Year: 2025
Type: conference-paper
Study design: Observational Study
Abstract: Background and Importance The off-label use of monoclonal antibody (mAbs) therapy is sometimes the only alternative when there are no official indication approved drugs regarding the disease or when the approved ones are ineffective or patients experience drug adverse events to the approved ones. Aim and Objectives To identify efficacy and safety of mAbs off-label use Material and Methods Retrospective observational study was conducted in adult patients with mAbs off-label prescription, at hospital setting, except Oncology Department, approved by Local Commission of Pharmacy and Therapeutics (CPT) between January 2021 and December 2022. Information on efficacy and safety was extracted from CPT files and Soarian Clinics files, and analysed using Microsoft Excel 5.0. Treatment was considered effective when it was referred in the patient files and/or when the administration of mAbs was maintained for at least 6 months. The study was authorised by Local Ethical Committee. Results We included 69 patients, with an average age of 51 years, mostly women (62%) and followed in Immune-Mediated Diseases Consultation (52%). The mAbs mostly used were Rituximab (RTX) (65%) in Glomerulopathy, Purpura idiopathic thrombocytopenia (PTI) and Systemic Lupus Erythematosus; Infliximab (IFX) (15%) in Sarcoidosis and Tocilizumab (TCZ) (10%) in severe chronic urticaria. In 90% of patients, off-label treatment was effective, in three cases it was partially effective and in two cases ineffective. In those 100% effective, patients were treated with Omalizumab (OMA) and TCZ, in partial response with Natalizumab in fulminant multiple sclerosis and two RTX for PTI and optical neuromyelitis. In patients unresponsive to treatment, RTX and IFX were the main drugs involved. Regarding safety, of the 49% of patients that had adverse events, 12% patients had infections, 7% worsening tiredness, 6% aphthous and 2% non-severe allergic reaction at the injection site of administration. Of the uneventful patients, mostly were treated with RTX and OMA. Two died during treatment due to severe pneumonia. Conclusion and Relevance The results showed high rates of efficacy to off-label treatment with mAbs, in line with other studies, as well as the minor and major complications found, namely infections. Additionally, autoimmune disease itself may be a risk factor for infection and further studies are needed to ascertain causal relationships. References and/or Acknowledgements Conflict of Interest No conflict of interest
Authors: M Nobre, A Prata, V Rodrigues
Language: English
Subfield: Toxicology
Domain: Life Sciences
Open Access status: gold
OpenAlex ID: W4408376111