ALTITUDE-1: Real-World Elranatamab Patterns in Patients With Multiple Myeloma

ALTITUDE-1, a real-world study presented at the European Hematology Association 2025 Congress, reveals the latest evidence of how doctors are using elranatamab to treat patients with relapsed or difficult-to-treat multiple myeloma. It is the first research of this kind to examine the current practice of administering this medication beyond clinical trials.

Elranatamab is a bispecific antibody form of immunotherapy used to bind T-cells that fight cancer to myeloma cells, facilitating the immune system to destroy the cancer cells. The medication has two targets: the B-cell maturation antigen (BCMA) on the myeloma cells and the CD3 on the T-cells. While earlier trials such as MagnetisMM-3 demonstrated that elranatamab is safe and effective, ALTITUDE-1 aimed to comprehend how the therapy is applied in real-life patients, particularly those who are older or have other health-related issues.

The study was based on a large U.S. claims database consisting of both public and private health insurers. It included 59 adult patients (median age, 74 years) with multiple myeloma treated with elranatamab from early 2023 to mid-2024. Almost half of patients were female, and 46% had previously undergone five or more treatments for myeloma. Approximately a quarter of patients had previously received another form of BCMA-directed therapy, and 15% had received prior chimeric antigen receptor (CAR) T-cell therapy.

Elranatamab dosing was monitored through three phases: first week (step up dosing), first five months (weekly dosing), and more than six months (long term maintenance). Most of the patients were given one to two doses during the first week. During the phase of weekly dosing, a total of 321 doses were administered across 52 patients. A high number of patients prematurely switched to every-other-week dosing. During the long-term period, a certain number of patients switched to a once-a-month administration, exhibiting flexibility in drug dosing.

Clinicians also used supportive care to manage side effects. Antiviral drugs were administered to about 73% of patients, antibiotics to 49% of patients, antifungal drugs to 22% of patients, and intravenous immunoglobulin to 41% of patients to protect against infection.

In conclusion, this study shows that elranatamab is already applied flexibly depending on patient needs. A large proportion of clinicians are prematurely modifying the dosing regimen, and patients appear to be responding well to the therapy. Further studies are underway, but this preliminary evidence indicates that elranatamab is a potentially viable treatment to use in the real world for multiple myeloma.