VIENNA — The use of immunosuppressive and antifibrotic drugs to treat skin and lung fibrosis leads updated recommendations from the European Alliance of Associations for Rheumatology (EULAR) for the treatment of systemic sclerosis.
"The most impactful new recommendation relates to the evidence for immunosuppressive agents and antifibrotics for the treatment of skin fibrosis and lung fibrosis," said Francesco Del Galdo, MD, PhD, professor of experimental medicine, consultant rheumatologist, and scleroderma and connective tissue diseases specialist at Leeds Teaching Hospitals NHS Trust, Leeds, England. Del Galdo presented the update at the EULAR 2024 Annual Meeting.
"But there are also new recommendations, including a redefined target population for hematopoietic stem cell transplantation following cyclophosphamide, the upfront combination treatment at the time of diagnosis of pulmonary arterial hypertension [PAH], and a negative recommendation for the use of anticoagulants for pulmonary arterial hypertension," noted Del Galdo, highlighting key updates in the 2024 recommendations.
Robert B.M. Landewé, MD, PhD, professor and rheumatologist at Amsterdam University Medical Center, Amsterdam, The Netherlands, and Zuyderland Medical Center, Heerlen, The Netherlands, comoderated the session on EULAR recommendations. "The management of systemic sclerosis is a field in which a lot is happening," he said. "The last update goes back to 2017, and in the meantime, many new approaches have seen the light, especially pertaining to skin fibrosis and interstitial lung disease. Six new recommendations have been coined, covering drugs like mycophenolate mofetil, nintedanib, rituximab, and tocilizumab. None of these therapies were present in the 2017 recommendations. It seems the field is now ready to further expand on targeted therapies for the management of musculoskeletal and gastrointestinal manifestations, calcinosis, and the local management of digital ulcers."
'Therapeutic Continuums' Aid Disease Management
Del Galdo and his colleagues grouped the various interventions across what the recommendations label as evidence-backed "therapeutic continuums." These span six of the eight different clinical manifestations of systemic sclerosis: Raynaud's phenomenon, digital ulcers, pulmonary hypertension, musculoskeletal manifestations, skin fibrosis, interstitial lung disease (ILD), and gastrointestinal and renal crisis.
A slide showing the different strengths of evidence for various drugs across the eight manifestations illustrated the principle behind the therapeutic continuums. "These 'therapeutic continuums' suggest a common pathogenetic mechanism driving the various manifestations of disease," said Del Galdo. For example, he noted, "If rituximab had a positive response in skin and in lung, it suggests that B cells play a role in the clinical manifestations of skin and lung in this disease."
Del Galdo highlighted the new immunosuppression continuum and associated treatments for skin and lung fibrosis. "For skin involvement, the task force recommended mycophenolate, methotrexate, and rituximab, with tocilizumab having a lower level of evidence and lower recommendation strength; similarly, in interstitial lung disease, we have rituximab, mycophenolate, cyclophosphamide, and nintedanib, and these all have the highest strength of evidence. Tocilizumab is assigned one strength of evidence below the other drugs."
He also cited the phosphodiesterase 5 inhibitor (PDE5i) drugs that are used across Raynaud's phenomenon, digital ulcers, and pulmonary arterial hypertension, which together form a vascular therapeutic continuum.
The complexity of systemic sclerosis and multiple manifestations was a major determinant of the recommendations, Del Galdo pointed out. "The task force realized that since this is such a complex disease, we cannot recommend one treatment unconditionally. For example, with mycophenolate mofetil, what works for most patients for the skin and lung manifestations might not for someone who experiences severe diarrhea, in which mycophenolate is contraindicated. So, the highest degree of recommendation that the task force felt comfortable with was 'should be considered.'"
Del Galdo stressed that the complex nature of systemic sclerosis means that "when thinking of treating one manifestation, you also always need to consider all the other clinical manifestations as experienced by the patient, and it is this multifaceted scenario that will ultimately lead to your final choice."
Turning to new evidence around drug use, Del Galdo said that rituximab has the highest level of evidence across skin and lung manifestations, nintedanib is new in lung, and tocilizumab is new across both skin and lung.
