Daratumumab Quadruplet Supported Transplant-Ineligible MM

In the treatment of patients with newly diagnosed multiple myeloma (MM) who are not eligible for stem cell transplant or are transplant-deferred, adding subcutaneous daratumumab to bortezomib/lenalidomide/dexamethasone (D-VRd) significantly improves minimal residual disease (MRD) outcomes among patients, the first results from the phase 3 CEPHEUS trial showed.

“CEPHEUS is the first phase 3 daratumumab trail with a primary endpoint of MRD negativity,” said first author Saad Z. Usmani, MD, of the Memorial Sloan Kettering Cancer Center, New York City, in presenting late-breaking findings at the International Myeloma Society (IMS) 21st Annual Meeting & Exposition in Rio de Janeiro, Brazil in late September.

“We found that adding daratumumab to VRd significantly improved depth and duration of response,” Usmani said. “[The quadruplet regimen] has the potential to improve clinical outcomes for transplant-ineligible or transplant-deferred patients with newly diagnosed MM who can tolerate bortezomib.”

For newly diagnosed patients with MM who are not eligible for a stem cell transplant, the triplet MAIA regimen of daratumumab, lenalidomide, and dexamethasone is a recommended standard of care, having shown a median overall survival of 7.5 years.

However, for those who are transplant eligible, the PERSEUS regimen of D-VRd followed by daratumumab/lenalidomide maintenance, has shown significant progress-free survival benefits compared with the standard of care.

For the ongoing, multicenter, open-label CEPHEUS study, Usmani and his colleagues investigated the efficacy of the quadruplet D-VRd regimen compared with VRd alone among newly diagnosed patients who are transplant-ineligible or deferred (not planned as initial therapy).

In the trial, 395 adult patients with transplant-ineligible or transplant-deferred newly diagnosed MM all were initially treated with eight 21-day cycles of VRd, followed by 28-day cycles of lenalidomide until disease progression.

The patients were then randomized to VRd either with (n = 197) or without subcutaneous daratumumab (n = 198).

Those receiving daratumumab received the subcutaneous therapy weekly in cycles 1 and 2, every 3 weeks in cycles 3-8, and every 4 weeks in cycles 9 or more, until disease progression.

The patients had a median age of 70 years; 28.1% had International Staging System stage III disease, and 13.2% had high-risk cytogenetics.

For the primary endpoint, with a median follow-up of 58.7 months, those in the daratumumab group had a significantly higher rate of being MRD-negative (60.9%) than the VRd-only group (39.4%; odds ratio [OR] 2.37; P< .0001).

Likewise, progression-free survival (PFS) was significantly improved with the daratumumab regimen vs VRd (hazard ratio [HR] 0.57; P = .0005).

A median PFS was not reached for daratumumab plus VRd, compared with 52.6 months for the VRd group, while estimated 54-month PFS rates were 68.1% vs 49.5%, respectively.

A complete response or better was achieved among 81.2% in the daratumumab regimen vs 61.6% with VRd alone (P< .0001) and a sustained rate of MRD-negativity was achieved in 48.7% vs 26.3%, respectively (P< .0001).

There was a trend of overall survival in favor of daratumumab plus VRd (HR, 0.85), with an HR of 0.69 in a sensitivity analysis adjusting for deaths related to COVID-19.

Patients in the daratumumab group had a substantially longer median duration of treatment (56.3 months) than the VRd-only group (34.3 months), with the most common reason for treatment discontinuation being disease progression.

The benefit of daratumumab was generally consistent across the study’s prespecified subgroups, and the relative dose intensity of VRd was not affected by combination with daratumumab.

In terms of safety, treatment-emergent adverse events (TEAEs) were consistent with the known profile of daratumumab and VRd, with grade 5 TEAEs comparable between the two groups after adjusting for treatment exposure.

Quality of life, as measured by EORTC QLQ-C30 score, was improved in both arms over time, with no detriment related to treatment with daratumumab.

Of note, frail patients were not included in the trial. Asked in the Q and A why they were excluded, Usmani explained that “all of these options are wonderful for our patients, and we are entering a phase where quadruplet therapies will become a mainstay for majority of patients,” he said.

“But we have to be careful as we think about not overtreating patients or giving too many side effects of therapies, and that’s why it made sense for us to exclude the frail patients.”

Along those lines, he noted that a key concern in the CEPHEUS trial was tolerance of bortezomib.

“Peripheral sensory neuropathy tends to occur in about half of the patients receiving bortezomib, and about half of that number is grade 2 or higher,” he noted in an interview.

“In some patients, the symptoms do not completely resolve. [Therefore], in transplant-ineligible patients, quadruple regimens may be more relevant for the fit or intermediate-fit patients.”

He concluded that “the CEPHEUS trial compliments the MAIA regimen in supporting a daratumumab-based quadruplet or triplet standard-of-care option across transplant-ineligible patients and those deferring transplant.”

Commenting on the study, Philippe Moreau, MD, who is president of the IMS, noted that “the CEPHEUS study is important because [determining] the best treatment upfront for elderly patients is very important.”

“We need confirmation of the very good results achieved with the IMROZ trial, which showed an estimated 5-year PFS of 63.2%, said Moreau, professor of clinical hematology and head of the translational research program in hematology and oncology at the University Hospital of Nantes, Nantes, France.

“If we can achieve the same results, we will have the confirmation that quadruplet is probably here to stay,” Moreau said.

Usmani disclosed relationships with Abbvie, Amgen, BioPharma, Bristol Myers Squibb, Celgene, GSK, Janssen, Merck, Pharmacyclics, Sanofi, Seattle Genetics, SkylineOx, and Takeda.