DeMichele Angela, Clark Amy S, Shea Emily, Bayne Lauren J, Sterner Christopher J, Rohn Killian, Dwyer Samantha, Pan Tien-Chi, Nivar Isoris, Chen Yan, Wileyto Paul, Berry Lindsay R, Deluca Shannon, Savage Jessica, Makhlin Igor, Pant Dhruv K, Martin Heather, Egunsola Adetutu, Mears Nathan, Goodspeed Brooke L, Chislock Elizabeth M, Graves Jewell, Wang Jianping, Shih Natalie, Belka George K, Berry Don, Nayak Anupma, Feldman Michael, Chodosh Lewis A
Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, USA.
Nat Med. 2025 Sep 2. doi: 10.1038/s41591-025-03877-3.
Breast cancer recurrence may arise from dormant disseminated tumor cells (DTCs) that persist in bone marrow and other sites. Clinically, DTCs are independently associated with breast cancer recurrence and death. Preclinical studies in mouse models identified autophagy and mammalian target of rapamycin (mTOR) signaling as critical mechanisms of tumor dormancy and escape. We subsequently tested the effects of transient versus chronic inhibition of autophagy with chloroquine or hydroxychloroquine (HCQ) and mTOR signaling with rapamycin (RAPA) or everolimus (EVE) on residual tumor cell (RTC) burden and recurrence-free survival (RFS). In mice harboring dormant RTCs, inhibition of mTOR alone or in combination with autophagy inhibition decreased RTC burden and improved RFS in a duration-dependent manner. RTC number was strongly and inversely correlated with RFS, suggesting that RTC reduction mediated an improvement in RFS. To translate findings clinically, we performed a randomized phase 2 trial (CLEVER) of HCQ, EVE or their combination in breast cancer survivors within 5 years of diagnosis who had detectable DTCs on bone marrow aspirate. Primary endpoints were feasibility and safety; secondary endpoints included DTC reduction/clearance and RFS. In total, 51 DTC patients initiated HCQ (n = 15), EVE (n = 15) or HCQ + EVE (n = 21). Treatment was feasible and tolerable; only one patient discontinued early for grade 3 toxicity. At 42 months median follow-up, landmark 3-year RFS for HCQ, EVE and HCQ + EVE was 91.7%, 92.9% and 100%, respectively, and was greater in those who cleared DTCs versus those who did not (hazard ratio (HR) = 0.21 (95% confidence interval 0.01-3.4)). Posterior probabilities were 98-99.9% that three cycles of HCQ, EVE or HCQ + EVE led to reduced or undetectable DTCs compared to observation alone, with estimated DTC reductions of 80%, 78% and 87%, respectively. These findings provide proof-of-concept that targeting dormant RTCs with HCQ, EVE or their combination in breast cancer survivors or mouse models depletes minimal residual disease, warranting a definitive human randomized controlled trial. ClinicalTrials.gov registration: NCT03032406 .
乳腺癌复发可能源于潜伏在骨髓和其他部位的休眠播散肿瘤细胞（DTCs）。临床上，DTCs与乳腺癌复发和死亡独立相关。在小鼠模型中的临床前研究确定自噬和雷帕霉素哺乳动物靶标（mTOR）信号传导是肿瘤休眠和逃逸的关键机制。我们随后测试了用氯喹或羟氯喹（HCQ）短暂或长期抑制自噬以及用雷帕霉素（RAPA）或依维莫司（EVE）抑制mTOR信号传导对残余肿瘤细胞（RTC）负荷和无复发生存期（RFS）的影响。在携带休眠RTCs的小鼠中，单独抑制mTOR或与自噬抑制联合使用以时间依赖性方式降低了RTC负荷并改善了RFS。RTC数量与RFS呈强烈负相关，表明RTC减少介导了RFS的改善。为了将研究结果转化为临床应用，我们对诊断后5年内骨髓穿刺可检测到DTCs的乳腺癌幸存者进行了一项关于HCQ、EVE或其联合用药的随机2期试验（CLEVER）。主要终点是可行性和安全性；次要终点包括DTC减少/清除和RFS。共有51例DTC患者开始接受HCQ（n = 15）、EVE（n = 15）或HCQ + EVE（n = 21）治疗。治疗是可行且可耐受的；只有1例患者因3级毒性而提前停药。在中位随访42个月时，HCQ、EVE和HCQ + EVE的标志性3年RFS分别为91.7%、92.9%和100%，清除DTCs的患者的RFS高于未清除者（风险比（HR）= 0.21（95%置信区间0.01 - 3.4））。与单独观察相比，HCQ、EVE或HCQ + EVE三个周期导致DTC减少或无法检测的后验概率为98 - 99.9%，估计DTC减少分别为80%、78%和87%。这些发现提供了概念验证，即在乳腺癌幸存者或小鼠模型中用HCQ、EVE或其联合用药靶向休眠RTCs可清除微小残留病灶，值得进行一项确定性的人类随机对照试验。ClinicalTrials.gov注册号：NCT03032406 。
