Table 1. Rationales for primary... | American Society of Hematology

Table 1.

Rationales for primary immunoglobulin RT prophylaxis with bsAb therapy in MM

Rationale	Summary	Relevance to decision-making
The risk of infections with bsAb therapy is concerningly high.	With every continued month on BCMA bsAb therapy, 3% of patients develop de novo high-grade infections.¹¹	High-grade infections can cause morbidity and treatment delays for patients; these infections are also very expensive for payers.
Primary IgRT prophylaxis almost certainly lowers this risk of infections.	Primary prophylaxis has been associated with a 90% reduction in grade ≥3 infection rates.²⁸	Given its safety and tolerability in this setting, the benefit-risk ratio of IgRT supports its use as primary prophylaxis to prevent infections.
An IgG threshold of 400 mg/dL does not adequately risk-stratify infections.	IgG ≥400 mg/dL does not guarantee protection against circulating pathogens and may be inaccurately normal.∗	Restricting IgRT until IgG falls below 400 mg/dL is not evidence-based and may put patients at risk of high-grade infections.

Rationale	Summary	Relevance to decision-making
The risk of infections with bsAb therapy is concerningly high.	With every continued month on BCMA bsAb therapy, 3% of patients develop de novo high-grade infections.¹¹	High-grade infections can cause morbidity and treatment delays for patients; these infections are also very expensive for payers.
Primary IgRT prophylaxis almost certainly lowers this risk of infections.	Primary prophylaxis has been associated with a 90% reduction in grade ≥3 infection rates.²⁸	Given its safety and tolerability in this setting, the benefit-risk ratio of IgRT supports its use as primary prophylaxis to prevent infections.
An IgG threshold of 400 mg/dL does not adequately risk-stratify infections.	IgG ≥400 mg/dL does not guarantee protection against circulating pathogens and may be inaccurately normal.∗	Restricting IgRT until IgG falls below 400 mg/dL is not evidence-based and may put patients at risk of high-grade infections.

In the setting of an IgG κ or λ paraprotein, which is present in approximately half of patients with MM.^29-31