Ribociclib (trade name Kisqali) has been approved in Germany since August 2017 for the treatment of hormone-receptor-positive breast cancer in women, if the cancer has already spread to other parts of the body or is locally advanced. It is used as a part of hormone therapy in combination with an aromatase inhibitor or the anti-estrogen drug fulvestrant. Ribociclib can be used both in first-line hormone therapy as well as in a subsequent treatment if previous hormone therapy wasn't successful. In women before and during menopause, ribociclib is combined with a GnRH analogue.
Breast tumors are surgically removed, if possible. But sometimes the tumor has become too large or the cancer has spread to other parts of the body (metastasis) through the blood or lymphatic system. This is called advanced breast cancer.
One factor affecting the speed at which breast cancer cells grow and spread is whether they have receptors for hormones such as estrogen or progesterone. If they do, the tumor is called hormone-receptor-positive (HR-positive) cancer. In these tumors, hormones such as estrogen or progesterone accelerate the growth of cancer cells.
A certain protein on the surface of the cancer cells, called the HER2 receptor (human epidermal growth factor receptor 2), also reacts to growth signals and accelerates tumor growth. If there are a smaller number of these receptors on the cells of a breast tumor, it is called HER2-negative breast cancer. Ribociclib is approved only for the treatment of HER2-negative breast cancer in women.
Ribociclib inhibits cell division in the cancer cells, slowing down tumor growth.