RNase drug shows promise for Sjögren’s fatigue



– RSLV-132, a novel drug that eliminates circulating nucleic acids, improved the symptoms of mental fatigue in patients with primary Sjögren’s syndrome (pSS) in a phase 2, double-blind, randomized, placebo-controlled “proof-of-concept” study.

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The mental component of fatigue on the Profile of Fatigue (PRO-F) scale improved by 1.53 points among the patients given RSLV-132, while there was a worsening of 0.06 points in the placebo group (P = .046). Scores range from 0 to 7 on the PRO-F.

There were also improvements in some patient-reported outcomes, namely the EULAR pSS Patient Reported Index (ESSPRI) and the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue (FACIT-F), and improvement of neuropsychological measures of cognitive function, but none were statistically significant. All of these outcomes, including fatigue, were secondary outcomes of the study.

“Fatigue is a major issue for patients with Sjögren’s syndrome,” Wan-Fai Ng, MBChB, PhD, said in an interview at the European Congress of Rheumatology. Indeed, fatigue can be disabling in the majority of individuals, he added.

Currently, the best way to manage fatigue is to first ask about it, said Dr. Ng, who is professor of rheumatology at the Institute of Cellular Medicine at Newcastle University, Newcastle-upon-Tyne, England. He then checks for any underlying problem that could be better managed – sleep problems or anemia, for example – and optimizes treatment for any underlying disease. “I think many people would at least feel satisfied that people take the symptoms seriously.”

Dr. Ng and his coauthors investigated the effects of RSLV-132, a first-in-class human RNase fused to the human Fc domain of human immunoglobulin (Ig) G1, in the RESOLVE 132-04 study. This novel drug been designed to increase serum RNase activity to digest RNA-associated immune complexes, Dr. Ng and associates observed in their abstract. As a consequence of this, they say, activation of toll-like receptors and the production of interferon (IFN) is affected, as is B-cell proliferation and the production of autoantibodies – all mechanisms that are “key to pSS pathogenesis.”

The IFN pathway has been implicated in fatigue, Dr. Ng observed when he presented the RESOLVE 132-04 study’s findings, which involved 30 patients with pSS who had been treated for 3 months. Inclusion criteria were pSS as defined by the American-European Consensus Group 2002 criteria, anti-Ro antibody positivity, and increased expression of three IFN-regulated genes: HERC5, EPSTI1, and CMPK2. Exclusion criteria were the use of hydroxychloroquine, prednisolone at daily doses above 10 mg, and the use of biologic disease-modifying antirheumatic drugs.

Patients were randomized in a 3:1 ratio to receive either 10 mg/kg of RSLV-132 (n = 20) or placebo (n = 8) at weeks 0, 1, 2, and then every fortnight until week 12. Dr. Ng noted that although 30 patients were randomized, two patients had dropped out in the placebo group before they could be “treated.”

The primary endpoint was the change in the blood cell gene expression or serum protein levels indicative of reduced inflammation. The results indicated reductions in noncoding RNA molecules in patients who received RSLV-132 versus placebo, “consistent with the mode of action of the molecule.” In addition, “the majority of inflammatory markers were reduced,” Dr. Ng said.

Another finding showed a nonsignificant trend for improvement of 0.8 units in the physical component in the RSLV-132 group, compared against 0.06 units with placebo (P = .142).

Patients who received RSLV-132 reduced the time needed to complete the Digital Symbol Substitution Test by 16.4 s, compared with an increase of 2.8 s for placebo (P = .024).

Similar trends were observed for ESSPRI and FACIT-F scores.

These are very early data and clearly a bigger study would be needed before any conclusions could be drawn, Dr. Ng said in an interview. What these data suggest is that “maybe there is some way that we could manage fatigue, and we just need to go and explore that.”

RSLV-132 has also been studied in patients with systemic lupus erythematosus (Lupus. 2017;26:825-34).

The trial was sponsored by Resolve Therapeutics. Dr. Ng was an investigator in the trial and disclosed other research collaborations with electroCore, GlaxoSmithKline, and AbbVie. He also disclosed acting as a consultant for Novartis, GlaxoSmithKline, AbbVie, MedImmune, Pfizer, and Bristol-Myers Squibb.

Source: Fisher B et al. Ann Rheum Dis. 2019 Jun;78(suppl 2):177, Abstract OP0202. doi: 10.1136/annrheumdis-2019-eular.3098.

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