Background: In cancer immunotherapy, T-lymphocyte activation can lead to secondary autoimmune diseases named OASI for Opportunistic Autoimmunity Secondary to cancer Immunotherapy [1]. The epidemiology of OASI deserves to be further studied due to the unadapted reporting of clinical trials and the lack of prospective studies. Moreover, literature focuses on the most severe OASI and/or on specific OASI (myocarditis, colitis, arthritis).

Objectives: Our goal was to determine incidence, severity of all grade OASI using a multicentric prospective patient cohort starting treatment with cancer immunotherapy.

Methods: We present a multicentric, prospective, observational, longitudinal, real life, French e-cohort. 900 patients treated with ipilimumumab and/or nivolumab will be included. Data is collected from the patient and the oncologist at inclusion, then patients report directly any symptom that could be suggestive of OASI with the help of monthly digital questionaries. In case an OASI is suspected, further confirmation is made with the practician in charge and by a paired analysis with the Système National De Santé (SNDS), the French health insurance registry.

Results: On the 19/01/2022, 439 patients were included, 310 males (70.6%) and 129 females (29.4%). Mean age is 66 years old with a median follow up of 192 days. 354 patients (80.6%) are treated with Nivolumab alone, 7 (1.6%) with Ipilimumab alone and 76 (17.8 %) with combined Nivolumab + Ipilimumab. 136 patients (31.6%) are treated for a non-small cell lung carcinoma, 107 patients (24.9%) for a clear cell renal carcinoma, 91 patients (21.2%) for a skin melanoma, 49 patients (11.4%) for a head or neck epidermoid carcinoma, 24 patients (5.6%) for another lung cancer sub-type, and 32 patients (5.3%) for another histological cancer type. The mean follow-up is 294 days (+/- 192). 83 patients (18.9%) died since the beginning of the follow up.

47 patients (10.7%) developed 63 OASI. The mean delay between the beginning of cancer immunotherapy and the OASI is 134.7 days (+/- 103.4).

Approximately, one third of the OASI were musculoskeletal diseases. The OASI included polymyalgia rheumatica (3 patients), psoriatic arthritis (1 patient), polyarthritis (1 patient) systemic lupus (1 patient), arthralgias and myalgias (8 patients), colitis (11 patients), dysthyroïditis (6 patients), hepatitis (4 patients), nephritis (3 patients), pneumonitis (2 patients), hypophysitis (2 patients), adrenal insufficiency (4 patients), myocarditis (1 patient), hemophagocytic lympho-histiocytosis (1 patient), and other types of OASI (15 patients).

26 patients (55% of patients with OASI, 5,9% of all patients) had to stop cancer immunotherapy due to an OASI, one because of a rheumatic disease (systemic lupus). 52 patients were treated with corticosteroids, 1 patient with methotrexate (psoriatic arthritis), 3 patients with infliximab (colitis) and 1 patient with abatacept (myocarditis). 1 patient died after an OASI (colitis).

Conclusion: The first results of this prospective study, using an original patient-centered methodology, confirm the expected incidence of autoimmune events secondary to cancer immunotherapy and the role of rheumatologists in their therapeutic management.

REFERENCES:

[1]Kostine M, Chiche L, Lazaro E, et al. Opportunistic autoimmunity secondary to cancer immunotherapy (OASI): An emerging challenge. Rev Med Interne . 2017;38(8):513-525. doi:10.1016/j.revmed.2017.01.004

Acknowledgements: BMS funded the study (unrestricted grant) but had no role in study design, data collection, analysis or decision to publish.

Disclosure of Interests: Eden Sebbag: None declared, Nicolas Cloarec: None declared, Philippe Barthelemy: None declared, Nathanaël Sedmak: None declared, Naima Hamamouche Consultant of: Work for Sanoia Digital CRO, Hervé Servy Consultant of: Work for Sanoia Digital CRO, Guillaume Desjeux Consultant of: Work for Sanoia Digital CRO, Isabelle Monnet: None declared, Abeer Najem: None declared, Marc Porneuf: None declared, Laetitia-Shanna Rajpar: None declared, Jérôme Meunier: None declared, Tévy San: None declared, Laure Chauvenet: None declared, Ariane DARUT JOUVE: None declared, Sabrina FALKOWSKI: None declared, Claudia Rizzo: None declared, Noémie Litrowski: None declared, Anthony Canellas: None declared, Jean-François Paitel: None declared, Marc Pracht: None declared, Jacques Cadranel: None declared, Laurence Weiss: None declared, Christos Chouaid: None declared, Thomas Aparicio: None declared, Stephane Nancey: None declared, Cécile Arnold: None declared, Erik Sauleau: None declared, Jaqcues-Eric Gottenberg: None declared