What Lies Ahead for the Big Three RA Drugs?

Are biosimilars that can potentially compete with Humira, Enbrel, and Remicade going to be able to pose a threat to the “Big Three” rheumatoid arthritis (RA) biologics?

What about other new products currently on the horizon for the treatment of RA? Seeking Alpha recently analyzed the large RA market—expected to be upwards of $20 billion by 2020--with special attention to biosimilars and new RA medications waiting in the wings and weighs in what the future might bring.

RA affects approximately 4.9 million people globally (1.3 million Americans). The biologics Humira, Enbrel, and Remicade are usually used as a second-line treatments when patients do not have an adequate response to the first-line treatment for RA, usually disease-modifying antirheumatic drugs (DMARDs) like methotrexate. But about a third of RA patients have an inadequate response to DMARDs, so biologics for RA can be used in conjunction with DMARDs to increase clinical remission rates, or in some cases, as a first-line treatment. Most biologics marketed for RA are tumor necrosis factor-alpha (TNF-alpha) inhibitors, which have demonstrated high efficacy when combined with DMARDs, and strong safety profiles, with adverse events and serious adverse events similar to those seen with methotrexate therapy.

In the RA market, biologics have the highest rate of sales growth: over 92% of global RA sales come from biologics. Yet, as Seeking Alpha notes, biologics are not the first-line treatment for RA, so DMARDs and other therapies have a higher volume but generate less than 10% of total sales because of their low pricing.

The top-selling biologics (including all approved indications) globally were AbbVie (Humira) with a third of the market, Amgen (Enbrel) and Johnson & Johnson (Remicade) with 17% each, and Rituxan (Genentech) with 14% of the market (Rituxan’s main sales are for cancer). Simponi (Janssen) sales, at 6% of the market, is the next largest seller among biologics. Thus, the “Big Three” are far above the rest of the biologics. But by 2018 there should be a biosimilar of each of the Big Three drugs on the US market, says Seeking Alpha, after which it’s expected that sales in the RA market will begin to contract as more biologics and biosimilar enter the market and put pricing pressure on the industry.

So far, however, only one biosimilar has launched: Pfizer’s Inflectra, a biosimilar for Remicade. Seeking Alpha believes that Inflectra will likely negatively affect the sales of all biologics, not just Remicade. But Amjevita, an approved biosimilar for Humira, is not expected to launch in the US until 2018 at the earliest as it appears to be caught up in litigation delays, as is Erelzi, an approved Enbrel biosimilar. Other potentially approvable biosimilars are still in Phase III development.

Beyond biosimilars, according to Seeking Alpha, there looms approvals of new RA treatments immediately on the horizon that show high clinical efficacy even as monotherapies, especially for patients who failed prior TNF-alpha inhibitor treatments. The closest to launch among these is baricitinib (Lilly/Incyte), which may be a “blockbuster” because it is an oral treatment and has shown clinical superiority over both Humira and Xeljanz, the other Janus kinase (JAK) inhibitor on the market. It has a strong safety profile. The deadline for the FDA to review the NDA for baricitinib is January 19, 2016, so unless there are delays, baricitinib could be launched this year. There are many other drugs for RA in the US pipeline as well.

Summing Up

In the near future, Pfizer--the first to market with a Remicade biosimilar—will likely benefit from being able to generate sales while the other biosimilars fight it out in court. But once baricitinib enters the market, all of the RA products will feel it, especially if baricitinib can position itself ahead of TNF-alpha inhibitors. Johnson & Johnson may stop some of the losses caused by Inflectra if its new RA products in the pipeline launch, but it will likely see a decline in market share. AbbeVie should do well because Humira’s longer effectiveness remains a selling point, and the company is fighting Amgen’s Humira biosimilar in court. AbbeVie’s new RA drug in the pipeline is expected to help keep revenues flowing should baricitinib be the blockbuster it may become. Finally, Amgen appears to be the least well positioned in the RA market because Amjevita, its biosimilar to Humira, is tied up in a legal fight, and the company has no products in its pipeline for RA besides biosimilars.