A new treatment for patients with myeloma can lead to a 61% reduction in the risk of progression or death
The Castor Trial, published in the New England Journal of Medicine, is a phase III randomized study that includes 498 patients with relapsed myeloma who had previous received, at least, one treatment.
The study evaluated if adding a monoclonal antibody, daratumumab, that targets a CD38 antigen present in the surface of myeloma plasma cells to the standard regimen for these patients, bortezomib plus dexamethasone, was more successful than bortezomib plus dexamethasone alone.
The triple combination was indeed more successful, and by adding daratumumab to bortezomib and dexamethasone they achieved a 61% reduction in the risk of progression or death, compared with a regimen of bortezomib and dexamethasone; a result that has never been achieved with other combinations. In addition, the proportion of patients achieving a complete response with daratumumab, bortezomib and dexamethasone is doubled, compared with bortezomib plus dexamethasone. And, for the first time in a trial like this, it evaluates the minimal residual disease of which the impact on duration of response and survival is still pending. We must highlight that the benefit of adding the monoclonal antibody daratumumab is not linked to a significant increase of toxicity: slightly higher rates of neutropenia and thrombocytopenia, together with reactions to the daratumumab infusion, for the first infusions, are not severe and can be controlled with maintenance treatment.
The results of the trial for this triple combination based on bortezomib and dexamethasone plus daratumumab, the first monoclonal antibody approved for monotherapy in patients with myeloma, prepare the road for the future use of this new combination to treat patients with myeloma.