Abstract 1098P
Background
Neoadjuvant therapy (NAT) with immunotherapy (anti-PD1-based) has shown promising event-free survival (EFS) and pathologic complete response (pCR) in resectable melanoma patients. We performed a systematic review and meta-analysis to evaluate anti-PD1-based NAT for stage III and IV resectable melanoma.
Methods
We searched PubMed, Scopus, and Cochrane Library databases for clinical trials and observational cohort studies. Outcomes of interest were pCR, major pathologic response (MPR), EFS, and overall survival (OS). Subgroups analysis included clinical stages and mucosal and acral melanomas (MM/AM) subpopulation. Heterogeneity was examined with I2 statistics; We used a DerSimonian and Laird random effects model.
Results
Eleven studies were included, comprising nine phase II/Ib clinical trials and two observational cohort studies with 486 patients. Of them, 85% had cutaneous melanoma, and 15% had MM/AM. Overall, 43% received single-agent NAT. In a pooled analysis, the pCR rate was 35.1% (95%CI 25.7-44.4). Stage III patients achieved a pCR of 36.9% (95%CI 28.9-71.5), whereas studies including stages III/IV reported pCR in 34.1% (95%CI 19.9-48.4). Single-agent therapy led to pCR in 30.5% (95%CI 20.2-40.9) of patients, while those treated with combination therapy had a pCR rate of 42.1% (95%CI 25.6-58.5). MPR was reached in 49.0% (95% 39.6-58.5) of patients. 231 (82.4%) remained free-of-events with a minimum follow-up of 14.6 months. OS was 90.1% (95%CI 86.0-93.1) in two years (27 deaths). Overall pathological response (CR+MPR+PR) was seen in 71.2% (95%CI 63.5-79.0) of patients, and the overall radiographic response in 50.8% (95%Cl 45.0-56.5). According to pCR, responders had a greater EFS than non-responders with an OR of 0.10 (95%CI 0.02-0.49 p=0.004). Among MM/AM, 19.9% (95%CI 7.8-34.9) of patients had pCR. There were no treatment-related deaths or delays of surgery.
Conclusions
Our study supports anti-PD1-based NAT anti-tumor activity in patients with resectable melanoma. Patients with pCR and stage III seem to benefit most from NAT, while rare melanomas still have a worse response. Other ongoing studies and more mature data are needed to confirm our findings.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
M.F. Ribeiro: Financial Interests, Personal, Invited Speaker: Bristol Myers Squibb. All other authors have declared no conflicts of interest.
Resources from the same session
941P - Risk factors for progressive disease after immune checkpoint inhibitors (ICIs) in advanced head and neck squamous cell carcinoma (HNSCC): Who might not be candidate for ICI?
Presenter: Seo Yoon Jang
Session: Poster session 12
942P - Response to salvage chemotherapy with paclitaxel +/- cetuximab after progression on immune checkpoint inhibitors in platinum-refractory recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) patients (CeTax study)
Presenter: Ruth Gabriela Herrera Gomez
Session: Poster session 12
944TiP - Randomized phase II study of immune stimulation with pembrolizumab and radiotherapy of recurrent and/or metastatic head and neck squamous cell carcinoma : The IMPORTANCE trial
Presenter: Bálint Tamaskovics
Session: Poster session 12
1089P - Adjuvant nivolumab (NIVO) vs ipilimumab (IPI) in resected stage III/IV melanoma: 7-y results from CheckMate 238
Presenter: Paolo Ascierto
Session: Poster session 12
1090P - Outcome impact of time from complete resection to start of adjuvant immunotherapy in stage III-IV melanoma patients
Presenter: Sergio Martinez Recio
Session: Poster session 12
1092P - Adjuvant treatment with anti-PD-1 in acral melanoma patients: A nationwide study
Presenter: Manja Bloem
Session: Poster session 12
1093P - Neoadjuvant (NeoAd) intratumoral (IT) TAVO-EP (plasmid IL-12 electro gene transfer) in combination with nivolumab (NIVO) for patients (pts) with operable locoregionally advanced melanoma
Presenter: Ahmad Tarhini
Session: Poster session 12
1094P - Relapse free survival (RFS) at 3 years by pathological (path) response to neoadjuvant systemic treatment (NST) in patients (pts) with surgically resectable, high-risk melanoma
Presenter: Elizabeth Burton
Session: Poster session 12