WAYRILZ

1 INDICATIONS AND USAGE WAYRILZ is indicated for the treatment of adult patients with persistent or chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment. WAYRILZ is a kinase inhibitor indicated for the treatment of adult patients with persistent or chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment. ( 1 )

2 DOSAGE AND ADMINISTRATION See Full Prescribing Information for important recommendations prior to treatment. ( 2.1 , 2.3 ) Recommended dosage: 400 mg orally twice daily; swallow whole with water, with or without food. Do not cut, crush, or chew tablets. ( 2.2 ) 2.1 Recommended Testing Before Initiating WAYRILZ Verify pregnancy status of females of reproductive potential prior to initiating WAYRILZ treatment [see Warnings and Precautions (5.3) and Use in Specific Populations (8.1 , 8.3) ] . 2.2 Recommended Dosage The recommended dosage of WAYRILZ is 400 mg taken orally twice daily. WAYRILZ can be taken at approximately the same time each day with or without food. In patients who experience gastrointestinal symptoms, taking WAYRILZ with food may improve tolerability. Advise patients to swallow tablets whole with a glass of water. Advise patients not to cut, crush or chew the tablets. If a dose is missed, patients should take the missed dose of WAYRILZ as soon as possible on the same day and at least 2 hours apart from the next regular scheduled dose. If taking antacid or histamine H2 receptor antagonist, administer the dose of WAYRILZ at least 2 hours before the antacid or histamine H2 receptor antagonist. 2.3 Monitoring and Dose Modifications for Hepatotoxicity Evaluate bilirubin and transaminases at baseline and as clinically indicated during treatment with WAYRILZ. For patients who develop abnormal liver tests after WAYRILZ, monitor more frequently for liver test abnormalities and clinical signs and symptoms of hepatic toxicity. If Drug-Induced Liver Injury (DILI) is suspected, withhold WAYRILZ. Upon confirmation of DILI, discontinue WAYRILZ.

4 CONTRAINDICATIONS None None

5 WARNINGS AND PRECAUTIONS Serious Infections: Monitor patients for signs and symptoms of infection, evaluate promptly, and treat. ( 5.1 ) Hepatotoxicity, Including Drug-Induced Liver Injury: Evaluate bilirubin and transaminases at baseline and as clinically indicated during treatment. ( 5.2 ) Embryo-Fetal Toxicity: Based on preliminary animal data, WAYRILZ may cause fetal harm. Advise females of reproductive potential of the potential risk and to use effective contraception. ( 5.3 , 8.1 , 8.3 ) 5.1 Serious Infections An increased risk of serious infections (including bacterial, viral, or fungal) can occur in patients treated with Bruton's tyrosine kinase (BTK) inhibitors, including WAYRILZ. In the LUNA-3 trial, fatal pneumonia occurred in one participant in the WAYRILZ group. Other serious infections [one each (0.8%)] included COVID-19 infection, wound infection, and one patient experienced urinary tract infection and kidney abscess. Monitor patients for signs and symptoms of infection and treat appropriately. 5.2 Hepatotoxicity, Including Drug-Induced Liver Injury Hepatotoxicity, including severe, life-threatening, and potentially fatal cases of DILI, can occur in patients treated with BTK inhibitors. In the clinical trials of WAYRILZ in patients with ITP, elevations of liver transaminases occurred and were generally mild to moderate in severity. Evaluate bilirubin and transaminases at baseline and as clinically indicated during treatment with WAYRILZ. For patients who develop abnormal liver tests after WAYRILZ, monitor more frequently for liver test abnormalities and clinical signs and symptoms of hepatic toxicity. If DILI is suspected, withhold WAYRILZ. Upon confirmation of DILI, discontinue WAYRILZ. 5.3 Embryo-Fetal Toxicity Based on findings from preliminary animal reproduction studies, WAYRILZ may cause fetal harm when administered to a pregnant woman. Adverse visceral and skeletal findings occurred in rat fetuses at a maternally toxic dose at exposures 22-times the human exposure [based on area under the curve (AUC)] at the maximum recommended human dose (MRHD), and renal visceral malformations occurred in a single rabbit fetus at 5.6-times the human exposure (based on AUC) at the MRHD. Verify pregnancy status of females of reproductive potential prior to initiating WAYRILZ treatment. Advise females of reproductive potential to use an effective method of contraception during treatment with WAYRILZ and for 1 week after the final dose [see Use in Specific Populations (8.1 , 8.3) ] .

