PO:07:103 | Tocilizumab use in patients with rheumatoid arthritis and malignancy: a monocentric experience

Vittorio Dibenedetto^1|2|3, Nicola Farina^1|2, Nicola Boffini^1|2, Alessandro Tomelleri^1|2, Adriana Cariddi^1|2, Elena Baldissera^1|2, Marco Matucci-Cerinic^1|2|3, Lorenzo Dagna^1|2|3. | ¹Unit of Immunology, Rheumatology, Allergy and Rare Diseases, IRCCS San Raffaele Hospital, Milano, Italy; ²Inflammation, Fibrosis and Ageing Intitiative ^INFLAGE, IRCCS San Raffaele Hospital, Milano, Italy; ³Vita-Salute San Raffaele University, Milano, Italy.

Background. In 2024, the EULAR published a set of points to consider for initiating targeted therapy in rheumatoid arthritis (RA) patients with a history of malignancy, indicating TNF inhibitors are preferred in solid tumors, while rituximab is recommended for hematological malignancies. Although the interleukin-6 receptor inhibitor tocilizumab (TCZ) showed a favourable oncological safety profile, the EULAR taskforce did not issue specific recommendations in favour of its use in this clinical context due to a lack of robust evidence. Our aim was to evaluate in a single-center study the oncological safety of TCZ in RA patients with prior malignancy.

Methods. Within the cohort of patients followed at the Arthritis Clinic of our hospital, we retrospectively identified RA patients (according to 2010 ACR/EULAR criteria) treated with TCZ for at least 3 months following cancer diagnosis, either active or in remission at treatment start. Data were collected on the characteristics of both rheumatologic and oncologic diseases, treatments before and after TCZ, and outcomes including rheumatic disease activity (based on the Disease Activity Score, DAS28) and oncologic response (complete remission, partial response, stable disease, progression, relapse).

Results. We identified and included 34 patients who met the study criteria. Their demographic, rheumatologic, and oncologic characteristics are summarized in Table 1. Patients had a median age of 60 years (IQR, 51-69) at RA diagnosis and 68 years (IQR, 62-75) at TCZ start. TCZ was started in 21 patients in remission and in 13 with active malignancy. Median interval between cancer diagnosis and TCZ start was 35 months (IQR, 11–70). Ten patients had another bDMARD between cancer diagnosis and TCZ start. Two patients were already on TCZ at cancer diagnosis and continued uninterrupted. Median TCZ duration was 19 months (IQR 8–43). Concomitant csDMARDs were used in 19 cases, and methotrexate was the most frequently used (11 cases). TCZ treatment was also associated with a significant reduction in disease activity, with a decrease in DAS28 from 5.50 (IQR 4,46 – 6,68) at the visit before TCZ start to 2.28 (IQR 1.52 – 2.85) at the last follow-up visit during TCZ therapy. Among patients with malignancy in remission, only one case of cancer recurrence (lung adenocarcinoma) was observed (Figure 1). No cancer progression occurred in patients with active malignancy. No discontinuations were due to oncologic concerns while TCZ was stopped for lack of efficacy in 4 patients (Table 1).

Conclusions. In this single-center cohort, TCZ showed a favourable oncologic safety profile in RA patients with prior malignancy, including those with active cancer at treatment start. No cancer progression was observed; only one recurrence occurred. Further prospective studies are needed, but these findings suggest TCZ may be a safe and effective option in RA patients with prior malignancy.