What is the recommended treatment strategy for symptomatic multiple myeloma, including induction regimens, transplant eligibility criteria, and options for transplant‑ineligible patients?

Treatment Strategy for Symptomatic Multiple Myeloma

For transplant-eligible patients, initiate a quadruplet induction regimen with daratumumab plus bortezomib/lenalidomide/dexamethasone (DaraVRd), followed by autologous stem cell transplantation and maintenance with daratumumab plus lenalidomide; for transplant-ineligible patients, use either DaraRd or bortezomib/melphalan/prednisone (VMP) as first-line therapy.

Transplant-Eligible Patients (Age <65 or Fit)

Induction Therapy

Triplet regimens containing at least bortezomib and dexamethasone are the standard of care 1. The most recent evidence strongly supports quadruplet therapy:

• DaraVRd (Preferred, Category 1): The 2024 PERSEUS trial demonstrated superior outcomes with 4-year PFS of 84.3% versus 67.7% with VRd alone (HR 0.42, P<0.001) 2. This represents the highest quality recent evidence and should be the preferred approach.

• Alternative triplet regimens if quadruplet unavailable 1:

  • VRd (bortezomib/lenalidomide/dexamethasone) - Category 1
  • VTD (bortezomib/thalidomide/dexamethasone)
  • VCD (bortezomib/cyclophosphamide/dexamethasone) - particularly for acute renal insufficiency 3
  • PAD (bortezomib/doxorubicin/dexamethasone)

Administer 3-4 cycles before stem cell collection 1.

Critical Pitfall to Avoid

Limit exposure to alkylating agents (melphalan, cyclophosphamide) and nitrosoureas before stem cell harvest to preserve stem cell reserve 4, 5. Consider harvesting peripheral blood stem cells before prolonged lenalidomide exposure 4.

Transplantation

• High-dose melphalan 200 mg/m² followed by ASCT is standard 1
• Peripheral blood progenitor cells are preferred over bone marrow 1
• Single ASCT is standard; tandem ASCT may benefit patients not achieving very good partial response after first transplant 1

Maintenance Therapy

DaraR (daratumumab plus lenalidomide) until progression based on AURIGA trial showing superior MRD negativity (50.5% vs 18.8%, P<0.0001) and improved PFS 2.

• Lenalidomide alone remains an acceptable Category 1 alternative 4
• Bortezomib is another option 4

Important caveat: Discuss increased risk of secondary malignancies with lenalidomide maintenance, though benefits typically outweigh risks 4, 3.

Transplant-Ineligible Patients (Elderly/Frail)

First-Line Options

Preferred regimens 1:

1. VMP (bortezomib/melphalan/prednisone) - Category 1, EMA-approved
2. MPT (melphalan/prednisone/thalidomide) - Category 1, EMA-approved
3. DaraVMP - Newer option with anti-CD38 antibody 3

Alternative for patients with pre-existing neuropathy: Bendamustine plus prednisone (EMA-approved when thalidomide or bortezomib contraindicated) 1.

Lenalidomide/low-dose dexamethasone (Category 1): The FIRST trial demonstrated continuous therapy reduced progression/death risk by 28% versus MPT (HR 0.72, P<0.001) with OS benefit (HR 0.78, P=0.02) 3. Continue until progression based on this evidence 3.

Regimen Selection Algorithm

• Triplet regimens are standard; use doublets only in very elderly or frail patients 4
• If neuropathy present: Avoid bortezomib and thalidomide; use bendamustine/prednisone 1
• If renal insufficiency: Consider cyclophosphamide-based regimens 3
• Younger transplant-ineligible (<80 years): Consider quadruplet DaraRd or carfilzomib/lenalidomide/dexamethasone 3

Essential Supportive Care

• Herpes zoster prophylaxis for all patients receiving proteasome inhibitors 4, 5
• Subcutaneous bortezomib preferred for patients with pre-existing or high-risk peripheral neuropathy 4, 5
• Thromboprophylaxis: Full-dose aspirin with immunomodulator-based therapy; therapeutic anticoagulation for high-risk patients 4, 5

Transplant Eligibility Criteria

Eligibility based on:

• Age <65 years OR fit patients in good clinical condition regardless of age 1
• Adequate organ function
• No prohibitive comorbidities

Key distinction: Fitness matters more than chronological age. A fit 70-year-old may be transplant-eligible while a frail 60-year-old may not be 1.

Treatment Initiation

Begin treatment immediately in all patients with symptomatic myeloma meeting CRAB criteria (hypercalcemia >11 mg/dL, creatinine >2 mg/dL, anemia Hb <10 g/dL, bone lesions) 1.

Do NOT treat asymptomatic/smoldering myeloma outside clinical trials, with the exception of high-risk smoldering myeloma where daratumumab for 3 years can be considered pending regulatory approval 2, 6.