“It is not a big leap of faith to imagine that, in the near future, with the availability of quadruplets and T-cell therapies, the role of high-dose melphalan and autologous stem cell transplant will be diminished,” said Dickran Kazandjian, MD, and Ola Landgren, MD, PhD, of the myeloma division, Sylvester Comprehensive Cancer Center, University of Miami.
They commented in a editorial in JAMA Oncology, prompted by a paper describing new results with a novel quadruple combination of therapies. These treatments included the monoclonal antibody elotuzumab (Empliciti) added onto the established backbone of carfilzomib (Kyprolis), lenalidomide (Revlimid), and dexamethasone (known as KRd).
“Regardless of what the future holds for elotuzumab-based combinations, it is clear that the new treatment paradigm of newly diagnosed MM will incorporate antibody-based quadruplet regimens,” the editorialists commented.
“Novel immunotherapies are here to stay,” they added, “as they are already transforming the lives of patients with multiple MM and bringing a bright horizon to the treatment landscape.”
Study details
The trial of the novel quadruplet regimen was a multicenter, single-arm, phase 2 study that involved 46 patients with newly diagnosed multiple myeloma, explain first author Benjamin A. Derman, MD, of the University of Chicago Medical Center, and colleagues.
These patients had a median age of 62; more than two-thirds were male (72%) and White (70%). About half (48%) had high-risk cytogenetic abnormalities.
All patients were treated with 12 cycles of the quadruple therapy Elo-KRd regimen. They underwent bone marrow assessment of measurable residual disease (MRD; with 10-5 sensitivity) after cycle 8 and cycle 12.
“An MRD-adapted treatment approach is rational because it may identify which patients can be administered shorter courses of intensive therapy without compromising efficacy,” the authors explained.
Patients who had MRD negativity at both time points did not receive further Elo-KRd, while patients who converted from MRD positivity to negativity in between cycles 8 and 12 received 6 additional cycles of Elo-KRd. Those who remained MRD positive or converted to positivity after 12 cycles received an additional 12 cycles of Elo-KRd.
Following Elo-KRd treatment, all patients transitioned to triple therapy with Elo-Rd (with no carfilzomib), for indefinite maintenance therapy or until disease progression.
For the primary endpoint, the rate of stringent complete response and/or MRD-negativity after cycle 8 was 58% (26 of 45), meeting the predefined definition of efficacy.
Importantly, 26% of patients converted from MRD positivity after cycle 8 to negativity at a later time point, while 50% of patients reached 1-year sustained MRD negativity.
Overall, the estimated 3-year, progression-free survival was 72%, and the rate was 92% for patients with MRD-negativity at cycle 8. The overall survival rate was 78%.
The most common grade 3 or 4 adverse events were lung and nonpulmonary infections (13% and 11%, respectively), and one patient had a grade 5 MI. Three patients discontinued the treatment because of intolerance.
“An MRD-adapted design using elotuzumab and weekly KRd without autologous stem cell transplantation showed a high rate of stringent complete response (sCR) and/or MRD-negativity and durable responses,” the authors wrote.
“This approach provides support for further evaluation of MRD-guided de-escalation of therapy to decrease treatment exposure while sustaining deep responses.”
To better assess the difference of the therapy versus treatment including stem cell transplantation, a phase 3, randomized trial is currently underway to compare the Elo-KRd regimen against KRd with autologous stem cell transplant in newly diagnosed MM.
“If Elo-KRd proves superior, a randomized comparison of Elo versus anti-CD38 mAb-based quadruplets would help determine the optimal combination of therapies in the frontline setting,” the authors noted.