NEW YORK – There’s more to induction therapy for transplant-eligible multiple myeloma patients than the go-to combination of bortezomib, lenalidomide, and dexamethasone, commonly known as VRD, according to Joseph R. Mikhael, MD.
“Outstanding evidence” has emerged that demonstrates the value of combining multiple mechanisms of action, but there are numerous options available – there is a trend toward increasing use of carfilzomib, for example – and VRD isn’t necessarily the best option for all patients, nor is it available in all cases, Dr. Mikhael of Mayo Clinic Arizona, Scottsdale, said at an international congress on hematologic malignancies.
Further, choosing the treatment method shown to give the most powerful or deepest response as a default isn’t necessarily the best option, either, he said, noting data showing that the regimen most often associated with at least very good partial response (VGPR) after four cycles in newly diagnosed multiple myeloma (carfilzomib, lenalidomide, dexamethasone, or KRD, about a 90% response rate) costs 2.5 times more than does the regimen (lenalidomide, dexamethasone, or RD) that provided about a 50% response rate ($250,000 vs. $100,000 per year).“But it’s also the toxicity cost ... do we need that many [drugs]?” he said, adding that “just because a clinical trial shows that three drugs work better than two, it doesn’t mean that every time I have a patient who is eligible I’m going to go with all three.”
It may be that a patient can start on two, with a third added if needed, he added.
“That being said, we want to maximize the synergy of those three, especially in high-risk patients,” he said.
Prior to 2016, popular regimens included CyBorD (cyclophosphamide, bortezomib, dexamethasone) and VTD (bortezomib, thalidomide, dexamethasone), which were commonly used worldwide. CTD (cyclophosphamide, thalidomide, dexamethasone) was used in Brazil and other countries where it was difficult to obtain bortezomib; VRD was “king of the hill” in the United States, and transplant was routinely recommended, Dr. Mikhael said.
A number of recent studies are changing that paradigm, he said.
One such study, the prospective randomized Intergroupe Francophone du Myélome (IFM) 2013-04 trial, showed that VTD is superior to bortezomib-cyclophosphamide-dexamethasone (VCD) for induction in patients with de novo multiple myeloma. VGPR and PR rates were significantly superior in the VTD arm.
Of note, hematologic toxicity increased in the VCD arm, and the peripheral neuropathy rate was higher in the VTD arm. However, the study was conducted at a time when bortezomib was generally used twice weekly; now it is standard to use it once weekly and subcutaneously, which significantly reduces the risk of peripheral neuropathy.
The authors advocated the preferential use of VTD over VCD for induction, based on the synergistic effect of a proteasome inhibitor and immunomodulatory drug, Dr. Mikhael said.
“Meanwhile, back in the United States, many trials were starting to be built with VRD,” he said, noting that “really extraordinary” responses were seen in phase I and phase II studies.
Perhaps the VRD study (called RVD in this case) that is most cited is the phase III IFM 2009 study comparing RVD with and without autologous stem cell transplant in newly diagnosed younger multiple myeloma patients. Although final results are still pending, interim results reported at the American Society of Hematology 2015 meeting (abstract 391) have been very helpful, Dr. Mikhael said.
The authors reported a 31% reduction in the risk of progression or death with autologous stem cell transplant versus RVD alone in patients with newly diagnosed multiple myeloma, as well as improved rates of thrombotic thrombocytopenic purpura (TTP) and minimal residual disease negativity (MRD). Mortality rates were similar.
The findings show that transplantation is feasible (93%), and associated with acceptable mortality (1.4%), an increased rate of negative MRD versus with RVD alone (80% vs. 65%), an improved 4-year progression-free survival (47% vs. 35%), and improved 4-year TTP (49% vs. 35%).
“Here the question was not so much is RVD the standard ... but is RVD plus transplant superior to RVD alone,” he said.
Surprising to many, especially the “dissenters in the crowd” who thought perhaps RVD would be the death knell to autologous stem cell transplant, transplant actually significantly improved the depth of response, he added.
Median progression-free survival at 10 months was 43% with versus 34% without transplantation.
“So there was definitely an argument here that transplant remains the standard of care,” he said, noting that transplant should be considered as decisions are made about up-front therapy.
As for the trend of bringing carfilzomib in earlier on in treatment, a number of studies, including the phase II CYKLONE study by Dr. Mikhael and his colleagues, suggest it improves the rates of deep response; some show that is especially true when used with transplant.
One study looking at KRD showed that the regimen provides high rates of deep and durable responses with acceptable tolerability – a finding that needs confirmation in a randomized setting.
Other studies are comparing KRD and VRD, and KRD and KCyd (carfilzomib, cyclophosphamide), as well as adding monoclonal antibodies such as daratumumab to treatment regimens, and results are very much anticipated, Dr. Mikhael said.
Currently, however, VRD remains the standard of care in standard risk and intermediate risk patients.
“But consideration in the highest-risk patients should be given to something like KRD,” he said. “We still recommend transplant across the board, we still recommend some form of maintenance therapy, be it with lenalidomide for most patients, but potentially bortezomib combined with carfilzomib in the highest risk patients.”
Dr. Mikhael reported consulting for Abbvie, Celgene, Onyx, and Sanofi.