ZYNLONTA

1 INDICATIONS AND USAGE ZYNLONTA is indicated for the treatment of adult patients with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy, including diffuse large B-cell lymphoma (DLBCL) not otherwise specified, DLBCL arising from low-grade lymphoma, and high-grade B-cell lymphoma. This indication is approved under accelerated approval based on overall response rate [see Clinical Studies (14.1) ] . Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s). ZYNLONTA is a CD19-directed antibody and alkylating agent conjugate indicated for the treatment of adult patients with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy, including diffuse large B-cell lymphoma (DLBCL) not otherwise specified, DLBCL arising from low-grade lymphoma, and high-grade B-cell lymphoma. ( 1 ) This indication is approved under accelerated approval based on overall response rate. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s). ( 1 )

2 DOSAGE AND ADMINISTRATION ZYNLONTA is an intravenous infusion over 30 minutes on Day 1 of each cycle (every 3 weeks). The recommended dosage is: 0.15 mg/kg every 3 weeks for 2 cycles. 0.075 mg/kg every 3 weeks for subsequent cycles. ( 2.1 ) Premedicate with dexamethasone 4 mg orally or intravenously twice daily for 3 days beginning the day before ZYNLONTA. ( 2.2 ) See Full Prescribing Information for instructions on preparation and administration. ( 2.4 ) 2.1 Recommended Dosage ZYNLONTA as an intravenous infusion administered over 30 minutes on Day 1 of each cycle (every 3 weeks). Administer intravenous infusion as follows: 0.15 mg/kg every 3 weeks for 2 cycles. 0.075 mg/kg every 3 weeks for subsequent cycles. 2.2 Recommended Premedication Unless contraindicated, administer dexamethasone 4 mg orally or intravenously twice daily for 3 days beginning the day before administering ZYNLONTA. If dexamethasone administration does not begin the day before ZYNLONTA, dexamethasone should begin at least 2 hours prior to administration of ZYNLONTA. 2.3 Dosage Modifications and Delays Table 1: Recommended Dosage Modifications for Adverse Reactions Adverse Reactions Severity Dosage Modification Hematologic Adverse Reactions Neutropenia [see Warnings and Precautions (5.2) ] Absolute neutrophil count less than 1 × 10 9 /L Withhold ZYNLONTA until neutrophil counts returns to 1 × 10 9 /L or higher Thrombocytopenia [see Warnings and Precautions (5.2) ] Platelet count less than 50,000/mcL Withhold ZYNLONTA until platelet count returns to 50,000/mcL or higher Nonhematologic Adverse Reactions Edema or Effusion [see Warnings and Precautions (5.1) ] Grade 2 National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0 or higher Withhold ZYNLONTA until the toxicity resolves to Grade 1 or less Pericardial Effusion [see Warnings and Precautions (5.1) ] Grade 2 Withhold ZYNLONTA until the toxicity resolves. Discontinue ZYNLONTA if effusion recurs Grade 3 or higher Discontinue ZYNLONTA Hepatotoxicity [ see Warnings and Precautions (5.4) ] Grade 3 or higher increase in AST or ALT or suspected DILI Withhold ZYNLONTA until toxicity resolves to Grade 1 or less, discontinue for confirmed DILI Other Adverse Reactions [see Warnings and Precautions (5.3) , (5.5) , Adverse Reactions (6.1) ] Grade 3 or higher Withhold ZYNLONTA until the toxicity resolves to Grade 1 or less Recommendations for Dosage Delays If dosing is delayed by more than 3 weeks due to toxicity related to ZYNLONTA, reduce subsequent doses by 50%. If toxicity reoccurs following dose reduction, consider discontinuation. Note: If toxicity requires dose reduction following the second dose of 0.15 mg/kg (Cycle 2), the patient should receive the dose of 0.075 mg/kg for Cycle 3. 2.4 Reconstitution and Administration Instructions Reconstitute and further dilute ZYNLONTA prior to intravenous infusion. Use appropriate aseptic technique. ZYNLONTA is a hazardous drug. Follow applicable special handling and disposal procedures. 1 Dose calculation Calculate the total dose (mg) required based on the patient's weight and prescribed dose [see Dosage and Administration (2.1) ] . For patients with a body mass index (BMI) ≥35 kg/m 2 , calculate the dose based on an adjusted body weight (ABW) as follows: ABW in kg = 35 kg/m 2 × (height in meters) 2 More than one vial may be needed to achieve the calculated dose. Convert the calculated dose (mg) to volume using 5 mg/mL, which is the concentration of ZYNLONTA after reconstitution. Reconstitution of lyophilized ZYNLONTA Reconstitute each ZYNLONTA vial using 2.2 mL of Sterile Water for Injection, USP with the stream directed toward the inside wall of the vial to obtain a final concentration of 5 mg/mL. Swirl the vial gently until the powder is completely dissolved. Do not shake . Do not expose to direct sunlight. Inspect the reconstituted solution for particulate matter and discoloration. The solution should appear clear to slightly opalescent, c…

