Lilly’s Taltz scrapes win against Humira in psoriatic arthritis

Eli Lilly’s Taltz has beaten AbbVie’s blockbuster Humira in a psoriatic arthritis study involving patients who hadn’t been treated before with a disease-modifying drug, but only just.

Lilly reported last year that the SPIRIT-H2H trial had shown Taltz (ixekizumab) met its primary endpoint of superiority to Humira (adalimumab) as measured by the proportion of patients who saw their disease activity cut by 50% as well as complete skin clearance, without providing the data.

At the Annual European Congress of Rheumatology (EULAR) in Madrid it has now revealed that the proportion of patients who achieved the primary endpoint at 24 weeks was 36% with Taltz and 28% with Humira, which just met the threshold for statistical significance with a P value of less than <0.05.

Breaking down the results, the IL-17 inhibitor was found to be around the same as Humira on the 50% improvement in disease activity (ACR50) score – at 51% versus 47% with AbbVie’s drug – and had a stronger impact on the skin clearance (PASI 100) measure (60% versus 47%) with a P value of 0.001.

The results of the open-label phase 3b/4 trial show that most of the benefit over Humira appears to come from resolving the skin symptoms of psoriatic arthritis, an indication for which Taltz was approved in 2017 after getting the go-ahead initially in plaque psoriasis in 2016.

Psoriatic arthritis is a form of arthritis that typically occurs in people with psoriasis, with pain, stiffness, and swelling of the joints often accompanied by a red, scaly rash on the skin.

According to Lilly’s senior medical director for the UK and Northern Europe – Arash Tahbaz – “treatment options which offer potential benefit for both skin and joint symptoms [are] incredibly important.”

The question for Lilly is whether the data are strong enough to encourage doctors to choose Taltz over Humira in psoriatic arthritis, particularly as lower-cost biosimilar alternatives to AbbVie’s $20 billion-a-year brand are now available in Europe and due to reach the US market in 2023, pending the outcome of patent litigation.

In Europe, biosimilar rivals have undercut Humira's list price from 10% to 80%, allowing the UK for example to cut £150 million off its annual £400 million spending on the drug by 2021. Taltz may have edged it on clinical outcomes, but Lilly will have to persuade payers that those benefits warrant a formulary change.

For now, Taltz is the only drug in the IL-17 class to have head-to-head data against Humira in psoriatic arthritis. However, its main rival in the IL-17 space – Novartis – has a superiority trial running for its Cosentyx (secukinumab) drug against Humira (EXCEED) that should have results before the end of this year.

Cosentyx was the first drug in the class to market and brought in $791m in revenues in the first quarter of this year, while Lilly booked $253m in Taltz sales.