Founded in 1964, the American Society of Clinical
Oncology (ASCO) is the world's leading professional organization for
physicians, researchers and specialists in the field of oncology.
Major annual event for clinical research and
innovation in oncology, the ASCO International Conference is held every year in
Chicago. Several tens of thousands of international specialists meet there to
present research that aimed at improving treatment standards and patient care.
https://conferences.asco.org/
For the 2025 edition, our team was involved in the
following study:
Neoadjuvant nivolumab plus ipilimumab and adjuvant
nivolumab in patients with localized microsatellite instability-high
(MSI)/mismatch repair deficient (dMMR) oeso-gastric adenocarcinoma: Long-term
follow-up of the GERCOR NEONIPIGA phase II study.
Authors : Thomas Samaille, Julie
Henriques, David Tougeron, Guillaume Piessen, Christelle de la Fouchardière, Christophe
Louvet, Antoine Adenis, Marine Jary, Marie-Line Garcia-Larnicol, Romain Cohen, Dewi
Vernerey, Jeremie H. Lefevre, Magali Svrcek, Thierry Andre.
Background:
Neoadjuvant
nivolumab and ipilimumab in localized MSI/dMMR gastric cancer were evaluated in
the NEONIPIGA study (NCT04006262). The primary endpoint was pathological
complete response (pCR) and has been previously reported. Here, we report on
the long-term follow-up analysis and the secondary objectives of event-free
survival (EFS) and overall survival (OS).
Methods:
This
phase II, single-arm study evaluated neoadjuvant nivolumab 240 mg q2w x 6 and
ipilimumab 1 mg/kg q6w x 2, followed by surgery 5 weeks (±1 week) after the
last injection of nivolumab and adjuvant nivolumab 480 mg q4w x 9 in patients
with resectable MSI/dMMR, T2-T4 NxM0 oeso-gastric adenocarcinoma. EFS and OS
were evaluated through Kaplan-Meier curves.
Results:
32
patients were included: 16 (50%) with gastric location and 16 (50%) with
gastro-esophageal junction; 28 (88%) were initially classified as usT3 and four
(12%) as usT2; 23 (72%) were lymph node positive. Three patients did not
undergo surgery (one metastatic progression, two refusals). 27 (84%) patients
completed the planned 6 cycles of neoadjuvant therapy, and 14 (44%) received
the full neoadjuvant and adjuvant treatment. Median follow-up was 48.3 months
(44.8-52.0). In the ITT population, 4-year OS was 84.1% (65.8-93). In the
population eligible for surgery, 4-year EFS was 83.5% (64.8-92.8). Only one
patient (classified as ypT0N1 and TRG1b at surgery) relapsed with cerebral
metastases 29 months after initiation of neoadjuvant treatment. Six deaths were
reported, including two related to gastric cancer (one post-operative due to
surgery complications, one from cerebral metastases). The four remaining deaths
were unrelated to gastric cancer or treatment toxicity and were due to
pulmonary infections (n = 2; 33 and 60 months after initiation of
neoadjuvant treatment), perforation of a strangulated hernia (13 months), and
metastatic tongue cancer (30 months). All three patients without surgery
achieved a clinical complete response after immunotherapy (including one
deceased patient reported above). Combined with the 17 (59%) patients in pCR
previously reported, 20 of 32 (62.5%) patients achieved complete response. No
new safety signals were reported during extended follow-up.
Conclusions:
Neoadjuvant nivolumab and ipilimumab before surgery and adjuvant nivolumab in localized MSI/dMMR oeso-gastric adenocarcinoma achieved a high curative rate. These findings strongly support further investigation of a watch-and-wait approach in case of clinical complete response after immune checkpoint inhibitors, which is currently being evaluated in the DEWI GERCOR phase II study (NCT06059495).
About Sophie PAGET-BAILLY
Sophie Paget-Bailly is a research engineer in epidemiology and clinical research. She passed with honours the East of France inter-region master’s degree in public health and occupational and environmental risks. During the master’s degree’s internship in the Interregional Epidemiology Unit of Bourgogne/Franche-Comté, she realized a quantitative health risk assessment in the context of chemical contamination of groundwater. She defended a PhD in Public Health and Epidemiology in Paris XI University, Doctoral School 420, working in the Centre for Research in Epidemiology and Population Health in Villejuif, France. Her PhD research focused on occupational exposures and head and neck cancer.