Squamous-cell carcinoma of the tongue following therapy of rheumatoid arthritis with abatacept

A patient affected by rheumatoid arthritis developed a squamous-cell carcinoma probably due to abatacept, according to Naranjo algorithm. The case describes this adverse reaction for the first time and highlights the need for additional studies to establish the long-term risk profile of abatacept.

Abatacept is a fusion protein composed of the extracellular domain of Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) and the Fc region of the human immunoglobulin G1 (IgG1) that acts as a selective T-cell costimulation modulator [1]. Therapeutic indications of abatacept include rheumatoid arthritis (RA) not responding to traditional disease-modifying antirheumatic drugs (DMARDs) and refractory active polyarticular juvenile idiopathic arthritis (JIA) [2]. Summary of product characteristics (SPC) [2] for abatacept reports the possibility of basal-cell carcinoma and skin papilloma as uncommon events, lymphoma and malignant lung neoplasm as rare events. We describe the case of a patient who developed a squamous-cell carcinoma (SCC) of the tongue after 1 year of treatment with abatacept for refractory RA. The case was reported by the University Hospital of Sassari (AOUSS) to the “Sardinian Regional Center of Pharmacovigilance”, Unit of Clinical Pharmacology, University Hospital of Cagliari (AOUCA), as provided by the project entitled “Development of a Pharmacovigilance Network in Sardinia”. As biologics are newer drugs, there is a lack of long-term safety data. This case report adds to the little information available about them.