Preclinical Efficacy of Bevacizumab with CRLX101, an Investigational Nanoparticle-Drug Conjugate, in Treatment of Metastatic Triple-Negative Breast Cancer.
VEGF pathway-targeting antiangiogenic drugs, such as bevacizumab, when combined with chemotherapy have changed clinical practice for the treatment of a broad spectrum of human cancers. However, adaptive resistance often develops, and one major mechanism is elevated tumor hypoxia and upregulated hypoxia-inducible factor-1α (HIF1α) caused by antiangiogenic treatment. Reduced tumor vessel numbers and function following antiangiogenic therapy may also affect intratumoral delivery of concurrently administered chemotherapy. Nonetheless, combining chemotherapy and bevacizumab can lead to improved response rates, progression-free survival, and sometimes, overall survival, the extent of which can partly depend on the chemotherapy backbone. A rational, complementing chemotherapy partner for combination with bevacizumab would not only reduce HIF1α to overcome hypoxia-induced resistance, but also improve tumor perfusion to maintain intratumoral drug delivery. Here, we evaluated bevacizumab and CRLX101, an investigational nanoparticle-drug conjugate containing camptothecin, in preclinical mouse models of orthotopic primary triple-negative breast tumor xenografts, including a patient-derived xenograft. We also evaluated long-term efficacy of CRLX101 and bevacizumab to treat postsurgical, advanced metastatic breast cancer in mice. CRLX101 alone and combined with bevacizumab was highly efficacious, leading to complete tumor regressions, reduced metastasis, and greatly extended survival of mice with metastatic disease. Moreover, CRLX101 led to improved tumor perfusion and reduced hypoxia, as measured by contrast-enhanced ultrasound and photoacoustic imaging. CRLX101 durably suppressed HIF1α, thus potentially counteracting undesirable effects of elevated tumor hypoxia caused by bevacizumab. Our preclinical results show pairing a potent cytotoxic nanoparticle chemotherapeutic that complements and improves concurrent antiangiogenic therapy may be a promising treatment strategy for metastatic breast cancer. Cancer Res; 76(15); 4493-503. ©2016 AACR.
Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada.
Elizabeth
E
Pham
Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada.
Melissa
M
Yin
Cerulean Pharma Inc., Waltham, Massachusetts.
Christian G
CG
Peters
Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada.
Christina R
CR
Lee
Cerulean Pharma Inc., Waltham, Massachusetts.
Donna
D
Brown
Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada.
Ping
P
Xu
Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada.
Shan
S
Man
Cerulean Pharma Inc., Waltham, Massachusetts.
Lata
L
Jayaraman
Cerulean Pharma Inc., Waltham, Massachusetts.
Ellen
E
Rohde
Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada.
Annabelle
A
Chow
Cerulean Pharma Inc., Waltham, Massachusetts.
Douglas
D
Lazarus
Cerulean Pharma Inc., Waltham, Massachusetts.
Scott
S
Eliasof
Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada. Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
F Stuart
FS
Foster
Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada. Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada. robert.kerbel@sri.utoronto.ca.
Robert S
RS
Kerbel
D020533:Angiogenesis Inhibitors / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000068258:Bevacizumab / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D003505:Cyclodextrins / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D053758:Nanoparticles; D064726:Triple Negative Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology
D020533:Angiogenesis Inhibitors; D003505:Cyclodextrins; C542292:IT-101; D000068258:Bevacizumab; D002166:Camptothecin