OGSIVEO

Warnings and Precautions ( 5.6 ) 08/2026

1 INDICATIONS AND USAGE OGSIVEO is indicated for adult patients with progressing desmoid tumors who require systemic treatment. OGSIVEO is a gamma secretase inhibitor indicated for adult patients with progressing desmoid tumors who require systemic treatment. ( 1 )

2 DOSAGE AND ADMINISTRATION The recommended dosage is 150 mg orally twice daily until disease progression or unacceptable toxicity. ( 2.1 ) See Full Prescribing Information for dosage modifications due to adverse reactions. ( 2.2 ) 2.1 Recommended Dosage The recommended dosage of OGSIVEO is 150 mg administered orally twice daily until disease progression or unacceptable toxicity. OGSIVEO may be taken with or without food. Instruct patients to swallow OGSIVEO tablets whole and not to break, crush, or chew prior to swallowing. If a patient vomits or misses a dose, instruct the patient to take the next dose at its scheduled time. 2.2 Dos ag e Modifications for Adverse Reactions The recommended dose modifications for OGSIVEO for selected severe adverse reactions are summarized in Table 1 [ see Warnings and Precautions ( 5 ) , Adverse Reactions ( 6 ) ]. For other severe adverse reactions, life-threatening adverse reactions, or persistent intolerable Grade 2 adverse reactions, withhold drug until resolved to Grade ≤ 1 or baseline. Only restart at a dosage of 100 mg twice daily after considering the potential benefit and likelihood of recurrence of the adverse reaction. Permanently discontinue OGSIVEO for recurrence of severe or life-threatening adverse reaction upon rechallenge at the reduced dose. Table 1. Recommended Dose Modifications for Adverse Reactions Adverse Reaction Severity OGSIVEO Dosage Modifications Diarrhea persisting for ≥ 3 days despite maximal medical therapy [ see Warnings and Precautions ( 5.1 ) ] Grades 3 or 4 Withhold OGSIVEO until resolved to Grade ≤ 1 or baseline, then restart at a dosage of 100 mg twice daily. Increased ALT or AST [see Warnings and Precautions ( 5.3 ) ] Grade 2 (≥ 3 to 5 × ULN) Withhold OGSIVEO until ALT, AST, or both are resolved to 5 × ULN) Permanently discontinue. Hypophosphatemia persisting for ≥ 3 days despite maximal replacement therapy [see Warnings and Precautions ( 5.5 ) ] Grades 3 or 4 Withhold OGSIVEO until resolved to Grade ≤ 1 or baseline, then restart at a dosage of 100 mg twice daily. Hypokalemia despite maximal replacement therapy [see Warnings and Precautions ( 5.5 ) ] Grades 3 or 4 Withhold OGSIVEO until resolved to Grade ≤ 1 or baseline, then restart at a dosage of 100 mg twice daily. Anaphylaxis or other severe hypersensitivity reaction [see Warnings and Precautions (5.6) ] Grades 3 or 4 Permanently discontinue.

3 DOSAGE FORMS AND STRENGTHS The 100 mg tablets are round, light orange, film-coated, and debossed with "100" on one face. Each 100 mg tablet contains 100 mg nirogacestat. The 150 mg tablets are oval, yellow orange, film-coated, and debossed with "150" on one face. Each 150 mg tablet contains 150 mg nirogacestat. Tablets: 100 mg, and 150 mg. ( 3 )

