Treatment Perspectives

Atif Hussein, MD

Program Director, Hematology Oncology Fellowship Program

Memorial Cancer Institute

Hollywood, Florida

“Desmoid tumors can pose a significant burden for patients. In my practice, I follow the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) recommendations for initiating treatment when my patients have worsening symptoms, tumor growth documented on imaging, or impairment of functioning or daily activities.

See how desmoid tumors can impact patients’ lives.

Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) for Soft Tissue Sarcoma V.3.2026. © National Comprehensive Cancer Network, Inc. 2026. All rights reserved. Accessed March 13, 2026. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.

Dr Atif Hussein is a paid consultant of SpringWorks Therapeutics, Inc.

Desmoid tumor
management

See how desmoid tumor management is evolving

OGSIVEO clinical
trial results

Examine data from the DeFi study

OGSIVEO dosing

Review dosing and dose modifications for OGSIVEO

OGSIVEO use for
desmoid tumors

Explore insights for your region

Atif Hussein, MD

Program Director, Hematology Oncology Fellowship Program

Memorial Cancer Institute

Hollywood, Florida

Desmoid tumors can pose a significant burden for patients. In my practice, I follow the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) recommendations for initiating treatment when my patients have worsening symptoms, tumor growth documented on imaging, or impairment of functioning or daily activities.

Atif Hussein, MD

Program Director, Hematology Oncology Fellowship Program

Memorial Cancer Institute

Hollywood, Florida

Dr Atif Hussein is a paid consultant of SpringWorks Therapeutics, Inc.

Patients with desmoid tumors may face uncontrollable growth and a high symptom burden^1-4

Even though they do not metastasize, desmoid tumors often interfere with everyday activities and can be life-threatening^1,2

Desmoid tumor characteristics:^2,3,5,6

Rare
Locally aggressive
Unpredictable clinical course
Vital organs can be impacted

Desmoid tumors are associated with a potentially high and multifaceted burden of illness:^4,*

Pain
Disfigurement
Decreased physical function

In focus groups and interviews, patients reported that pain was the most debilitating symptom of desmoid tumors^1,†

In medical literature and clinical practice, desmoid tumors may also be referred to as aggressive fibromatosis, desmoid-type fibromatosis, or deep fibromatosis

Data from a Memorial Sloan Kettering/Desmoid Tumor Research Foundation patient-reported outcome (PRO) validation study that included patients with desmoid tumors (n=31, age range 20-68, 77% female). Patients participated in 60-minute qualitative phone interviews to provide their perspectives on disease symptoms and impact on their quality of life. The majority of the patients in this study were symptomatic (84%). Tumor site and type varied across patients. The concepts discussed during interviews were used to develop a draft patient-reported outcome scale, which was further refined in cognitive interviews of additional patients with desmoid tumors (n=15).⁴

Twenty-seven patients with desmoid tumors were interviewed from the Royal Marsden Hospital in the United Kingdom. Two focus groups and 13 interviews explored health-related quality of life issues and experiences of health care related to their desmoid tumors.¹

Examples of desmoid tumors and potential symptoms

Image adapted from Cohen S, et al. World J Surg Oncol. 2008;6:28. Reused under Creative Commons License 2.0 (https://creativecommons.org/licenses/by/2.0). Image background changed to gray.

Image reproduced from Scaramussa FS, et al. SM J Orthop. 2016;2(3):1036. Reused under Creative Commons License 4.0 (https://creativecommons.org/licenses/by/4.0).

Image adapted from Weschenfelder W, et al. Case Rep Surg. 2015;2015:262654. Reused under Creative Commons License 3.0 (https://creativecommons.org/licenses/by/3.0). False color added.

Image adapted from Styring E, et al. Am J Med Case Rep. 2019;7(3):36-40. Reused under Creative Commons License 4.0 (https://creativecommons.org/licenses/by/4.0). False color added.

Find out more about desmoid tumors

CT, computed tomography; MRI, magnetic resonance imaging.