7 DRUG INTERACTIONS CYP3A Inhibitors: Avoid co-administration with moderate or strong CYP3A inhibitors. ( 7.1 ) CYP3A Inducers: Avoid co-administration with moderate or strong CYP3A inducers. ( 7.1 ) Gastric Acid Reducing Agents: Avoid co-administration with proton pump inhibitors (PPIs). WAYRILZ should be administered at least 2 hours before taking an antacid or H2 receptor antagonist. ( 7.1 ) 7.1 Effect of Other Drugs on WAYRILZ Strong and Moderate CYP3A Inhibitors Avoid concomitant use of WAYRILZ with strong or moderate CYP3A inhibitors. If a strong or moderate CYP3A inhibitor cannot be avoided, and these inhibitors will be used short term (such as anti-infectives for seven days or less), interrupt treatment with WAYRILZ. Avoid concomitant use of grapefruit, starfruit and products containing these fruits, and Seville oranges with WAYRILZ, as these are moderate and strong inhibitors of CYP3A. Rilzabrutinib is a CYP3A substrate. Concomitant use with a strong or moderate CYP3A inhibitor increases rilzabrutinib C max and AUC [see Clinical Pharmacology (12.3) ] , which increases the risk of WAYRILZ adverse reactions. Strong and Moderate CYP3A Inducers Avoid concomitant use of WAYRILZ with strong or moderate CYP3A inducers. Rilzabrutinib is a CYP3A substrate. Concomitant use with a strong or moderate CYP3A inducer decreases rilzabrutinib C max and AUC [see Clinical Pharmacology (12.3) ] , which may reduce WAYRILZ efficacy. Gastric Acid Reducing Agents Administer the dose of WAYRILZ at least 2 hours before administration of an antacid or histamine H2 receptor antagonist. Avoid concomitant use of proton pump inhibitors with WAYRILZ. Rilzabrutinib exhibits pH-dependent solubility. Acid reducing agents decrease rilzabrutinib exposure [see Clinical Pharmacology (12.3) ] , which may reduce WAYRILZ efficacy. 7.2 Effect of WAYRILZ on Other Drugs CYP3A Substrates Monitor for adverse reactions of the concurrently administered CYP3A substrate more frequently and consider dosage adjustment in accordance with the Prescribing Information of the CYP3A substrate. Rilzabrutinib is a moderate inhibitor of CYP3A and increases exposure of these substrates [see Clinical Pharmacology (12.3) ] , which increases the risk of adverse reactions related to these substrates. P-gp, BCRP, and OATP1B Substrates Monitor for adverse reactions of the concurrently administered P-gp, BCRP, or OATP1B substrate more frequently, unless otherwise recommended in the substrate Prescribing Information, when WAYRILZ is used concomitantly with P-gp, BCRP, or OATP1B substrates where minimal substrate concentration changes may lead to serious adverse reactions. Rilzabrutinib is an inhibitor of P-gp, BCRP and OATP1B in vitro . The effect of concomitant use of WAYRILZ with OATP1B and BCRP substrates has not been established in clinical studies. However, based on in vitro inhibitory potential [see Clinical Pharmacology (12.3) ] , concomitant use of WAYRILZ may increase the risk of adverse reactions related to these substrates.

