In upcoming skin disease clash, doctors see Novartis' Cosentyx as an underdog

Atopic dermatitis and psoriasis are well-established battlefields for anti-inflammatory biologic drugs. Now, two drugmakers are preparing to launch products in a lesser-known disease area with significant unmet medical need: hidradenitis suppurativa (HS).

With an FDA decision expected in the second half of 2023, Novartis’ Cosentyx looks on track to become the next biologic agent in HS, a painful skin disease where only one biologic treatment, AbbVie’s off-patent Humira, is approved in the U.S.

But two dermatologist opinion leaders believe a rival—UCB’s bimekizumab—may actually have an advantage over Cosentyx, according to analysts at SVB Securities.

In data recently shared at the American Academy of Dermatology's annual meeting, bimekizumab significantly beat placebo on the proportion of patients who achieved at least 50% reduction of inflammatory lesions on an endpoint called hidradenitis suppurativa clinical response (HiSCR50).

At two different dosing schedules, treatment with bimekizumab led to an absolute HiSCR50 advantage over placebo ranging from 16.1 percentage points to 21.6 percentage points at Week 16 across two phase 3 studies.

On a similar trial marker that identifies non-responders slightly differently, bimekizumab’s edge hit higher at between 19.5 percentage points to 26.3 percentage points. In a March note, analysts at SVB pointed out this marker is more relevant for comparisons because it’s used in other pivotal studies, including Cosentyx’s trials.

By comparison, Cosentyx, in its own two phase 3 trials, helped more patients achieve HiSCR50 than placebo did, with the differences ranging between 8.1 percentage points to 14.9 percentage points for the Novartis drug.

Both experts view bimekizumab’s data as “incrementally better than” Cosentyx, according to a new SVB note. While Cosentyx targets IL-17A, bimekizumab inhibits IL-17A and IL-17F, which might explain its better efficacy, one doctor said.

Bimekizumab does appear to have one tolerability issue; the drug was linked to an increased risk of an infection called oral candidiasis. But both experts believe the additional efficacy is still worth it given the debilitating nature of HS symptoms, the SVB analysts wrote.

HS comes with painful, boil-like abscesses that can become open wounds. The disease is estimated to affect about 1 in 100 people globally. But because of relatively low disease awareness among non-dermatologists, only about half of HS patients are diagnosed, and far fewer are treated, the experts said.

Humira can initially treat about half of HS patients by one expert’s estimate, but she noted that the drug’s efficacy may wane over time. The lack of effective treatment options leaves a significant unmet need.

Novartis hopes HS, along with potential new indications in giant cell arteritis and lupus nephritis, can drive Cosentyx’s next phase of growth. The Swiss pharma estimates that the three indications, if all successful, could bring over $2 billion in additional peak sales for Cosentyx.

Bimekizumab is slightly behind on its regulatory path. After a prior FDA rejection, UCB is awaiting an FDA decision in psoriasis. And the company plans to file for an HS label in the third quarter after a potential psoriasis nod. Meanwhile, the drug won a European go-ahead in psoriasis in December under the brand name Bimzelx.

Despite what appears to be a better efficacy profile, bimekizumab might not be widely used in HS right after approval because of payer access hurdles, one expert figured. She expects the situation will improve for the drug a few years into the launch.