Article: JAK inhibitors gaining traction for rheumatoid arthritis in EU5

The new class of JAK inhibitor therapies is making a strong impression in the European market for rheumatoid arthritis (RA), according to recent prescribing data from specialist physicians.

Our latest Therapy Watch RA study, conducted in the key EU5 countries (France, Germany, Italy, Spain and the UK), found that in the dynamic segment of the RA market – defined as patients who have started or switched onto their current RA treatment in the three months preceding inclusion in the study – the orally -administered JAK inhibitors expanded their market share across the EU5 from 3.1% in the third quarter of 2017 to 15.6% in the second quarter of 2018.

Uptake of JAK inhibitors was particularly marked in France, where they secured a dynamic-market share of 30.6% in Q2 2018. The slowest uptake for the new RA therapies was in Italy, where their dynamic-market share was just 3.8% in the latest quarter.

Currently, just two drugs that tackle RA by inhibiting Janus kinase (JAK) enzymes are available across the European Union. The European Commission cleared the first of the JAK inhibitors for marketing in February 2017.

Competitive market

Conventional disease-modifying anti-rheumatic drugs (DMARDs), such as methotrexate, are routinely used as first-line treatments for RA in the EU5 markets. Originator biologics and biosimilars for RA (e.g., TNF-inhibitors), as well as targeted synthetic DMARDs, are generally reserved for patients who may not respond well to DMARDs .

A number of other JAK inhibitors for RA and associated autoimmune conditions are in late-stage clinical development. Also raising the competitive stakes are lower-cost biosimilar versions of injectable biologics for RA, as the latter progressively lose patent protection in Europe.

Of particular interest to physicians and healthcare systems in the EU5 markets will be the pending biosimilar challenge to the market-leading TNF inhibitor brand Humira (adalimumab). In Europe, biosimilar competition is expected to arrive sometime in the fourth quarter of 2018, once Humira’s primary European patent protection expires this October.

Oral advantage

Nonetheless, the advantages of convenient oral administration with JAK inhibitors may be overriding cost considerations that would otherwise favour biosimilar uptake.
In France, for example, which showed the strongest uptake of JAK inhibitors in the Therapy Watch RA study, there has been a concerted effort to encourage use of biosimilars, including leeway for pharmacists to substitute originator biologics under certain conditions.

Another encouraging signal from the EU5 markets is that use of the JAK inhibitors for RA is not confined to later lines of therapy. On the contrary, Therapy Watch data showed the new drugs being prescribed as first-line therapy following treatment failure with standard DMARDs.

When physicians were asked to cite their reasons for choosing JAK inhibitors in Q2 2018, foremost among these were rapid onset of action, route of administration, improvement in patient quality of life, and control of RA flares.

Oral administration is seen as particularly attractive. The largest difference – 15% – in reasons to prescribe between the JAK inhibitors and other advanced therapies is the route of administration, compared with a 4% difference overall in reasons to prescribe between the two product classes.

About the study

Therapy Watch RA is an online tracking study conducted among 40 rheumatologists in each of the EU5 countries each quarter. Physicians submit Patient Report Forms detailing therapy choices for RA, psoriatic arthritis and axial spondyloarthritis patients. At least 50% of these patients must be dynamic (initiating or switching onto their current advanced therapy in the three months prior to their inclusion in the study), and all patients must be on an advanced therapy. The data are weighted based on physician workload to ensure an accurate representation of market dynamics.