New Treatment Can Benefit Patients With MM Refractory to Multiple Other Therapies

Patients with multiple myeloma (MM) whose disease is refractory to available treatments may have better a better response if they are treated with selinexor with dexamethasone, according to a study published in New England Journal of Medicine.

Researchers from Mount Sinai found that patients taking the oral combination therapy saw a response within 2 months. Selinexor is able to cause cancer cells to die by blocking the export of protein and messenger RNAs from the cancer cell to the cytoplasm.

“This study is meaningful for patients with multiple myeloma who haven’t had success on multiple other therapies,” the study’s first author Ajai Chari, MD, director of clinical research in the Multiple Myeloma Program at The Tisch Cancer Institute at Mount Sinai, said in a statement. “An increasing number of patients have resistance to the standard drugs used in the treatment of multiple myeloma, and the overall survival in these patients is short, sometimes less than three months.”

Patients in the STORM Part 2 Study had MM and had been treated previously with bortezomib, carfilzomib, lenalidomide, pomalidomide, daratumumab, glucocorticoids, and an alkylating agent. The patients had disease progression during treatment or within 60 days after completing treatment or had less than a 25% response to therapy.

A total of 122 patients were included with a median age of 65.2 years and a median disease duration of 6.6 years. The vast majority of patients (118; 97%) discontinued the treatment, with the most common reasons being disease progression and adverse events (AEs). However, 5 patients (4%) continued to receive treatment at the last date of follow-up and another 34 (28%) discontinued treatment and remained in follow-up for long-term survival.

Approximately one-fourth (26%) of patients had a partial response or better. Of those, 2 patients had stringent complete responses, 6 had very good partial responses, and 24 had partial responses. However, 48 patients (39%) had stable disease and 26 (21%) had progressive disease or disease that could be not evaluated.

The researchers found that the median progression-free survival was 3.7 months and the median overall survival (OS) was 8.6 months. Patients with a minimal response or better had a median OS of 15.6 months.

Thrombocytopenia was the most common AE, occurring in 73% of the patients, followed by nausea in 72% and anemia in 67%. Thrombocytopenia was also the most common grade 3 or 4 AE (59% of patients). AEs considered to be related to selinexor or dexamethasone led to 18% of the patients discontinuing the treatment.

The researchers reported that 16 patients died during the study from disease progression and another 12 from an AE. Of the patients who died from AEs, 2 were considered as related to treatment.

“This study proved that a novel, first-in-class drug with a new mechanism of action can kill a patient’s cancer cells,” said the study’s senior author, Sundar Jagannath, MBBS, director of the Multiple Myeloma Program and professor of medicine (hematology and medical oncology) at The Tisch Cancer Institute at Mount Sinai. “This proved that the drug worked in patients who had exhausted every other treatment and who would have been placed on hospice care otherwise.”

Reference

Chari A, Vogl DT, Gavriatopoulou M, et al. Oral selinexor—dexamethasone for triple-class refractory multiple myeloma. N Engl J Med. 2019;381(8):727-738. doi: 10.1056/NEJMoa1903455.