ASCO 2026: Elranatamab Shows Promising Early Activity in High-Risk Smoldering Multiple Myeloma

By: Wendy LaGrego
Posted: Monday, June 15, 2026

Early intervention with the BCMA×CD3 bispecific antibody elranatamab produced high response rates and an encouraging safety profile in patients with high-risk smoldering multiple myeloma (SMM), according to the initial results from the phase II ERASMM (EMN34) study presented at the 2026 ASCO Annual Meeting (Abstract 7500).

High-risk SMM represents a precursor state to active multiple myeloma, and prior studies have demonstrated that early treatment with agents such as lenalidomide or daratumumab can delay disease progression. Investigators hypothesized that introducing a T-cell–engaging therapy earlier in the disease course—when immune function may be less compromised—may improve outcomes. Elranatamab has previously demonstrated substantial activity and manageable toxicity in patients with relapsed multiple myeloma.

Study Details

ERASMM is an international, open-label, multicenter phase II trial evaluating fixed-duration elranatamab monotherapy in adults with high-risk SMM, defined by the presence of at least two Mayo 2018 “20-2-20” risk criteria. Treatment consisted of subcutaneous elranatamab administered over a planned 2-year period, beginning with step-up priming doses followed by maintenance dosing on a 28-day cycle schedule. The primary endpoint was complete response rate, with safety designated as a key secondary endpoint.

Between May 2024 and September 2025, 50 previously untreated patients with high-risk SMM were enrolled across 17 European Myeloma Network centers. The median age was 65 years. High-risk features included an M-protein level greater than 20 g/L in 84% of patients, bone marrow plasma cell involvement greater than 20% in 72% of patients, and a free light-chain ratio above 20 in 66% of patients. At the data cutoff in December 2025, median follow-up was 10 months.

Key Results

The overall response rate was 92%, with 82% of patients achieving a very good partial response or better and 45% attaining a complete response or better. Survival outcomes were also favorable, with 9-month progression-free survival and overall survival rates of 95% and 100%, respectively.

Cytokine-release syndrome occurred in 68% of patients, although nearly all events were grade 1 or 2; only two grade 3 events were reported. No cases of immune effector cell–associated neurotoxicity syndrome were observed. Infections occurred in 50% of patients, with grade 3 or 4 infections reported in 14%. Other common nonhematologic adverse events included skin rash (34%), elevated AST/ALT levels (28%), diarrhea (26%), fatigue (20%), and peripheral neuropathy (20%), most of which were grade 1 or 2. Four patients discontinued treatment because of adverse events, including elevated liver enzymes, Guillain-Barré syndrome, and infections.

The investigators concluded: “In high-risk SMM patients, single-agent elranatamab was highly active, with a 92% objective response rate, 45% of patients achieving a complete response or better, and a favorable safety profile.”

DISCLOSURE: The study was funded by Pfizer. For full disclosures of the study authors, visit coi.asco.org.

2026 ASCO Annual Meeting (Abstract 7500)