An experimental monoclonal antibody delayed disease progression or death in people with multiple myeloma, according to an announcement by drug developer Sanofi. These results have not yet been presented at a scientific conference or published in a medical journal.

The new therapy, isatuximab, binds to the CD38 protein on malignant myeloma cells, leading to cell suicide (apoptosis) and helping the immune system recognize and attack the cancer. It is in the same drug class as the approved therapy Darzalex (daratumumab).

Multiple myeloma is an uncommon blood cancer that involves uncontrolled growth of plasma cells, a type of B cell that produces antibodies. These malignant cells multiply in the bone marrow and can crowd out normal blood-forming cells as well as cells that build new bone, which can lead to fractures.

About 32,110 new cases of multiple myeloma will be diagnosed this year, according to the American Cancer Society. Isatuximab has received the Food and Drug Administration’s orphan drug designation as a therapy for a disease that affects only a small number of people.

Treatment for multiple myeloma may include traditional chemotherapy; steroids such as dexamethasone and prednisone; immunomodulators such as Revlimid (lenalidomide) and Pomalyst (pomalidomide); proteasome inhibitors such as Velcade (bortezomib) and Kyprolis (carfilzomib); and other targeted therapies. Treatment can slow disease progression but relapse is common.

The Phase III ICARIA-MM trial enrolled 307 people with relapsed or refractory (nonresponsive) multiple myeloma. They had tried at least two prior therapies, including Revlimid and a proteasome inhibitor.

Participants were randomly assigned to received isatuximab plus the standard regimen of Pomalyst and low-dose dexamethasone or else standard therapy alone. Isatuximab was given by IV infusion once weekly for four weeks, then every other week in monthly cycles.

Sanofi announced the top-line results of the study, showing that isatuximab met its primary endpoint of improved progression-free survival (PFS), meaning patients were still alive without worsening of disease. The company did not give details about the PFS duration or overall response rates, stating that these findings would be submitted for presentation at an upcoming medical meeting.

ICARIA-MM is one of four ongoing Phase III trials evaluating isatuximab in combination with currently available standard treatments for people with newly diagnosed, relapsed or refractory multiple myeloma, according to Sanofi. The company said it expects to use the findings to support a request for approval later this year.

Click here to read the Sanofi press release about the study results.

Click here to learn more about multiple myeloma.

Click here to read Yolanda Brunson-Sarrabo’s story about living with multiple myeloma in the Winter issue of Cancer Health.