References: 1. Husson O, Younger E, Dunlop A, et al. Desmoid fibromatosis through the patients’ eyes: time to change the focus and organisation of care? Support Care Cancer. 2019;27(3):965-980. 2. Constantinidou A, Scurr M, Judson I, Litchman C. Clinical presentation of desmoid tumors. In: Litchman C, ed. Desmoid Tumors. Springer; 2012:chap 2. Accessed October 4, 2024. https://www.researchgate.net/publication/226455135 3. Kasper B, Baumgarten C, Garcia J, et al. Desmoid Working Group. An update on the management of sporadic desmoid-type fibromatosis: a European Consensus Initiative between Sarcoma Patients EuroNet (SPAEN) and European Organization for Research and Treatment of Cancer (EORTC)/Soft Tissue and Bone Sarcoma Group (STBSG). Ann Oncol. 2017;28(10):2399-2408. 4. Gounder MM, Maddux L, Paty J, Atkinson TM. Prospective development of a patient-reported outcomes instrument for desmoid tumors or aggressive fibromatosis. Cancer. 2020;126(3):531-539. 5. Penel N, Chibon F, Salas S. Adult desmoid tumors: biology, management and ongoing trials. Curr Opin Oncol. 2017;29(4):268-274. 6. Sbaraglia M, Bellan E, Dei Tos AP. The 2020 WHO Classification of Soft Tissue Tumours: news and perspectives. Pathologica. 2021;113(2):70-84. 7. Cohen S, Ad-El D, Benjaminov O, Gutman H. Post-traumatic soft tissue tumors: case report and review of the literature a propos a post-traumatic paraspinal desmoid tumor. World J Surg Oncol. 2008;6:28. 8. Scaramussa FS, Castro UB. Desmoid tumor in hand: a case report. SM J Orthop. 2016;2(3):1036. 9. Weschenfelder W, Lindner R, Spiegel C, et al. Desmoid tumor of the popliteal fossa during pregnancy. Case Rep Surg. 2015;2015:262654. 10. Styring E, Ahlstrom M, Rissler P, et al. Desmoid fibromatosis in the brachial plexus mimicking an ulnar nerve entrapment. Am J Med Case Rep. 2019;7(3):36-40.

Victoria Rizk, MD

Medical Oncologist, Sarcoma

Tampa General Hospital Cancer Institute

Tampa, Florida

Systemic therapies are recommended as a first-line treatment option for progressive, morbid, or symptomatic desmoid tumors, according to the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®). In my practice, I often look to NCCN Guidelines^® for recommended options when making treatment decisions for my patients with desmoid tumors.

Victoria Rizk, MD

Medical Oncologist, Sarcoma

Tampa General Hospital Cancer Institute

Tampa, Florida

Dr Victoria Rizk is a paid consultant of SpringWorks Therapeutics, Inc.

Desmoid tumor management

Clear margins are often challenging to achieve with surgery and may require extensive resection that can lead to additional pain and functional impairment.^1-4

Surgery is no longer recommended by guidelines as first-line treatment for most clinical situations^5,6

Up to 77% recurrence rates after surgical resection of desmoid tumors^3,7,*
In a retrospective analysis, extremity, chest wall, and intra-abdominal desmoid tumors were associated with higher risk of recurrence than tumors located at other sites⁸
Independent studies have reported desmoid tumor recurrence rates of up to 30% even with clear margins^8-11
Surgical trauma and growth factors released during wound healing may worsen desmoid tumors and promote recurrence^2,3,12
According to the NCCN Clinical Practice Guidelines In Oncology (NCCN Guidelines^®): In general, surgery is not considered a first-line treatment option for desmoid tumors, except in certain situations if agreed upon by a multidisciplinary tumor board⁵

Systemic therapies are recommended as a first-line treatment option for progressive, morbid, or symptomatic desmoid tumors, according to the NCCN Guidelines^® and Desmoid Tumor Working Group (DTWG) Guideline.^5,6,† NCCN Guidelines include the following systemic therapy agents and regimens for the treatment of desmoid tumors (aggressive fibromatosis):^5,‡

Preferred regimens: nirogacestat (NCCN Category 1); sorafenib (NCCN Category 1); methotrexate and vinorelbine; methotrexate and vinblastine; imatinib; liposomal doxorubicin; doxorubicin +/- dacarbazine; pazopanib
Useful in certain circumstances: sulindac or other NSAIDs, including celecoxib (for pain)

Systemic (medical) therapy is recommended as a first-line option across all desmoid tumor locations by the DTWG Guideline.⁶

Based on retrospective, observational data. Factors associated with local recurrence postsurgery include tumor location, age of the patient, tumor size, margin status, and prior recurrence.^8,13

