MADRID – , according to a secondary endpoint analysis of the phase 3, double-blind, randomized, controlled focuSSced trial.
After 48 weeks, a significantly lower proportion of patients treated with tocilizumab than placebo experienced any decline in lung function from baseline (50.5% versus 70.3% (P = .015), as defined by the percentage increase in predicted forced vital capacity (%pFVC). When only patients with interstitial lung disease (ILD) were considered, the respective percentages were 51.7% and 75.5% (P = .003).
In SSc-ILD patients, a clinically meaningful decline of 10% or more of the %pFVC in lung function was seen in 24.5% given placebo but in just 8.6% of those treated with tocilizumab.
“ILD is a major complication of scleroderma; it has high morbidity and mortality ... and it’s largely irreversible,”, said at the European Congress of Rheumatology.
“In this day and age, when we treat ILD, we wait for a patient to develop clinical ILD,” added Dr. Khanna, director of the scleroderma program at the University of Michigan, Ann Arbor. Clinical ILD can be defined by symptoms, abnormal pulmonary function tests, and marked abnormalities on high resolution computed tomography (HRCT) scans. He indicated that if improving ILD was not possible, then the next best thing would be to stabilize the disease and ensure there was no worsening in lung function.
As yet, there are no disease-modifying treatments available to treat SSc but there are “ample data that interleukin-6 plays a very important role in the pathogenesis of scleroderma,” Dr. Khanna observed. Tocilizumab is a humanized monoclonal antibody against the interleukin-6 receptor.
Data from the phase 2showed initial promise for the drug in SSc where a numerical, but not statistically significant, improvement in skin thickening was seen, and the results had hinted at a possible benefit on lung function ( ).
However, in the phase 3, there was no statistically significant difference in the change from baseline to week 48 modified Rodnan skin score (mRSS) between tocilizumab and placebo, which was the primary endpoint. The least square mean change in mRSS was –6.14 for tocilizumab and –4.41 for placebo (P = .0983).
A total of 205 patients with SSc were studied and randomized, 1:1 in a double-blind fashion, to receive either a once-weekly, subcutaneous dose of 162 mg tocilizumab or a weekly subcutaneous placebo injection for 48 weeks.
For inclusion in the study, patients had to have SSc that met American College of Rheumatology and European League Against Rheumatism (EULAR) criteria and be diagnosed less than 60 months previously. Patients had to have an mRSS of 10-35 units and active disease with one or more of the following: C-reactive protein of 6 mg/L or higher; erythrocyte sedimentation rate of 28 mm/h or higher; and platelet count of330 x 109 L.
“What was astonishing in the trial was that every patient had HRCT at baseline and at the end of the study,” Dr. Khanna reported. These scans showed that 64% of patients had evidence of ILD at baseline and that those treated with tocilizumab had less evidence of fibrosis at week 48 versus placebo, indicating a stabilization rather than worsening of disease.
A time to treatment failure analysis also favored tocilizumab over placebo, but there were no significant changes in patient-reported outcomes.
Dr. Khanna’s slides stated that “given that the primary endpoint for mRSS was not met, all other P values are presented for information purposes only and cannot be considered statistically significant despite the strength of the evidence.” During the Q&A after his presentation, he noted that it was unlikely that the study’s sponsors (Roche/Genentech) will now pursue a license for tocilizumab in SSc.
Nevertheless, Dr. Khanna concluded, “we have the opportunity, based on these data, to treat these patients early on, where you can preserve the lung function, which is a paradigm shift versus waiting for the lung function to decline, become clinically meaningful, significant, and then treat this patient population.”
Roche/Genentech sponsored the study. Dr. Khanna acts as a consultant to Roche/Genentech and eight other pharmaceutical companies. He owns stock in Eicos Sciences.
SOURCE: Khanna D et al. Ann Rheum Dis. Jun 2019;78(Suppl 2):202-3.