Mosunetuzumab

CYTOKINE RELEASE SYNDROME Cytokine release syndrome (CRS), including serious or life-threatening reactions, can occur in patients receiving LUNSUMIO. Initiate treatment with the LUNSUMIO step-up dosing schedule to reduce the risk of CRS. Withhold LUNSUMIO until CRS resolves or permanently discontinue based on severity [see Dosage and Administration (2.1 and 2.4) and Warnings and Precautions (5.1) ] . WARNING: CYTOKINE RELEASE SYNDROME See full prescribing information for complete boxed warning. Cytokine release syndrome (CRS), including serious or life-threatening reactions, can occur in patients receiving LUNSUMIO. Initiate treatment with the LUNSUMIO step-up dosing schedule to reduce the risk of CRS. Withhold LUNSUMIO until CRS resolves or permanently discontinue based on severity. ( 2.1 , 2.4 , 5.1 )

Neurologic Toxicity, including Immune Effector Cell-Associated Neurotoxicity Syndrome : Can cause serious and life-threatening neurologic toxicity, including immune effector cell-associated neurotoxicity syndrome (ICANS). Monitor patients for signs and symptoms of neurologic toxicity during treatment; withhold or permanently discontinue based on severity. ( 5.2 ) Infections : Can cause serious or fatal infections. Monitor patients for signs and symptoms of infection, including opportunistic infections, and treat as needed. ( 5.3 ) Hemophagocytic Lymphohistiocytosis: Can cause serious or fatal reactions. For suspected cases, interrupt LUNSUMIO and evaluate and treat promptly. ( 5.4 ) Cytopenias : Monitor complete blood cell counts during treatment. ( 5.5 ) Tumor Flare : Can cause serious tumor flare reactions. Monitor patients at risk for complications of tumor flare. ( 5.6 ) Risk of Medication Errors with Incorrect Product Use : Ensure that the correct formulation is being prescribed, dispensed, and administered. ( 5.7 ) Embryo-Fetal Toxicity : May cause fetal harm. Advise females of reproductive potential of the potential risk to the fetus and to use effective contraception. ( 5.8 , 8.1 , 8.3 )

Cytokine Release Syndrome LUNSUMIO can cause CRS, including serious or life-threatening reactions [see Adverse Reactions (6.1 )] . CRS occurred in 39% of patients who received LUNSUMIO at the recommended dosage in the clinical trial, with Grade 1 CRS occurring in 28%, Grade 2 in 15%, Grade 3 in 2%, and Grade 4 in 0.5% of patients. Among 86 patients who experienced CRS, CRS recurred in 28%. Most cases of CRS occurred following doses of 1 mg on Cycle 1 Day 1 (15%), 2 mg on Cycle 1 Day 8 (5%), and 60 mg on Cycle 1 Day 15 (33%). Five percent of patients experienced CRS after receiving 60 mg on Cycle 2 Day 1 with 1% of patients experiencing CRS following subsequent dosages of LUNSUMIO. The median time to onset of CRS from the start of administration of LUNSUMIO in Cycle 1 Day 1 was 5 hours (range: 1 hour to 3 days), Cycle 1 Day 8 was 28 hours (range: 5 hours to 3 days), Cycle 1 Day 15 was 25 hours (range: 0.1 hours to 16 days), and Cycle 2 Day 1 was 46 hours (range: 12 hours to 3 days). The median duration of CRS was 3 days (range: 1 to 29 days). Clinical signs and symptoms of CRS included, but were not limited to, fever, chills, hypotension, tachycardia, hypoxia, and headache. Concurrent neurologic adverse reactions occurred in 6% of patients and included but were not limited to headache, confusional state, and anxiety. Initiate therapy according to LUNSUMIO step-up dosing schedule to reduce the risk of CRS [see Dosage and Administration (2.3) ] . Administer pretreatment medications to reduce the risk of CRS, ensure adequate hydration, and monitor patients following administration of LUNSUMIO accordingly. At the first sign of CRS, immediately evaluate patients for hospitalization, manage per current practice guidelines and administer supportive care; withhold or permanently discontinue LUNSUMIO based on severity [see Dosage and Administration (2.4) ] . Patients who experience CRS (or other adverse reactions that impair consciousness) should be evaluated and advised not to drive and to refrain from operating heavy or potentially dangerous machinery until resolution.

