Ribociclib requires structured safety monitoring because it can affect blood counts, liver function, cardiac electrical activity, pulmonary function and skin.
Interstitial lung disease and pneumonitis
Ribociclib can cause ILD or pneumonitis, including severe, life-threatening or fatal cases. New or worsening respiratory symptoms require appropriate clinical evaluation.
Severe cutaneous adverse reactions
Severe cutaneous adverse reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis and DRESS, have been identified in the prescribing information. Life-threatening cutaneous reactions require permanent discontinuation under the label.
QT prolongation
Ribociclib can prolong the QT interval in a concentration-dependent manner. ECGs and electrolytes should be assessed according to the prescribing information. Concomitant use of medicines known to prolong QT should generally be avoided.
Hepatotoxicity
Liver-enzyme elevations can occur. Liver-function tests are required before treatment and at defined intervals during therapy.
Neutropenia
Ribociclib causes concentration-dependent neutropenia. CBC monitoring is required before treatment and during therapy.
Drug interactions
Strong CYP3A inhibitors should generally be avoided; if unavoidable, dose modification may be required. Strong CYP3A inducers should also be avoided. Ribociclib can affect exposure to some CYP3A substrates, and QT-prolonging medicines require particular caution.
Pregnancy and breastfeeding
Ribociclib can cause embryo-fetal toxicity. Current U.S. labeling advises against breastfeeding during treatment.