NCCN Guidelines also recommend ablation/embolization and definitive radiation therapy as first-line treatment options for progressive, morbid, or symptomatic desmoid tumors for certain patients.⁵

All recommendations are Category 2A unless otherwise indicated.⁵

NCCN Guidelines and DTWG Guideline recommendations for initiating treatment:^5,6,*

image represents NCCN Guidelines® and DTWG Guideline recommendations for initiating treatment

A course of ongoing observation is an appropriate option even for patients with disease progression, if the patient is minimally symptomatic and the anatomical location of the tumor is not critical.⁵

Learn more about management considerations

CT, computed tomography; MRI, magnetic resonance imaging; NCCN, National Comprehensive Cancer Network^® (NCCN^®).

References: 1. Lewis JJ, Boland PJ, Leung DHY, et al. The enigma of desmoid tumors. Ann Surg. 1999;229(6):866-872. 2. Bonvalot S, Desai A, Coppola S, et al. The treatment of desmoid tumors: a stepwise clinical approach. Ann Oncol. 2012;23 (suppl 10):x158-x166. 3. Skubitz KM. Biology and treatment of aggressive fibromatosis or desmoid tumor. Mayo Clin Proc. 2017;92(6):947-964. 4. Dafford K, Kim D, Nelson A, Kline D. Extraabdominal desmoid tumors. Neurosurg Focus. 2007;22(6):E21. 5. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) for Soft Tissue Sarcoma V.3.2026. © National Comprehensive Cancer Network, Inc. 2026. All rights reserved. Accessed March 13, 2026. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way. 6. Kasper B, Baldini EH, Bonvalot S, et al; Desmoid Tumor Working Group. Current management of desmoid tumors: a review. JAMA Oncol. 2024;10(8):1121-1128. 7. Easter DW, Halasz NA. Recent trends in the management of desmoid tumors. Summary of 19 cases and review of the literature. Ann Surg. 1989;210(6):765-769. 8. Crago AM, Denton B, Salas S, et al. A prognostic nomogram for prediction of recurrence in desmoid fibromatosis. Ann Surg. 2013;258(2):347-353. 9. Peng PD, Hyder O, Mavros MN, et al. Management and recurrence patterns of desmoids tumors: a multi-institutional analysis of 211 patients. Ann Surg Oncol. 2012;19(13):4036-4042. 10. Janssen ML, van Broekhoven DL, Cates JM, et al. Meta-analysis of the influence of surgical margin and adjuvant radiotherapy on local recurrence after resection of sporadic desmoid-type fibromatosis. Br J Surg. 2017;104(4):347-357. 11. Nuyttens JJ, Rust PF, Thomas CR Jr, Turrisi AT 3rd. Surgery versus radiation therapy for patients with aggressive fibromatosis or desmoid tumors: a comparative review of 22 articles. Cancer. 2000;88(7):1517-1523. 12. Cheon SS, Cheah AYL, Turley S, et al. Beta-catenin stabilization dysregulates mesenchymal cell proliferation, motility, and invasiveness and causes aggressive fibromatosis and hyperplastic cutaneous wounds. Proc Natl Acad Sci USA. 2002;99(10):6973-6978. 13. Tsagozis P, Stevenson JD, Grimer R, Carter S. Outcome of surgery for primary and recurrent desmoid-type fibromatosis. A retrospective case series of 174 patients. Ann Med Surg (Lond). 2017;17:14-19.

“ Systemic therapies are recommended as a first-line treatment option for progressive, morbid, or symptomatic desmoid tumors, according to the NCCN...

Victoria Rizk, MD

Medical Oncologist, Sarcoma

Tampa General Hospital Cancer Institute

Tampa, Florida

Atif Hussein, MD

Program Director, Hematology Oncology Fellowship Program

Memorial Cancer Institute

Hollywood, Florida

When choosing systemic therapies for adult patients with desmoid tumors, I rely on data from clinical trials. For me, the results from the DeFi study offer meaningful insight into the efficacy and safety of OGSIVEO in adult patients with progressing desmoid tumors. Long-term data from a post hoc analysis can also be informative.

Atif Hussein, MD

Program Director, Hematology Oncology Fellowship Program

Memorial Cancer Institute

Hollywood, Florida

Dr Atif Hussein is a paid consultant of SpringWorks Therapeutics, Inc.

