CLASS OF DRUG
- Janus kinase (JAK) inhibitor
- 2mg or 4mg film-coated tablets
MECHANISM OF ACTION
- JAK1/2 inhibitors block the Janus-associated receptor tyrosine kinnases JAK1 and JAK2.
- JAKs phosphorylate and activate signal transducers and activators of transcription (STATs), which activate gene expression within the cell.
- JAK1/2 inhibitors block the signalling pathways of multiple cytokines, including IL-2, IL-6, IL-12, and interferons.
- As such they are more focussed than corticosteroids (potential for less side-effects) but have a wider spectrum of action than monoclonal antibodies (potential for greater effects).
- Baricitinib also inhibits AP2-associated protein kinase 1 (AAK-1), which regulates endocytosis in alveolar type II cells, but it is uncertain if this action significantly affects SARS-CoV-2 virus replication in vivo.
- Moderate-to-severe active rheumatoid arthritis
- patients who have had an inadequate response to, or are intolerant to, one or more disease-modifying anti-rheumatic drugs as monotherapy or in combination with methotrexate
- Atopic dermatitis (moderate-severe)
- COVID19 disease
- hospitalised patients who require supplemental oxygen, high-flow oxygen and/or non-invasive ventilation.
- Absolute lymphocyte count <0.5 x10E9 cells /L
- absolute neutrophil count <1 x10E9 cells /L
- haemoglobin less than 80 g/L
- Active, chronic or recurrent infection (interrupt treatment if no response to standard therapy)
- risk of diverticulitis
- risk of viral reactivation
- severe hepatic impairment
- renal impairment (GFR <30 mL/min/1.73 m2)
- 4mg po daily (adults), or
- 2mg po daily if age >75 years or dose reduction due to: history of infections or sustained control of rheumatoid arthritis disease activity
- A: oral ioavailability 79%; peak plasma levels at 0.5-3h; slightly affected by food (14% less bioavailability)
- D: Protein binding 50%; VD ~1L/kg
- M: minority is hepatically metabolised by CYP3A4 enzymes (<10%)
- E: elimination t1/2 =12.5 hours; 75% exreted in urine and 20% in faeces; clearance ~10L/kg/min
- Lymphopenia, anemia, and neutropenia
- opportunistic infections/ reactivation (e.g. herpes simplex virus and varicella zoster virus)
- Oropharyngeal pain
- Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE)
- Weight gain
DRUG-DRUG INTERACTIONS (DDIs)
- Potential additive effect with other immunosuppressants.
- Probenecid inhibits renal excretion of baricitinib by ~ 50%
- Use with live, attenuated vaccines during, or immediately prior to, baricitinib therapy is not recommended.
- Category D (contraindicated in pregnancy)
- Contraception advised during and up to 1 week after treatment with baricitinib
- Enters breat milk in animal studies (avoid if possible)
- ACTT-2 Trial (Kalil et al, 2020)
- Small randomised controlled trial that found that barictinib in combination with Remdesivir accelerated time to recovery compared with Remdesivir alone. It was not powered to detect a mortality difference.
- COV-BARRIER trial (Marconi et al, 2021)
- multicentre, randomised, double-blind, placebo-controlled, parallel-group, phase 3 trial (n= 1525) of non-mechanically ventilated COVID19 pneumonia pateints with atleast one elevated inflammatory marker (CRP, D-dimer, ferritin, or LDH). There was no difference in the primary outcome, a composite endpoint of progression in NIAID-OS (score 6,7 or 8) by Day 28. However, the secondary outcome of mortality at 60 days was improved for baricitinib: 10% vs 15% (HR 0.62, 95% CI 0.47-0.83, p= 0.005).
- Lipid profile
- Liver function tests
- Full blood count (hemoglobin, neutrophils, platelets)
- Baseline testing for hepatitis B, HCV and tuberculosis
FOAM and web resources
- Baricitinib | C16H17N7O2S – PubChem
- TGA Product Information – Baricitinib
- The Bottom Line – COV-BARRIER
- PulmCrit – Baricitinib for COVID-19: The rise of the jakinibs
- Assadiasl S, Fatahi Y, Mosharmovahed B, Mohebbi B, Nicknam MH. Baricitinib: From Rheumatoid Arthritis to COVID-19. J Clin Pharmacol. 2021 Oct;61(10):1274-1285. doi: 10.1002/jcph.1874. Epub 2021 Jun 12. PMID: 33870531; PMCID: PMC8250677. [article]
- Kalil A, Patterson T, Mehta A, et al. Baricitinib plus Remdesivir for Hospitalized Adults with Covid-19. N Engl J Med. Published online December 11, 2020. doi:10.1056/NEJMoa2031994 [article]
- Marconi VC, Ramanan AV, de Bono S, et al; COV-BARRIER Study Group. Efficacy and safety of baricitinib for the treatment of hospitalised adults with COVID-19 (COV-BARRIER): a randomised, double-blind, parallel-group, placebo-controlled phase 3 trial. Lancet Respir Med. 2021 Aug 31:S2213-2600(21)00331-3. doi: 10.1016/S2213-2600(21)00331-3. Epub ahead of print. Erratum in: Lancet Respir Med. 2021 Sep 8;: PMID: 34480861; PMCID: PMC8409066. [article]