The US FDA has approved isatuximab-irfc (Sarclisa) in combination with pomalidomide and dexamethasone (pom-dex) for the treatment of adults with relapsed refractory multiple myeloma (RRMM).
The treatment is indicated for those who have received at least two prior therapies including lenalidomide and a proteasome inhibitor.
Isatuximab is a monoclonal antibody that binds to the CD38 receptor on multiple myeloma cells. It is designed to induce programmed tumour cell death (apoptosis) and immunomodulatory activity. CD38 is highly and uniformly expressed on multiple myeloma cells and cell surface receptors, making it a potential target for antibody-based therapeutics.
In the ICARIA-MM study, isatuximab added to pom-dex demonstrated a statistically significant improvement in progression-free survival (PFS) with a median PFS of 11.53 months compared to 6.47 months with pom-dex alone (HR 0.596, 95% CI: 0.44-0.81, p=0.0010). The combination therapy also demonstrated a significantly greater overall response rate compared to pom-dex alone (60.4% vs. 35.3%, p<0.0001).
The most common adverse reactions (occurring in 20% or more of patients) in patients who received isatuximab combination therapy were neutropenia (96%), infusion-related reactions (39%), pneumonia (31%), upper respiratory tract infection (57%) and diarrhoea (26%). Serious adverse reactions that occurred in more than 5% of patients who received the combination therapy included pneumonia (25.3%) and febrile neutropenia (12.3%). Permanent discontinuation of the therapy due to an adverse reaction (Grades 3-4) occurred in 7% of patients, and 3% of patients discontinued due to an infusion-related reaction.
Isatuximab offers an intravenous (IV) administration and is dosed at 10 mg/kg, in combination with pom-dex, every week for four weeks and then every two weeks, until disease progression or unacceptable toxicity. The first cycle is administered in an infusion time of 200 minutes, which can decrease to 75 minutes for the third cycle onwards. A treatment cycle is 28 days.
Isatuximab has Orphan Drug Designation status from the FDA and the European Medicines Agency (EMA).
The drug is also being evaluated in multiple ongoing phase 3 clinical trials in combination with current standard treatments for people with relapsed refractory or newly diagnosed multiple myeloma. It is also under investigation for the treatment of other blood cancer types (hematologic malignancies) and solid tumours.