The US Food and Drug Administration (FDA) have approved a new drug to treat patients with advanced or metastatic breast cancer that has progressed after taking prior treatment. The drug — Verzenio (abemaciclib) — can be used for treatment of people with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2) — negative advanced or metastatic breast cancer that progressed after taking therapy that alters a patient’s hormones (endocrine therapy), the regulators said in a statement on Thursday. “Verzenio provides a new targeted treatment option for certain patients with breast cancer who are not responding to treatment, and unlike other drugs in the class, it can be given as a standalone treatment to patients who were previously treated with endocrine therapy and chemotherapy,” said Richard Pazdur, Director at FDA. The FDA granted the approval of developing Verzenio to Eli Lilly and Company — a US-based pharmaceuticals firm. Verzenio works by blocking certain molecules (known as cyclin-dependent kinases 4 and 6), involved in promoting the growth of cancer cells, the statement said. The median progression-free survival for patients taking Verzenio in combination with fulvestrant was 16.4 months compared to 9.3 months for patients taking a placebo with fulvestrant. When taken as a standalone treatment, 19.7 per cent of patients experienced complete or partial shrinkage of their tumours for a median 8.6 months. However, use of Verzenio also revealed some common side effects including diarrhoea, low levels of certain white blood cells (neutropenia and leukopenia), nausea, abdominal pain, infections, fatigue , low levels of red blood cells (anaemia), decreased appetite, vomiting and headache, the statement said.