Pfizer’s immunology portfolio includes the JAK inhibitor Xeljanz and a pipeline of five mid- to late-stage experimental drugs—a huge stable of assets that seems well-positioned to fuel strong growth over the next five years.
But one influential Wall Street firm took a deep dive into that immunology portfolio and found a troublesome undercurrent that made its analysts wonder just how much it will really contribute to Pfizer’s future growth.
Analysts at SVB Leerink warned clients in a note on Wednesday that “our review of the competitive landscape suggests Pfizer’s compounds could be beaten on speed to market, or better clinical data, in nearly all indications.”
One challenge is that Pfizer is heavily dependent on JAK inhibitors, SVB Leerink said. Xeljanz is approved to treat rheumatoid arthritis, psoriatic arthritis and ulcerative colitis. Pfizer’s nearest-term prospect in its immunology portfolio is JAK inhibitor abrocitinib, which is in phase 3 trials to treat atopic dermatitis.
The SVB Leerink analysts expect abrocitinib to be bringing in $2 billion in sales by 2027. Another phase 3 JAK inhibitor, PF-06651600 for alopecia, should peak at $500 million a year, they added.
But abrocitinib will likely carry the Black Box warning that the FDA has slapped on the JAK class, which warns of a high risk of serious infections, cancer, blood clots and other issues. That warning “should relegate the drug to [second-line] behind Regeneron’s Dupixent until physicians gain experience and confidence in the product.”
Dupixent is far from the only rival drug that could pose challenges for Pfizer. AbbVie’s JAK inhibitor Rinvoq, approved to treat rheumatoid arthritis last year, could score a green light in atopic dermatitis before abrocitinib does, SVB Leerink analysts predicted. “In this situation, abrocitinib would not offer as much safety as Dupixent, or the efficacy of Rinvoq, and we'd expect it to struggle to gain market share,” they said.
Last month, AbbVie released clinical trial data showing that Rinvoq was better than placebo at producing a 75% drop in atopic dermatitis symptoms and clear or almost clear skin after 16 weeks. At the time, SVB Leerink predicted Rinvoq could become the standard of care for patients who don’t do well on Dupixent.
Pfizer has produced some positive data of its own, though it hasn’t yet been impressive enough to convince analysts that abrocitinib will shoot to the top of the competitive class of JAK inhibitors. Last October, Pfizer said the drug produced clear or almost clear skin in 43.8% of eczema patients participating in a phase 3 trial, versus 7.9% of those taking a placebo. More recently, Pfizer reported a statistically significant improvement in symptoms among teenagers in a phase 3 trial.
Pfizer is also testing a TYK2 inhibitor in psoriasis, but it’s facing stiff competition there, too. Bristol Myers Squibb is working on a TYK2 inhibitor, BMS-986165. SVB Leerink analysts pointed out that BMS recently posted clinical trial data suggesting its drug could offer double the effectiveness of Otezla, the drug BMS had to sell to Amgen in order to consummate its Celgene takeover. Add to that the fact that Pfizer is roughly two years behind BMS, and it’s hard to imagine it could make much of a mark in TYK2 inhibition, SVB Leerink said.
All in all, the analysts are projecting that Pfizer’s immunology sales will be flat this year and next at about $4.3 billion. From there, sales could grow 5% to 10% a year, they said—but only if the company’s JAK inhibitors are successful.
Ultimately, though, Pfizer may not be well-positioned to grab a significant piece of a rapidly growing market. “Global JAK inhibitor sales could grow from $2.7bn to $19.3bn with additional launches and indications,” SVB Leerink predicted, “but if it materializes, Pfizer might get only a small share.”