Treatment with an antibody therapy targeting immune and cancer cells eradicates residual traces of multiple myeloma, a cancer of blood cells, according to interim results from a clinical trial in 18 patients.
None of the 18 patients who received up to six cycles of treatment with the linvoseltamab antibody had detectable disease in high-sensitivity testing.
This preliminary success suggests that the treatment, a bispecific antibody, could allow patients to avoid bone marrow transplants, which involve intense and very powerful chemotherapy. This also highlights the long-term possibility of improving patients’ chances of contracting this disease.
“These patients received modern, effective initial treatment that eliminated 90% of their tumor,” says Dickran Kazandjian of the Sylvester Myeloma Institute. “Normally, patients like these would receive high-dose chemotherapy and need a transplant. “Instead, we gave them treatment with the drug linvoseltamab.”
For researcher Ola Landgren, the results obtained so far are “extremely impressive”.
A curative treatment?
“From my experience, I predict that after such a good response in such a short time, the disease could probably be controlled for many years,” he emphasizes. “Could this never come back in some patients? I would say it’s possible.
Multiple myeloma arises from antibody-producing immune cells called plasma cells. These cancer cells build up, interfering with normal blood cells and causing damage. There is no established cure.
Currently, most patients with newly diagnosed multiple myeloma receive a combination of three or four medications. In some cases, this therapy eradicates myeloma cells, but in other cases, the cancer persists. These traces of myeloma may appear at such low levels that they are not detected in standard bone marrow evaluations.
After treatment, no trace of myeloma was found and the patients’ bone marrow was analyzed with two very sensitive tests.
Sylvester doctors use a highly sensitive genetic test to detect minimal residual disease (MRD) in myeloma patients, capable of identifying one cancer cell among a million normal cells. Having a negative MRD is associated with longer survival. Traditionally, patients who continue to suffer from MRD after treatment receive high-dose chemotherapy, an aggressive procedure started in 1983, followed by a transplant of their own stem cells to enable recovery.
Despite these efforts, in most cases myeloma eventually returns.
Therapeutic targets
While most therapeutic antibodies bind to only one target, bispecific antibodies bind to two. Linvoseltamab binds to CD3, a T cell protein that destroys cancer cells, and to a second target, BCMA, a protein found in multiple myeloma cells. By bringing these two types of cells into contact, the antibody strengthens the body’s immune response against cancer.
After treatment, bone marrow was analyzed with two highly sensitive tests to detect minimal residual disease, and no evidence of myeloma was found in patients who completed treatment.
Based on its performance so far, Kazandjian hopes that linvoseltamab can offer patients more durable responses than transplants, perhaps allowing long-term control of the disease: a “functional cure”.