Bortezomib/ixazomib/lenalidomideThrombocytopenia, renal insufficiency, lack of efficacy and rebound effect: case report A 73-year-old woman developed severe thrombocytopenia and renal insufficiency during treatment with lenalidomide and ixazomib and exhibited rebound effect with lenalidomide for multiple myeloma. Additionally, the woman exhibited lack of efficacy during treatment with bortezomib for multiple myeloma [dosages and routes not stated].The woman was initially admitted to the department of cardiology for overt heart failure. Her medical history was significant for diabetes, hypertension and coronary heart disease. She had anaemia, proteinuria, hypoalbuminaemia and hyperglobulinaemia. Also, she had plasma dyscrasia. Therefore, she was transferred to the department of haematology. Subsequently, she was diagnosed with IgA-λ multiple myeloma in May 2019 and started receiving bortezomib and dexamethasone in June 2019. However, her IgA level continued to rise. Therefore, she started receiving lenalidomide and her IgA level began to decrease 1 month later. She was refractory to bortezomib, indicating its lack of efficacy. Therefore, in August 2019 her treatment switched to an IRD regimen which consist of ixazomib, lenalidomide and dexamethasone. During this treatment, very good partial response was noted. Subsequently, due to intolerance lenalidomide was withdrawn. After 3 months, her disease quickly rebounded and she developed severe thrombocytopenia and renal insufficiency which was determined to be related to lenalidomide and ixazomib [exact time to reaction onset and outcome not stated].The woman was therefore included in the Chimeric antigen receptor T (CAR-T)-cell therapy clinical trial. As CAR-T was not available initially, she was again initiated on dose-reduced IRD regimen which consist of ixazomib, lenalidomide and dexamethasone. Exacerbation of renal impairment was noted. Subsequently, she was initiated on CAR-T cell therapy along with fludarabine and cyclophosphamide and all other treatments discontinued. Significant improvement in her underlying disease condition was noted. Subsequently, she developed fever, hypofibrinogenaemia and neutropenia [aetiology not stated]. Therefore, she was treated with tocilizumab. Her fever resolved but neutropenia and hypofibrinogenaemia did not improve. Later, she received dexamethasone. Subsequently, she went to coma and later died of pulmonary infection.