Emergence of targeted immune therapies for systemic lupus

The Biomarkers of Lupus Disease Study: A Bold Approach May Mitigate Interference of Background Immunosuppressants in Clinical Trials

OBJECTIVE

Molecular medicine raised expectations for strategically targeted biologic agents in systemic lupus erythematosus (SLE), but clinical trial results have been disappointing and difficult to interpret. Most studies add investigational agents to various, often effective, standard therapy immunosuppressants used at baseline, with unknown treatment interactions. Eliminating polypharmacy in trials of active lupus remains controversial. We undertook the Biomarkers of Lupus Disease study to test withdrawal of immunosuppressants as a novel approach to rendering SLE trials interpretable.

METHODS

In 41 patients with active, non-organ-threatening SLE flare (group A), temporary steroids were given while background immunosuppressants were withdrawn. Time to loss of disease suppression (time to disease flare) and safety were evaluated; standard therapy was immediately resumed when symptoms recurred. Immunologic impacts of standard therapy were studied at baseline by multiplex assay, enzyme-linked immunosorbent assay, and messenger RNA array in group A patients plus 62 additional patients donating a single sample (group B).

RESULTS

Patients with lower or higher baseline disease activity had median times to flare of 71 or 45 days, respectively; 40 of 41 patients (98%) had disease flares by 6 months. All flares were treated and resolved within 6 weeks. No serious adverse events occurred from flare or infection. Type I interferon (IFN), Th17, and B lymphocyte stimulator pathways tracked together. Baseline immunosuppressants had distinct impacts on Th17 and B lymphocyte stimulator, depending on IFN signature.

CONCLUSION

Trials in active, non-organ-threatening SLE can safely withdraw background treatments if patients who have disease flares are designated nonresponders and returned to standard therapy. Immunologic effects of standard therapy vary between IFN-defined subsets. These findings provide a strategy for minimizing or optimizing treatment combinations in lupus trials and clinical care.

Immunomodulatory drug CC-4047 is a cell-type and stimulus-selective transcriptional inhibitor of cyclooxygenase 2

COX2 (prostaglandin G/H synthase, PTGS2) is a well-validated target in the fields of both oncology and inflammation. Despite their significant toxicity profile, non-steroidal anti-inflammatory drugs (NSAIDs) have become standard of care in the treatment of many COX2-mediated inflammatory conditions. In this report, we show that one IMiDs((R)) immunomodulatory drug, CC-4047, can reduce the levels of COX2 and the production of prostaglandins (PG) in human LPS-stimulated monocytes. The inhibition of COX2 by CC-4047 occurs at the level of gene transcription, by reducing the LPS-stimulated transcriptional activity at the COX2 gene. Because it is a transcriptional rather than an enzymatic inhibitor of COX2, CC-4047 inhibition of PG production is not susceptible to competition by exogenous arachadonic acid (AA). The distinct mechanisms of action allow CC-4047 and a COX2-selective NSAID to work additively to block PG secretion from monocytes. CC-4047 does not, however, block COX2 induction in or prostacyclin secretion from IL-1beta stimulated human umbilical vein endothelial cells (HUVEC) cells, nor does it inhibit COX1 in either monocytes or HUVEC cells. CC-4047 also inhibits COX2 and PG production in monocytes derived from patients with sickle cell disease (SCD). Taken together, the data in this manuscript suggest CC-4047 will provide important anti-inflammatory benefit to patients and will improve the safety of NSAIDs in the treatment of SCD or other inflammatory conditions.