{
  "abstract": "Background The use of neoadjuvant/perioperative immunotherapy in the NADINA and SWOG S1801 trials has shown improved treatment outcomes in stage III cutaneous melanoma compared to adjuvant therapy. However, real-world data (RWD) on neoadjuvant immunotherapy remain limited.Methods We retrospectively analyzed 52 patients with resectable stage III-IV cutaneous melanoma treated with neoadjuvant immunotherapy at a single academic center. Patients received either nivolumab + ipilimumab (n=21) or pembrolizumab monotherapy (n=31). Radiological responses were assessed using RECIST v1.1, and pathological responses were classified as major pathological response (MPR, ≤10% viable tumor) and complete pathological response (pCR). Patients receiving combination therapy who achieved a major pathological response (MPR) did not undergo further adjuvant treatment, whereas those treated with pembrolizumab continued it in the adjuvant setting for a total treatment duration of up to one year. Survival outcomes were estimated using Kaplan-Meier methodology.Results Radiological objective response rates (ORR) were similar in both groups: 57.1% for nivolumab/ipilimumab and 51.6% for pembrolizumab (p=0.78). However, pathological responses favored combination therapy: MPR was achieved in 71.4% vs. 32.2% (p=0.01, table 1); pCR in 42.6% vs. 29.0% (table 1). Grade 3 immune-related toxicity occurred in 19% (combination therapy) vs. 12.9% (monotherapy). Radiological-pathological concordance (CR/PR vs. MPR) was 68.9% (κ = 0.368).Trend-level associations were observed for baseline body weight (OR 1.35 per 10 kg, p=0.065) and treatment regimen (nivolumab/ipilimumab OR 36.78, p=0.061) with MPR.Median progression-free survival (PFS) was not reached after 16 months of follow-up. One- and two-year PFS rates were higher in the combination group (87% at both timepoints) versus pembrolizumab (77% and 68%, respectively). Achieving MPR was associated with significantly better PFS (p=0.026): 94% 2-year PFS with MPR vs. 61% without.Conclusions The use of combination immunotherapy regimens is associated with higher rates of pathological response and a trend toward improved progression-free survival (PFS) compared to monotherapy. Moreover, achieving a major pathological response (MPR) may allow for de-escalation of systemic therapy after surgery, despite the increased treatment-related toxicity observed with combination approaches.Abstract 525 Table 1Pathological response",
  "authors": [
    {
      "affiliations": [
        "Moscow City Oncology Hospital No 62, Moscow, Russia"
      ],
      "name": "Alexandr Iurchenkov"
    },
    {
      "affiliations": [
        "Moscow City Oncology Hospital No 62, Moscow, Russia"
      ],
      "name": "Daniil Stroyakovskiy"
    },
    {
      "affiliations": [
        "Moscow City Oncology Hospital No 62, Moscow, Russia"
      ],
      "name": "Anastasia Danilova"
    },
    {
      "affiliations": [
        "Lahta Clinic, Saint Petersburg, Russia"
      ],
      "name": "Polina Shilo"
    },
    {
      "affiliations": [
        "Ledin Clinic, Moscow, Moscow, Russia"
      ],
      "name": "Vladimir Stoliarov"
    },
    {
      "affiliations": [
        "Moscow City Oncology Hospital No 62, Moscow, Russia"
      ],
      "name": "Nikita Savelov"
    },
    {
      "affiliations": [
        "Moscow City Oncology Hospital No 62, Moscow, Russia"
      ],
      "name": "Viktor Grishakov"
    },
    {
      "affiliations": [
        "Moscow City Oncology Hospital No 62, Moscow, Russia"
      ],
      "name": "Evgeniy Tyschenko"
    }
  ],
  "title": "525 Real-world effectiveness of neoadjuvant immunotherapy in resectable stage III-IV melanoma: a comparative analysis of nivolumab/ipilimumab versus pembrolizumab",
  "uid": "cf0dbd89-42cf-59e7-b76f-e7e8643afccd"
}