Neurologic Toxicity, including Immune Effector Cell-Associated Neurotoxicity Syndrome LUNSUMIO can cause serious and life-threatening neurologic toxicity, including immune effector cell-associated neurotoxicity syndrome (ICANS) [see Adverse Reactions (6.1) ] . Neurologic toxicity occurred in 39% of patients who received LUNSUMIO at the recommended dosage in the clinical trial, with Grade 3 neurologic toxicity occurring in 3% of patients. The most frequent neurologic toxicities were headache (21%), peripheral neuropathy (13%), dizziness (11%) and mental status changes (6%, including confusional state, disturbance in attention, cognitive disorder, delirium, encephalopathy, and somnolence). ICANS was reported in 1% of patients (Grade 1: 0.5%, Grade 2: 0.5%) who received LUNSUMIO at the recommended dosage in the clinical trial. Across a broader clinical trial population, ICANS or suspected ICANS occurred in 2.2% (21/949) of patients who received LUNSUMIO or LUNSUMIO VELO. The most frequent manifestations included confusional state and lethargy. Twenty patients had Grade 1-2 events and 1 patient had a Grade 3 event. The majority of cases (75%) occurred during the first cycle of treatment. The median time to onset was 17 days (range: 1 to 48 days). In total, 88% of cases resolved after a median duration of 3 days (range: 1 to 20 days). Coadministration of LUNSUMIO with other products that cause dizziness or mental status changes may increase the risk of neurologic toxicity. Monitor patients for signs and symptoms of neurologic toxicity during treatment. At the first sign of neurologic toxicity, including ICANS, immediately evaluate the patient, consider neurology evaluation as appropriate, and provide supportive therapy based on severity; withhold or permanently discontinue LUNSUMIO based on severity and follow management recommendations [see Dosage and Administration (2.4) ] . Patients who experience neurologic toxicity such as tremors, dizziness, insomnia, severe neurotoxicity, or any other adverse reactions that impair consciousness should be evaluated, including potential neurology evaluation, and patients at increased risk should be advised not to drive and to refrain from operating heavy or potentially dangerous machinery until resolution.

Infections LUNSUMIO can cause serious or fatal infections [see Adverse Reactions (6.1) ] . Among patients who received LUNSUMIO at the recommended dosage in the clinical trial, serious infections, including opportunistic infections, occurred in 17%, with Grade 3 or 4 infections in 14% and fatal infections in 0.9% of patients. The most common Grade 3 or greater infections were pneumonia, sepsis, and upper respiratory infection. Monitor patients for signs and symptoms of infection prior to and during treatment with LUNSUMIO and treat appropriately. LUNSUMIO should not be administered in the presence of active infection. Caution should be exercised when considering the use of LUNSUMIO in patients with a history of recurring or chronic infections (e.g., chronic, active Epstein-Barr Virus), with underlying conditions that may predispose to infections or who have had significant prior immunosuppressive treatment. Administer prophylactic antimicrobials according to guidelines. Withhold LUNSUMIO or consider permanent discontinuation of LUNSUMIO based on severity [see Dosage and Administration (2.4) ] .

Hemophagocytic Lymphohistiocytosis LUNSUMIO can cause fatal or serious hemophagocytic lymphohistiocytosis (HLH). HLH is a potentially life-threatening, hyperinflammatory syndrome that is independent of CRS. Common manifestations include fever, elevated ferritin, hemophagocytosis, cytopenias, coagulopathy, hepatitis, and splenomegaly. Across a broader clinical trial population, HLH occurred in 0.5% (7/1536) of patients. Most cases (5/7) were identified within the first 28 days following initiation of LUNSUMIO or LUNSUMIO VELO, with 3 cases preceded by diagnosed or suspected CRS. Of the 7 cases of HLH, 6 had fatal outcomes, with 2 deaths from HLH alone and 4 deaths with concurrent unresolved HLH. Of the 7 cases of HLH, 4 occurred in the context of concurrent EBV and/or CMV infection. Monitor for clinical signs and symptoms of HLH. Consider HLH when the presentation of CRS is atypical or prolonged, or when there are features of macrophage activation. For suspected HLH, interrupt LUNSUMIO and evaluate and treat promptly for HLH per current practice guidelines.

Cytopenias LUNSUMIO can cause serious or severe cytopenias, including lymphopenia, neutropenia, anemia, and thrombocytopenia [see Adverse Reactions (6.1) ] . Among patients who received LUNSUMIO at the recommended dosage in the clinical trial, Grade 3 or 4 decreased lymphocytes occurred in 92%, decreased neutrophils in 38%, decreased hemoglobin in 19%, and decreased platelets in 12% of patients. Grade 4 decreased lymphocytes occurred in 71%, decreased neutrophils in 19%, and decreased platelets in 5% of patients. Febrile neutropenia occurred in 2% of patients. Monitor complete blood counts throughout treatment. Based on the severity of cytopenias, temporarily withhold, or permanently discontinue LUNSUMIO. Consider prophylactic granulocyte colony-stimulating factor administration as applicable [see Dosage and Administration (2.4) ] .

Tumor Flare LUNSUMIO can cause serious or severe tumor flare [see Adverse Reactions (6.1) ] . Among patients who received LUNSUMIO at the recommended dosage in the clinical trial, tumor flare occurred in 4%. Manifestations included new or worsening pleural effusions, localized pain and swelling at the sites of lymphoma lesions, and tumor inflammation. Patients with bulky tumors or disease located in close proximity to airways or a vital organ should be monitored closely during initial therapy. Monitor for signs and symptoms of compression or obstruction due to mass effect secondary to tumor flare. If compression or obstruction develops, institute standard treatment of these complications.

Risk of Medication Errors with Incorrect Product Use Mosunetuzumab-axgb is available in two formulations: as an injection for intravenous use (LUNSUMIO) and as an injection for subcutaneous use (LUNSUMIO VELO). Check the product labels to ensure that the correct formulation is being prescribed, dispensed, and administered to the patient [see Dosage and Administration (2.2 and 2.5) ] . Do not substitute LUNSUMIO for or with LUNSUMIO VELO.

Embryo-Fetal Toxicity Based on its mechanism of action, LUNSUMIO may cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to the fetus. Advise females of reproductive potential to use effective contraception during treatment with LUNSUMIO and for 3 months after the last dose [see Use in Specific Populations (8.1 , 8.3) ] .