TOP1 and postmenopausal osteoporosis: For example, Ranibizumab is used in age-related macular degeneration to target FLT1 and Topetecan, a second line of therapy against small cell lung cancer is an inhibitor of TOP1. Denosumab is an approved drug, targeted against TNFSF11, and is currently being used for rheumatoid arthritis and postmenopausal osteoporosis (Table 5).