Daratumumab plus VRd showed a deepened MRD and PFS rate for patients with transplant-ineligible or -deferred newly diagnosed multiple myeloma.
Deepend minimal residual disease (MRD) rates were observed when daratumumab (Darzalex) was added to bortezomib (Velcade), lenalidomide (Revlimid), and dexamethasone (VRd) for patients with transplant-ineligible or -deferred newly diagnosed multiple myeloma, according to results from the phase 3 CEPHEUS trial (NCT03652064) presented at the2024 American Society of Hematology Annual Meeting and Exposition.1
In addition, the combination led to improved progression-free survival (PFS), regardless of MRD negative or positive status.
“These data support the use of daratumumab in combination with VRD as a normal standard of care in patients with newly diagnosed multiple myeloma who are transplant ineligible or when transplant is deferred,” Sonja Zweegman, MD, PhD, Department of Hematology, Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Netherlands, said during a presentation of the data.
After a median follow-up of 58.7 months, at a 10-5 sensitivity, the overall MRD-negativity rate was 60.9% for patients treated with daratumumab plus VRd (n = 197) vs 39.4% for those given VRd alone (n = 198; odds ratio [OR], 2.37; 95% CI, 1.58-3.55; P < .0001). At a 10-6 sensitivity, the overall MRD-negativity rates were 46.2% for the daratumumab plus VRd arm vs 27.3% for the VRd arm (OR, 2.24; 95% CI, 1.48-3.40; P = .0001).
“It can be appreciated … that adding daratumumab to VRd led to a 50% increase in MRD negativity,” Zweegman said.
The 54-month PFS rates were 68.1% and 49.5%, respectively, reducing the risk for disease progression or death by 43% (HR, 0.57; 95% CI, 0.41-0.79; P = .0005). Zweegman noted that the MRD negativity rates were generally consistent across prespecified subgroups.
When evaluating cumulative MRD negative CR rates from the sensitivity level 10-5, patients reached MRD negativity faster, with higher rates at all time points. “And that the difference of the MRD negativity rates between the 2 arms are increasing up to 3 years,” Zweegman added.
This same effect was seen at the sensitivity level 10-6, which is even more related to PFS, she noted. “And importantly…daratumumab almost doubles the MRD negative CR rates that sustained for more than 12, 24, and 36 months.”
As sensitivity level 10-6, MRD-negative patients experienced superior PFS, compared with MRD-positive patients in both treatment arms. Further, the 54-month PFS rates for MRD-negative patients treated with daratumumab plus VRd or VRd alone were 86.2% and 79.0%, respectively. In MRD-positive patients, these rates were 51.0% and 36.5%.
“So daratumumab provides PFS benefit regardless of the MRD negativity CR status,” Zweegman said.
Additional Findings from CEPHEUS
The complete response (CR) or better rate was 81.2% in the daratumumab arm vs 61.6% in the VRd arm (OR, 2.73; 95% CI, 1.71-4.34; P < .0001). In the daratumumab plus VRd arm, the stringent CR, CR, very good partial response (PR), and PR rates were 65.0%, 16.2%, 11.7%, and 4.1%, respectively. In the VRd arm, these respective rates were 44.4%, 17.2%, 25.3%, and 6.1%.2
Regarding safety, grade 3/4 treatment-emergent AEs (TEAEs) occurred in 92.4% of patients in the daratumumab arm vs 85.6% of patients in the VRd arm. TEAEs led to discontinuation of all study drugs in 7.6% and 15.9% of patients, respectively.
The most common any-grade TEAEs included blood and lymphatic disorders (daratumumab arm, 82.7%; VRd arm, 64.6%), including neutropenia (55.8%; 39.0%), thrombocytopenia (46.7%; 33.8%), and anemia (37.1%; 31.8%); gastrointestinal disorders (79.7%; 81.5%), including diarrhea (56.9%; 59.0%) and constipation (38.1%; 42.1%); general disorders and administration-site conditions (80.7%; 75.4%), including peripheral edema (42.1%; 39.0%) and fatigue (32.0%; 30.8%); psychiatric disorders (46.2%; 49.2%), including insomnia (32.0%; 32.3%); infections (91.9%; 85.6%), including upper respiratory tract infection (39.6%; 32.8%) and COVID-19 (38.1%; 24.6%); and second primary malignancies (7.6%; 9.2%).
MRD Negativity as an End Point
“We all know that MRD negativity is associated with longer survival, and it's a strong prognostic for clinical end points in multiple myeloma and a key goal of multiple myeloma therapy,” Zweegman explained. “And therefore, MRD negativity was supported by the [FDA Oncologic Drugs Advisory Committee] as an early end point for accelerated approval in multiple myeloma.”
The multicenter, open-label, randomized, phase 3 CEPHEUS trial was the first phase 3 study of daratumumab with MRD as a primary end point. In the trial, investigators demonstrated that the addition of subcutaneous daratumumab with VRd in patients with transplant-ineligible or transplant-deferred newly diagnosed multiple myeloma led to superior rates of overall and sustained MRD negativity, as well as more CR and it significantly improved PFS.2
At the 2024 ASH Annual Meeting, Zweegman reported on an expanded analysis of MRD outcomes from the CEPHEUS trial.
In the trial, investigators randomly assigned patients 1:1 to receive daratumumab at 1800 mg once per week in cycles 1 and 2, then once every 3 weeks in cycles 3 to 8, plus 1.3 mg/m2 of bortezomib on days 1, 4, 8, and 11 of each 21-day cycle; 25 mg of lenalidomide on days 1 to 14 of each cycle, and 20 mg of dexamethasone on days 1, 2, 4, 5, 8, 9, 11, and 12 of each cycle for 8 cycles; or VRd alone at the same dosing schedule. Starting in cycle 9, patients in the experimental arm received 1800 mg of daratumumab once every 4 weeks plus 25 mg of lenalidomide on days 1 to 21 and 40 mg of dexamethasone on days 1, 8, 15, and 22 of each 28-day cycle; those in the control arm received Rd at the same dosing schedule.
The overall MRD-negativity rate with a CR or better served as the trial’s primary end point. Secondary end points included PFS; the proportion of patients with sustained MRD negativity with a CR or better for at least 12 months; and CR or better rate.
Patients were required to have an ECOG performance status (PS) of 0 to 2 and a frailty score of 0 or 1.