Dapirolizumab Cuts Disease Activity, Steroid Use in SLE

WASHINGTON — The investigational anti-CD40 ligand agent dapirolizumab pegol (DZP) outperformed placebo in improving disease activity and reducing high-dose corticosteroid use in patients with systemic lupus erythematosus (SLE) in the phase 3 PHOENYCS GO trial.

“We really think that dapirolizumab pegol may represent a novel treatment for lupus, particularly given its broad immune modulatory effects,” said Megan Clowse, MD, MPH, associate professor of medicine and chief of the Division of Rheumatology and Immunology at Duke University School of Medicine in Durham, North Carolina. She presented the study in a late-breaking poster session at the American College of Rheumatology (ACR) 2024 Annual Meeting.

There is a “huge unmet need” for drugs for lupus, Clowse told Medscape Medical News. Patients with SLE continue to have high disease burden, including ongoing symptoms often driven by inflammation. Corticosteroids are often the best medications to control disease activity, she said, but they can result in long-term toxicity.

What Makes DZP Unique?

Through CD40 ligand signaling, DZP has been shown to reduce B- and T-cell activation and to downregulate interferon pathways. Previous antibodies targeting the CD40 ligand have been associated with an increased risk for thromboembolic events. However, DZP lacks the Fc portion of the antibody, which can bind to platelets and cause clotting. Data from phase 1, 2, and 3 trials thus far do not show an elevated risk for these events, Clowse explained. In fact, safety signals were strong enough that patients with antiphospholipid antibodies — a key driver for blood clots in patients with SLE — were included in the trial.

In PHOENYCS GO, investigators enrolled 321 patients with moderate to severe SLE with persistently active or frequently flaring/relapsing-remitting disease activity despite stable standard of care (SOC) medications such as antimalarials, corticosteroids, and immunosuppressants.

Patients were randomized 2:1 to receive intravenous DZP (24 mg/kg) plus SOC or intravenous placebo plus SOC every 4 weeks, with patients and investigators blinded to treatment assignments.

Patients taking a corticosteroid dose > 7.5 mg/day began a mandatory steroid taper by week 8 of the trial, with the goal of reducing that to

The primary endpoint was British Isles Lupus Assessment Group–based Composite Lupus Assessment (BICLA) response at week 48.

Patients in the DZP and placebo groups were on average 43.5 and 41.5 years old, respectively. More than 90% of patients were women, all on concomitant SLE medications. About half of the participants took a daily corticosteroid dose > 7.5 mg.

At 48 weeks, half of the DZP group (49.5%) achieved BICLA response compared with 34.6% in the placebo group (P = .0110). A higher proportion of patients taking DZP achieved SLE Responder Index-4 response than those taking placebo (60.1% vs 41.1%, respectively; P = .0014), and the rate of severe British Isles Lupus Assessment Group flares in the DZP group was half that of the placebo group (11.6% vs 23.4%; P = .0257). In the subgroup of patients who underwent corticosteroid tapering, 72.4% receiving DZP and 52.9% taking placebo reduced their dose to P = .0404).

DZP was generally well tolerated. Over 48 weeks, 82.6% of the DZP group and 75% of the placebo group reported treatment-emergent adverse events, but serious occurrences were more common in the placebo group (14.8%) than in the DZP group (9.9%). Herpes viral infections were higher in the placebo group, although there were three ophthalmic herpes cases in the DZP group. There was one case of acute myocardial infarction and one death linked to gangrene-related sepsis in patients receiving DZP.

A ‘Mild to Moderate’ Response

Although these are definitely positive results, they show a “mild to moderate response” to DZP, commented Gregory Gardner, MD, an emeritus professor in the Division of Rheumatology at the University of Washington, Seattle, and chair of the American College of Rheumatology’s annual meeting planning committee. He moderated the session where the research was presented. Although DZP showed efficacy among some patients, he noted, “there were still 51% patients that it didn’t work for.” 

The drug uses an alternative pathway to current lupus drugs, Gardner added, and more research is needed to understand how best to use this medication in practice.

Clowse noted that DZP could be particularly beneficial for patients with SLE who want to get pregnant. Many drugs used to treat the disease are teratogenic; however, “because of the lack of Fc portion on this drug, it very likely does not cross the placenta in any kind of significant amount,” she said. Although there are not yet any reproductive safety data on DZP, she added, “that is a great potential niche.”

Biogen and UCB, which are jointly developing DZP, aim to start a second phase 3 trial of DZP in patients with SLE, called PHOENYCS FLY, in 2024.

The trial was sponsored by UCB. Clowse is a consultant and has received grant/research support from GSK and UCB. Gardner had no relevant disclosures.