Stifel analyst Paul Matteis called Tuesday’s readout a “positive surprise” that could reinvigorate some investor enthusiasm for Biogen as the company “has essentially become an out-of-favor value stock,” driven by the slow launch of its Alzheimer’s disease therapy Leqembi.
Biogen and UCB announced that their drug candidate dapirolizumab pegol aced the Phase III PHOENYCS GO study in systemic lupus erythematosus, according to a topline readout released on Tuesday.
Data in the announcement were sparse, with the partners only revealing that when used with standard of care, dapirolizumab pegol met its primary efficacy endpoint demonstrating “greater improvement of moderate-to-severe disease activity” at 48 weeks versus placebo. The investigational treatment also elicited “clinical improvements” among its “key secondary endpoints,” such as disease activity and flares.
In terms of safety, dapirolizumab pegol’s side effects were consistent with what had been established in other studies and with the usual toxicities reported in systemic lupus erythematosus (SLE) patients treated with an immunomodulator, according to the companies.
“These results demonstrate that dapirolizumab pegol has the promise to provide meaningful benefit in this serious, chronic, and often devastating disease,” Diana Gallagher, head of the Alzheimer’s disease, multiple sclerosis and immunology disease units at Biogen, said in a statement. Encouraged by Tuesday’s readout, Biogen and UCB will start another Phase III study of dapirolizumab pegol this year, dubbed PHOENYS FLY.
Patients in PHOENYCS GO will be followed in a long-term open-label study, according to the companies’ announcement. Full results will be presented at an upcoming medical congress.
Tuesday’s Phase III win is a bit of a comeback for Biogen and UCB after dapirolizumab pegol failed its mid-stage study back in 2018. At the time, Phase IIb data showed that the drug candidate failed to show a dose response at 24 weeks, as measured using the British Isles Lupus Assessment Group-based Composite Lupus Assessment.
However, the partners decided to gamble on dapirolizumab pegol, pinning their hopes on what they flagged as “consistent and potentially meaningful improvements” across “majority of clinical endpoints.” That bet appeared to pay off on Tuesday with the PHOENYCS GO readout, though it remains to be seen how big the magnitude of dapirolizumab pegol’s effects are.
Stifel analyst Paul Matteis called Tuesday’s readout a “positive surprise” that could reinvigorate some investor enthusiasm for Biogen as the company “has essentially become an out-of-favor value stock,” driven by the slow launch of its Alzheimer’s disease therapy Leqembi.
Still, Matteis cautions that dapirolizumab pegol isn’t in the clear yet, given its mixed mid-stage data. Though this point “doesn’t necessarily detract” from the Phase III win on Tuesday, “it does augment the importance of seeing the full data—and understanding whether it does/doesn’t firmly derisk another” Phase III study.
Jefferies analyst Michael Yee agrees, pointing out that there were no data revealed in the press release, and noting that the partners will need to run a second Phase III study “to confirm the benefits” of dapirolizumab pegol treatment. If approved, however, Yee expects the drug to hit the market from 2027 to 2028 and could unlock a $1 billion to $2 billion opportunity for the companies. In that scenario, Biogen and UCB will co-promote dapirolizumab pegol and split sales evenly.
