IRAPture: Interleukin Receptor Antagonist Therapy (a.k.a. Regenokine)

How effective is Regenokine? This re-branding of serum IRAP therapy for orthopedic problems has exploded into the media this past several months. To date the coverage has been nothing short of “IRAPture”. This has confused me as my experience with IRAP has been different. About 6 years ago, while we were developing the Regenexx procedure, I nurtured a working relationship with some of the veterinarians who had experience using mesenchymal stem cells in athletic horses. They asked what I thought of IRAP. I had no idea what this was, so they explained that vets had been using a natural, serum anti-inflammatory called IRAP for years. I then learned that the company marketing this process to vets had not gotten US medical approval for their machine, so it was unavailable to U.S. physicians. IRAP (then marketed under the trade name “Orthokine”) was a therapy out of Germany where a patient’s own blood serum was incubated overnight with glass beads to produce a natural anti-inflammatory protein called Interleukin Receptor Antagonist (IRAP). I gleaned from my vet colleagues that they used IRAP like a steroid shot. While pharmaceutical steroid medications would give a few months of relief and had possibly serious side effects, IRAP would give 6+ months of relief. This same group of equine vets was also using stem cells to repair tissues, so after extensive experience with both technologies they had decided that IRAP was a good anti-inflammatory and that stem cells were a regenerative tool (capable of repairing damaged tissue).

Over the last 6 months I’ve received several e-mails from physician colleagues and patients asking if I had heard of “IRAP” or its “rebranded” procedure now known as “Regenokine”. The rebranding of IRAP as a regenerative tool by changing out “Ortho” for “Regeno” was interesting to me, as from what I had learned from my vet friends, this didn’t make sense. As a result, I decided to review the medical literature to determine if there was something new on IRAP that I had missed. My first question was if there was human data showing that IRAP regenerates tissue and thus should be considered a “regenerative” procedure. Performing a PubMed search on the topic (knee IRAP), I found a review article with animal models that seem to show that IRAP can control swelling and possibly retard the advancement of degenerative arthritis. However, there were no human studies that confirmed this claim. I then began searching for published information about how an injection of IRAP to treat knee arthritis might help patients. I found a well done clinical study on knee arthritis that fit this bill. This second study is the most interesting as it provides some data about how IRAP compares to what else is being offered to patients with knee arthritis. This study followed two groups of 50+ patients, one which was given IRAP knee injections and the other which was given placebo knee injections. The patients treated weren’t the most severely impacted by knee arthritis, but patients with mild to moderate knee arthritis. The authors only followed patients for a year, so we have no idea of what happened after the one year mark. Upon reviewing the study, the most striking thing is how little the IRAP helped these patients (see chart above). The blue bars above are the amount of knee function as measured by a questionnaire (WOMAC), a scale where a higher score means better knee function. The red bars in the chart above represent the changes in function of the placebo injection patients. Notice that the height of the these blue and red bars is barely different, meaning that the IRAP wasn’t helping much more than a placebo. The study authors noted this problem of “barely there” differences by stating that the improvements in the IRAP patients versus the placebo treatments were small. In fact, some of the measures at some of the time points (for example at 3 months versus 6 months) showed such small differences that they weren’t statistically significant. The 3 month improvement over placebo was 13%, the 6 month difference was a measly 3%, and the 12 month difference was 19%. Not many of my patients would sign up for 6 knee injections if they knew that the possible average improvement was somewhere between 3-19% over not doing anything. If the IRAP results don’t look that great, how does the therapy stack up against common treatments in the U.S. like PRP? Not well. For example, below I’ve graphed the results of several PRP studies and normalized the improvements reported in various functional scales to a percentage improvement. So for example, if the questionnaire used to measure improvement in that study showed a 25% higher score after the therapy, the result was reported as a 25% improvement. Note that at 6 months and 12 months, the IRAP improvements reported in this study are dwarfed by the improvements reported in PRP knee injection studies. In this graph, mild arthritis patients are reported in the “PRP-Filardo-IKDC” group and in the Kon and Sampson studies. However the “PRP-Filardo-Adv-OA-IKDC” group represents the lackluster response of the more severe arthritis patients injected with PRP (see my blog on this topic of how PRP underperforms stem cell injections in more severe knee arthritis patients). The IRAP group’s improvement in less severe arthritis patients is dismal compared to PRP.

irap regenokine

The upshot? The current IRAPture in the media doesn’t appear justified by the published data. While IRAP may help to reduce the advancement of arthritis, that’s only been demonstrated in animals and not real patients. In addition, when just pain and function improvements are considered, an IRAP shot only slightly edges out a placebo injection. Finally, overall improvements with a knee injection of IRAP don’t appear nearly as good as a commonly available PRP shot.

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Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile

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NOTE: This blog post provides general information to help the reader better understand regenerative medicine, musculoskeletal health, and related subjects. All content provided in this blog, website, or any linked materials, including text, graphics, images, patient profiles, outcomes, and information, are not intended and should not be considered or used as a substitute for medical advice, diagnosis, or treatment. Please always consult with a professional and certified healthcare provider to discuss if a treatment is right for you.