSI (n = 40), umbilical cord tissue-derived mesenchymal stromal cells (UCT; n = 120) and CSI (n = 40), and stromal vascular fraction (SVF; n = 120) and CSI (n = 40). The patients had an average age of 58.3 years, an average body mass index of 30.8, were mostly female (54.9%), and mostly white.

“Various types of cellular injection have become a popular and costly treatment option for patients with knee osteoarthritis despite a paucity of literature establishing relative efficacy to each other or corticosteroid injections,” Boden and colleagues wrote.¹

READ MORE: MSC Therapy Improves Pain, Stiffness, Function in Osteoarthritis Compared to Placebo

All treatments exceeded the minimally clinically important difference for both visual analog scale (VAS) and Knee injury and Osteoarthritis Outcome Score (KOOS) pain scores sustained at 12 months versus baseline, but at 1 year post injection, none of the 3 orthobiologic injections was superior to another, or to the CSI control. Sensitivity analyses only revealed a significant interaction between treatment group and age group (P = 0.02) and between treatment group and sex (P = 0.01) for VAS pain score. Notably, none of the 4 groups (biologics or CSI) showed a significant change in magnetic resonance imaging osteoarthritis score compared to baseline. Via EQ-5D, treatment by time interaction was not found to be significant.

"Future papers from the ongoing analysis of our data will determine if certain subgroups of patients might preferentially benefit from one of these treatments more than another. The findings offer an important step forward in answering key questions about the comparative effectiveness of certain OA treatment options, but more in-depth analysis using MRIs and cellular analysis of each injectate will continue to help inform standards of care,” Boden said.²

Investigators found that there were no procedure-related serious adverse events (AEs) reported during the study period. AEs related to cell therapy treatments include joint swelling, post-procedural contusion, and post-procedural hematoma. There were significant differences in rates of joint swelling (CSI, 7.4%; UCT, 24.1%; P = .01), post-procedural contusion (SCF, 38.6%; BMAC, 12.2%; UCT/CSI, 0%; P <.0001), and post-procedural hematoma (BMAC, 2.9%; SVF, 12.4%; P = .02).

“Given the complexity of the study, patients and cells involved, no direct knowledge was attained from our primary analysis about the personalization of cellular injections for patients,” Boden and colleagues wrote.¹

REFERENCES

1. Mautner K, Gottschalk M, Boden SD, et al. Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial. Nat Med. 2023 (29), 3120–3126 doi: 10.1038/s41591-023-02632-w
2. New study findings call into question the superiority of stem cell therapy for treating knee pain. News release. Emory University. November 2, 2023. https://news.emory.edu/stories/2023/11/hs_stem_cell_nature_paper_02-11-2023/story.html#:~:text=Through%20a%20grant%20from%20the,causes%20of%20chronic%20knee%20pain.