4 CONTRAINDICATIONS None. None. ( 4 )

6 ADVERSE REACTIONS The following serious adverse reactions are described elsewhere in the labeling: Diarrhea [ see Warnings and Precautions ( 5.1 )] Ovarian Toxicity [ see Warnings and Precautions ( 5.2 )] Hepatotoxicity [see Warnings and Precautions ( 5.3 )] Non-Melanoma Skin Cancers [see Warnings and Precautions ( 5.4 )] Electrolyte Abnormalities [ see Warnings and Precautions ( 5.5 )] Hypersensitivity Reactions [see Warnings and Precautions (5.6) ] The most common ( > 15 %) adverse reactions are diarrhea, ovarian toxicity, rash, nausea, fatigue, stomatitis, headache, abdominal pain, cough, alopecia, upper respiratory tract infection and dyspnea. ( 6.1 ) The most common laboratory abnormalities (≥15%) are decreased phosphate, increased urine glucose, increased urine protein, increased AST, increased ALT, and decreased potassium. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact SpringWorks Therapeutics Inc. at 1-888-400-7989 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 OGSIVEO was evaluated in 69 patients enrolled in DeFi with progressing desmoid tumor [see Clinical Studies ( 14 ) ]. Patients received OGSIVEO 150 mg orally twice daily or placebo orally twice daily until disease progression or unacceptable toxicity. The median duration of exposure to OGSIVEO was 20.6 months (range: 0.3 to 33.6). Serious adverse reactions occurred in 20% of patients who received OGSIVEO. Serious adverse reactions occurring in ≥ 2% of patients were ovarian toxicity (4%). Permanent discontinuation of OGSIVEO due to an adverse reaction occurred in 20% of patients. Adverse reactions which resulted in permanent discontinuation of OGSIVEO in ≥ 2% of patients were diarrhea, ovarian toxicity, increased ALT, and increased AST. Dosage interruptions of OGSIVEO due to an adverse reaction occurred in 51% of patients. Adverse reactions which required dosage interruption in ≥ 2% of patients included diarrhea, rash, stomatitis, hypophosphatemia, fatigue, folliculitis, nausea, and ovarian toxicity. Dose reductions of OGSIVEO due to an adverse reaction occurred in 42% of patients. Adverse reactions which required dose reductions in ≥ 2% of patients included diarrhea, rash, stomatitis, hypophosphatemia, folliculitis, hidradenitis, and ovarian toxicity. The most common (≥ 15% with a difference between arms of ≥ 5% compared to placebo) adverse reactions that occurred in patients receiving OGSIVEO were diarrhea, ovarian toxicity, rash, nausea, fatigue, stomatitis, headache, abdominal pain, cough, alopecia, upper respiratory tract infection and dyspnea. Table 2 summarizes the adverse reactions that occurred in DeFi. Table 2. Adverse Reactions (≥ 15%) in Patients with Desmoid Tumor Who Received OGSIVEO with a Difference Between Arms of ≥ 5% Compared to Placebo on DeFi Adverse Reaction OGSIVEO (N = 69) Placebo (N = 72) All Grades (%) Grade 3 (%) All Grades (%) Grade 3 (%) Gastrointestinal Diarrhea 84 16 35 1.4 Nausea 54 1.4 39 0 Stomatitis a 39 4 4 0 Abdominal pain a 22 1.4 14 1.4 Reproductive S ystem Ovarian toxicity a , b 75 c 0 0 0 Skin and S ubcutaneous T issue Rash a 68 6 14 0 Alopecia 19 0 1.4 0 General Fatigue a 54 2.9 38 0 Nervous S ystem Headache a 30 0 15 0 Respiratory Cough a 20 0 6 0 Dyspnea 16 0 6 0 Infections Upper respiratory tract 17 0 2.8 0 infection a a Includes multiple related composite terms. b Investigator assessment of ovarian toxicity included ovarian failure, premature menopause, amenorrhea, and menopause c The number of females of reproductive potential in each arm is used as the denominator (OGSIVEO N = 36, Placebo N = 37) Clinically relevant adverse reactions occurring in < 15% of patients receiving OGSIVEO in DeFi included no …

