Anifrolumab

12.1 Mechanism of Action Anifrolumab-fnia is a human IgG1κ monoclonal antibody that binds to subunit 1 of the type I interferon receptor (IFNAR) with high specificity and affinity. This binding inhibits type I IFN signaling, thereby blocking the biologic activity of type I IFNs. Anifrolumab-fnia also induces the internalization of IFNAR1, thereby reducing the levels of cell surface IFNAR1 available for receptor assembly. Blockade of receptor mediated type I IFN signaling inhibits IFN responsive gene expression as well as downstream inflammatory and immunological processes. Inhibition of type I IFN blocks plasma cell differentiation and normalizes peripheral T-cell subsets. Type I IFNs play a role in the pathogenesis of SLE. Approximately 60-80% of adult patients with active SLE express elevated levels of type I IFN inducible genes.

1 INDICATIONS AND USAGE SAPHNELO (anifrolumab-fnia) is indicated for the treatment of adult patients with moderate to severe systemic lupus erythematosus (SLE), who are receiving standard therapy [see Clinical Studies (14) ] . Limitations of Use The efficacy of SAPHNELO has not been evaluated in patients with severe active lupus nephritis or severe active central nervous system lupus. Use of SAPHNELO is not recommended in these situations. SAPHNELO is a type I interferon (IFN) receptor antagonist indicated for the treatment of adult patients with moderate to severe systemic lupus erythematosus (SLE), who are receiving standard therapy. ( 1 ) Limitations of Use: The efficacy of SAPHNELO has not been evaluated in patients with severe active lupus nephritis or severe active central nervous system lupus. Use of SAPHNELO is not recommended in these situations. ( 1 )

2 DOSAGE AND ADMINISTRATION The recommended dosage is 300 mg as an intravenous infusion over a 30‑minute period every 4 weeks. For complete dilution and intravenous administration instructions see Full Prescribing Information. ( 2.1 ) 2.1 Dosage Recommendations SAPHNELO must be diluted prior to intravenous administration [see Dosage and Administration (2.2) ] . The recommended dosage of SAPHNELO is 300 mg, administered as an intravenous infusion over a 30-minute period, every 4 weeks. Missed dose If a planned infusion is missed, administer SAPHNELO as soon as possible. Maintain a minimum interval of 14 days between infusions. 2.2 Instructions for Preparation and Administration SAPHNELO is supplied as a single-dose vial. Prepare the diluted infusion solution using aseptic technique, by the following procedure: 1. Visually inspect the vial for particulate matter and discoloration. SAPHNELO is a clear to opalescent, colorless to slightly yellow, solution. Discard the vial if the solution is cloudy, discolored or visible particles are observed. Do not shake the vial. 2. Withdraw and discard 2 mL of solution from a 50 mL or 100 mL 0.9% Sodium Chloride Injection, USP infusion bag. 3. Withdraw 2 mL of solution from the vial of SAPHNELO and add it to the infusion bag. Mix the solution by gentle inversion. Do not shake. 4. Each vial is intended for one time use only. Discard any unused portion remaining in the vial. 5. Administer the infusion solution immediately after preparation. 6. If the infusion solution is not administered immediately, store the diluted solution of SAPHNELO at room temperature (59°F to 77°F, 15°C to 25°C) for up to 4 hours, or refrigerated (36°F to 46°F, 2°C to 8°C) for up to 24 hours. Do not freeze. Protect from light. If refrigerated, allow the diluted SAPHNELO solution to reach room temperature prior to administration. 7. Administer the infusion solution intravenously over a 30-minute period through an infusion line containing a sterile, low-protein binding 0.2 to 15 micron in-line or add-on filter. 8. To ensure the complete dose of SAPHNELO has been administered, flush the entire infusion line with 25 mL of 0.9% Sodium Chloride Injection, USP at the end of the infusion. 9. Do not co-administer other medicinal products through the same infusion line. 10. Dispose of any unused medicinal product or waste material in accordance with local requirements .