5 WARNINGS AND PRECAUTIONS Effusion and Edema, Including Capillary Leak Syndrome : Monitor for the development of pleural effusion, pericardial effusion, ascites, peripheral edema, and general edema. Consider diagnostic imaging when symptoms develop or worsen. ( 5.1 ) Myelosuppression: Monitor blood cell counts. Withhold, reduce, or discontinue ZYNLONTA based on severity. ( 5.2 ) Infections : Monitor for infection and treat promptly. ( 5.3 ) Hepatotoxicity, Including Drug-Induced Liver Injury : Monitor liver function tests during treatment. Withhold or permanently discontinue ZYNLONTA based on severity. ( 5.4 ) Cutaneous Reaction s: Monitor patients for new or worsening cutaneous reactions, including photosensitivity reactions. Dermatologic consultation should be considered. ( 5.5 ) Embryo-Fetal Toxic ity: Can cause fetal harm. Advise patients of the potential risk to a fetus and to use effective contraception. ( 5.6 , 8.1 , 8.3 ) 5.1 Effusion and Edema, Including Capillary Leak Syndrome Serious effusion and edema, including capillary leak syndrome, occurred in patients treated with ZYNLONTA. Grade 3 edema occurred in 3% (primarily peripheral edema or ascites) and Grade 3 pleural effusion occurred in 3%, and Grade 3 or 4 pericardial effusion occurred in 1% [see Adverse Reactions (6.1) ] . Rare cases of cardiac tamponade have been reported in patients with Grade 3 or 4 pericardial effusion. Grade 3 or higher capillary leak syndrome occurred in 0.6%. Monitor patients for new or worsening edema or effusions. Consider diagnostic imaging in patients who develop symptoms of pleural effusion or pericardial effusion, such as new or worsened dyspnea, chest pain, and/or ascites such as swelling in the abdomen and bloating. Institute appropriate medical management for edema or effusions. Evaluate and institute appropriate medical management for capillary leak syndrome in patients experiencing worsening effusion or edema, with signs and symptoms of weight gain, severe hypotension, hypoalbuminemia, and/or hemoconcentration (by elevated hemoglobin/hematocrit, etc.). Withhold or discontinue ZYNLONTA based on severity [see Dosage and Administration (2.3) ] . 5.2 Myelosuppression Treatment with ZYNLONTA can cause serious or severe myelosuppression, including neutropenia, thrombocytopenia, and anemia. Grade 3 or 4 neutropenia occurred in 32%, thrombocytopenia in 20%, and anemia in 12% of patients. Grade 4 neutropenia occurred in 21% and thrombocytopenia in 7% of patients. Febrile neutropenia occurred in 3% [see Adverse Reactions (6.1) ]. Monitor complete blood counts throughout treatment. Cytopenias may require interruption, dose reduction, or discontinuation of ZYNLONTA. Consider prophylactic granulocyte colony-stimulating factor administration as applicable [see Dosage and Administration (2.3) ]. 5.3 Infections Fatal and serious infections, including opportunistic infections, occurred in patients treated with ZYNLONTA. Grade 3 or higher infections occurred in 10% of patients, with fatal infections occurring in 2%. The most frequent Grade ≥3 infections included sepsis and pneumonia [see Adverse Reactions (6.1) ] . Monitor for any new or worsening signs or symptoms consistent with infection. For Grade 3 or 4 infection, withhold ZYNLONTA until infection has resolved [see Dosage and Administration (2.3) ] . 5.4 Hepatotoxicity, Including Drug-Induced Liver Injury Cholestatic and hepatocellular liver injury, including severe, life-threatening, and fatal cases of drug-induced liver injury (DILI), have occurred in patients treated with ZYNLONTA. Monitor liver function tests at baseline and throughout treatment with ZYNLONTA. In the event of suspected DILI or Grade ≥3 increase in ALT or AST, withhold ZYNLONTA until toxicity resolves to Grade 1 or lower. Upon confirmation of DILI, discontinue ZYNLONTA. [see Dosage and Administration (2.3) ] . ZYNLONTA should be avoided in patients with severe hepatic impairment [see Clinical Pharmacology (8.6 , 12.3) ]…

