Initial predictors of skin thickness progression in patients with diffuse cutaneous systemic sclerosis: Results from a multicentre prospective cohort in Japan

Enrichment strategies for clinical trials targeting skin fibrosis and interstitial lung disease in systemic sclerosis

PURPOSE OF REVIEW

This review gives an update on enrichment strategies for clinical trials in patients with systemic sclerosis (SSc) in two contexts - skin fibrosis in early diffuse cutaneous disease, and SSc-related interstitial lung disease (ILD) - focusing on reports from the last 18 months. Lessons have been learnt from recent studies, making this review timely.

RECENT FINDINGS

Recent trials have highlighted how patients included into trials must be carefully selected to include 'progressors', that is, those most likely to benefit from treatment, and how drug mechanism action of action will influence trial design. For skin fibrosis, current enrichment strategies are mainly on clinical grounds (including disease duration, extent of skin thickening, tendon friction rubs and anti-RNA polymerase III positivity). Gene expression signatures may play a role in the future. For ILD, current enrichment strategies (degree of lung involvement as assessed by pulmonary function and high-resolution computed tomography) may help to recruit the most informative patients, but should avoid being too stringent to be feasible or for findings to be generalizable.

SUMMARY

Both skin fibrosis and ILD trials are challenging in SSc. Ongoing work on enrichment strategies should help to differentiate effective new treatments from placebo with smaller sample sizes than have been included in recent studies.

Scleroderma Skin: How Is Treatment Best Guided by Data and Implemented in Clinical Practice?

As skin involvement is the hall mark of systemic sclerosis (SSc) and changes of skin involvement have shown to correlate with internal organ involvement, assessing the extend of skin involvement is key. Although the modified Rodnan skin score is a validated tool used to evaluate the skin in SSc, it has its drawbacks. Novel imagine methods are promising but should be further evaluated. As for molecule markers for skin progression there are conflicting data on the predictive significance of baseline SSc skin gene expression profiles, but immune cell type signature in SSc skin correlates with progression.

Skin involvement in early diffuse cutaneous systemic sclerosis: an unmet clinical need

Diffuse cutaneous systemic sclerosis (dcSSc) is associated with high mortality resulting from early internal-organ involvement. Clinicians therefore tend to focus on early diagnosis and treatment of potentially life-threatening cardiorespiratory and renal disease. However, the rapidly progressive painful, itchy skin tightening that characterizes dcSSc is the symptom that has the greatest effect on patients' quality of life, and there is currently no effective disease-modifying treatment for it. Considerable advances have been made in predicting the extent and rate of skin-disease progression (which vary between patients), including the development of techniques such as molecular analysis of skin biopsy samples. Risk stratification for progressive skin disease is especially relevant now that haematopoietic stem-cell transplantation is a treatment option, because stratification will inform the balance of risk versus benefit for each patient. Measurement of skin disease is a major challenge. Results from clinical trials have highlighted limitations of the modified Rodnan skin score (the current gold standard). Alternative patient-reported and other potential outcome measures have been and are being developed. Patients with early dcSSc should be referred to specialist centres to ensure best-practice management, including the management of their skin disease, and to maximize opportunities for inclusion in clinical trials.

Outcomes in patients with systemic sclerosis undergoing early versus delayed intervention with potential disease-modifying therapies

OBJECTIVE

To examine whether early therapeutic intervention, compared with delayed intervention, is beneficial for patients with early systemic sclerosis (SSc).

METHODS

This is a single-center, retrospective cohort study of SSc patients who received cyclophosphamide, mycophenolate mofetil, methotrexate, or tocilizumab for diffuse cutaneous SSc (dcSSc) or interstitial lung disease (ILD) within 6 years after disease onset. The patients were divided into early and delayed intervention groups based on the disease duration of ≤ 18 and >18 months at treatment introduction, respectively. Clinical worsening was defined as the development of any original or revised ACR Composite Response Index in Systemic Sclerosis (CRISS) step 1 event or progressive fibrosing ILD (PF-ILD).

RESULTS

There was no difference in baseline characteristics between the early (n = 25) and delayed (n = 21) intervention groups except forced vital capacity (FVC), which was better in the early vs delayed intervention groups. The early intervention group less frequently had stable pulmonary function over one year than did the late intervention group (odds ratio 0.087, 95% confidence interval 0.0079-0.51, p = 0.003). The active disease was significantly decreased from 79% to 42% in the early intervention group (p = 0.007), but the change in the delayed intervention group was not statistically significant (68% to 42%, p = 0.11). Cumulative rates free from clinical worsening events defined by revised ACR-CRISS and PF-ILD were significantly higher in the early vs delayed intervention groups (p = 0.03 and 0.003, respectively).

CONCLUSION

A therapeutic "window of opportunity" might exist in SSc patients.

The rationale for targeting the JAK/STAT pathway in scleroderma-associated interstitial lung disease

The etiopathogenesis of systemic sclerosis (SSc)-associated interstitial lung disease (ILD) is still debated and no therapeutic options have proved fully effective to date. The intracellular Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is highly conserved among either immune or nonimmune cells and involved in inflammation and fibrosis. Evidence from preclinical studies shows that the JAK/STAT signaling cascade has a crucial role in the differentiation of autoreactive cells as well as in the extracellular matrix remodeling that occurs in SSc. Therefore, it is likely that the use of oral small molecule JAK-inhibitors, especially if prescribed early, may prevent or slow the progression of SSc-associated ILD, but few clinical studies currently support this hypothesis.

Efficacy and safety of nintedanib in Asian patients with systemic sclerosis-associated interstitial lung disease: Subgroup analysis of the SENSCIS trial

BACKGROUND AND OBJECTIVE

In the SENSCIS trial in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD), nintedanib reduced the rate of decline in forced vital capacity (FVC) (mL/year) over 52 weeks by 44% in comparison with placebo, with manageable adverse events in most patients. We analyzed the efficacy and safety of nintedanib in patients of Asian race.

METHODS

Patients with SSc-ILD were randomized to receive nintedanib or placebo. The outcomes over 52 weeks were analyzed in Asian versus non-Asian patients.

RESULTS

Of the 288 patients in each treatment group, 62 (21.5%) in the nintedanib group and 81 (28.1%) in the placebo group were Asian; 90.2% of the Asian patients were enrolled in Asian countries. In the placebo group, the rate of FVC decline over 52 weeks was consistent between Asian and non-Asian patients (-99.9 and -90.6 mL/year, respectively). The effect of nintedanib on reducing the rate of FVC decline over 52 weeks was consistent between Asian (difference, 44.3 mL/year [95% CI: -32.8, 121.4]) and non-Asian patients (difference, 39.0 mL/year [95% CI: -5.1, 83.1]) (treatment-by-time-by-subgroup interaction, p = 0.91). Diarrhea was the most frequent adverse event and was reported in similar proportions of Asian and non-Asian patients in the nintedanib group (80.6% and 74.3%, respectively) and placebo group (28.4% and 32.9%, respectively).

CONCLUSIONS

In patients with SSc-ILD, nintedanib had a consistent benefit on slowing the progression of SSc-ILD in Asian and non-Asian patients, with a similar adverse event profile.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02597933.