The most common side effects (which may affect more than 1 in 10 people) are neutropenia (low levels of neutrophils, a type of white blood cell), cytokine release syndrome (a potentially life-threatening condition that can cause fever, vomiting, shortness of breath, pain and low blood pressure), anaemia (low red blood cell count), thrombocytopenia (low platelet counts), infections, leucopenia (low white blood cell count), tiredness, diarrhoea, hypokalaemia (low blood potassium levels), hypophosphataemia (low blood phosphate levels), nausea (feeling sick), lymphopenia (low levels of lymphocytes), fever, cough, hypocalcaemia (low blood levels of calcium), headache, hypomagnesaemia (low blood levels of magnesium), upper respiratory tract infection (nose and throat infection), joint pain, peripheral oedema (swelling especially of the ankles and feet), decreased appetite, hypogammaglobulinaemia (low levels of immunoglobulins) and febrile neutropenia (low blood levels of neutrophils with fever).

The most common serious side effects include cytokine release syndrome (17%), pneumonia (7%), febrile neutropenia (6%) and fever (6%).

People who cannot have chemotherapy to clear away their existing white blood cells (as per the package leaflet of the relevant chemotherapy) must not receive Abecma.

For the full list of side effects and restrictions with Abecma, see the package leaflet.