進行大腸がん患者の生存期間延長 （Abstract # CRA3503）

進行大腸がん初回増悪後のセカンドライン化学療法にベバシズマブを継続することにより生存期間が延長する

Continuing bevacizumab with second-line chemotherapy after first progression extends survival for advanced colorectal cancer

第48回American Society of Clinical Oncology学会で発表された大規模第3相臨床試験の結果、ファーストラインとしてベバシズマブ併用療法を受けた進行大腸がん患者のセカンドラインとしての標準的な化学療法とベバシズマブによる併用療法が全生存期間を延長したことが示された。この第3相無作為化トライアルでは、転移性の切除不能大腸がん患者820人が標準的なファーストライン化学療法（医師の選択によりオキサリプラチンまたはイリノテカンベース）とベバシズマブの併用で治療された。疾患増悪を受けて、患者はもう片方の化学療法薬とベバシズマブまたはプラセボ併用群に無作為に割り付けられた。その結果、全生存期間（11.2か月対9.8か月）および無増悪生存期間（5.7か月対4.1か月）は、ベバシズマブ投与群において有意に長かった。全体的に両群患者とも治療の忍容性は良好であった：ベバシズマブによる副作用は過去のスタディで認められたものと同等であった。これはファーストラインとしてベバシズマブ併用療法を受けた患者に対するセカンドライン治療としてのベバシズマブ継続併用療法を評価した、はじめての無作為化トライアルである。
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Results from a large, Phase III clinical trial presented at the American Society of Clinical Oncology's 48th Annual Meeting show that combination treatment with bevacizumab and standard chemotherapy in the second line setting in patients with advanced colorectal cancer who have received bevacizumab combination treatment first-line extends overall survival.

"These findings confirm what many physicians and researchers have long suspected – that extended bevacizumab treatment provides meaningful benefits for patients with advanced colorectal cancer, without adding significant side effects," said Dirk Arnold, M.D., Director of the Hubertus Wald Tumor Center, University Cancer Center (UCCH) of University Clinic Eppendorf, Hamburg, Germany, and Speaker of the German AIO Colorectal Cancer Collaborative Study Group (which initiated the trial). "But the findings also provide an important new insight about the biology of advanced colorectal cancer, showing us that if the disease develops resistance to chemotherapy, it does not necessarily mean that tumors become resistant to anti-angiogenic therapy. By simply switching chemotherapy drugs when the cancer progresses and continuing with bevacizumab, we can make second-line treatment even more powerful. This finding will likely spur research into other cancer types that are sensitive to both bevacizumab and chemotherapy."

Bevacizumab is known as an anti-angiogenic targeted therapy. This is the first randomized trial to evaluate the combination regimen in second-line in patients who have previously been treated with a bevacizumab regimen in the first-line setting.

In this Phase III randomized trial, 820 patients with metastatic, inoperable colorectal cancer were treated with standard first-line chemotherapy (physician's choice of oxaliplatin- or irinotecan- based) plus bevacizumab. Following disease progression, patients were randomized to receive the opposite chemotherapy drug plus bevacizumab or placebo. Researchers observed that both overall survival (11.2 months vs. 9.8 months) and progression-free survival (5.7 vs. 4.1 months) were significantly longer among patients who received bevacizumab.

Overall, treatment was well-tolerated by patients in both arms: side effects associated with bevacizumab therapy were comparable with those observed in past studies.