Psoriasis is a key battleground for several Big Pharma, seeking to gain or maintain market share for their biologic drugs in the face of growing competition – including cheaper copies of AbbVie’s Humira (adalimumab), whose multiple licensed indications include psoriasis.
It is all good news for the estimated 125 million patients suffering with this chronic, inflammatory skin disease, who now enjoy a much wider range of treatment options. Psoriasis is characterised by scaly, crusty lesions on the skin, scalp or nails, which can be sore and itchy, and are caused by abnormally rapid skin-cell growth cycles. Symptoms may come and go; stress and diet just two of the possible triggers. Although scientists understand a lot more about psoriasis than they did 20 years ago, the exact cellular mechanisms of this auto-immune disorder remain elusive.
Hence there is no cure for psoriasis. Treatment may begin with vitamin D analogs or topical corticosteroids, progressing to photo-therapy, systemic oral drugs such as ciclosporin or methotrexate and, in the most severe cases, injectable biologics such as Humira, Remicade and a growing cohort of monoclonal antibodies that target pro-inflammatory molecules called cytokines.
It is here – among the injectable therapies for psoriasis – that the clinical and commercial battle is being fought most vigorously. AbbVie’s IL-23 inhibitor Skyrizi (risankizumab) is the most recent entrant, gaining approval earlier in 2019 in the US and Europe for patients with mid- to severe plaque psoriasis. It is hoping the drug will contribute $5 billion (across several indications) to revenues by 2023, helping plug at least a bit of the gaping hole left by the $20 billion Humira juggernaut. Meanwhile, the company continues to defend Humira against the biosimilar onslaught, already underway in Europe, and due to hit the US in 2023.
Indeed, AbbVie licensed Skyrizi, in 2016, from the very same Boehringer Ingelheim that is now snapping at its heels with a biosimilar adalimumab. The companies settled some patent litigation in May 2019, delaying BI’s biosimilar launch in the US until July 2023 and putting the German company on the hook for IP-related royalty payments. But royalties may flow the other way, too, if Skyrizi sells as well as the partners hope.
One tailwind may come from Johnson & Johnson’s Phase III ECLIPSE study, which pitted its own Tremfya (guselkumab) head-to-head against Novartis’ top-selling Cosentyx (secukinumab). Tremfya, like Skyrizi, inhibits an inflammation-linked cytokine called IL-23, while Cosentyx targets IL-17A. Data from ECLIPSE, published in December 2018, showed that Tremfya improved patients’ psoriasis severity scores more than Cosentyx did. That could pull Skyrizi along too –plus the AbbVie drug is dosed quarterly, rather than once every two months as for Tremfya, potentially adding points for convenience.
Novartis is not sitting still, however. With 2018 sales of $2.8 billion, Cosentyx is the Swiss group’s largest drug, and it is growing strongly across psoriasis and related conditions such as psoriatic arthritis (swelling and pain in the joints) and ankylosing spondylitis (inflammation of the spinal joints). Cosentyx has over five years’ worth of efficacy and safety data from the over 200,000 patients treated so far. The Swiss group is aggressively defending its territory with further clinical studies.
These include ARROW, designed to prove that targeting IL-17A is more effective, mechanistically, than hitting IL-23. Novartis believes that IL-17 is a more pivotal cytokine, common to more disease-causing pathways than IL-23.
ARROW is expected to read out at the end of 2019. Meanwhile, other players like Eli Lilly with IL-17A inhibitor Taltz (ixekizumab) are themselves trying to find a competitive edge: Lilly is pushing the drug’s effectiveness in the long-term (five-year) maintenance of clear skin.