Real-world sequential treatment patterns and outcomes in the new era of immunotherapy for advanced gastric cancer in Japan

We investigated treatment patterns and outcomes in patients with advanced gastric cancer (AGC) after nivolumab first-line therapy approval in Japan in 2021. This retrospective study used data from the Medical Data Vision database. Treatment patterns were described. Overall time-to-treatment discontinuation (TTD) from the start of each line was estimated. Among 11,276 included patients, 1589 received anti-HER2+chemotherapy (Cx) at any line and regarded as HER2-positive AGC (anti-HER2+Cx group). Among the other, 9687 who presumably had HER2-negative AGC, 5722 received nivolumab+Cx at first-line (Nivo+Cx group), and 3965 received Cx alone at first-line (Cx group). Nivolumab+S-1+oxaliplatin (4,104/11,276; 36.4%) was the most common first-line regimen. The most common second-line and third-line regimens were ramucirumab+paclitaxel (PTX) (or NabPTX) (3092/4345; 71.2%) and nivolumab (490/1712; 28.6%). Median overall TTD from start of first-line therapy was 13.3, 10.5, and 6.8 months in anti-HER2+Cx, Nivo+Cx, and Cx groups. Median overall TTD from start of second-line therapy was 6.2, 3.5, and 4.9 months with ramucirumab combination therapy, ramucirumab monotherapy, and other therapies. After first-line nivolumab was introduced for AGC in Japan, treatment patterns remained consistent with Japanese Gastric Cancer Association guidelines. Optimizing sequential therapy, including nivolumab at first-line and ramucirumab combination at second-line, may improve outcomes. Treatment Patterns and Outcomes in Patients with Advanced Gastric Cancer in Japan This study looked at how people in Japan with advanced stomach cancer are treated, and how long they stay on treatment. The focus was on treatments used after immunotherapy, especially nivolumab, a medicine that helps the body’s immune system attack cancer. Researchers analyzed data from 11,276 patients diagnosed between September 2021 and September 2024, categorizing them by the presence or absence of the protein called HER2 on their cancer cells. This distinction is important because a drug called trastuzumab may be used in patients whose cancer cells have HER2. The most popular first treatment was a combination of three drugs: nivolumab, S-1, and oxaliplatin. When that first treatment stopped working, roughly half of the patients went on to a second treatment, most commonly a combination of two other drugs called ramucirumab and paclitaxel. The study found that patients receiving targeted therapies such as nivolumab or trastuzumab tended to remain on their first treatment for longer. Those receiving ramucirumab combination therapy tended to remain on their second treatment for longer. Patients who were older, physically weaker (such as those losing muscle mass or experiencing fluid buildup), or whose cancer had spread to the lining of the abdomen tended to stop treatment sooner. Overall, the findings confirm that doctors in Japan are following recommended treatment guidelines. Starting with immunotherapy and then moving to ramucirumab-based treatment appears to help patients stay on treatment longer and is associated with better outcomes.