Study: Immune-Boosting Antibody Treatment Isatuximab Meets Primary Endpoint for Multiple Myeloma

Patients who received the anti-CD38 monoclonal antibody isatuximab in addition to the standard 3-component induction therapy lenalidomide, bortezomib, and dexamethasone (RVd) for newly diagnosed multiple myeloma were significantly more likely to achieve minimal residual disease negativity, with no evidence of cancer in the bone marrow, compared with those receiving RVd alone, according to first primary endpoint results from a phase 3 trial presented at the American Society of Hematology Annual Meeting.

According to the study authors, 50.1% of participants administered isatuximab-RVd achieved minimal residual disease negativity in the bone marrow after their induction treatment compared with 35.6% of those administered RVd only.

“This is the first phase 3 trial to successfully challenge a standard of care that is broadly used in the US and Europe,” said professor Hartmut Goldschmidt, MD, in a press release. “Our results support this treatment as a new standard of care in transplant-eligible patients with newly diagnosed myeloma.”

The researchers hoped to further increase survival rates and completely eradicate the cancer in the bone marrow for more patients by adding isatuximab to RVd. This trial is the first to assess the use of isatuximab as a first-line treatment for newly diagnosed, transplant-eligible patients up to 70 years of age, according to the study authors.

“Isatuximab acts in 2 ways—one is the direct effect of the antibody on myeloma cells, and the other is the immunostimulatory effect,” Goldschmidt said in the press release. “The idea is that if the immune system is stimulated by isatuximab, treatment of myeloma will be more effective.”

The trial enrolled 662 newly diagnosed patients at 67 medical centers throughout Germany, with half of the patients receiving induction therapy isatuximab plus RVd and half receiving RVd alone. The duration of induction therapy was 18 weeks for both treatment arms.

Patients who received isatuximab were significantly more likely to achieve a complete response or a very good partial response and less likely to show evidence of disease progression, according to the study. The research team also found no differences among subgroups, suggesting all patients benefit from the addition of isatuximab to RVd, with no major difference between groups in terms of overall adverse events (AEs) or serious AEs.

The most common AEs in both groups were blood and lymphatic system disorders, infections, and nervous system disorders, with the low white blood cell counts being more frequent in the isatuximab-RVd group, according to the study authors.

This trial is ongoing and will next analyze the impact of isatuximab-RVd versus RVd induction therapy after autologous stem cell transplantation, as well as the drug’s potential effects when used as part of the maintenance regimen with lenalidomide.

REFERENCE

Researchers examine opportunities for immune-modulating approaches to improve outcomes and reduce side effects- Immune-boosting antibody treatment isatuximab meets primary endpoint for multiple myeloma. December 11, 2021. Accessed December 13, 2021. https://www.hematology.org/newsroom/press-releases/2021/new-studies-highlight-how-immunotherapies-are-transforming-care-for-blood-cancers