Several neutralizing monoclonal antibodies (mAbs) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed and are now under evaluation in clinical trials. With the US Food and Drug Administration recently granting emergency use authorizations for neutralizing mAbs in non-hospitalized patients with mild-to-moderate COVID-19, there is an urgent need to discuss the broader potential of these novel therapies and to develop strategies to deploy them effectively in clinical practice, given limited initial availability. Here, we review the precedent for passive immunization and lessons learned from using antibody therapies for viral infections such as respiratory syncytial virus, Ebola virus and SARS-CoV infections. We then focus on the deployment of convalescent plasma and neutralizing mAbs for treatment of SARS-CoV-2. We review specific clinical questions, including the rationale for stratification of patients, potential biomarkers, known risk factors and temporal considerations for optimal clinical use. To answer these questions, there is a need to understand factors such as the kinetics of viral load and its correlation with clinical outcomes, endogenous antibody responses, pharmacokinetic properties of neutralizing mAbs and the potential benefit of combining antibodies to defend against emerging viral variants.

Tofacitinib and baricitinib are the first orally available, small-molecule inhibitors of Janus kinase (JAK) enzymes to be approved for the treatment of RA. Tofacitinib is a selective JAK1, 3 inhibitor with less activity against JAK2 and TYK2 and baricitinib is a selective, oral JAK1, 2 inhibitor with moderate activity against TYK2 and significantly less activity against JAK3. Both drugs have undergone extensive phase III clinical trials in RA and demonstrated rapid improvements in disease activity, function and patient-reported outcomes as well as disease modification. Tofacitinib 5 mg bd, was approved by the Federal Drug Administration in 2012 for the treatment of RA in patients who are intolerant or unresponsive to MTX. An extended release formulation for the treatment of RA was approved by Federal Drug Administration in 2016. In 2017 the European Medicines Agency approved tofacitinib 5 mg bd in combination with MTX and baricitinib 4 mg and 2 mg once daily for the treatment of moderate to severe active RA in adult patients who are intolerant or unresponsive to one or more conventional synthetic DMARDs.

ObjectiveTo report long-term safety from the completed extension trial of baricitinib, an oral selective Janus kinase inhibitor, in patients with active rheumatoid arthritis (RA).MethodsTreatment-emergent adverse events are summarised from an integrated database (9 phase III/II/Ib and 1 long-term extension) of patients who received any baricitinib dose (All-bari-RA). Standardised incidence ratio (SIR) for malignancy (excluding non-melanoma skin cancer (NMSC)) and standardised mortality ratio (SMR) were estimated. Additional analysis was done in a subset of patients who had ever taken 2 mg or 4 mg baricitinib.Results3770 patients received baricitinib (14 744 patient-years of exposure (PYE)). All-bari-RA incidence rates (IRs) per 100 patient-years at risk were 2.6, 3.0 and 0.5 for serious infections, herpes zoster and major adverse cardiovascular events (MACE), respectively. In patients aged ≥50 with ≥1 cardiovascular risk factor, the IR for MACE was 0.77 (95% CI 0.56 to 1.04). The IR for malignancy (excluding NMSC) during the first 48 weeks was 0.6 and remained stable thereafter (IR 1.0). The SIR for malignancies excluding NMSC was 1.07 (95% CI 0.90 to 1.26) and the SMR was 0.74 (95% CI 0.59 to 0.92). All-bari-RA IRs for deep vein thrombosis (DVT)/pulmonary embolism (PE), DVT and PE were 0.5 (95% CI 0.38 to 0.61), 0.4 (95% CI 0.26 to 0.45) and 0.3 (95% CI 0.18 to 0.35), respectively. No clear dose differences were noted for exposure-adjusted IRs (per 100 PYE) for deaths, serious infections, DVT/PE and MACE.ConclusionsIn this integrated analysis including long-term data of baricitinib from 3770 patients (median 4.6 years, up to 9.3 years) with active RA, baricitinib maintained a similar safety profile to earlier analyses. No new safety signals were identified.Trial registration numberNCT01185353, NCT00902486, NCT01469013, NCT01710358, NCT02265705, NCT01721044, NCT01721057, NCT01711359 and NCT01885078.