OGSIVEO is the #1 prescribed systemic therapy for adults with desmoid tumors¹

OGSIVEO clinical trial results

OGSIVEO was evaluated in DeFi—the largest completed*
Phase 3 trial of an FDA-approved therapy in adult patients with desmoid tumors

The primary analysis from the landmark DeFi study was published in The New England Journal of Medicine
DeFi: An international, multicenter, randomized (1:1), double-blind, placebo-controlled, Phase 3 study of OGSIVEO in patients with progressing desmoid tumors not amenable to surgery. Patients had treatment-naïve, refractory, or recurrent disease (N=142).^2,3

All patients had histologically confirmed desmoid tumors that had progressed ≥20% by RECIST v1.1 within 12 months before screening²
If patients had multiple target tumors that were located in the intra- and extra-abdominal locations, they were classified as intra-abdominal²

Patients were randomized to receive 150 mg OGSIVEO or placebo orally twice daily until disease progression or unacceptable toxicity³
Tumor imaging occurred every 3 months³

Primary End Point

Key Secondary Efficacy End Points^§

Primary End Point

Progression-Free Survival: Progression-free survival was defined as the time from randomization until the date of imaging-based or clinical progression or death. Progression-free survival was based on RECIST v1.1 as assessed by blinded independent central review or on clinical progression by the investigator (and confirmed by independent review). Clinical progression required worsening of symptoms resulting in a global deterioration of health status causing the permanent discontinuation from trial treatment and the initiation of emergent treatment (eg, radiotherapy, surgery, or systemic therapy including chemotherapy or tyrosine kinase inhibitors) for desmoid tumors.^2,3

Key Secondary
Efficacy End Points^§

Objective Response Rate: Objective response rate was defined as complete response or partial response according to RECIST v1.1. Assessed by blinded independent central review.^II Partial response was defined as a ≥30% decrease in the sum of the longest diameters of target tumors. Complete response was defined as disappearance of all target and non-target tumors.^2,3
Worst Pain Intensity (change from baseline at Cycle 10^¶): Patient-reported worst pain intensity was assessed daily using item 3 of the Brief Pain Inventory-Short Form (BPI-SF), an 11-point numerical rating scale ranging from 0 (“no pain”) to 10 (“pain as bad as you can imagine”) and averaged over 7 days prior to each visit.^2,3

Completed double-blind, randomized, Phase 3 trial in adult patients with desmoid tumors.^2,3

Imaging-based progression or completion of the primary analysis.²

Eligible patients were given the option to enroll in the open-label extension phase.²

Additional secondary efficacy end points were evaluated in the DeFi study.²

Confirmed by repeat assessments that were performed no less than 4 weeks after the criteria for response were first met.²

Each cycle was 28 days.²

Long-term post hoc analysis of the DeFi study

Patients from both the placebo and OGSIVEO treatment arms were eligible to enroll in the open-label extension phase and receive OGSIVEO 150 mg BID⁴
A post hoc analysis at annual milestones of 1 (n=46), 2 (n=40), 3 (n=33), and 4 (n=15) years for patients who initially received OGSIVEO was conducted^4,*

Data cutoff date was August 13, 2024.⁴

OGSIVEO significantly improved progression-free survival³

Primary End Point:
Patients receiving OGSIVEO achieved a 71% reduction in the risk of disease progression or death vs placebo (HR=0.29; 95% CI: 0.15, 0.55; P<0.001*)³

Median PFS in the OGSIVEO arm was not reached (95% CI: NR, NR) compared with 15.1 months (95% CI: 8.4, NR) in the placebo arm^3,†,‡,§
– PFS events occurred in 12 patients (17%) in the OGSIVEO arm and 37 patients (51%) in the placebo arm³
The Kaplan-Meier median PFS for OGSIVEO could not be estimated due to the low number of events²

P-value was from a one-sided stratified log-rank test with placebo as reference.³

Progression-free survival was defined as the time from randomization until the date of imaging-based or clinical progression or death. Progression-free survival was based on RECIST v1.1 as assessed by blinded independent central review or on clinical progression by the investigator (and confirmed by independent review). Clinical progression required worsening of symptoms resulting in a global deterioration of health status causing the permanent discontinuation from trial treatment and the initiation of emergent treatment (eg, radiotherapy, surgery, or systemic therapy including chemotherapy or tyrosine kinase inhibitors) for desmoid tumors.^2,3

