This drug induces apoptosis of tumor cells and activates immune effector mechanisms such as complement dependent cytotoxicity (CDC), antibody-dependent cellular phagocytosis (ADCP), and antibody-dependent cell-mediated cytotoxicity (ADCC). Isatuximab-irfc is able to stimulate natural killer (NK) cells in the absence of CD38-positive target tumor cells and blocks CD38-positive T-regulatory cells. Furthermore, the NADase activity of CD38 is adjusted by isatuximab, similarly to other CD38 antibodies. Contrarily to daratumumab however, isatuximab can incite apoptosis directly without cross-linking, and in its binding epitope. According to the FDA, isatuximab-irfc alone has reduced ADCC and direct tumor cell killing activity in vitro in comparison to when it is combined with pomalidomide. As well as increased anti-tumor activity as opposed to isatuximab-irfc or pomalidomide only in a human multiple myeloma xenograft model. Metabolism and toxicity
Metabolism
Isatuximab-irfc is likely to be metabolized through catabolic pathways into smaller peptides. When isatuximab is at a constant state it is expected that the ≥99% elimination will occur approximately two months after the last dose was administered. The clearance percentage diminished when the dosages were increased over time, as well as when multiple doses were administered. However, the elimination of isatuximab-irfc did not differ when applied as a single agent or as a combination therapy. Toxicity
A dose-limiting toxicity (DLT) has been characterized as the development of any of the following: grade ≥ 3 non-hematologic toxicity; grade 4 neutropenia or grade 4 thrombocytopenia lasting more than 5 days; grade ≥ 2 allergic reactions or hypersensitivity (i.e., infusion reactions); or any other toxicity considered to be dose-limiting by the investigators or sponsor.
There is currently no treatment for MM, however promising improvements have been made and the study is still ongoing.In March 2020, it was approved for medical use in the United States.The U.S. Food and Drug Administration (FDA) approved isatuximab-irfc in March 2020, based on evidence from a clinical trial (NCT02990338) of 307 subjects with previously treated multiple myeloma. The trial was conducted at 102 sites in Europe, North America, Asia, Australia and New Zealand.The trial evaluated the efficacy and side effects of isatuximab-irfc in subjects with previously treated multiple myeloma. Subjects were randomly assigned to receive either isatuximab-irfc (in combination with pomalidomide and low-dose dexamethasone) or active comparator (pomalidomide and low-dose dexamethasone). Treatment was administered in both groups in 28-day cycles until disease progression or unacceptable toxicity. Both subjects and health care providers knew which treatment was given. The trial measured the time patients lived without the cancer growing (progression-free survival or PFS).It was approved for medical use in the European Union in May 2020. Structure and reactivity
The structure of isatuximab consists of two identical immunoglobulin kappa light chains and also two equal immunoglobulin gamma heavy chains. Chemically, isatuximab is similar to the structure and reactivity of daratumumab, hence both drugs show the same CD38 targeting. However, isatuximab shows a more potent inhibition of its ectozyme function. The latter gives potential for some non-cross reactivity. Isatuximab shows action of an allosteric antagonist with the inhibition of the CD38 enzymatic activity. Additionally, isatuximab shows potential where it can induce apoptosis without cross linking.