As Lilly Deals with Yet Another Set-Back in Entering the US Rheumatoid Arthritis Market, Pfizer's Xeljanz Further Solidifies Its Position as a Go-To Alternate Mechanism of Action Agent, According to a Recently Published Study by Spherix Global Insig

EXTON, Pa., Feb. 20, 2018 /PRNewswire/ — Since receiving a Complete Response Letter from the FDA for their Incyte partnered investigational JAK 1/2 inhibitor, baricitinib (Olumiant), Eli Lilly’s entrance into the rheumatoid arthritis (RA) market has been met with challenge. Most recently, it has been reported that the company, in partnership with Korea-based Hamni Pharmaceutical, will be ceasing development of its investigational Bruton’s TKI inhibitor, LY3337641, due to a lack of efficacy in the RA population.

Despite this newest set-back, Lilly has reported that the FDA has accepted a Class II resubmission of baricitinib, likely initiating a new six month review cycle, and thus allowing Pfizer’s Xeljanz some additional breathing room and time to further capitalize on its status as the only JAK on the US market. Recent feedback from 100 US rheumatologists surveyed in January 2018 suggests Xeljanz is doing just that. Study results reveal that the percent of rheumatologists who prescribe Xeljanz to more than 10% of their RA biologic/JAK-treated patients has consistently grown quarter over quarter since early 2017, while overall brand share for Pfizer’s JAK is also up for the first time in over a year. Satisfaction amongst users is high, and is only surpassed by the market-leading TNF-inhibitors, Amgen’s Enbrel and AbbVie’s Humira. Furthermore, if limited to just three brands for the treatment of RA, Pfizer’s Xeljanz was selected the most frequently, followed by Humira, BMS’ Orencia, and Enbrel. Had Lilly gained approval for baricitinib in January 2017, at their first PDUFA date, this story would likely read much differently.

Looking ahead, use of Xeljanz in the US will likely continue to grow in 2018 and six month projected share reveals rheumatologists anticipate significantly increasing their use of the brand, largely to the detriment of the long-standing TNFs – Enbrel, Humira, and infliximab (Janssen’s Remicade and biosimilars). Furthermore, use of Xeljanz in the US will be further bolstered by the new psoriatic arthritis indication, with rheumatologists predicting rapid incorporation into the PsA treatment armamentarium (RealTime Dynamix™: Psoriatic Arthritis). Another potential catalyst for Xeljanz this year is securing an indication in ulcerative colitis, a win that could give Pfizer more leverage in the payer setting.

Though both Olumiant and Xeljanz are approved in the EU, the JAK battle across the pond is a bit different, where Lilly secured the first-to-market position. Spherix Global Insights’ Q4 publication of RealTime Dynamix™: Rheumatoid Arthritis EU5, revealed that, as of the end of 2017, the two agents were largely seen as interchangeable; however, when rheumatologists (n=257) were asked directly which of the newly approved agents would bring the most value to their practice, Olumiant was selected 2:1 over Xeljanz.

Despite Pfizer’s ability to capitalize on baricitinib’s US delay over the course of 2017 and into early 2018, the agent will likely make its way to the US market during this calendar year. While many rheumatologists would most like to see the next RA approval having a unique mechanism of action compared to those already on the market, familiarity with baricitinib is high and significantly surpasses that of other major JAKs in development for RA, namely AbbVie’s upadacitinib and Gilead/Galapagos filgotinib.

About Spherix Global Insights
Spherix Global Insights is an independent business intelligence and market research company, specializing in renal, autoimmune, neurologic and rare disease markets. Our aim is to apply our commercial experience and unique relationships within core specialty markets to translate data into insight, enabling our clients to make smarter business decisions.

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