CP-751,871 + exemestane

**CP-751,871 + exemestane** is a combination of two drugs studied for the treatment of hormone receptor positive advanced breast cancer, particularly in postmenopausal women. **CP-751,871 (figitumumab)** is a fully human IgG2 monoclonal antibody that targets and inhibits the insulin-like growth factor 1 receptor (**IGF-1R**), a receptor implicated in tumor cell proliferation and resistance to hormonal therapies. Its antitumor effects are due to blocking IGF-1 and IGF-2 mediated activation of IGF-1R, thereby inhibiting downstream signaling involved in cancer cell survival and proliferation. **Exemestane** is an aromatase inhibitor that reduces estrogen synthesis, used to treat estrogen receptor-positive breast cancers. The combination was hypothesized to overcome hormone resistance by blocking IGF-1R-mediated escape pathways. Clinical studies, including phase II trials, were conducted in postmenopausal women with hormone receptor positive advanced breast cancer, but the combination's clinical development was terminated and it did not proceed to approval[1][3][5].

Other names

figitumumab + exemestane