International, multi-center, open-label, treatment extension study in patients with multiple myeloma who are still benefitting from isatuximab-based therapy following completion of a Phase 1, 2, or 3 parental study

The primary objective of this study is to assess the long-term safety of isatuximab administered as monotherapy or in combination regimens in participants previously treated with isatuximab. This objective is clinically relevant as it evaluates the extended safety profile of isatuximab-based therapy in patients with multiple myeloma who have demonstrated clinical benefit from prior isatuximab treatment in Phase 1, 2, or 3 parental studies. The assessment of long-term tolerability and adverse event profiles in this patient population is essential for understanding the risk-benefit ratio of continued isatuximab therapy and informing treatment duration decisions in clinical practice.

This clinical trial enrolled a total of **29 participants** previously diagnosed with **cancer**. The study population included both **male and female participants** aged **18 years and older** (or the legal age of consent in the respective jurisdiction). Participants were selected from parental Phase 1, 2, or 3 clinical studies in which they had previously received **isatuximab** either as **monotherapy** or in **combination regimens**, with all study objectives of the parental study completed. Eligible participants were those still receiving isatuximab at the time of parental study closure and continuing to benefit from the treatment as determined by the treating physician, or those not receiving isatuximab at the end of the parental study who lacked local access to ongoing treatment. Key inclusion criteria required participants to meet the criteria for initiating a subsequent cycle of therapy as outlined in the parental study protocol, to be capable of providing signed informed consent, and to adhere to contraceptive requirements including double contraception methods for both male and female participants, with additional stipulations that female participants must not be pregnant or breastfeeding and male participants must refrain from sperm donation. The trial population included vulnerable populations.

This Phase 4, international, multi-center, open-label, treatment extension study is designed to evaluate the long-term safety of isatuximab when administered as a monotherapy or within combination regimens. The study involves participants with multiple myeloma who have previously participated in a parental Phase 1, 2, or 3 clinical trial and continue to derive clinical benefit from isatuximab-based therapy. The primary endpoint is the number of participants experiencing treatment-emergent adverse events. The study period is estimated to occur between April 2023 and January 2027. Eligible participants must be at least 18 years of age and meet specific criteria regarding the completion of parental study objectives and the ability to initiate subsequent therapy cycles. The research methodology focuses on monitoring safety in patients who were receiving isatuximab at the time of parental study closure or those who lack local access to ongoing treatment. Clinical involvement is contingent upon the continued benefit from therapy as determined by a treating physician and adherence to necessary contraception protocols.

Isatuximab is administered as a solution for infusion via intravenous infusion at a dosage of 20 mg/kg, or as a solution for injection via subcutaneous injection at a dosage of 1400 mg. Other investigational treatments include cemiplimab, administered as a concentrate for solution for infusion via intravenous infusion at a dose of 250 mg, and carfilzomib, provided as a powder for solution for infusion via intravenous infusion at a dosage of 56 mg/m².

Pomalidomide is administered in hard capsule or capsule form via the oral route at a dosage of 4 mg. Lenalidomide is administered in hard capsule form via oral use at a dosage of 25 mg. Dexamethasone is provided as either a tablet via oral administration at a dosage of 40 mg or as a solution for injection via intravenous infusion at a dosage of 40 mg. Additional auxiliary substances utilized in the study include montelukast sodium, dexamethasone base, diphenhydramine, paracetamol, methylprednisolone acetate, and lidocaine hydrochloride monohydrate.

The primary efficacy endpoint in this study is the number of participants with treatment-emergent adverse events. This assessment is conducted to evaluate the long-term safety of isatuximab when administered as monotherapy or within combination regimens in patients with multiple myeloma.