7 DRUG INTERACTIONS Strong or moderate CYP3A inhibitors : Avoid concomitant use. ( 7.1 ) Strong or moderate CYP3A inducers : Avoid concomitant use. ( 7.1 ) Gastric acid reducing agents : Avoid concomitant use with proton pump inhibitors and H2-receptor antagonists. If concomitant use cannot be avoided, OGSIVEO administration can be staggered with antacids. ( 7.1 ) 7.1 Effect s of Other Drugs on OGSIVEO Table 4. Effects of Other Drugs on OGSIVEO Strong or Moderate CYP3A Inhibitors Prevention or Management Avoid concomitant use of OGSIVEO with strong or moderate CYP3A inhibitors including grapefruit products, Seville oranges, and starfruit. Clinical Effect Nirogacestat is a CYP3A substrate. Strong or moderate CYP3A inhibitors increase nirogacestat exposure [see Clinical Pharmacology ( 12.3 ) ], which may increase the risk of OGSIVEO adverse reactions . Strong or Moderate CYP3A Inducers Prevention or Management Avoid concomitant use of OGSIVEO with strong or moderate CYP3A inducers. Clinical Effect Nirogacestat is a CYP3A substrate. Strong or moderate CYP3A inducers decrease serum nirogacestat exposure [ see Clinical Pharmacology ( 12.3 ) ], which may reduce the effectiveness of OGSIVEO. Gastric Acid Reducing Agents Prevention or Management Avoid concomitant use with proton pump inhibitors and H2 blockers . If concomitant use cannot be avoided, OGSIVEO can be staggered with antacids (e.g., administer OGSIVEO 2 hours before or 2 hours after antacid use). Clinical Effect Nirogacestat is poorly soluble at pH ≥ 6. Gastric acid reducing agents may decrease serum nirogacestat exposure [ see Clinical Pharmacology ( 12.3 ) ], which may reduce the effectiveness of OGSIVEO. 7.2 Effects of OGSIVEO on Other Drugs Table 5. Effects of OGSIVEO on Other Drugs Certain CYP3ASubstrates Prevention or Management Avoid concomitant use with CYP3A substrates where minimal concentration changes may lead to serious adverse reactions . Clinical Effect Nirogacestat increases exposure of CYP3A substrates [see Clinical Pharmacology ( 12.3 ) ], which may increase the risk of adverse reactions related to these substrates. Certain CYP2C19 Substrates Prevention or Management Avoid concomitant use with OGSIVEO where decreased concentrations of CYP2C19 substrates may lead to significant decreases in efficacy of the CYP2C19 substrate unless otherwise recommended in the Prescribing Information for the CYP2C19 substrate. Clinical Effect Nirogacestat decreases exposure of CYP2C19 substrates [see Clinical Pharmacology ( 12.3 ) ], which may decrease efficacy of these substrates.

8 USE IN SPECIFIC POPULATIONS Lactation : Advise not to breastfeed. ( 8.2 ) 8.1 Pregnancy Risk Summary Based on findings from animal studies and its mechanism of action, OGSIVEO can cause fetal harm or loss of pregnancy when administered to a pregnant woman [ see C linical Pharmacology ( 12.1 ) ] . Oral administration of nirogacestat to pregnant rats during the period of organogenesis resulted in embryo-fetal toxicity and embryo-fetal death at maternal exposures below the human exposure at the recommended dose of 150 mg twice daily [see Data ] . There are no available data on the use of OGSIVEO in pregnant women. Advise pregnant women of the potential risk to a fetus. 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 Daily oral administration of nirogacestat to pregnant rats during the period of organogenesis resulted in decreased fetal body weights, pre- and post-implantation loss, and fetal subcutis edema at doses ≥ 20 mg/kg/day (approximately 0.85 times the recommended dose of 150 mg twice daily based on area under the curve). 8.2 Lactation Risk Summary There are no data on the presence of nirogacestat or its metabolites in human milk or the effects of nirogacestat on a breastfed child or milk production. Because of the potential for serious adverse reactions in breastfed children, advise women not to breastfeed during treatment with OGSIVEO and for 1 week after the last dose. 8.3 Females and Males of Reproductive Potential OGSIVEO can cause fetal harm when administered to a pregnant woman (see Use in Specific Populations ( 8.1 ) ]. Pregnancy Testing Verify the pregnancy status of females of reproductive potential prior to initiating OGSIVEO [ see Use in Specific Populations ( 8.1 ) ]. Contraception Females Advise females of reproductive potential to use effective contraception during treatment with OGSIVEO and for 1 week after the last dose. OGSIVEO can affect ovarian function and the development of the ovarian follicle and therefore may reduce the effectiveness of hormonal contraceptives. Addition of a barrier method is recommended for females using hormonal contraceptives. Males Advise males with female partners of reproductive potential to use effective contraception during treatment with OGSIVEO and for 1 week after the last dose. Infertility Based on findings in animal studies, OGSIVEO can impair female and male fertility. OGSIVEO has been shown to interfere with folliculogenesis and spermatogenesis in nonclinical studies resulting in changes that included ovarian atrophy [ see Nonclinical Toxicology ( 13.1 ) ]. 8.4 Pediatric Use The safety and effectiveness of OGSIVEO have not been established in pediatric patients. Epiphyseal disorder, manifesting as a widening of the epiphyseal growth plate, has been reported in pediatric patients with open growth plates treated with OGSIVEO. 8.5 Geriatric Use Of the total number of OGSIVEO-treated patients in the DeFi study, 3 (4%) were 65 years of age and older and none were 75 years of age and older. Clinical studies of OGSIVEO did not include sufficient numbers of patients 65 years of age and older to determine whether they respond differently than younger adult patients.

