Six Years Later, Most Myeloma Patients on a Darzalex Regimen Are Still Progression-Free

For people newly diagnosed with multiple myeloma who are healthy enough for a stem cell transplant, updated results from the PERSEUS trial offer some of the most encouraging long-term news in years.

The study continues to show that adding Darzalex Faspro (daratumumab) to a commonly used multiple myeloma treatment regimen can help people live longer without their disease getting worse. The latest results also provide more information about an important question for patients: How long do people need to stay on treatment if their myeloma becomes undetectable?

What Is the PERSEUS Regimen?

PERSEUS tested adding Darzalex Faspro, an antibody given as an injection under the skin, to the standard combination known as VRd: Velcade (bortezomib), Revlimid (lenalidomide) and dexamethasone.

Patients in the trial received the four-drug combination, known as D-VRd, as part of their initial treatment before and after a stem cell transplant. Afterward, they received maintenance treatment with Darzalex and Revlimid.

The goal of this approach is to attack myeloma in multiple ways from the beginning, then continue treatment to help keep any remaining cancer cells under control.

The FDA approved D-VRd for people with newly diagnosed multiple myeloma who are eligible for a stem cell transplant in July 2024, making the regimen an important treatment option for this group of patients.

What the Six-Year Results Show

The updated findings were based on a median follow-up of nearly seven years, giving researchers a longer look at how well the treatment continued to control the disease.

At six years:

• About 81% of people who received D-VRd were alive without their myeloma getting worse, compared with about 56% of those who received VRd alone.
• The median time without disease progression had not yet been reached for people who received D-VRd. This means that at least half of the patients in that group had still not experienced progression when the analysis was conducted.
• Among people who received VRd alone, the median progression-free survival was about 81 months, or roughly 6.8 years.
• Six-year overall survival was 85.9% with D-VRd compared with 78.6% with VRd.

In other words, the addition of Darzalex continued to provide a meaningful benefit years after treatment began.

Progression-free survival is particularly important in multiple myeloma because the disease can return after an initial response. Delaying progression can give patients more time without needing a new line of treatment and may help maintain quality of life for longer.

Why MRD Negativity Matters

Another important part of the PERSEUS findings involves measurable residual disease, or MRD.

MRD testing looks for extremely small amounts of myeloma that may remain in the body even when standard tests show that a patient is responding well. A person who is MRD-negative has no detectable myeloma at the sensitivity level of the test being used.

Achieving MRD negativity has become an increasingly important goal in multiple myeloma because deeper responses have been associated with longer periods without the disease getting worse.

In PERSEUS, patients who achieved and maintained MRD negativity had particularly favorable long-term outcomes. This raises an important question about whether some people who have had a deep and sustained response need to remain on every part of their maintenance treatment indefinitely.

Many Patients Were Able to Stop Darzalex

One of the more practical findings from PERSEUS was the trial's approach to maintenance treatment.

Patients who achieved sustained MRD negativity could stop Darzalex if they had maintained that response for at least 12 months after receiving at least two years of maintenance therapy. Those patients continued taking Revlimid alone.

Importantly, most of the people who stopped Darzalex had not needed to restart it at the time of the analysis.

For patients, this could be meaningful. Darzalex is given regularly, so stopping it can mean fewer injections, fewer treatment-related appointments and potentially less treatment burden over time.

However, stopping treatment does not mean that the myeloma has been permanently cured. Patients still need ongoing monitoring, and the PERSEUS approach relied on regular testing to identify whether the disease remained undetectable.

The findings also don't mean that every patient who becomes MRD-negative should stop Darzalex. Treatment decisions depend on factors such as a person's response, risk of relapse, overall health, side effects and the doctor's assessment.

What Happens If Myeloma Comes Back?

Multiple myeloma is considered a chronic blood cancer for most people, meaning that even after a strong response to treatment, there is a possibility that the disease can return.

That's why long-term monitoring remains an important part of care. If testing shows that myeloma is becoming detectable again, doctors can evaluate whether treatment should be restarted or changed.

The PERSEUS findings suggest that some patients may be able to maintain their response without continuing every medication indefinitely, but researchers will need longer follow-up to understand how often treatment needs to be restarted and how those patients do over many more years.

Who This Applies To

PERSEUS enrolled adults 70 or younger with newly diagnosed multiple myeloma who were eligible for a stem cell transplant.

That distinction is important. The findings don't directly apply to everyone with multiple myeloma, particularly people who are not candidates for a transplant or those whose disease has already returned.

A person's age, overall health, other medical conditions, disease characteristics and treatment goals can all influence which treatment approach is recommended.

What This Could Mean for Patients

The long-term PERSEUS results add to evidence supporting a four-drug approach for transplant-eligible people newly diagnosed with multiple myeloma.

Perhaps just as importantly, the findings offer a glimpse at a future in which treatment could become more personalized. Instead of assuming that everyone needs the same medications for the same amount of time, doctors may increasingly use sensitive tests such as MRD testing to help determine who needs continued treatment and who may be able to safely reduce treatment.

For patients, that could eventually mean maintaining the benefits of a deep response while reducing the burden of long-term therapy.

More follow-up will be needed to determine how durable these treatment-free periods are and whether stopping Darzalex affects outcomes over the longer term.

References

1. CancerNetwork. "PERSEUS Trial Shows Daratumumab Regimen Deepens Responses in NDMM." Sept. 26, 2026.
2. Inkl. "Daratumumab Regimen Keeps 81% of Newly Diagnosed Transplant-Eligible Myeloma Patients Progression-Free at Six Years in PERSEUS Update." Sept. 29, 2026.
3. OncLive. "D-VRd Boosts MRD-Negativity Rates in Newly Diagnosed, Transplant-Eligible Multiple Myeloma." 2026.

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