Last Updated on
February 23, 2015 – Multiple myeloma is a form of blood cancer that arises from plasma cells, a type of white blood cell, found in bone marrow. According to the National Cancer Institute, approximately 21,700 Americans are diagnosed with multiple myeloma and 10,710 die from the disease annually.
Primarily affecting older adults, multiple myeloma causes plasma cells to rapidly multiply and crowd out other healthy blood cells from the bone marrow. When the bone marrow has too many plasma cells, the cells may move to other parts of the body, which can weaken the body’s immune system, lead to anemia and cause other bone and kidney problems.
The US Food and Drug Administration (FDA) has just approved Panobinostat [Farydak] for the treatment of certain patients. Farydak works by inhibiting the activity of enzymes, known as histone deacetylases (HDACs). This process may slow the over-development of plasma cells in multiple myeloma patients or cause these dangerous cells to die. Farydak is the first HDAC inhibitor approved to treat multiple myeloma. It is intended for patients with multiple myelome who have received at least two prior standard therapies, including bortezomib and an immunomodulatory agent. Farydak is to be used in combination with bortezomib, a type of chemotherapy, and dexamethasone, an anti-inflammatory medication. “Farydak has a new mechanism of action that distinguishes it from prior drugs approved to treat multiple myeloma, making it a potentially attractive candidate agent for the treatment of multiple myeloma,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Farydak’s approval is particularly important because it has been shown to slow the progression of multiple myeloma.”
The safety and efficacy of Farydak in combination with bortezomib and dexamethasone was demonstrated in 193 clinical trial participants with multiple myeloma who received at least two prior treatments that included bortezomib and an immunomodulatory agent. Participants were randomly assigned to receive a combination of Farydak, bortezomib and dexamethasone, or bortezomib and dexamethasone alone. Study results showed participants receiving the Farydak combination saw a delay in their disease progression (progression-free survival) for about 10.6 months, compared to 5.8 months in participants treated with bortezomib and dexamethasone alone. Additionally, 59 percent of Farydak-treated participants saw their cancer shrink or disappear after treatment (response rate), versus 41 percent in those receiving bortezomib and dexamethasone.
Farydak comes with an impressively heavy burden of adverse side effects, some of of them potentially fatal, however. Farydak carries a Boxed Warning alerting patients and health care professionals that severe diarrhea and severe and fatal cardiac events, arrhythmias and electrocardiogram (ECG) changes have occurred in patients receiving Farydak. Because of these risks, Farydak is being approved with a Risk Evaluation and Mitigation Strategy (REMS) consisting of a communication plan to inform health care professionals of these risks and how to minimize them.
The most common side effects of Farydak were diarrhea, tiredness, nausea, swelling in the arms or legs, decreased appetite, fever, vomiting and weakness. The most common laboratory abnormalities were low levels of phosphorus in the blood (hypophosphatemia), low potassium levels in the blood (hypokalemia), low levels of salt in the blood (hyponatremia), increased creatinine, low platelets (thrombocytopenia), low white blood cell counts (leukopenia) and low red blood cell counts (anemia). Healthcare professionals should also inform patients of the risk of bleeding in the gastrointestinal tract and the lungs, and liver damage (hepatotoxicity).
In any case, if you were an eligible patient for treatment with Farydak, you and your treating physician would be confronted with a taff decision. On one side, you see the impressive apparent efficacy of Farydak; on the other hand, you are confronted with the equally impressive, or better, disturbing safety profile of the drug. And. at the moment, you have little possibility to find out if you were one of the severely affected patients. A real puzzle, turning into a mind game in front of a potentially (more acurately, ultimatively) deadly disease.