Exemestane and Everolimus: Hormone and Biological Therapy Treatment Combination

Exemestane and Everolimus: Hormone and Biological Therapy Treatment Combination


Exemestane, also known as Aromasin,  is a type of oral, targeted cancer therapy called an aromatase inhibitor and works by a mechanism that stops the production of estrogen in postmenopausal women by blocking an enzyme called aromatase., which is important in the production of estrogen. Inhibiting the actions of aromatase means less estrogen is available to stimulate the growth of hormone-receptor positive breast cancer cells.

Exemestane dissolves in the digestive system and is absorbed into the blood stream, where it blocks the production of estrogen from fat tissue.


Everolimus, also known as Afinitor, is a biologic immunosuppressant therapy that was first used to prevent the body from rejecting organ transplants. It has been repurposed as an oncology therapy that helps estrogen-blocking cancer drugs, such as exemestane, to sustain their estrogen-blocking mechanism for longer periods of time.

Benefits in Combining Exemestane and Everolimus

The combination of exemestane and everolimus has shown to be significantly more effective in the increase of progressive-free survival of patients than with the hormonal therapy alone. The two drugs work together to stop the growth of cancer cells, and this significant treatment response only works when the drugs are used in combination.

In the clinical study BOLERO-2, conducted at MD Anderson Cancer Treatment Center in Houston, researchers looked at patients receiving the exemestane-everolimus combination. Results revealed that in patients receiving the combination therapy, there was a progression-free survival of 7.4 months, compared to 3.2 months in those who took exemestane alone. The clinical benefit rate – complete responses, partial responses, and stability exceeding six months – was 50.5 percent in people in the combination arm, compared to 25.5 percent in those who received the hormonal therapy alone. Adverse effects, such as shortness of breath, hyperglycemia, mouth sores, and fatigue, were all higher in the combination group, but were manageable and did not disrupt patients’ quality of life.

The clinical side-effects associated with this therapeutic combination include:

  • Mouth pain or open sores on the tongue or in the mouth;
  • Fatigue or weakness;
  • Diarrhea;
  • Rash;
  • Infections;
  • Changes in blood sugar levels;
  • Lung changes;
  • Changes in sense of taste;
  • Decreased appetite and weight loss;
  • Hot flashes;
  • Menopause symptoms or vaginal changes;
  • Headache, joint, or muscle pains;
  • Decreased bone density (osteoporosis or osteopenia).

It is important to remember that every patient responds differently and anyone who is considering this therapeutic approach should consult their physician for any questions or concerns.