Not all CD20-targeting bispecifics can be combined with rituximab. Mosunetuzumab binds the same epitope, causing competition. However, glofitamab and epcoritamab bind different epitopes, allowing for logical and potentially synergistic combinations with rituximab-based regimens.
To manage hypogammaglobulinemia from bispecific antibodies, clinicians are adopting a more proactive approach. Following the model from myeloma care, they are initiating IVIG therapy earlier to prevent infections, rather than waiting for recurrent infections to occur as was standard with rituximab.
When treating testicular DLBCL, administering systemic methotrexate for CNS prophylaxis before testicular radiation is crucial. Reversing the order can cause a severe skin reaction known as radiation recall, a critical and potentially dangerous complication.
Unlike neuropathy from vincristine which peaks during therapy, polatuzumab vedotin exhibits a "late cresting phenomenon." Patients can experience worsening neuropathy even after completing their sixth and final cycle, a crucial detail for patient counseling and proactive management.
The traditional "germinal center" (GC) classification for DLBCL is overly simplistic. Molecular analysis reveals distinct subtypes within GC, such as "dark zone" and "light zone" signatures, which have different prognoses and responses to targeted therapies like polatuzumab.
A patient with a history of DLBCL presenting with a relapse confined to the skin without lymphadenopathy should raise suspicion. This presentation "smells a lot like Marginal Zone Lymphoma," a less aggressive cancer that may be managed differently, highlighting the need to question histology in atypical relapses.
In follicular lymphoma, the treatment goal is durable remission with manageable toxicity, not necessarily a cure. Therefore, clinicians frequently prefer using a bispecific antibody first, reserving the more complex and toxic CAR-T cell therapy for transformed disease or after a bispecific fails.
Unlike some targeted therapies that lead to antigen loss, treatment with the CD19-directed antibody tafasitamab does not appear to eliminate CD19 expression on lymphoma cells. This is a critical finding, as it preserves the target for subsequent potent therapies like CD19-directed CAR T-cells.
The STARGLO trial (glofitamab-gemox) showed a strong survival benefit in Asia-Pacific patients but not in the small North American cohort. This geographic discrepancy, with only 9% of patients from the US, was a key reason the FDA did not approve the combination, while European agencies did.
The ECHELON-3 trial showed that brentuximab vedotin plus R-squared is effective in relapsed/refractory DLBCL, even in patients with negligible CD30 expression. This suggests the drug's benefit may stem from immune synergy or other mechanisms, not just direct CD30 targeting.
Before initiating a CD20-targeting bispecific antibody in patients who have failed CAR-T therapy, a new biopsy is mandatory. Up to 30% of these patients experience CD20 antigen loss, which would render the bispecific therapy ineffective and necessitates choosing a drug with a different target.
Despite new therapies for follicular lymphoma (FL), bendamustine-rituximab (BR) will likely remain the community standard due to its simplicity. This may create a growing gap in treatment approaches between academic centers using novel agents and community practices favoring the familiar BR regimen.