Data cutoff as of April 7, 2022 for PFS.²

Obtained using Kaplan-Meier methodology.³

Double-Blind Phase:

OGSIVEO demonstrated a statistically significant improvement in objective response rate vs placebo

Key Secondary Efficacy End Point:
OGSIVEO treatment resulted in a 41% objective response rate with a 7% complete response rate³

Response definitions were based on RECIST criteria

Objective response rate was defined as complete response or partial response according to RECIST v1.1. Assessed by blinded independent central review^2,3
Partial response was defined as a ≥30% decrease in the sum of the longest diameters of target tumors²
Complete response was defined as a disappearance of all target and non-target tumors²
PR and CR required confirmation by subsequent scans²

Desmoid tumors can have an unpredictable course and may exhibit spontaneous regression.⁵

Obtained using exact method based on binomial distribution.³

P-value was from a two-sided Cochran-Mantel-Haenszel test.³

Objective response rate and tumor size reductions in a long-term analysis

Long-term post hoc analysis of the DeFi study

Objective response rate was 45.7% and complete response rate was 11.4% with OGSIVEO (up to 4-year exposure)^4,6,*

OGSIVEO exposure, median (range): 33.6 (0.3-61.8) months.⁴

Median best percent change in target-tumor size after each year of treatment with OGSIVEO^4,†

Objective response rate was defined as the proportion of patients with a confirmed best response of complete response or partial response assessed by central reader per RECIST v1.1. Results for patients receiving OGSIVEO for up to 4 years is presented.^4,6

Best percent change from baseline was defined as the lowest value by landmark year, calculated as the sum of lesions read by independent central review.⁴

Analysis Limitations

Based on a post hoc analysis in patients initially randomized to OGSIVEO in the DeFi study
In an open-label extension, there is a potential for enrichment of the long-term data in the remaining patient populations since patients who are unable to tolerate or do not respond to the drug often drop out. Extension data are as observed and should be considered descriptive in nature
No conclusions of safety or efficacy should be made based on these results. These data are not included in the OGSIVEO Prescribing Information

Adverse reactions in the DeFi trial

95% of adverse events were Grade 1 or 2 and first onset for most patients occurred within 1 month of starting OGSIVEO²

Adverse reactions (≥15%) in patients with desmoid tumor who received OGSIVEO with a difference between the arms of ≥5% compared to placebo in DeFi³

In the DeFi trial, the median duration of exposure for OGSIVEO was 20.6 months (range: 0.3 to 33.6 months)³
Clinically relevant adverse reactions occurring in <15% of patients receiving OGSIVEO in DeFi included non-melanoma skin cancers, epistaxis, hidradenitis suppurativa, folliculitis, influenza-like illness, and renal tubular disorder.³

Includes multiple related composite terms.³

Investigator assessment of ovarian toxicity included ovarian failure, premature menopause, amenorrhea, and menopause.³

The number of females of reproductive potential in each arm is used as the denominator (OGSIVEO N=36, placebo N=37).³

Long-term post hoc analysis of the DeFi study

After a median duration of 33.6 months (range: 0.3 to 61.8 months) of treatment with OGSIVEO⁴:

The most frequently reported all-grade TEAEs were diarrhea, nausea, fatigue, hypophosphatemia, and headache
Most adverse events were Grade 1 or 2, with the first onset occurring in the first year of treatment for most patients

Analysis Limitations

Based on a post-hoc analysis in patients initially randomized to OGSIVEO in the DeFi study In an open-label extension, there is a potential for enrichment of the long-term data in the remaining patient populations since patients who are unable to tolerate or do not respond to the drug often drop out. Extension data are as observed and should be considered descriptive in nature
No conclusions of safety or efficacy should be made based on these results. These data are not included in the OGSIVEO Prescribing Information

Discover more about OGSIVEO

BID, twice daily; CI, confidence interval; CR, complete response; DB, double-blind; DeFi, Desmoid Fibromatosis; HR, hazard ratio; NR, not reached; OLE, open-label extension; ORR, objective response rate; PFS, progression-free survival; PR, partial response; RECIST, Response Evaluation Criteria in Solid Tumors; TEAE, treatment-emergent adverse event.

