Plain language summary of the MonumenTAL-1 study of talquetamab in people with relapsed or refractory multiple myeloma.

peer reviewed ; WHAT IS THIS SUMMARY ABOUT?: This plain language summary describes the results of a phase 1 research study (or clinical trial) called MonumenTAL-1 published in the New England Journal of Medicine in December 2022. A phase 1 study is an early clinical trial where researchers evaluate how safe a medicine is at different doses in a small number of people. In the MonumenTAL-1 study, researchers looked at a new medicine under development called talquetamab, for people living with multiple myeloma (a type of blood cancer) who did not respond (refractory), stopped responding (relapsed), or who had difficulty dealing with their previous treatments. HOW WAS THE STUDY CONDUCTED?: The phase 1 MonumenTAL-1 study was performed in 2 parts. Safety was the main focus of Part 1 in which side effects, and how serious they were, were assessed. The results of Part 1 were used to identify doses of talquetamab that were well tolerated, without a need to stop treatment or reduce the doses, for further study in Part 2. Part 2 of the study examined how well talquetamab worked to decrease signs of the cancer and what side effects, and their severity, people experienced at the doses identified in Part 1. WHAT WERE THE RESULTS?: In Part 1 of the study, researchers identified 2 doses of talquetamab for further study: 405 micrograms for every kilogram of body weight (μg/kg) given weekly and 800 μg/kg every other week. All participants experienced at least one side effect of treatment at these 2 doses. Less than half of participants (43% at 405 μg/kg weekly dose and 34% at the 800 μg/kg every other week dose) experienced serious side effects which are those side effects that led to hospitalization, death, or permanent or life-threatening damage). The most common side effects at both doses were a condition known as cytokine release syndrome (CRS); changes in blood cell levels (where different types of cells in the blood were measured); changes in skin such as itching, dry skin, eczema, ulcers or shedding; changes in nails such ...