6 ADVERSE REACTIONS The following clinically important adverse reactions are described elsewhere in the labeling: Serious Infections [see Warnings and Precautions (5.1) ] Hepatotoxicity, Including Drug-Induced Liver Injury [ see Warnings and Precautions (5.2) ] Most common adverse reactions (incidence ≥10%) were diarrhea, nausea, headache, abdominal pain, and COVID-19. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Genzyme Corporation at 1-800-633-1610 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 WAYRILZ was evaluated in a randomized, double-blind (DB), placebo-controlled, parallel-group study (LUNA-3), in which 202 adult patients with persistent or chronic ITP received either WAYRILZ (n=133) or placebo (n=69) [see Clinical Studies (14) ] . During the 24-week DB period, the median duration of WAYRILZ exposure was 98 days (range: 22 to 182). The most common adverse reactions (≥10%) were diarrhea, nausea, headache, abdominal pain, and COVID-19. Adverse reactions resulting in discontinuation of WAYRILZ included erythema nodosum, neutropenia, arthralgia, dyspepsia, headache, pain in extremity, abdominal discomfort, diarrhea, nausea, and pneumonia and occurred in 4.5% of patients. Table 1 presents common adverse reactions from the LUNA-3 Study. Table 1: Common Adverse Reactions Adverse reactions that occurred in at least 5% of WAYRILZ treated patients and at least 3% higher than placebo-treated patients. in Patients with ITP During Double-Blind Period of the LUNA-3 Study Adverse Reactions WAYRILZ (N=133) Placebo (N=69) All Grades % Grade 3 or Higher % All Grades % Grade 3 or Higher % Diarrhea 32 0 10 0 Nausea 20 0 6 0 Headache 18 0 7 0 Abdominal Pain Grouped term 14 0 1 0 COVID-19 14 0.8 4 0 Arthralgia 9 0 4 0 Dizziness 8 0 1 0 Nasopharyngitis 7 0 3 0 Vomiting 7 0 1 0 Dyspepsia 5 0 0 0 Cough 5 0 0 0 Specific Adverse Reactions Gastrointestinal Events In the LUNA-3 Study DB period, the most common gastrointestinal (GI) adverse reactions were diarrhea (32%), nausea (20%), and abdominal pain (14%) in the WAYRILZ group. These events were Grade 1 or 2. Of those who experienced GI adverse reactions, 2 patients discontinued due to GI adverse reactions. Recovery or resolution with supportive treatment allowing continuation of WAYRILZ treatment occurred in 91% of patients with diarrhea, 85% with nausea and 79% with abdominal pain. Neutropenia In the LUNA-3 Study DB period, Grade 1 or 2 neutropenia occurred in 11% of patients in the WAYRILZ group.

8.1 Pregnancy Risk Summary Based on animal data, WAYRILZ may cause fetal harm when administered to a pregnant woman. In animal reproduction studies, oral administration of rilzabrutinib to pregnant rats and rabbits during organogenesis at exposures 4- to 10-times the human exposure (based on AUC) at the maximum recommended human dose (MRHD) of 400 mg twice daily did not cause adverse developmental effects. However, adverse visceral and skeletal findings occurred in rat fetuses at a maternally toxic dose at exposures 22-times the human exposure (based on AUC) at the MRHD ( see Data ). There are no available clinical data on the use of WAYRILZ during pregnancy to evaluate for a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Advise pregnant women of the potential risk to a fetus. The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defects, loss, and 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% to 4% and 15% to 20%, respectively. Data Animal Data Rilzabrutinib given to pregnant rats by oral gavage at 50, 150 or 300 mg/kg/day during the period of organogenesis (gestation day 7 to 17) did not cause adverse effects on embryo-fetal development at exposures approximately 10-times the clinical exposure at the maximum recommended human dose (MRHD), based on AUC. Increased incidence of post-implantation loss (25%), delayed ossification associated with a markedly lower (24%) mean fetal weight, and increased skeletal (scoliosis) and visceral malformations (abnormalities of major vessels, urogenital tract, and kidney) occurred in a preliminary study in rats at a maternally toxic dose of 500 mg/kg/day that resulted in exposures 22-times the clinical exposure at the MRHD, based on AUC. Rilzabrutinib given to pregnant rabbits by oral gavage at 10, 30 or 100 mg/kg/day during the period of organogenesis (gestation day 7 to 19) did not cause adverse effects on embryo-fetal development at exposures approximately 4-times the clinical exposures at the MRHD, based on AUC. Renal visceral malformations occurred in a single fetus in a preliminary study in rabbits at 150 mg/kg/day that resulted in exposures 5.6-times the clinical exposure at the MRHD, based on AUC. In a pre- and postnatal developmental toxicity study, pregnant rats were given rilzabrutinib by oral gavage at doses of 50, 150 or 300 mg/kg/day during the periods of gestation, parturition, and lactation (gestation day 7 to lactation day 21). Decreased body weight was observed in pups in the presence of maternal toxicity at 300 mg/kg/day, at exposures approximately 18-times the MRHD based on AUC. There were no effects of rilzabrutinib on the ability of F1 offspring to reproduce or on subsequent F2 development at any dose.