On July 9, 2026, the U.S. Food and Drug Administration (FDA) approved isatuximab-irfc (Sarclisa Escena, Sanofi-Aventis U.S. LLC) as a subcutaneous (SC) injection for the treatment of multiple myeloma (MM) across three distinct clinical settings — expanding administration options for this anti-CD38 monoclonal antibody.

Clinical Takeaway

Subcutaneous isatuximab-irfc demonstrates non-inferior pharmacokinetics and comparable efficacy to its intravenous formulation across newly diagnosed and relapsed/refractory multiple myeloma settings, with response rates ranging from 71% to 97% depending on the combination regimen. The SC route offers a more convenient administration option for patients and clinical settings, administered at a fixed dose of 1,400 mg via an on-body delivery system or manual syringe.

Drug Profile & Mechanism

  • Drug name: Isatuximab-irfc (Sarclisa Escena)
  • Manufacturer: Sanofi-Aventis U.S. LLC
  • Class: Anti-CD38 monoclonal antibody
  • New formulation: Subcutaneous injection (previously approved as intravenous infusion)
  • Recommended dose: 1,400 mg SC, administered via the CirCLIQ on-body delivery system (OBDS) or manually with a syringe and infusion set
  • Designation: Orphan Drug Designation
  • Regulatory note: FDA Assessment Aid utilized to facilitate review

Approved Indications & Target Populations

The FDA approved subcutaneous isatuximab-irfc for three indications in adult patients with multiple myeloma:

  • Isa-Pd (relapsed/refractory MM, ≥1 prior line): In combination with pomalidomide and dexamethasone for adult patients who have received at least one prior line of therapy including lenalidomide and a proteasome inhibitor
  • Isa-Kd (relapsed/refractory MM, 1–3 prior lines): In combination with carfilzomib and dexamethasone for adult patients with relapsed or refractory MM who have received one to three prior lines of therapy
  • Isa-VRd (newly diagnosed MM, transplant-ineligible): In combination with bortezomib, lenalidomide, and dexamethasone for adult patients with newly diagnosed MM who are not eligible for autologous stem cell transplant (ASCT)

Supporting Study Designs

  • IRAKLIA (NCT05405166) — Isa-Pd:
    • Design: Open-label, non-inferiority randomized controlled trial
    • N = 531 patients, randomized 1:1 to SC isatuximab-irfc (via OBDS) vs. IV isatuximab-irfc, both in combination with pomalidomide and dexamethasone
    • Primary endpoints: Overall response rate (ORR) by Independent Review Committee (IRC) and pharmacokinetic (PK) non-inferiority (Ctrough at steady state, pre-dose Cycle 6 Day 1)
  • IZALCO (NCT05704049) — Isa-Kd:
    • Design: Phase 2 clinical study
    • N = 74 patients with relapsed and/or refractory MM
    • Primary endpoint: ORR by IRC
  • IsaSocut (NCT05889221) — Isa-VRd:
    • Design: Single-arm, investigator-sponsored phase 2 clinical study
    • N = 74 patients with newly diagnosed MM not eligible for stem cell transplantation
    • Primary endpoint: ORR

Efficacy Outcomes

  • IRAKLIA (Isa-Pd, relapsed/refractory MM):
    • ORR (SC arm): 71.1% (95% CI: 65.2–76.5)
    • ORR (IV arm): 70.5% (95% CI: 64.7–75.9)
    • PK non-inferiority: SC/IV geometric mean ratio (GMR) for Ctrough at steady state = 1.53 (90% CI: 1.32–1.78), confirming non-inferior systemic drug exposure compared with IV administration
  • IZALCO (Isa-Kd, relapsed/refractory MM):
    • ORR by IRC: 79.7% (95% CI: 68.8–88.2)
  • IsaSocut (Isa-VRd, newly diagnosed, transplant-ineligible MM):
    • ORR: 97.3% (95% CI: 90.6–99.7)

Safety

The prescribing information for subcutaneous isatuximab-irfc includes the following warnings and precautions, consistent with the established safety profile of the IV formulation:

  • Hypersensitivity and other administration reactions
  • Neutropenia
  • Infections
  • Secondary primary malignancies
  • Laboratory test interference
  • Embryo-fetal toxicity

Healthcare professionals should report all serious adverse events suspected to be associated with isatuximab-irfc to the FDA MedWatch Reporting System at 1-800-FDA-1088.

Key Clinical Implications

✔ Subcutaneous isatuximab-irfc provides a more convenient alternative to IV infusion, potentially reducing chair time and infusion suite burden without compromising efficacy or drug exposure.

✔ The fixed 1,400 mg SC dose simplifies dosing logistics compared to weight-based IV regimens, and can be administered via the CirCLIQ OBDS or manually, offering flexibility across practice settings.

✔ Non-inferiority in PK was demonstrated with a Ctrough GMR of 1.53, supporting comparable systemic drug exposure with the SC formulation while maintaining clinical efficacy.

✔ The approval spans three distinct myeloma settings — transplant-ineligible newly diagnosed, early relapse (1–3 prior lines), and later relapse (≥1 prior line post-lenalidomide/PI) — giving clinicians broad flexibility to incorporate SC isatuximab-irfc across the treatment continuum.

✔ The remarkably high ORR of 97.3% in the IsaSocut trial (Isa-VRd in transplant-ineligible NDMM) warrants attention, though the single-arm design and small sample size (n=74) should be considered when interpreting these results in the broader clinical context.

Bottom Line

The FDA approval of subcutaneous isatuximab-irfc (Sarclisa Escena) on July 9, 2026 extends the clinical utility of this anti-CD38 therapy across three myeloma treatment settings with a more patient- and practice-friendly delivery method. Supported by robust efficacy data from the IRAKLIA, IZALCO, and IsaSocut trials — including ORRs of 71.1%, 79.7%, and 97.3%, respectively — and confirmed PK non-inferiority, the SC formulation provides clinicians with a more convenient administration option while maintaining efficacy and pharmacokinetic performance comparable to the IV formulation.

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