Biological agents and respiratory infections: Causative mechanisms and practice management

Biological agents are increasingly being used to treat patients with immune-mediated inflammatory disease. In Japan, currently approved biological agents for patients with rheumatoid arthritis (RA) include tumor necrosis factor inhibitors, interleukin-6 receptor-blocking monoclonal antibody, and T-cell costimulation inhibitor. Rheumatologists have recognized that safety issues are critical aspects of treatment decisions in RA. Therefore, a wealth of safety data has been gathered from a number of sources, including randomized clinical trials and postmarketing data from large national registries. These data revealed that the most serious adverse events from these drugs are respiratory infections, especially pneumonia, tuberculosis, nontuberculous mycobacteriosis, and Pneumocystis jirovecii pneumonia, and that the most common risk factors associated with these respiratory infections are older age, concomitant corticosteroid use, and underlying respiratory comorbidities. Because of this background, in 2014, the Japanese Respiratory Society published their consensus statement of biological agents and respiratory disorders. This review summarizes this statement and adds recent evidence, especially concerning respiratory infections in RA patients, biological agents and respiratory infections, and practice management of respiratory infections in patients treated with biological agents. To decrease the incidence of infections and reduce mortality, we should know the epidemiology, risk factors, management, and methods of prevention of respiratory infections in patients receiving biological agents.

Subcutaneous formulation of tocilizumab for treatment of rheumatoid arthritis

Tocilizumab (TCZ) is a humanized monoclonal antibody against the IL-6 receptor that is indicated for the treatment of rheumatoid arthritis (RA), juvenile idiopathic arthritis and Castleman's disease. TCZ was developed as an intravenous (IV) formulation and approved for RA treatment in Japan (2008), the EU (2009) and the USA (2010). Recently, a subcutaneous (SC) formulation of TCZ was developed and approved for RA treatment. Efficacy and safety of TCZ-SC were reported through three randomized trials: MUSASHI, SUMMACTA and BREVACTA. Clinical efficacy and overall safety of TCZ-SC was comparable to that of TCZ-IV. However TCZ-SC, which is provided in a fixed dose, the efficacy was affected by patient weight. The frequencies of injection site reactions and anti-TCZ antibodies were increased with TCZ-SC compared with TCZ-IV, although differences were minimal and at a negligible level for daily clinical practice. This review highlights the potential of TCZ-SC in RA treatment.

The incidence of tuberculosis in patients treated with certolizumab pegol across indications: impact of baseline skin test results, more stringent screening criteria and geographic region

Objectives

We report the incidence of tuberculosis (TB) across certolizumab pegol (CZP) clinical trials in rheumatoid arthritis (RA), psoriasis, psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), before and after the introduction of stricter TB screening.

Methods

TB incidence rates (IRs) were assessed and stratified according to screening guidelines used at the time of CZP trials. Before 2007 (original trials), purified protein derivative (PPD) tuberculin skin test positivity varied according to local standards (induration ≥5 up to ≥20 mm). Since 2007, all CZP trial protocols have been amended, including trials spanning (intermediate) and initiated after 2007 (current), mandating that any patient with PPD≥5 mm receives treatment for latent TB infection (LTBI). All cases of suspected TB or PPD≥5 mm, in pooled data from 5402 CZP patients across all CZP trials up to 2012, underwent blinded central review by independent experts.

Results

44 TB cases were confirmed in pooled CZP RA trials (IR 0.47/100PY, patient-years) with no cases in Japanese RA trials (J-RAPID, HIKARI). Single TB cases were confirmed in psoriasis and axSpA trials (RAPID-axSpA), and no cases in the PsA trial (RAPID-PsA). IR of TB was 0.51/100PY across original or intermediate RA trials and 0.18/100PY in current trials. The majority of TB cases in RA occurred in Eastern (IR 1.02/100PY) and Central Europe (IR 0.58/100PY). Of 242/370 PPD≥5 mm patients who received 9 months isoniazid (INH) treatment for latent TB infection (LTBI), none developed TB, versus 7.8% of 128 untreated PPD≥5 mm patients.

Conclusions

Implementation of more stringent LTBI screening, plus treatment for LTBI, reduced the IR of TB, even when INH was administered after starting CZP therapy.

Trigeminal herpes zoster: early recognition and treatment are crucial

Reactivation of varicella zoster virus (VZV) is not uncommon in older patients, particularly in cases of chronic autoimmune disorders and in patients taking immunosuppressant drugs. We present a case of a 57-year-old woman presenting with severe herpes zoster infection, involving the maxillary and ophthalmic branches of the trigeminal nerve. Despite an initial delay in instigating crucial antiviral treatment, the patient achieved an excellent recovery, with only some mild scarring at 2 months postinfection. Trigeminal herpes zoster is a potentially devastating clinical occurrence, and is associated with severe long-term neurological sequelae, including encephalitis, vision loss and postherpetic neuralgia. Physicians must be aware of risk factors and treatment modalities.

Tofacitinib for the treatment of moderate-to-severe psoriasis

Because of the increased knowledge about the underlying cytokine network in psoriasis, selective systemic agents for the treatment of moderate-to-severe psoriasis have been developed during the past decade. The marked upregulation of JAK/STAT pathways in psoriasis and the identification of multiple key mediators in psoriasis pathogenesis that signal through JAK/STAT pathways led to investigation of JAK proteins as potential therapeutic targets for psoriasis treatment. A novel JAK-STAT inhibitor, tofacitinib, has been tested in preclinical studies for the treatment of psoriasis. Considering the satisfactory safety profile and the encouraging efficacy observed in the Phase II and Phase III trials, tofacitinib may represent an important therapeutic to be included into the psoriasis paradigm.