6 ADVERSE REACTIONS The following clinically significant adverse reactions are also discussed elsewhere in the labeling: • Serious Infections [see Warnings and Precautions (5.1) ] • Hypersensitivity Reactions Including Anaphylaxis [see Warnings and Precautions (5.2) ] • Malignancy [see Warnings and Precautions (5.3) ] Most common adverse drug reactions (incidence ≥5%) are nasopharyngitis, upper respiratory tract infections, bronchitis, infusion related reactions, herpes zoster and cough. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact AstraZeneca at 1-800-236-9933 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 safety of SAPHNELO was assessed through 52 weeks in patients with moderate to severe SLE who received anifrolumab-fnia 300 mg by intravenous infusion every 4 weeks (N=459), compared to placebo (N=466) in controlled clinical trials (Trials 1, 2 and 3) [see Clinical Studies (14) ]. The population studied had a mean age of 41 years (range: 18 to 69), of which 93% were female, 60% White, 13% Black/African American, and 10% Asian. In the controlled-clinical trials, adverse reactions, irrespective of causality, were reported in 87% of patients receiving SAPHNELO and 79% of patients receiving placebo. Adverse reactions that occurred at greater than or equal to 2% incidence are shown in Table 1. Table 1 Adverse Reactions Occurring in ≥2% of Patients on SAPHNELO 300 mg (Trials 1, 2 and 3) at 52 weeks Adverse Reaction SAPHNELO (N=459) % Placebo (N=466) % Upper respiratory tract infection Upper respiratory tract infections (including Upper respiratory tract infections, Nasopharyngitis, Pharyngitis) 34 23 Bronchitis Bronchitis (including Bronchitis, Bronchitis viral, Tracheobronchitis) 11 5.2 Infusion‑related reactions 9.4 7.1 Herpes Zoster 6.1 1.3 Cough 5.0 3.2 Respiratory tract infection Respiratory tract infection (including Respiratory tract infection, Respiratory tract infection viral, Respiratory tract infection bacterial) 3.3 1.5 Hypersensitivity 2.8 0.6 All patients received standard therapy. Long-term Safety Patients who completed Trials 2 and 3 (Phase III feeder trials) were eligible to continue on treatment in a randomized, double-blind, placebo-controlled long-term extension (LTE) study, for an additional 3 years. The long-term safety of SAPHNELO was assessed in 257 patients who received anifrolumab-fnia 300 mg and 112 patients who received placebo in both a feeder trial and the LTE. Of these, 177 patients who received SAPHNELO (68.9%) and 52 patients who received placebo (46.4%) completed a total of 4 years on treatment. The overall long-term safety profile of SAPHNELO was consistent with Trials 1, 2 and 3. Specific Adverse Reactions Infections In the 52‑week controlled-clinical trials, infections were reported in a greater proportion of patients while on treatment with SAPHNELO compared to placebo (69.7% [320/459] versus 55.4% [258/466]), corresponding to exposure-adjusted incidence rates (EAIR) of 141.8 and 99.9 per 100 patient years (PY), respectively. Serious Infections In the 52‑week controlled-clinical trials, the incidence of serious infections while on treatment was 4.8% (22/459) in patients treated with SAPHNELO compared with 5.6% (26/466) in patients receiving placebo, corresponding to EAIR of 5.4 and 6.6 per 100 PY, respectively. The most frequent serious infection was pneumonia. In the 52‑week controlled-clinical trials, fatal infections occurred in 0.4% of patients receiving SAPHNELO and 0.2% of the patients receiving placebo. During the LTE study, the most common serious infections were COVID-19 and pneumonia. Herpes Zoster In the 52‑week controlled-clinical trials, the incidence of herpes zoster in patients while on treatment with SAPHNELO was 6.1% (28/459) and 1.3% (6/466) in patients on placebo, corresponding to EAIRs of 6.9 and 1.5 per 100 PY, respectively. Cases with multidermatomal involvement and disseminated presentation have been reported. Of the 28 SAPHNELO-treated patients with herpes zoster, 2 experienced disseminated disease requiring hospitalization compared to none among patients who received placebo. Hypersensitivity Reactions Including Anaphylaxis During the SLE development program, there was one report of an anaphylactic reaction in a patient who received 150 mg anifrolumab-fnia, and 4 reports of angioedema after 300 mg. In general, the hypersensitivity reactions were predominantly mild or moderate in intensity and did not lead to discontinuation of SAPHNELO. In the 52‑week controlled-clinical trials, hypersensitivity reactions occurred in 2.8% (13/459) of patients while on treatment with SAPHNELO and 0.6% (3/466) of patients on placebo, corresponding to EAIR of 3.2 a

7 DRUG INTERACTIONS No formal drug interaction studies have been conducted.