The general consensus surrounding the FDA advisory panel’s 8-2 vote in favor of Pfizer’s rheumatoid arthritis hopeful tofacitinib yesterday was that Abbott’s Humira doesn’t have to watch its back.
“Tofa has yet to demonstrate any clear advantages with respect to either efficacy or safety,” Deutsche analyst Barbara Ryan wrote in a research note.
“Humira should not be threatened,” was a sub-headline in an analysis by Jefferies analyst Jeffrey Holford, who went on to write, “we believe that many commentators have overestimated the ability of tofacitinib to have an impact on Humira’s sales growth.”
The oral drug is slated for an overall agency review in August, but the advisory panel’s consensus may guide the final decision as to whether this JAK3 inhibitor will be allowed into the marketplace, which would put it in pursuit of the same patients Amgen chases with the injectable RA biologic Enbrel, which until recently Pfizer had co-promoted in the US. (Pfizer still retains overseas rights to the biologic.)
Like Enbrel and Humira, which are approved across multiple autoimmune diseases, tofa is being studied in other indications, too, and these could boost revenues. “In a category of products that sells ~$25B/yr (for rheumatoid arthritis and other indications that many of the existing products have—tofacitinib is being studied in these too) and is still growing double digits percent, it is easy to see tofacitinib hitting—and likely surpassing—our current sales estimates of $1.7B in 2016 and $2.5B in 2020,” wrote Bernstein Research’s Tim Anderson, in an estimate which was issued after the vote and which assumes approval of both the 5mg and 10mg doses.
Although the panel’s vote suggests a “yes,” it’s still not a clear win for the drug. As expected, committee members knocked the 10mg dose in favor of a 5mg dose, and even floated the idea of a 3mg dose which Pfizer had not tested. Among the concerns are malignancy rates, shown to increase with exposure, and tests showing 10mg really didn’t do anything significant in terms of slowing disease progression, compared with the 5mg version.
The pill also seems to suppress the immune system, and Pfizer is recommending patients be vaccinated with the shingles vaccine before going on tofacitinib. Jefferies’ Holford noted that this could make it harder to switch patients from anti-TNF medications because they’d need a gap between their current treatment and the vaccine before starting tofacitinib. In a run-up to the panel vote, ISI Group analyst Mark Schoenebaum said the drug would most likely target TNF switchers during its first two to three years on the market.
