Ingested Type I Interferon-State of the Art as Treatment for Autoimmunity Part 2

Tolerizing Strategies for the Treatment of Autoimmune Diseases: From ex vivo to in vivo Strategies

Autoimmune diseases such as multiple sclerosis (MS), type I diabetes (T1D), inflammatory bowel diseases (IBD), and rheumatoid arthritis (RA) are chronic, incurable, incapacitating and at times even lethal conditions. Worldwide, millions of people are affected, predominantly women, and their number is steadily increasing. Currently, autoimmune patients require lifelong immunosuppressive therapy, often accompanied by severe adverse side effects and risks. Targeting the fundamental cause of autoimmunity, which is the loss of tolerance to self- or innocuous antigens, may be achieved via various mechanisms. Recently, tolerance-inducing cellular therapies, such as tolerogenic dendritic cells (tolDCs) and regulatory T cells (Tregs), have gained considerable interest. Their safety has already been evaluated in patients with MS, arthritis, T1D, and Crohn’s disease, and clinical trials are underway to confirm their safety and therapeutic potential. Cell-based therapies are inevitably expensive and time-consuming, requiring laborious ex vivo manufacturing. Therefore, direct in vivo targeting of tolerogenic cell types offers an attractive alternative, and several strategies are being explored. Type I IFN was the first disease-modifying therapy approved for MS patients, and approaches to endogenously induce IFN in autoimmune diseases are being pursued vigorously. We here review and discuss tolerogenic cellular therapies and targeted in vivo tolerance approaches and propose a novel strategy for cell-specific delivery of type I IFN signaling to a cell type of choice.

Effect of Inhaled Interferon Beta-1a on Carbon Monoxide Transfer Factor in Healthy Volunteers

Interferon beta-1a (IFNβ-1a) 30 μg weekly by intramuscular (IM) injection is used to treat relapsing forms of multiple sclerosis. We assessed if it can be given safely by inhalation. Twenty-one healthy volunteers inhaled IFNβ-1a 300 μg, formulated for deep delivery to the lungs, in a randomized, parallel-group, repeat-dose trial. Comparators were room air and placebo. The primary outcome measure was carbon monoxide transfer factor corrected for hemoglobin (TLCOc), which measures the CO transfer from inspired gas to pulmonary capillary blood. After 3 and 4 once-weekly doses, IFNβ-1a significantly reduced TLCOc compared with room air: after the third dose, mean standard deviation (SD) change in percent predicted TLCOc was-10.9 (2.8), and after the fourth dose was-12.1 (2.7). After 2, 3, and 4 doses, IFNβ-1a significantly reduced TLCOc compared with placebo: after the second dose, mean (SD) change in percent predicted TLCOc was-8.8 (5.5), after the third dose was-10.9 (2.8), and after the fourth dose was-12.1 (2.7). Circulating IFNβ-1a concentrations were about one-third those of the intramuscular dose regimen. Tolerability of IFNβ-1a and the comparators was equally good. In conclusion, IFNβ-1a reduced TLCOc, whereas placebo and room air did not. A dose of IFNβ-1a 300 μg by inhalation may not be safe for general use.