|The following article features coverage from the ASCO Gastrointestinal Cancers Symposium 2022. Click here to read more of Cancer Therapy Advisor’s conference coverage.|
Neoadjuvant treatment with immune checkpoint inhibitors, followed by surgery and adjuvant immunotherapy, appears effective for patients with microsatellite instability-high/mismatch repair deficient (MSI/dMMR) gastric or gastroesophageal junction (GEJ) adenocarcinoma, phase 2 data suggest.
The results raise the question of whether surgery can be delayed or avoided for some patients with localized MSI/dMMR gastric/GEJ cancer if immune checkpoint inhibitors are effective, said Thierry Andre, MD, of Sorbonne University in Paris.
Dr Andre presented these results, from the phase 2 NEONIPIGA trial, at the ASCO Gastrointestinal Cancers Symposium 2022.
The trial (ClinicalTrials.gov Identifier: NCT04006262) included 32 patients with resectable MSI/dMMR gastric/GEJ adenocarcinoma. The median age was 65 (range, 40-84) years, and 72% of patients were men.
All 32 patients started neoadjuvant treatment with nivolumab at 240 mg every 2 weeks and ipilimumab at 1 mg/kg every 6 weeks. There were 29 patients who went on to surgery 5 weeks after the last injection of nivolumab.
One patient did not have surgery because of metastatic disease progression, and 2 patients refused surgery because they had achieved a complete response to immunotherapy.
After surgery, 25 patients received adjuvant nivolumab at 480 mg every 4 weeks, and 10 patients were still receiving adjuvant therapy at last follow-up.
The study’s primary endpoint was pathologic complete response (pCR), and the pCR rate was 58.6% (17/29).
The median follow-up was 12 months. There was 1 death at day 3 after surgery, and 1 patient had progressive disease after 6 cycles of treatment. The patient who progressed did not undergo surgery.
A total of 31 patients were still alive at last follow-up, and 30 had not relapsed. This translates to an event-free survival rate of 94%.
In all 32 enrolled patients, the rate of grade 3/4 treatment-related adverse events was 25%. Peri and/or post-operative complications (until 90 days after surgery) occurred in 58.5% of patients. Surgical complications were as expected, Dr Andre said.
Disclosures: This research was supported by GERCOR and Bristol Myers Squibb. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
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Andre T, Tougeron D, Piessen G, et al. Neoadjuvant nivolumab plus ipilimumab and adjuvant nivolumab in patients (pts) with localized microsatellite instability-high (MSI)/mismatch repair deficient (dMMR) oseo-gastric adenocarcinoma (OGA): The GERCOR NEONIPIGA phase II study. Presented at ASCO GI 2022; January 20-22, 2022. Abstract 244.