Cerulean Pharma, a company based in Cambridge, MA has received Orphan Drug Designation from the US Food and Drug Administration for its poly-CD-PEG-camptothecin (CRLX101) for the treatment of ovarian cancer. CRLX101 is a nanoparticle-drug conjugate designed to concentrate in tumors and slowly release camptothecin inside tumor cells. Captothecin is a potent topoisomerase 1 inhibitor, a validated cancer target. Besides inhibition of topoisomerase 1, CRLX101 has also shown activities against HIF-1alpha (hypoxia-inducible factor 1 alpha), a cancer target for which there are no approved drug that provide durable inhibition. By upregulation of HIF-1alpha in response to chemotherapy, cancer cells activate multiple adaptive pathways to promote tumor cell survival resulting in treatment failures. Therefore, CRLX101 alone or in combination with other chemotherapeutics may offer more effective treatment for cancer. Ovarian cancer, if diagnosed before metastasis has a relatively good prognosis, however, the overwhelming majority of patients present with metastatic disease and the prognosis is poor. Recurrence after the initial treatment is common among metastatic ovarian and there are limited treatment options available for these patients. According to the company, CRLX101 is currently in clinical trials for renal cell carcinoma, ovarian cancer and rectal cancer.