References: 1. Data on file. SpringWorks Therapeutics, Inc. February 1, 2024, through July 31, 2024. 2. Gounder M, Ratan R, Alcindor T, et al. Nirogacestat, a gamma-secretase inhibitor for desmoid tumors. N Engl J Med. 2023;388(10):898-912. 3. OGSIVEO. Prescribing Information. SpringWorks Therapeutics, Inc. 4. Ratan R, Kasper B, Alcindor T, et al. Efficacy and safety of long-term continuous nirogacestat treatment in adults with desmoid tumors: results from the DeFi trial. J Clin Oncol. 2025;43(34):3646-3651. 5. Penel N, Chibon F, Salas S. Adult desmoid tumors: biology, management and ongoing trials. Curr Opin Oncol. 2017;29(4):268-274. 6. Data on file. SpringWorks Therapeutics, Inc.

“ When choosing systemic therapies for adult patients with desmoid tumors, I rely on data from clinical trials...

Atif Hussein, MD

Program Director, Hematology Oncology Fellowship Program

Atif Hussein, MD

Program Director, Hematology Oncology Fellowship Program

Victoria Rizk, MD

Medical Oncologist, Sarcoma

Tampa General Hospital Cancer Institute

Tampa, Florida

In addition to efficacy and safety, I also consider the route of administration when evaluating treatment options for my adult patients with desmoid tumors. The recommended dosage of OGSIVEO is 150 mg administered orally twice daily until disease progression or unacceptable toxicity, and many of my patients find the oral dosing convenient.

Victoria Rizk, MD

Medical Oncologist, Sarcoma

Tampa General Hospital Cancer Institute

Tampa, Florida

Dr Victoria Rizk is a paid consultant of SpringWorks Therapeutics, Inc.

OGSIVEO dosing

OGSIVEO offers convenient oral dosing¹

The recommended dosage of OGSIVEO is 150 mg administered orally twice a day until disease progression or unacceptable toxicity

OGSIVEO is available in 150 mg and 100 mg tablets in blister packs

Each blister pack contains a 7-day supply
Four blister packs provide a 28-day supply

Blister packs may help simplify tracking of AM/PM dosing

blister pack image 1 + blister pack image 2

Tablets shown are not actual size.

Tablets shown are not actual size.

Images shown are for illustration only.

OGSIVEO safety information

Warnings and Precautions associated with OGSIVEO include diarrhea, ovarian toxicity, hepatotoxicity, non-melanoma skin cancers, electrolyte abnormalities, and embryo-fetal toxicity¹
The most common adverse reactions (≥15%) in patients receiving OGSIVEO in the DeFi study were diarrhea (84%), ovarian toxicity (75% in the 36 females of reproductive potential), rash (68%), nausea (54%), fatigue (54%), stomatitis (39%), headache (30%), abdominal pain (22%), cough (20%), alopecia (19%), upper respiratory tract infection (17%), and dyspnea (16%)¹
Serious adverse reactions occurred in 20% of patients who received OGSIVEO. Serious adverse reactions occurring in ≥2% of patients were ovarian toxicity (4%)¹

Setting expectations at treatment initiation may help patients stay on track with therapy

Median time to onset of adverse reactions that led to dose reductions or discontinuations in ≥2% of patients receiving OGSIVEO in the DeFi study^1,2*

In patients who received OGSIVEO in the DeFi trial, 42% had dose reductions, 51% had dose interruptions, and 20% permanently discontinued due to an adverse reaction. Adverse reactions that led to dose reduction, interruption, or discontinuation in ≥2% of patients receiving OGSIVEO included: diarrhea, ovarian toxicity, increased ALT/AST, rash, stomatitis, hypophosphatemia, fatigue, folliculitis, nausea, and hidradenitis.¹

In DeFi, ovarian toxicity was identified by investigators in females of reproductive potential based on abnormal reproductive hormone values or presence of perimenopausal symptoms (eg, changes in menstrual cycle regularity), or both.³

These are not all the possible side effects of OGSIVEO. Patients should consult their doctor for medical advice about side effects.

