In this HER2+ breast cancer model, Mice treated with Lerociclib elicits 8% tumor regression after 21 days of treatment while control animals have a 577% increase in tumor burden over the same treatment period. Compared to the vehicle-treated mice, daily treatment with 100 mg/kg of Lerocyclib or palbociclib shows tumor regression within 10 days in the MCF7 xenograft model. After 27 days of treatment, tumor growth inhibition is observed in the 10, 50, and 100 mg/kg Lerociclib cohorts (approximately 12%, 74%, and 90% inhibition, respectively). Daily oral palbociclib treatment causes an 18%, 66%, and 87% tumor growth inhibition in the 10, 50, and 100 mg/kg dosage cohorts, respectively. Interestingly, at 50 mg/kg, Lerociclib is significantly more efficaciou than palbociclib. Similar results are seen in the ER+ZR-75-1 breast cancer xenograft model when comparing Lerocyclib and palbociclib at the 50 mg/kg dose. Lerociclib treated mice exhibits 77% TGI with an overall 60% tumor growth delay demonstrating Lerocyclib alone is highly efficacious in this NSCLC tumor model.
