Despite the well-documented infection risks and clear guideline recommendations, uptake of immunoglobulin therapy in clinical practice remains inconsistent, often influenced by evolving evidence and variable prescriber awareness.¹⁰ From a managed care perspective, this variability presents challenges in ensuring appropriate utilization while aligning with value-based care principles to ensure sustainable care.  

At the same time, the high cost of immunoglobulin, which ranges from approximately $5,000 to $15,000 per month, must be carefully balanced against the significant economic burden of infection-related complications in MM.¹¹˒¹² Infections in MM members, particularly those receiving immune-based therapies, are associated with high rates of hospitalization, emergency department visits and antimicrobial use, all of which drive up total cost of care.¹² Some studies show that IVIG can reduce the incidence of all-grade infection by up to 40% and serious infection by as much as 90%.⁹˒¹⁰ This suggests that use of immunoglobulin therapy may offset downstream costs related to infection management. 

However, a systematic review found limited and low-quality evidence supporting its economic value in hematologic malignancies, with some analyses suggesting that if used the subcutaneous route of administration may be more cost-effective.¹³ Furthermore, a recent trial based economic evaluation comparing intravenous immunoglobulin to prophylactic antibiotics in members with hypogammaglobulinemia secondary to hematologic malignancies concluded that IVIG was significantly more expensive and did not yield better health outcomes.¹⁴  

According to the 2025 Prime Therapeutics Medical Pharmacy Trend Report, immunoglobulin ranked among the top 10 drug spend categories across all lines of business, accounting for 6% of commercial, 4.3% of Medicare and 4.1% of Medicaid total spend. Despite declining unit costs, overall spending rose due to increased utilization, with commercial and Medicare per member per month (PMPM) spend projected to exceed $4.00 by 2027. Notably, 92.8% of commercial spend occurs under the medical benefit, while Medicare shows a more balanced split: 46.3% medical and 53.7% pharmacy.¹¹ This real-world cost data highlights the urgency of understanding the clinical utility in hematologic malignancies, including MM, to ensure sustainable and cost-effective care.  

The data is conflicting and still evolving. For health plans, this underscores the criticality of adopting targeted strategies that balance clinical guidelines, cost-effectiveness and real-world outcomes. To support appropriate and sustainable use of immunoglobulin therapy, health plans should consider the following approaches.²˒¹³˒¹⁵ 

• Prior authorization policies aligned with guidelines, IgG thresholds and therapy type 
• Immunoglobulin dose optimization 
  • Vial rounding within 10% of the prescribed dose 
  • Adjusted body weight dosing 
• Subcutaneous dosage forms  
• Site of care optimization to physician offices and home 
• Development of real-world data to support clinical utility  

As immune-based therapies continue to redefine treatment paradigms in MM, their associated immunodeficiency and infection risks demand proactive, evidence-based supportive care strategies. For managed care stakeholders, optimizing the use of immunoglobulin therapy will be essential to delivering high-value care while managing total cost of care or this vulnerable population.