30th Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2015)
Updated efficacy and toxicity of treatment with the anti-CTLA-4 antibody ipilimumab in metastatic melanoma patients previously treated with anti-PD-1 therapy
Journal for ImmunoTherapy of Cancer volume 3, Article number: P126 (2015)
Immunotherapy with anti-CTLA-4 and anti-PD-1 antibodies has demonstrated overall survival benefits in patients (pts) with metastatic melanoma (MM) compared to previous standard therapy. Two randomised clinical trials indicate that combined anti-CTLA-4 and anti-PD-1 antibody therapy increases the response rate compared to single agent treatment, but is associated with increased toxicity [1, 2]. Both efficacy and toxicity of anti-PD-1 therapy appear independent of prior treatment with the anti-CTLA-4 antibody ipilimumab. To date, only limited evidence exists regarding the efficacy and toxicity of Ipilimumab in pts that have progressed on treatment with an anti-PD-1 agent.
We retrospectively identified pts with MM who received anti-PD-1 therapy (Nivolumab/Pembrolizumab) and were subsequently treated with ipilimumab. Ipilimumab was administered at a dose of 3mg/kg every three weeks for (up to) four doses and response assessed by CT scan 4-6 weeks after the last dose. Efficacy and toxicity outcomes were determined from clinical records.
The median age was 53 years with all pts having stage IVc disease and 4 pts (33%) with an elevated LDH at commencement of Ipilimumab dosing. The median time between the last dose of anti-PD-1 therapy and the commencement of Ipilimumab was 8 months (range 2-14 months). After a median follow-up of over 6 months, 1 patient (8%) achieved a partial remission as their best response to anti-PD-1 therapy with an additional 6 (50%) having stable disease. Five patients (42%) received all four doses of Ipilimumab. Two patients (17%) achieved an objective response to ipilimumab with another having prolonged stable disease. Four patients experienced grade 3/4 immune-related adverse events (irAE) including colitis (n=3) and pneumonitis (n=1).
Ipilimumab therapy can induce responses in patients who have failed treatment with an anti-PD-1 antibody. The response rate and clinical benefit rate appears similar compared to outcomes in pts who have not received prior anti-PD-1 antibody therapy. Although cases of severe and/or unusual irAEs such as pneumonitis have been observed, an analysis of a larger patient cohort will be required to test the significance of these observations.
Postow MA, Chesney J, Pavlick AC, Robert C, Grossmann K, McDermott D, et al: Nivolumab and ipilimumab versus ipilimumab in untreated melanoma. N Engl J Med. 2015, 372: 2006-2017.
Larkin J, Chiarion-Sileni V, Gonzalez R, Grob JJ, Cowey CL, Lao CD, et al: Combined Nivolumab and Ipilimumab or Monotherapy in Untreated Melanoma. N Engl J Med. 2015, 373: 23-34.
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Prithviraj, P., McArthur, G., Atkinson, V. et al. Updated efficacy and toxicity of treatment with the anti-CTLA-4 antibody ipilimumab in metastatic melanoma patients previously treated with anti-PD-1 therapy. j. immunotherapy cancer 3 (Suppl 2), P126 (2015). https://doi.org/10.1186/2051-1426-3-S2-P126
- Stable Disease
- Metastatic Melanoma
- Melanoma Patient
- Partial Remission