Immune checkpoint inhibitor treatment of advanced age metastatic melanoma (MM) patients.

Abstract

e14603 Background: Immune checkpoint inhibitor (ICI) treatment has become effective method of treating mm including in those over 65 years of age. Increasing number of advanced age mm patients (pts.) are eligible for ICI treatment but not much is known about its efficacy and safety in relation to senescent immune system. We are reporting our updated experience of ICI treatment of advanced age mm pts. from a single Institute. Methods: Between 2011 and 2016, 32 eligible pts. diagnosed with mm were treated at the University of Connecticut with ICI including anti CTLA-4 antibody Ipilimumab, anti PD-1 antibody Pembrolizumab or combination of Ipilimumab and Nivolumab at their FDA approved doses on a standard protocol. Pts. were monitored for immune related adverse events (irAE) that were graded and managed with standard immune suppressive regimens Results: 12 out of 32 mm pts. were over 70 years of age (median 82.5 years, range 73-88 years). Nine pts. were treatment naïve, two had previously failed Ipilimumab treatment and one anti-BRAF and anti- MEK targeted therapy. Clinical benefit occurred in 5 out of 12 pts. (Complete response (CR) 3, partial response 1 and stable disease 1). Nine out of 12 pts. developed irAE that included three grade II (fatigue, diarrhea, hypopituitarism each) and 6 grade IV events (skin rash-1, colitis-1, encephalopathy-1, myasthenia gravis-1, and pneumonitis in 2 pts. each respectively). Of note, an 87-year-old male developed polymyalgia rheumatica after second dose of anti PD-1 treatment that responded to steroids, but developed autoimmune diabetes mellitus and pneumonitis following third dose. Two pts. died from irAE that included an 87-year-old woman from treatment refractory myasthenia gravis and 77-year-old male who suffered sudden death during steroid treatment of pneumonitis. Six pts. died of progressive disease including sudden death in a 77-year old woman and a 87-year-old male following five and two anti PD-1 treatments respectively. One pt. died from pulmonary embolism and four pts. are alive, 2 in CR and two with disease. Conclusions: Our experience indicate advanced age mm pts. respond to ICI treatment but have heightened risk of developing serious irAEs.