Biosimilars And JAK Inhibitors Continue To Gain Popularity In The EU Rheumatoid Arthritis Market, According To Spherix Global Insights

Biosimilar use in the EU5 rheumatoid arthritis market leads to erosion of name brand drugs; JAK inhibitors slowly penetrate the market, while perceived safety risks may limit prescribing

Exton, PA /PRNewswire/ -- Twice a year, Spherix collects the responses of ~250 EU5 rheumatologists as part of their RealTime Dynamix™: Rheumatoid Arthritis (EU) service. This study, which includes trending back to 2017 as well as unique content with each wave, reveals ongoing changes in treatment preferences and the growing importance of newer advanced systemic agents.

According to the latest wave included in the service, self-reported biologic/JAK share of the TNF inhibitor class remains dominant in the EU rheumatoid arthritis (RA) market, largely fueled by continued uptake of biosimilar agents. In fact, biosimilar TNF inhibitors account for over one-third of the total TNF class share, while new prescription share (last five biologic/JAK prescriptions) shows the biosimilars capturing nearly equal amounts of the market as the combined share of all TNF inhibitor branded agents (including those without a biosimilar equivalent).

Etanercept biosimilars are the most entrenched in the EU5, with self-reported combined biosimilar share matching that of Amgen's Enbrel in the current wave. Biogen's Benepali, the first etanercept biosimilar referencing Enbrel to be approved in the EU RA market, accounts for the majority of use and is the top preferred etanercept biosimilar. Having said that, ongoing patent litigations could prevent such competition in the US for years, as Amgen recently announced a US court ruling in favor of Enbrel's patent validity on several claims and Sandoz's (with FDA approved Erelzi) failure to prove them invalid.

Regarding adalimumab biosimilars, Amgen's Amgevita has been embraced by nearly half of EU5 rheumatologists. While collective adalimumab biosimilar share has not yet caught up to AbbVie's Humira in the EU RA market, the agents have been gaining traction and have contributed to Humira's consistent erosion since their launch. Biologic/JAK share of the infliximab and rituximab biosimilars are nearly equal to their branded counterparts, though rituximab biosimilars are only fully ingrained in the UK and, to a lesser extent, Italy.

Overall, over two-thirds of surveyed rheumatologists agree they both expect their use of biosimilars to increase and that they are more willing to prescribe biosimilars in biologic-naïve patients than they are to switch patients who are doing well on the reference brand. However, biosimilars aren't the only aspect of this market ruffling some feathers – the increased adoption of JAK inhibitors has also had major impacts. Indeed, one-third of respondents state that they plan on prescribing JAK inhibitors more frequently and earlier in the treatment sequence within the next year.

JAK inhibitors account for just under one-tenth of first-line biologic/JAK share in the EU RA market; this figure grows with each progressing line of therapy (12% in the second line and nearly 20% in the third-or-later line). With each wave of research, Spherix has found that the JAK inhibitor class has captured a greater portion of share in all lines therapy over the past year and a half.

Indeed, the percent of rheumatologists selecting either Pfizer's Xeljanz or Eli Lilly's Olumiant as their preferred alternate mechanism of action agent to switch to after first-line TNF therapy has significantly grown since the previous quarter of fielding. Interestingly, Olumiant is chosen over Xeljanz for second-line use after TNF therapy in all EU5 countries except Germany. Though reported frequency of JAK cycling is uncommon, it does occur in a minority of patients who are prescribed a JAK inhibitor in the pre-biologic setting. Current biologic/JAK brand share in all lines of therapy are equal for the two agents, growing at essentially the same pace – a story that looks much different in the US, where Xeljanz's tenure on the market, first-in-class status, and lack of a required TNF failure (on top of the presumably less efficacious 2mg FDA approved dosing of Olumiant) provides Pfizer's agent with a substantial competitive advantage.

Despite the increasing popularity of Lilly and Pfizer's brands in the EU and the US, just under one-half of EU respondents agree they avoid using JAK inhibitors in patients who are at a high risk for developing venous thromboembolism. Over one-half of rheumatologists are aware of Pfizer's recent post-marketing study revealing an increased risk of cardiovascular events for the 10mg, twice-a-day dose. The majority also agree the announcement has had an impact on their opinion of Xeljanz, with many stating they would exercise more caution with the agent.

Stay tuned – another event likely to stir the market is the introduction of the third JAK, AbbVie's Rinvoq (upadacitinib), which was approved by the FDA for the treatment of moderate-to-severe RA last month and is currently under review by the EMA. The black box warning that comes along with all three currently approved JAKs in RA will likely limit the full commercial opportunity of these new agents in the market, though Gilead/Galapagos is working to get by without the warning on their pipeline JAK inhibitor, filgotinib.

Spherix will continue to monitor the lasting effects of the safety concerns that come with the JAK inhibitors and will be tracking the launch of Rinvoq in the US on a quarterly basis and in the EU (once available) on a bi-annual basis.

About RealTime Dynamix™
RealTime Dynamix™: Rheumatoid Arthritis (EU) is an independent service providing strategic guidance through rapid and comprehensive bi-annual reports, which include market trending, launch tracking, and a fresh infusion of unique content with each wave (n=250 EU5 rheumatologists). The 17th quarterly wave included in a parallel service tracking the evolution of the US RA market, RealTime Dynamix™: Rheumatoid Arthritis (US), will publish in September 2019 (n=100 US rheumatologists).

About Spherix Global Insights
Spherix Global Insights is a hyper-focused market intelligence firm that leverages our own independent data and expertise to provide strategic guidance, so biopharma stakeholders make decisions with confidence. We specialize in select immunology, nephrology, and neurology markets.

www.spherixglobalinsights.com