4 CONTRAINDICATIONS None. None. ( 4 )

8.1 Pregnancy Risk Summary Based on its mechanism of action, ZYNLONTA can cause embryo-fetal harm when administered to a pregnant woman, because it contains a genotoxic compound (SG3199) and affects actively dividing cells [see Clinical Pharmacology (12.1) and Nonclinical Toxicology (13.1) ] . There are no available data on the use of ZYNLONTA in pregnant women to evaluate for drug-associated risk. No animal reproduction studies were conducted with ZYNLONTA. Advise pregnant women of the potential risk to a fetus . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data Animal reproductive or developmental toxicity studies were not conducted with loncastuximab tesirine-lpyl. The cytotoxic component of ZYNLONTA, SG3199, crosslinks DNA, is genotoxic, and is toxic to rapidly dividing cells, suggesting it has the potential to cause embryotoxicity and teratogenicity.

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Effusion and Edema [see Warnings and Precautions (5.1) ] Myelosuppression [see Warnings and Precautions (5.2)] Infections [see Warnings and Precautions (5.3) ] Hepatotoxicity, including DILI [see Warnings and Precautions(5.4) ] Cutaneous Reactions [see Warnings and Precautions (5.5) ] Most common (≥20%) adverse reactions, including laboratory abnormalities, are thrombocytopenia, increased gamma-glutamyltransferase, neutropenia, anemia, hyperglycemia, transaminase elevation, fatigue, hypoalbuminemia, rash, edema, nausea, and musculoskeletal pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact ADC Therapeutics at 1-855-690-0340 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The pooled safety population described in the WARNINGS AND PRECAUTIONS reflect exposure to ZYNLONTA as a single agent at an initial dose of 0.15 mg/kg in 215 patients with DLBCL in studies ADCT-402-201 (LOTIS-2) and ADCT-402-101, which includes 145 patients from LOTIS-2 treated with 0.15 mg/kg × 2 cycles followed by 0.075 mg/kg for subsequent cycles. Among 215 patients who received ZYNLONTA, the median number of cycles was 3 (range 1 to 15) with 58% receiving three or more cycles and 30% receiving five or more cycles. In this pooled safety population of 215 patients, the most common (>20%) adverse reactions, including laboratory abnormalities, were thrombocytopenia, increased gamma-glutamyltransferase, neutropenia, anemia, hyperglycemia, transaminase elevation, fatigue, hypoalbuminemia, rash, edema, nausea, and musculoskeletal pain. Relapsed or Refractory Diffuse Large B-Cell Lymphoma LOTIS-2 The safety of ZYNLONTA was evaluated in LOTIS-2, an open-label, single-arm clinical trial that enrolled 145 patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), including high-grade B-cell lymphoma, after at least two prior systemic therapies [see Clinical Studies (14.1) ] . The trial required hepatic transaminases, including gamma-glutamyltransferase (GGT), ≤2.5 times upper limit of normal (ULN), total bilirubin ≤1.5 times ULN, and creatinine clearance ≥60 mL/min. Patients received ZYNLONTA 0.15 mg/kg every 3 weeks for 2 cycles, then 0.075 mg/kg every 3 weeks for subsequent cycles and received treatment until progressive disease or unacceptable toxicity. Among the 145 patients, the median number of cycles received was 3, with 34% receiving 5 or more cycles. The median age was 66 years (range 23 to 94), 59% were male, and 94% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1. Race was reported in 97% of patients; of these patients, 90% were White, 3% were Black, and 2% were Asian. Serious adverse reactions occurred in 28% of patients receiving ZYNLONTA. The most common serious adverse reactions that occurred in ≥2% receiving ZYNLONTA were febrile neutropenia, pneumonia, edema, pleural effusion, and sepsis. Fatal adverse reactions occurred in 1%, due to infection. Permanent treatment discontinuation due to an adverse reaction of ZYNLONTA occurred in 19% of patients. Adverse reactions resulting in permanent discontinuation of ZYNLONTA in ≥2% were gamma-glutamyltransferase increased, edema, and effusion. Dose reductions due to an adverse reaction of ZYNLONTA occurred in 8% of patients. Adverse reactions resulting in dose reduction of ZYNLONTA in ≥4% was gamma-glutamyltransferase increased. Dosage interruptions due to an adverse reaction occurred in 49% of patients receiving ZYNLONTA. Adverse reactions leading to interruption of ZYNLONTA in ≥5% were gamma-glutamyltransferase increased, neutropenia, thrombocyto…