Cost Effectiveness Of Updated Laboratory Monitoring Schedule For Immunotherapy Regimes.

e18363 Background: Patients being treated with immunotherapy undergo frequent laboratory testing to monitor for immune-related adverse events (IRAEs) as per National Cancer Control Programme (NCCP) guidelines in Ireland. Current NCCP guidelines advise pre-treatment testing of thyroid function, glucose and cortisol and follow-up TFTs and glucose levels with each cycle of therapy.1,2,3,4. Endocrinopathies occur in approximately 10% of patients on immunotherapy,5 with most occurring in the first three months of treatment.6 Hypophysitis is a relatively common adverse event associated with ipilimumab and with combination treatments, with incidence rates reported at 10-15%.7,8 Methods: On review of our own cohort and recent publications on incidence rates of IRAEs,5 we adopted updated guidelines for routine laboratory monitoring on immunotherapy. These guidelines incorporate increased monitoring intervals and enhanced surveillance for diabetes mellitus, hypophysitis and adrenal insufficiency. Results: Our proposed schedule advises pre-treatment testing of FBC, U&E, LFTs, TFTs, serum glucose, HbA1c, ACTH and serum cortisol levels. Monitoring then occurs every 3-4 weeks with FBC, LFTs, U&E, TFTs, serum glucose, and routinely testing ACTH and cortisol for Ipilimumab and combination treatments only, for six months duration. After six months, the interval increases to monitoring every 6-8 weeks with the same tests. We have compared the cost of monitoring for one year using our guidelines versus NCCP guidelines,1,2,3,4 using pricing as per a single institution laboratory. We also compared the frequency of monitoring over one year with monitoring versus NCCP guidelines. Conclusions: We conclude that our proposed algorithm for monitoring for IRAEs is cost effective, despite more frequent monitoring of ACTH and cortisol, and carries a lower burden of testing for patients, when compared with monitoring as per current NCCP guidelines. [Table: see text]