What is daratumumab?
Daratumumab is a medicine called monoclonal antibody, a drug with some specific features and a different mechanism of action than the drugs we have been using for myeloma. It is approved for use on its own to treat myeloma in adult patients whose disease has progressed despite previous treatment with proteasome inhibitors and immunomodulatory drugs. The European Medicines Agency (EMA) granted a conditional marketing authorisation for daratumumab in 2016 after it was reviewed under the EMA’s accelerated assessment programme. Several clinical trials are ongoing and it is subject to annual reviews.
How does daratumumab work?
Daratumumab is a monoclonal antibody that has been designed to recognise and bind to the CD38 protein, which is found in high amounts on myeloma cells. By attaching to CD38, daratumumab kills myeloma cells through a direct anti-tumour activity but it also activates the immune system to kill the cancer cells. It is the first monoclonal antibody single agent treatment approved for treating myeloma.
What are the benefits of daratumumab?
The safety and effectiveness of daratumumab were demonstrated in two clinical trials. In one study of 106 patients, 29% of patients had a complete or partial reduction in their tumour burden, which lasted for an average of 7.4 months. In the second study of 42 patients, 36% had a complete or partial reduction in their tumour burden. Another significant benefit is the stabilization of the disease reported in approximately 50% of the patients included in these trials, which is relevant because it means that daratumumab stopped the progression of the disease.
There are also clinical trials under way that assess combining daratumumab with standard two-drug regimens: bortezomib plus dexamethasone, and lenalidomide plus dexamethasone. Additional trials are testing various daratumumab-based regimens for patients with newly diagnosed myeloma.
What are the side effects?
Daratumumab can cause infusion reactions, but most of them occur during the first infusion and are not severe. You should receive medicines to reduce the risk of infusion-related reactions before and after the infusion and you should be monitored frequently during the entire infusion. Contact a member of the clinical staff if you notice a reaction. Your doctor may need to reduce the infusion rate or stop treatment if you have a severe reaction.
Other side effects may include:
- back pain
- cough, and
- upper respiratory tract infection
You may also develop the following blood abnormalities:
- low white blood cell counts (neutropenia)
- low red blood cells (anaemia) or
- low levels of blood platelets (thrombocytopenia)
How and when is daratumumab given?
Daratumumab is given as an infusion (drip) into a vein at a hospital out-patients department or clinic, under the supervision of a doctor who specialises in the treatment of cancer. The starting dose is calculated using your weight. It is given once a week for the first eight weeks, once every two weeks from week nine to week 24, and then every four weeks. Treatment continues for as long as you benefit from it.
- European Medicines Agency. Darzalex (daratumumab) European public assessment report (EPAR). Last updated 05/2016. http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/human/medicines/004077/human_med_001979.jsp&mid=WC0b01ac058001d124
- Manufacturer’s product information https://www.darzalex.com/
- Loniel, S. et al, Daratumumab monotherapy in patients with treatment-refractory multiple myeloma (SIRIUS): an open-label, randomised, phase 2 trial. Lancet 2016; 387: 1551–60
- Lokhorst HM et al. Targeting CD38 with daratumumab monotherapy in multiple myeloma. N Engl J Med 2015; 373:1207-1219
- Palumbo, A et al. Daratumumab, bortezomib, and dexamethasone for multiple myeloma. N Engl J Med 2016; 375:754-766
- Rajkumar, SV. Daratumumab in multiple myeloma. Lancet S0140-6736(15)01226-X
- Rajkumar, SV and Kumar, S. Multiple Myeloma: diagnosis and treatment. Mayo Clin Proc 2016;91(1):101-119