Empliciti Combo Prolongs Survival in Difficult-to-Treat Multiple Myeloma, New Phase 2 Trial Data Show

Adding Empliciti (elotuzumab) to a regimen including Pomalyst (pomalidomide) and low-dose dexamethasone extended survival and the time without disease progression in patients with relapsed or refractory multiple myeloma, according to updated results of a Phase 2 study.

The study, “Elotuzumab Plus Pomalidomide and Dexamethasone for Relapsed/Refractory Multiple Myeloma: Efficacy Results After Additional Follow-up of the Phase 2, Randomized ELOQUENT-3 Study,” was presented at the 24^th Congress of the European Hematology Association (EHA), recently held in Amsterdam.

The international ELOQUENT-3 trial (NCT02654132) included 117 patients who disease had progressed despite two or more prior therapies, including Revlimid (lenalidomide) and/or a proteasome inhibitor, such as Velcade (bortezomib), Kyprolis (carfilzomib), or Ninlaro (ixazomib).

Sixty patients received the triple combination and 57 were on Pomalyst and dexamethasone only, all in 28-day cycles of treatment.

Pomalyst was given at 4 mg over days 1–21 of each cycle, while dexamethasone was given at a weekly equivalent of 40 mg in patients age 75 or younger, and of 20 mg in those older than 75 years. Empliciti was administered intravenously at 10 mg/kg weekly for the first two cycles, and at 20 mg/kg every four weeks starting from cycle three.

Results revealed that adding Empliciti reduced the risk of death by 46%. At 18 months of treatment, 68% of the patients on the triple therapy were alive, compared to 49% of those not taking Empliciti.

Overall survival was 17.4 months in the group without Empliciti, but had not been reached in patients on Empliciti by the analysis cut-off date, showing that the response was more sustained.

The data further showed that progression-free survival rates — indicating no disease worsening during or after treatment — were 34% among patients on Empliciti and 11% for those in the Pomalyst and dexamethasone group at 18 months.

Safety results were similar between the treatment groups and in line prior findings with Empliciti and Pomalyst. The most common serious or life-threatening side effects were infections, neutropenia (reduced levels of neutrophils, a type of white blood cell), anemia, thrombocytopenia (lower platelet counts), and low blood sugar. Adverse events leading to death were reported in seven patients (12%) on Empliciti and nine (16%) not given this therapy.

Results from the primary analysis of ELOQUENT-3 supported the U.S. approval of the triple treatment for people with advanced (relapsed or refractory) multiple myeloma. The trial is due to fully conclude in December 2020.

“These data support the long-term favorable efficacy–safety profile of [the triple therapy] and suggest this regimen could be considered as a standard of care for [patients] with relapsed/refractory [multiple myeloma],” the scientists wrote.

“We continue to see meaningful improvements across key endpoints … including a positive trend in overall survival,” Meletios A. Dimopoulos, MD, with the Kapodistrian University of Athens School of Medicine in Greece, said in a press release.

Added Fouad Namouni, MD, Bristol-Myers Squibb’s head of oncology development: “The extended follow-up results from ELOQUENT-3 reinforce the [treatment] combination’s sustained efficacy and favorable safety profile.”

Empliciti, co-developed by Bristol-Myers Squibb and AbbVie, is an antibody therapy that specifically binds to a molecule known as SLAMF7, which is found on the surface of myeloma cells and of anti-tumor natural killer (NK) cells. The treatment works in two complementary ways — it activates the immune system by binding to NK cells, and tags the cancer for NK cell-mediated destruction by binding to myeloma cells.