Common Side Effects of Lunsumio
Lunsumio (mosunetuzumab), used for relapsed or refractory follicular lymphoma, most often causes cytokine release syndrome (CRS), with 44% of patients experiencing it in clinical trials—mostly grade 1 or 2, occurring after the first dose.1 Other frequent side effects include fatigue (up to 41%), headache (29%), COVID-19 infections (27%), pyrexia (26%), nausea (24%), and chills (23%).[1]
How CRS Happens and What to Watch For
CRS stems from the bispecific T-cell engager mechanism, rapidly activating immune cells and releasing cytokines. Symptoms like fever, low blood pressure, or breathing issues typically start within 1-2 days of infusion and resolve quickly with supportive care like tocilizumab. Premedication with steroids and antihistamines reduces risk; severe CRS (grade 3+) hit 1% of patients.1
Serious Side Effects Patients Report
Tumor lysis syndrome occurred in 2% (one fatal case), mainly in high tumor burden patients. Infections affected 28%, including pneumonia (6%). Neurological issues like immune effector cell-associated neurotoxicity syndrome (ICANS) were rare (3%, mostly mild).[1] Low blood cell counts—neutropenia (14%), anemia (13%), thrombocytopenia (13%)—also appear, raising infection or bleeding risks.
Side Effects by Infusion Cycle
Most issues peak after cycle 1: CRS in 37%, dropping to 3% later. Fatigue and infections persist across cycles but lessen over time. Discontinuation due to side effects happened in 7%.[1]
Differences from Similar Drugs Like Columvi
Lunsumio has lower CRS rates than Columvi (glofitamab, 51% CRS) due to its fixed-duration course (eight 21-day cycles max) versus ongoing treatment. Both share infection and cytopenia risks, but Lunsumio's outpatient-friendly step-up dosing cuts hospitalization needs.2
Managing Side Effects in Practice
Doctors monitor closely for the first cycle, often hospitalizing high-risk patients. Prophylactic hydration and anti-infectives help. Patients with liver issues or prior CAR-T therapy face higher risks—discuss with your oncologist.1
[1]: https://www.lunsumio.com/content/dam/centene/health-professionals/pdfs/Lunsumio-PI.pdf