The results during the Phase I trial showed that 26 out of the 45 patients discontinued the treatment due to progression of the disease. The patients had already been heavily pretreated. The latter lead to a manageable safety profile where the dose of isatuximab in combination with pomalidomide and dexamethasone would be capped to the maximum of 10 mg/kg weekly every two weeks for future studies.Based on the remarkable findings during the Phase I trial, a Phase II trial was launched where researchers investigated isatuximab as a single agent in patients with MM. The heavily pretreated patients reacted well to the single administration of isatuximab during Phase II of the trial.A Phase III combination trial for plasma cell myeloma is comparing pomalidomide and dexamethasone with and without isatuximab is in progress with an estimated completion date of 2021.Additionally, two Phase III trials were added in 2017. The first trial highlights whether there is an added value in the combination of isatuximab with bortezomib, lenalidomide and dexamethasone. The latter will be tested in patients with newly diagnosed MM who are not qualified for a transplant (IMROZ trial). The second trial evaluates the combinations of isatuximab with carfilzomib and dexamethasone compared to carfilzomib with dexamethasone. The second trial was designed for patients who were previously treated with one to three prior lines (IKEMA).
The binding of isatuximab to CD38 on multiple myeloma (MM) cells leads to a trigger to several mechanisms leading to direct apoptosis of target cancer cells. The triggered pathways are the caspase-dependent apoptotic and the lysosome-mediated cell death pathway in MM cells.It is used in a combination with dexamethasone and pomalidomide. The drug is thus to treat patients with multiple myeloma. Restrictions for the use of isatuximab is that the patients have to be adults who have at least received two previous treatments with lenalidomide and a proteasome inhibitor.Isatuximab is currently also being tested in a Phase II trial as a monotherapy against refractory/recurrent systemic light-chain amyloidosis. Efficacy and side effects
Efficacy
A Phase III study of patients with refractory and relapsed MM, who were resistant to lenalidomide and a proteasome inhibitor, and could not have received daratumumab, another anti-CD38 monoclonal antibody was published in 2019 (ICARIA-MM). The addition of isatuximab to pomalidomide and dexamethasone improved progression free survival to 11.5 months compared to 6.5 months, with an overall response rate of 63%. Side effects
Adverse reactions to isatuximab-irfc may include neutropenia, infusion-related reactions and/or secondary primary malignancies. Of these three the most commonly occurring ones are the infusion-related reactions. Examples of the most frequent symptoms of infusion-related reactions are dyspnea, cough, chills, and nausea, while the severest signs and symptoms included hypertension and dyspnea. Effects on animals
The activity of isatuximab has been researched in mouse tumor models. It has been proven that isatuximab leads to antitumor activity in MM cells.