Aims Gemcitabine has been associated with thrombotic microangiopathy (TMA). We conducted a national retrospective study of gemcitabine‐associated TMA (G‐TMA). Methods From 1998 to 2015, all cases of G‐TMA reported to the French Pharmacovigilance Network and the French TMA Reference Center, and cases explored for complement alternative pathway abnormalities, were analysed. Results G‐TMA was diagnosed in 120 patients (median age 61.5 years), after a median of 210 days of treatment, and a cumulative dose of 12 941 mg m–2. Gemcitabine indications were: pancreatic (52.9%), pulmonary (12.6%) and breast (7.6%) cancers, metastatic in 34.2% of cases. Main symptoms were oedema (56.7%) and new‐onset or exacerbated hypertension (62.2%). Most patients presented with haemolytic anaemia (95.6%) and thrombocytopenia (74.6%). Acute kidney injury was reported in 97.4% and dialysis was required in 27.8% of patients. Treatment consisted of: plasma exchange (PE; 39.8%), fresh frozen plasma (21.4%), corticosteroids (15.3%) and eculizumab (5.1%). A complete remission of TMA was obtained in 42.1% of patients and haematological remission in 23.1%, while 34.7% did not improve. The survival status was known for 52 patients, with 29 deaths (54.7%). Patients treated with PE, despite a more severe acute kidney injury, requiring dialysis more frequently, displayed comparable rates of remission, but with more adverse events. No abnormality in complement alternative pathway was documented in patients explored. Conclusion This large cohort confirms the severity of G‐TMA, associated with severe renal failure and death. Oedema and hypertension could be monitored in patients treated with gemcitabine to detect early TMA. The benefit of PE or eculizumab deserves further investigation.

BackgroundSafety of rechallenge of immune checkpoint inhibitor (ICI) after grade ≥2 immune-related adverse events (irAEs) leading to ICI discontinuation remains unclear.MethodsAll adverse drug reactions involving at least one ICI reported up to December 31, 2019 were extracted from the French pharmacovigilance database. Patients were included if they experienced at least one grade ≥2 irAE resulting in ICI discontinuation, with subsequent ICI rechallenge. The primary outcome was the recurrence of at least one grade ≥2 irAE in these patients after ICI rechallenge.ResultsWe included 180 patients: 61.1% were men (median age of 66 years), 43.9% had melanoma and 78.9% were receiving anti-programmed cell death 1. First ICI discontinuation was related to 191 irAEs. After ICI rechallenge, 38.9% of the patients experienced at least one grade ≥2 irAE. Among them, 70.0% experienced the same irAE, 25.7% a distinct irAE, and 4.3% both the same and a distinct irAE. Lower recurrence rates of irAEs were associated with rechallenge with the same ICI treatment (p=0.02) or first endocrine irAEs (p=0.003). Gastrointestinal irAEs were more likely to recur (p=0.007). The median duration from ICI discontinuation to rechallenge and the severity of the initial irAE did not predict recurrent irAEs after ICI rechallenge (p=0.53 and p=0.40, respectively).ConclusionsIn this study, 61.1% of the patients who discontinued ICI treatment for grade ≥2 irAEs experienced no recurrent grade ≥2 irAEs after ICI rechallenge. Although ICI rechallenge appears to be safe under close monitoring, it should always be discussed balancing usefulness of rechallenge, patient comorbidities and risk of recurrence of first irAE(s). Due to inherent bias associated with pharmacovigilance studies, further prospective studies are needed to assess risk factors that may influence patient outcomes after ICI rechallenge.