Which anti melanoma therapy can lead to immune mediated hyponatremia?
Ipilimumab(CTLA-4 inhibitor) has also been associated with electrolyte disturbances. Two cases of ipilimumab-induced hyponatremia due to panhypopituitarism from ipilimumab related hypophysitis have been reported. The incidence of hypophysitis in patients treated with this agent is close to 17% in clinical trials. Mechanistically, a loss of adrenocorticotrophic hormone-secreting corticotrophs leads to a secondary adrenal insufficiency and loss of regulatory effects of cortisol on arginine vasopressin. This could be the mechanism leading to the hyponatremia. While FDA reporting system has mentioned hyponatremia in PD1 inhibitors(nivolumab and pembrolizumab) and BRAF inhibitors(vemurafenib and dabrafenib), it is at a lower incidence and likely not immune mediated.