Decision Resources Group finds that the rheumatoid arthritis (RA) disease-modifying antirheumatic drug market will increase from $14 billion in 2013 to over $18.2 billion in 2023 in the US, France, Germany, Italy, Spain, the UK and Japan. TNF-alpha inhibitors will remain the leading drug class in both sales and patient shares in the RA market, but growth will be constrained and patient shares will decline due to the uptake of oral Janus kinase (Jak) inhibitors and the entry of alternative biological agents. In particular, the growth of the Jak inhibitor drug class, driven by the anticipated approval of Pfizer's tofacitinib (Xeljanz) in Europe and two emerging drugs (Eli Lilly/Incyte's baricitinib and Vertex's VX-509), will be the major contributor to the growth of the RA market from 2013 to 2023. Biosimilars of major TNF-alpha inhibitors—Janssen/Merck/Mitsubishi Tanabe's Remicade, followed by Amgen/Pfizer/Takeda's Enbrel and AbbVie/Eisai's Humira—are expected to launch by the end of 2014. While the uptake of biosimilars will constrain the sales of TNF-alpha inhibitors, it may help maintain the patient share of this drug class in the face of emerging therapies.
Other key findings from the Pharmacor Rheumatoid Arthritis advisory service:
- First-line biologic treatment: TNF-alpha inhibitors are deeply entrenched as first-line biologics in the RA treatment algorithm, as rheumatologists remain relatively satisfied with their efficacy and are comfortable with their long-term safety profiles.
- Use of alternative biologics: Rheumatologists increasingly and more rapidly turn to alternative biologics—Orencia (Bristol-Myers Squibb/Ono Pharmaceutical), Actemra/RoActemra (Roche/Chugai) or rituximab (Biogen Idec/Roche/Chugai/Zenyaku Kogyo's Rituxan, Roche's MabThera)—in patients who fail TNF-alpha inhibitor therapy due to their growing familiarity with the agents and long-term safety data; the preferred alternative biologic varies in the different markets under study.
- Oral agents face uptake hurdles: Although oral agents have the potential to alter the RA treatment algorithm, increasing regulatory pressure to demonstrate strong efficacy on structural progression end points will likely be a hurdle for approval and initial uptake.
Ronnie Yoo, PhD, group analyst at Decision Resources Group says: "TNF-alpha inhibitors continue to dominate as first-line biological agents, accounting for 71% of major-market sales in 2013. However, interviewed rheumatologists estimate that 15–40% of biologic-treated RA patients do not respond to the currently marketed biologics and many experience diminishing efficacy over the course of long-term TNF-alpha inhibitor treatment."
He adds: "Xeljanz will compete for patient share in two areas of the RA treatment algorithm. First, with the non-TNF-alpha inhibitor biologics for patients who fail to respond to TNF-alpha inhibitors. Second, to a lesser degree, it has the potential to compete at the same line of therapy as the TNF-alpha inhibitors, in patients with an inadequate response to methotrexate."