12.1 Mechanism of Action Nirogacestat is a gamma secretase inhibitor that blocks proteolytic activation of the Notch receptor. When dysregulated, Notch can activate pathways that contribute to tumor growth.

11 DESCRIPTION OGSIVEO oral tablets contain nirogacestat (as nirogacestat hydrobromide), a gamma (ɣ) secretase inhibitor. Nirogacestat hydrobromide is chemically known as (S)-2-(((S)-6,8-Difluoro-1,2,3,4-tetrahydronaphthalen-2-yl)amino)-N-(1-(2-methyl-1-(neopentylamino)propan-2-yl)-1H-imidazol-4-yl) pentanamide dihydrobromide. The empirical formula is C 27 H 43 Br 2 F 2 N 5 O and the molecular weight is 651.48 g/mol. Nirogacestat hydrobromide is a white to off white powder with an aqueous solubility of 11.4 mg/mL and a pH of 4.4 in water at 25°C. Nirogacestat dihydrobromide is highly soluble at low pH, however the solubility significantly decreases at pH > 6.0. The molecule has pKa's of 5.77 and 7.13. The structural formula for nirogacestat hydrobromide is: OGSIVEO (nirogacestat) tablets are immediate release (IR), film-coated tablets intended for oral administration. Each 100 mg tablet contains 100 mg nirogacestat as 133.050 mg nirogacestat hydrobromide. OGSIVEO 100 mg tablets are round, biconvex with an approximate diameter of 10 mm. They are film coated, light orange in color, and debossed with "100" on one face and plain on the other face. Each 150 mg tablet contains 150 mg nirogacestat as 199.574 mg nirogacestat hydrobromide. OGSIVEO 150 mg tablets are oval, biconvex with approximate dimensions of 8.5 × 17.5 mm. They are film coated, yellow orange in color, and debossed with "150" on one face and plain on the other face. OGSIVEO tablets contain the following inactive ingredients: lactose monohydrate, magnesium stearate, microcrystalline cellulose, and sodium starch glycolate type A. The tablets are finished with Opadry ® QX orange film coating consisting of the following ingredients: FD&C yellow #6/sunset yellow FCF aluminum lake, glycerol monocaprylocaprate type 1/mono/diglycerides, iron oxide yellow, macrogol (PEG) polyvinyl alcohol graft copolymer, polyvinyl alcohol – partially hydrolyzed, talc, and titanium dioxide. The structural formula for nirogacestat hydrobromide is: OGSIVEO oral tablets contain nirogacestat (as nirogacestat hydrobromide), a gamma (ɣ) secretase inhibitor. Nirogacestat hydrobromide is chemically known as (S)-2-(((S)-6,8-Difluoro-1,2,3,4-tetrahydronaphthalen-2-yl)amino)-N-(1-(2-methyl-1-(neopentylamino)propan-2-yl)-1H-imidazol-4-yl) pentanamide dihydrobromide. The empirical formula is C27H43Br2F2N5O and the molecular weight is 651.48 g/mol. Nirogacestat hydrobromide is a white to off white powder with an aqueous solubility of 11.4 mg/mL and a pH of 4.4 in water at 25C. Nirogacestat dihydrobromide is highly soluble at low pH, however the solubility significantly decreases at pH > 6.0. The molecule has pKa's of 5.77 and 7.13.

10 OVERDOSAGE Due to the high level of protein binding, OGSIVEO is not expected to be dialyzable [see Clinical Pharmacology ( 12.3 )] .

16 HOW SUPPLIED/STORAGE AND HANDLING OGSIVEO (nirogacestat) is supplied as 100 mg and 150 mg tablets. Each 100 mg light orange, film-coated tablet is debossed with a "100" on one face. Each 150 mg yellow orange, film-coated tablet is debossed with a "150" on one face. Strength Description Each carton contains NDC 100 mg Round, light orange, film-coated tablet debossed with "100" on one side. One blister card with 14 tablets 82448-100-14 150 mg Oval, yellow orange, film-coated tablet debossed with "150" on one side. One blister card with 14 tablets 82448-150-14 Store at 20°C to 25°C (68°F to 77°F). Excursions permitted between 15°C to 30°C (59°F to 86°F). See USP Controlled Room Temperature.