To treat systemic sclerosis-pulmonary arterial hypertension (SSc-PAH), as long as there are no contraindications, the task force recommends using PDE5i and endothelin receptor antagonists (ERAs) at diagnosis. Data from phase 3 trials show a better outcome when the combination is established early.
The task force suggests avoiding the use of warfarin in PAH. "This is supported by a signal from two trials showing an increase in morbidity and mortality in these patients," noted Del Galdo.
He also pointed out that selexipag and riociguat were new and important second-line additions for the treatment of PAH, and —consistent with the ERA approach — the EULAR recommendation supports frequent follow-up to establish a treat-to-target approach to maximizing clinical outcomes in SSc-PAH and SSc-ILD. "Specifically, for the first time, we recommend monitoring the effect of any chosen intervention selected within 3-6 months of starting. The evidence suggests there is a group of patients who respond and some who respond less well and who might benefit from a second-line intervention."
For example, results of one trial support the approach of adding an antifibrotic agent to reduce progression in people with progressive lung fibrosis. "Similarly, for pulmonary hypertension, we recommend putting patients on dual treatment, and if this fails, place them on selexipag or switch the PDE5i to riociguat," Del Galdo said.
Systemic Sclerosis Research Agenda and Recommendations Align
Del Galdo highlighted the value of therapeutic continuums in advancing disease understanding. "It is starting to teach us what we know and what we don't and where do we need to build more evidence. Effectively, they determine where the gaps in therapy lie, and this starts to guide the research agenda.
"In fact, what is really interesting about this recommendation update — certainly from the perspective of disease understanding — is that we are starting to have a bird's eye view of the clinical manifestations of scleroderma that have so often been dealt with separately. Now we are starting to build a cumulative evidence map of this disease."
In 2017, the research agenda largely advocated identifying immune-targeting drugs for skin and lung fibrosis, Del Galdo pointed out. "Now, we've done that — we've identified appropriate immunosuppressive drugs — and this is testimony to the importance of these recommendations because what prioritized the research agenda 10 years ago ended up informing the clinical trials and made it into the recommendations."
"We definitely are one step forward compared to this 2017 recommendation and closer to what we would like to do," he asserted.
Remission Elusive but Getting Closer
In some respects, according to Del Galdo, research and development is making relatively slow progress, especially compared with other rheumatologic diseases such as rheumatoid arthritis. "We cannot put patients with systemic sclerosis in remission yet. But I think we are one step ahead in that we've now established the treat-to-target approach to maximize the efficacy with which we can stall disease progression, but we cannot yet put these patients into remission," he said. Systemic sclerosis has multiple manifestations, and fibrotic damage cannot be reversed. "Right now, the scar will remain there forever," he noted.
Until remission is achievable, Del Galdo advises diagnosing and treating patients earlier to prevent fibrotic manifestations.
Del Galdo explained the three leading priorities on the systemic sclerosis research agenda. "There are three because it is such a complex disease. The first is considering the patient voice — this is the most important one, and the patients say they want a more holistic approach — so trialing and treating multiple manifestations together."
Second, Del Galdo said he would like to see a patient-reported measure developed that can capture the entire disease.
Third, from a physician's point of view, Del Galdo said, "We want to send the patients into remission. We need to continue to further deconvolute the clinical manifestations and find the bottleneck at the beginning of the natural history of disease.
"If we can find a drug that is effective very early on, before the patients start getting the eight different manifestations with different levels of severity, then we will be on the right road, which we hope will end in remission."
Del Galdo has served on the speaker's bureau for AstraZeneca and Janssen; consulted for AstraZeneca, Boehringer Ingelheim, Capella, Chemomab, Janssen, and Mitsubishi-Tanabe; and received grant or research support from AbbVie, AstraZeneca, Boheringer Ingelheim, Capella, Chemomab, Kymab, Janssen, and Mitsubishi-Tanabe. Landewé had no relevant disclosures.
Becky McCall, MSc, MScPH, is a medical journalist based in London, United Kingdom.