July 13, 2024

New Study Affirms the Effectiveness of Newer Medications for Arthritis

A recent study has verified that newer oral medications for rheumatoid arthritis (RA) are highly effective in real-world settings, dispelling doubts about their efficacy. The study involved 622 adults with RA, who were primarily being treated with a class of drugs known as JAK inhibitors. Unlike many other RA drugs, which require injections or infusions, JAK inhibitors can be taken orally.

In the United States, three JAK inhibitors—known as tofacitinib (Xeljanz), baricitinib (Olumiant), and upadacitinib (Rinvoq)—have been approved specifically for RA patients who do not respond well to or cannot tolerate older RA medications.

While JAK inhibitors have shown effectiveness in clinical trials, there has been uncertainty about their real-world efficacy, particularly for patients whose RA has not responded to conventional treatment.

This new study, published in the journal Rheumatology on November 1st, addresses these concerns. Researchers in Japan found that patients on any of the four JAK inhibitors approved in their country generally had positive outcomes.

Overall, approximately one-third of patients experienced remission of their RA within six months, while over 80% achieved low disease activity, indicating that their symptoms were largely under control.

Dr. Stanley Cohen, a rheumatologist at Rheumatology Associates in Dallas, commented on these findings, stating that the study confirms the effectiveness of JAK inhibitors and suggests that different JAK medications have an equal likelihood of success. Although no head-to-head trials have been conducted, individual studies on each medication have indicated similar efficacy. Real-world experiences, including this study, support these findings.

RA is caused by an immune system attack on the body’s joint tissue, resulting in pain, swelling, and stiffness. Over time, this systemic inflammation can lead to complications in various organs, such as the heart, lungs, skin, and eyes.

Many RA medications target different aspects of the immune response to slow down joint damage. JAK inhibitors are among these treatment options. However, they are not typically the first-line therapy for RA.

Dr. Cohen mentioned a 2021 trial that raised safety concerns about JAK inhibitors among older patients with RA. This study included patients aged 50 and older with at least one risk factor for heart disease or stroke. The trial found that patients treated with the JAK inhibitor tofacitinib had a higher risk of heart attack, stroke, and certain cancers compared to those receiving a TNF blocker.

TNF blockers, such as etanercept (Enbrel) and adalimumab (Humira), are older RA drugs delivered through injections or infusions.

Based on these findings, the US Food and Drug Administration (FDA) issued a boxed warning for all JAK inhibitors used to treat RA. The FDA recommended that doctors only prescribe a JAK inhibitor after a patient has tried at least one TNF inhibitor.

For this recent study, researchers led by Dr. Shinya Hayashi from Kobe University in Japan analyzed medical records from 622 RA patients treated at seven medical centers. All patients had received one of the four JAK inhibitors approved in Japan.

The results showed that approximately 90% of patients were still taking their medication six months after starting, with most experiencing symptom relief or even achieving remission. However, the researchers noted that the six-month follow-up was relatively short, and the long-term efficacy of JAK inhibitors is still unclear.

In addition to evaluating effectiveness, patients with RA must also consider the safety of their treatments. Dr. Cohen pointed out that while JAK inhibitors have been associated with a higher risk of certain adverse events compared to TNF inhibitors, overall, the risks are still relatively low.

In the trial that prompted the FDA warning, 3.4% of tofacitinib patients experienced a heart attack or stroke over four years, compared to 2.5% of TNF inhibitor users.

Dr. Cohen emphasized that the risks associated with JAK inhibitors are similar to those of TNF blockers and other biologic drugs that target the immune activity underlying RA.

As JAK inhibitors modulate a specific aspect of the immune response, individuals taking these medications may be more susceptible to certain infections. Dr. Cohen noted that JAK inhibitors appear to carry a slightly higher risk of shingles, a viral infection caused by the reactivation of the chickenpox virus. However, this risk can be mitigated with shingles vaccination.

The study received no external funding, and some of the co-researchers have disclosed funding from pharmaceutical companies that manufacture JAK inhibitors.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it