The following article, written by Irvin Molina, a Clinical Oncology Pharmacist at Oncology Analytics, is the third of a four-part series on key trends and findings from the American Society of Clinical Oncology (ASCO) Annual Meeting, held in Chicago May 31-June 4, 2019.
Multiple myeloma is a cancer of plasma cells, a type of blood cell found in the bone marrow. The bone marrow is the spongy tissue inside your bones that creates the components of your blood, with plasma cells being part of the immune system. Myeloma begins when healthy plasma cells change and grow out of control. This damages the surrounding bone, which can lead to multiple bone lesions that increase the risk of fracture. These abnormal plasma cells can also crowd out healthy blood cells and cause complications. Relapsed (or “recurrent”) multiple myeloma is the term used when the cancer returns after a period of remission.
Multiple myeloma is a relatively rare cancer; about 32,110 new cases will be diagnosed in 2019. Although it is rarely curable, it is a highly manageable disease. The prognosis for this cancer has improved greatly in the past decade due to continuing research. The 5-year survival rate for people with multiple myeloma is over 50%, compared to 13 years ago when it was 34.5%.
NBC News Senior Correspondent, Tom Brokaw was diagnosed with multiple myeloma in August 2013. He was 73 and leading an active lifestyle; including bicycling through South America. However, during this time he developed persistent lower back pain. Bone pain is a common symptom of multiple myeloma. Brokaw sought out medical help, and his physician diagnosed him with multiple myeloma. He then began chemotherapy to treat the cancer, finally achieving remission in 2015. Today, Brokaw remains on oral maintenance chemotherapy with lenalidomide to keep the multiple myeloma at bay.
Monoclonal antibodies are a type of drug class used to treat multiple myeloma. These drugs use the body’s own system to restore, enhance, or mimic the immune system’s attack on cancer cells. They bind to antigens on the surface of cancer cells more than healthy cells to help the immune system more effectively target the malignant cells.
A study presented at #ASCO2019 discussed a new subcutaneous formulation of daratumumab, a human monoclonal antibody used to treat multiple myeloma. This new formulation of daratumumab is combined with hyaluronidase PH20 to reduce rates of infusion-related reactions and decrease treatment burden due to shorter administration duration.
In this phase 3 non-inferiority study, 522 patients with relapsed or refractory multiple myeloma (RRMM) were randomized to either subcutaneous daratumumab with recombinant hyaluronidase or intravenous daratumumab. The median duration of infusion was consistently 5 minutes at each visit in the subcutaneous group. In the intravenous arm, the first infusion lasted 7 hours, the second infusion was 4.3 hours, and subsequent infusions lasted a median of 3.4 hours. Response rates were similar between the two groups. The median time to disease progression was 6.1 months with intravenous daratumumab versus 5.6 months with the subcutaneous formulation. Additionally, there were significantly fewer infusion-related reactions events in the subcutaneous group (12.7%) compared with the intravenous arm (34.5%). Overall, subcutaneous daratumumab significantly decreased infusion-related reactions and administration time with a comparable safety profile.
As a result of this study, the new formulation of daratumumab is currently pending FDA approval. At this time, we do not have any pricing information for the subcutaneous formulation. At Medicare allowable rates, intravenous daratumumab costs about $19,000 for the first month, with the price falling over subsequent months as the frequency of treatment falls from weekly to every three weeks and, after about one year, to every four weeks.