SUMMARY: The FDA on March 2, 2020 approved SARCLISA® (Isatuximab-irfc) in combination with POMALYST® (Pomalidomide) and Dexamethasone for adult patients with multiple myeloma who have received at least two prior therapies including REVLIMID® (Lenalidomide) and a Proteasome Inhibitor. Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 32,270 new cases will be diagnosed in 2020 and 12,830 patients are expected to die of the disease. Multiple Myeloma (MM) in 2020 remains an incurable disease. The therapeutic goal therefore is to improve Progression Free Survival (PFS) and Overall Survival (OS). Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years.
CD38, a transmembrane glycoprotein abundantly expressed on malignant plasma cells and with low levels of expression on normal lymphoid and myeloid cells. DARZALEX® (Daratumumab) is a human IgG1 antibody that targets CD38, and was approved for use in combination with POMALYST® (Pomalidomide) and Dexamethasone in 2017, for the treatment of patients with multiple myeloma, who have received at least two prior therapies including REVLIMID® and a Proteasome Inhibitor. DARZALEX® exerts its cytotoxic effect on myeloma cells by multiple mechanisms, including Antibody Dependent Cellular Cytotoxicity (ADCC), Complement Mediated Cytotoxicity and direct apoptosis. Additionally, DARZALEX® may have a role in immunomodulation by depleting CD38-positive regulator Immune suppressor cells, and thereby expanding T cells, in patients responding to therapy.
SARCLISA® (Isatuximab) is a CD38-targeting monoclonal antibody, similar to DARZALEX®, but unlike DARZALEX®, is not associated with complement activation, and can therefore be more readily given to patients with asthma or Chronic Obstructive Pulmonary Disease. Further, SARCLISA® targets a specific epitope on the CD38 receptor, and this distinction from DARZALEX® allows use of SARCLISA® in cases when DARZALEX® fails. Additionally, SARCLISA® infusions are less cumbersome.
The present FDA approval of SARCLISA® was based on ICARIA-MM trial, which is an open-label, randomized, multicentre Phase III study in which 307 adult patients with Relapsed and Refractory multiple myeloma who had received at least two previous lines of treatment, including REVLIMID® and a Proteasome Inhibitor were eligible. Patients were excluded if they were refractory to previous treatment with an anti-CD38 monoclonal antibody. Patients were randomly assigned 1:1 to receive either SARCLISA® along with POMALYST® and low-dose Dexamethasone (N =154) or POMALYST® and low-dose Dexamethasone alone (N = 153). Treatment consisted of 28-day cycles of SARCLISA® 10 mg/kg given IV on days 1, 8, 15, and 22 in the first cycle and days 1 and 15 in subsequent cycles. Both groups received POMALYST® 4 mg orally on days 1 to 21 of each cycle and Dexamethasone 40 mg (20 mg for patients aged 75 years or older) oral or IV on days 1, 8, 15, and 22 of each cycle. Treatment was continued until disease progression or unacceptable toxicity. The Primary endpoint was Progression Free Survival (PFS), determined by an Independent Response Committee, and assessed in the intent-to-treat population.
At a median follow up of 11.6 months, the median PFS was 11.5 months in the SARCLISA® group versus 6.5 months in the control group (HR= 0.596; P=0.001). This PFS improvement represented a 40% reduction in the risk of disease progression or death in the SARCLISA® group. In a prespecified subgroup analyses, which included patients with poor prognostic features, and those refractory to REVLIMID®, a Proteasome Inhibitor, or both, the Hazard Ratios were consistently in favor of SARCLISA®.(HR=0.58). The most common adverse events of any grade in the SARCLISA® vs control groups were infusion reactions (38% versus 0%, of which 3% were Grade 3 or 4), upper respiratory tract infection (28% versus 17%), and diarrhea (26% versus 20%).
It was concluded that the addition of SARCLISA® to POMALYST® and Dexamethasone significantly improves Progression Free Survival in patients with Relapsed and Refractory multiple myeloma, and is an important new treatment option for the management of patients who become refractory to REVLIMID® and a Proteasome Inhibitor. Multiple Myeloma patients will soon have the opportunity to choose between two equally effective treatment options with various modes of administration. Isatuximab plus pomalidomide and low-dose dexamethasone versus pomalidomide and low-dose dexamethasone in patients with relapsed and refractory multiple myeloma (ICARIA-MM): a randomised, multicentre, open-label, phase 3 study. Attal M, Richardson PG, Rajkumar SV, et al. The Lancet. November 14, 2019 DOI:https://doi.org/10.1016/S0140-6736(19)32556-5