{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T04:50:31Z","timestamp":1791521431728,"version":"4.3.4"},"reference-count":22,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T00:00:00Z","timestamp":1791504000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:p>Immune checkpoint inhibitors (ICIs) have improved outcomes in selected patients with metastatic triple-negative breast cancer (mTNBC), particularly those with high programed death-ligand 1 (PD-L1) expression. However, optimal dosing strategies balancing efficacy, toxicity, and cost remain unclear. We report the case of a 34-year-old woman with recurrent mTNBC and high PD-L1 expression (combined positive score, CPS \u2265 60; immunohistochemistry 22C3 pharmDx assay). She achieved durable disease control over 22 months (September 2024 to June 2026) using a combination of gemcitabine maintenance chemotherapy and low-dose intermittent nivolumab (40 mg fixed dose, administered 3-weekly). This de-escalated regimen was adopted due to early treatment toxicity and severe financial constraints. The patient achieved a confirmed partial response by RECIST v1.1 criteria (48% reduction in target lesion size), accompanied by manageable CTCAE Grade 2 hypothyroidism requiring oral levothyroxine replacement. This case illustrates that in biomarker-selected, PD-L1-high mTNBC, combination chemotherapy with low-intensity PD-1 blockade can maintain prolonged antitumor activity. These observations support the working hypothesis of a minimum effective immune dose, warranting prospective evaluation in resource-constrained clinical settings.<\/jats:p>","DOI":"10.3389\/fonc.2026.1964934","type":"journal-article","created":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T04:27:12Z","timestamp":1791520032000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Durable partial response with low-dose, intermittent nivolumab in combination with gemcitabine for high PD-L1 metastatic triple-negative breast cancer: a case report"],"prefix":"10.3389","volume":"16","author":[{"given":"Po Lin","family":"Ooi","sequence":"first","affiliation":[{"name":"Department of Clinical Oncology, Faculty of Medicine, Universiti Malaya, Jalan Universiti","place":["Kuala Lumpur, Malaysia"]},{"name":"Department of Clinical Oncology, Universiti Malaya Medical Centre, Jalan Profesor Diraja Ungku Aziz","place":["Petaling 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