Poster Presentation Joint 2016 COSA and ANZBCTG Annual Scientific Meeting

'Real world' pembrolizumab in metastatic melanoma (#226)

Alexandra E Flynn 1 , Fiona L Day 1 , Craig A Geyde 1 , Andre van der Westhuizen 1
  1. Calvary Mater Newcastle, Kotara, NSW, Australia

AIM:

We retrospectively reviewed all patients with metastatic melanoma treated with pembrolizumab in our institution in a 12 month period between 1st June 2015 and 1st June 2016. We aimed to identify the overall response rate (CR & PR), ongoing response rate and clinical benefit rate (CR, PR & SD) after 4 cycles of pembrolizumab for comparison with prospective published clinical trials.

METHODS:

We identified patients using ICD codes for melanoma and cross-linked this with our pharmacy record of pembrolizumab administration. All patients with metastatic melanoma given at least 1 cycle of pembrolizumab 2mg/kg every 3 weeks between 1/6/15 and 1/6/16 were included. Clinical data was sourced from the patients’ electronic medical record and response was determined by immune-related response criteria.

RESULTS:

77 patients were identified. Baseline characteristics: 52M:25F; median age 72y (range 39-90); 54 cutaneous primary site (70%), 12 unknown primary site, 3 ocular primary site ,2 mucosal primary site; 56 mutation wild type (73%), BRAF mutations in 15 patients, NRAS mutations 5 patients; 24 patients had brain metastasis (31%); pembrolizumab was first line treatment in 59 patients (77%); 4 patients had Grade 3/4 toxicity (5.2%).

Overall response (CR & PR) in 33 patients (43%); Responses were ongoing in 27 of 33 patients (82%) after a median follow-up of 5.3 months (3-426 days)

Clinical benefit (CR, PR & SD) in 43 patients (55.8%) after 4 cycles of pembrolizumab; Median 6 month progression free survival and estimated 1 year survival benefit expected by November 2016

CONCLUSIONS:

Unlike ’real world’ audits of chemotherapy benefit, our single institution experience of pembrolizumab in metastatic melanoma revealed comparative efficacy in overall response rate and clinical benefit rate after 4 cycles of pembrolizumab compared with published clinical trials. This is despite an older cohort of patients with a higher rate of brain metastasis using a lower dose of pembrolizumab. We hypothesize this result may be due to the high percentage of patients treated with pembrolizumab in the first line, though prospective clinical trials are needed to confirm this.

 

 

  1. Robert C, Schachter J, Long GV, Arance A, Grob JJ, Mortier L, Daud A, Carlino MS, McNeil C, Lotem M, Larkin J. Pembrolizumab versus ipilimumab in advanced melanoma. New England Journal of Medicine. 2015 Jun 25;372(26):2521-32.
  2. Hamid O, Robert C, Daud A, Hodi FS, Hwu WJ, Kefford R, Wolchok JD, Hersey P, Joseph RW, Weber JS, Dronca R. Safety and tumor responses with lambrolizumab (anti–PD-1) in melanoma. New England Journal of Medicine. 2013 Jul 11;369(2):134-44.
  3. Yanina Jansen, Max Schreuer, Bart Neyns; Vrije Universiteit Brussel (VUB), Brussels, Belgium; UZ Brussel, Brussel, Belgium. Single-center "real life experience" with pembrolizumab (PEMBRO) in pretreated advanced melanoma patients J Clin Oncol 34, 2016 (suppl; abstr e21049)