Dissociated Responses in Patients with Metastatic Solid Tumors Treated with Immunotherapy

Pauline Vaflard (1) , Xavier Paoletti (1, 2) , Vincent Servois (1) , Patricia Tresca (1) , E. Pons-Tostivint (3) , Marie Paule Sablin (1) , Francesco Ricci (1) , Delphine Loirat (1) , Ségolène Hescot (1) , Nouritza Torossian (1) , Diana Bello Roufai (1) , Maud Kamal (1) , Édith Borcoman (1) , Christophe Le Tourneau (1, 2)

1 Institut Curie [Paris]
2 UVSQ Santé - Université de Versailles Saint-Quentin-en-Yvelines - UFR Sciences de la santé Simone Veil
3 IUCT Oncopole - UMR 1037 - Institut Universitaire du Cancer de Toulouse - Oncopole

Background: Immune checkpoint inhibitors have been demonstrated to improve overall survival. Atypical patterns of response have been reported, including dissociated response (DR). We evaluated the prevalence of DR. Patients and methods: Patients had to have a baseline computed tomography (CT) scan and at least one follow-up CT scan and two target lesions (TLs). Three types of DR were evaluated using RECIST1.1: DR1, defined as at least one progressive and one responding TL; DR2, defined as at least one progressive and one stable TL; and DR3, defined as at least one stable and one responding TL. Results: A total of 1244 measurements of 272 TLs were performed in 100 patients. Forty-nine out of the 272 TLs (18%) had received old or recent radiotherapy, and 42 (15%) had been biopsied. An objective response was observed in 22 patients (22%) and on 52 TLs (19%). DR1 were observed in 8% of patients. At the tumor measurement level, the response rate was lower in the case of prior radiotherapy (29% vs 34%, p = 0.01) and higher in the case of prior biopsy (40% vs 32%, p = 0.02). Conclusions: A DR was observed in 8% of patients. Response rate was lower in the case of prior radiotherapy and higher in the case of prior biopsy.

Domaines: Sciences du Vivant [q-bio]

Pauline Vaflard, Xavier Paoletti, Vincent Servois, Patricia Tresca, E. Pons-Tostivint, et al.. Dissociated Responses in Patients with Metastatic Solid Tumors Treated with Immunotherapy. Drugs in R&D, 2021, 21 (4), pp.399-406. ⟨10.1007/s40268-021-00362-3⟩. ⟨hal-03487779⟩