美國明尼蘇達州梅奧診所的一項研究表明，綠茶中的一種活性成分兒茶素酸酯(EGCG)可有效控制慢性淋巴細胞性白血病(CLL)病情,，這為攻克該病帶來了新希望。該研究結(jié)果刊登在近日的《臨床腫瘤學雜志》（Journal of Clinical Oncology）網(wǎng)絡版上,。
在臨床試驗中,，梅奧診所的研究人員每天兩次給33名慢性淋巴細胞性白血病患者服用8種不同劑量的olyphenonE囊劑(該藥的主要活性成分是EGCG)，劑量介于400毫克到2000毫克之間,。結(jié)果發(fā)現(xiàn),，病人的淋巴細胞數(shù)量降低了三分之一。此外研究人員還發(fā)現(xiàn),，病人對該囊劑具有很強的耐受性,，即使是每次高達2000毫克，還是沒有達到病人的最大耐受劑量,。
研究人員發(fā)現(xiàn),，病人不僅能夠忍受這種高劑量綠茶提取物，而且許多人的慢性淋巴細胞白血病呈現(xiàn)某種程度的好轉(zhuǎn),，在患有淋巴結(jié)增大癥狀的病人中,，大部分人的淋巴結(jié)會縮小一半甚至更多。
該項臨床研究是梅奧診所多年來就綠茶提取物對癌細胞作用研究項目的最新舉措,，之前已在實驗室研究中證明了EGCG具有殺死白血病癌細胞的功能,。目前此項研究已進入第二階段，后續(xù)參與臨床試驗的病人數(shù)與第一階段人數(shù)大致相同,。所有人都將服用與原來試驗中同樣的最高劑量,。
在美國，慢性淋巴細胞性白血病是一種常見的白血病,。雖然在很多情況下可以通過血液測試進行早期診斷,，然而卻沒有有效的治療方法。統(tǒng)計顯示,，大約一半的該病患者會過早死亡,。研究人員希望，EGCG能夠穩(wěn)定早期慢性淋巴細胞性白血病患者的病情,，或者與其他治療手段結(jié)合,，提高對該疾病的治療效果。（生物谷Bioon.com）
生物谷推薦原始出處：
Journal of Clinical Oncology, 10.1200/JCO.2008.21.1284
Phase I Trial of Daily Oral Polyphenon E in Patients With Asymptomatic Rai Stage 0 to II Chronic Lymphocytic Leukemia
Tait D. Shanafelt,* Tim G. Call, Clive S. Zent, Betsy LaPlant, Deborah A. Bowen, Michelle Roos, Charla R. Secreto, Asish K. Ghosh, Brian F. Kabat, Mao-Jung Lee, Chung S. Yang, Diane F. Jelinek, Charles Erlichman, and Neil E. Kay
From the Department of Internal Medicine, Division of Hematology; Division of Biostatistics, and Departments of Immunology and Oncology, Mayo Clinical, Rochester, MN; and the Department of Chemical Biology, and the Ernest Mario School of Pharmacy Rutgers, the State University of New Jersey, Piscataway, NJ.
Purpose: To define the optimal dose of Polyphenon E for chronic daily administration and tolerability in patients with chronic lymphocytic leukemia (CLL).
Patients and Methods: Previously untreated patients with asymptomatic Rai stage 0 to II CLL were eligible for participation. Polyphenon E with a standardized dose of epigallocatechin-3-gallate (EGCG) was administered using the standard phase I design with three to six patients per dose level (range, 400 to 2,000 mg by mouth twice a day). Trough plasma EGCG levels were measured 1 month after initiation of therapy. Response was classified using the National Cancer Institute (NCI) Working Group (WG) Criteria.
Results: Thirty-three eligible patients were accrued to dose levels 1 to 8. The maximum-tolerated dose was not reached. The most common adverse effects included transaminitis (33%, all grade 1), abdominal pain (30% grade 1, 0% grade 2, and 3% grade 3), and nausea (39% grade 1 and 9% grade 2). One patient experienced an NCI WG partial remission. Other signs of clinical activity were also observed, with 11 patients (33%) having a sustained 20% reduction in absolute lymphocyte count (ALC) and 11 (92%) of 12 patients with palpable adenopathy experiencing at least a 50% reduction in the sum of the products of all nodal areas during treatment. Trough plasma EGCG levels after 1 month of treatment ranged from 2.9 to 3,974 ng/mL (median, 40.4 ng/mL).
Conclusion: Daily oral EGCG in the Polyphenon E preparation was well tolerated by CLL patients in this phase I trial. Declines in ALC and/or lymphadenopathy were observed in the majority of patients. A phase II trial to evaluate efficacy using 2,000 mg twice a day began in November 2007.