OGSIVEO dose modifications

Recommended dose modifications for adverse reactions¹

recommended dose modifications for AEs chart

Proactive monitoring and management can help support patients receiving OGSIVEO

Adverse reactions that led to dose reduction, interruption, or discontinuation of OGSIVEO included: diarrhea, ovarian toxicity, increased ALT/AST, rash, stomatitis, hypophosphatemia, fatigue, folliculitis, nausea, and hidradenitis.¹

For patients who were dose-reduced to 100 mg BID, no notable differences in PFS or ORR were observed²

Analysis Limitations

Based on a post hoc analysis comparing PFS and ORR in patients treated with OGSIVEO in the DeFi study who dose-reduced versus those who did not
DeFi was not powered to assess statistical differences between subgroups and this analysis should be considered descriptive only
Therefore, the results require cautious interpretation and could represent chance findings
These data are not included in the OGSIVEO Prescribing Information

See more about OGSIVEO

ALT, alanine aminotransferase; AST, aspartate aminotransferase; BID, twice daily; DeFi, Desmoid Fibromatosis; ORR, objective response rate; PFS, progression-free survival; ULN, upper limit of normal.

References: 1. OGSIVEO. Prescribing Information. SpringWorks Therapeutics, Inc. 2. Data on file. SpringWorks Therapeutics, Inc. 3. Loggers ET, Chugh R, Federman N, et al. Onset and resolution of ovarian toxicity with nirogacestat treatment in females with desmoid tumors: updated safety analyses from the DeFi phase 3 study. Cancer. 2024;130(16):2812-2821.

“ In addition to efficacy and safety, I also consider the route of administration when evaluating treatment options for my adult patients...

Victoria Rizk, MD

Medical Oncologist, Sarcoma

Tampa General Hospital Cancer Institute

Tampa, Florida

OGSIVEO Use for Desmoid Tumors

In the Southeast United States, OGSIVEO is the #1 prescribed systemic therapy for adults with desmoid tumors¹

	Total in the United States	Total in the Southeast United States
# of Patients With Desmoid Tumors¹	19,780+*	4320+*
*Based on desmoid tumor-specific ICD-10 code diagnosis (D48.11x) between November 2023 and June 2025.
# of HCPs Treating Patients With Desmoid Tumors With Active Treatment¹	4860+*	1010+*
*Reflects number of HCPs treating patients with a DT-specific ICD-10 diagnosis code with the following active treatment between November 2023 and June 2025: systemic therapy, surgery, and/or cryotherapy.
# of HCPs Prescribing OGSIVEO¹	850+*	190+*
*Reflects number of HCPs treating patients with a DT-specific ICD-10 diagnosis code and who prescribed at least 1 dose of OGSIVEO per unique patient through either SpringWorks specialty pharmacy network or through the SpringWorks CareConnections patient support program. This number does not include prescriptions through medically integrated dispensing pharmacies.

# of Patients With Desmoid Tumors¹
*Based on desmoid tumor-specific ICD-10 code diagnosis (D48.11x) between November 2023 and June 2025.
Total in the United States	Total in the Southeast United States
19,780+*	4320+*
# of HCPs Treating Patients With Desmoid Tumors With Active Treatment¹
*Reflects number of HCPs treating patients with a DT-specific ICD-10 diagnosis code with the following active treatment between November 2023 and June 2025: systemic therapy, surgery, and/or cryotherapy.
Total in the United States	Total in the Southeast United States
4860+*	1010+*
# of HCPs Prescribing OGSIVEO¹
*Reflects number of HCPs treating patients with a DT-specific ICD-10 diagnosis code and who prescribed at least 1 dose of OGSIVEO per unique patient through either SpringWorks specialty pharmacy network or through the SpringWorks CareConnections patient support program. This number does not include prescriptions through medically integrated dispensing pharmacies.
Total in the United States	Total in the Southeast United States
850+*	190+*

HCP, healthcare professional; NCCN, National Comprehensive Cancer Network^® (NCCN^®).

References: 1. Data on file. SpringWorks Therapeutics, Inc. 2. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) for Soft Tissue Sarcoma V.3.2026. © National Comprehensive Cancer Network, Inc. 2026. All rights reserved. Accessed March 13, 2026. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.

OGSIVEO: A systemic therapy for adult patients with progressing desmoid tumors in the Southeast United States

Patients with desmoid tumors may face uncontrollable growth and a high symptom burden^1-4

Examples of desmoid tumors and potential symptoms

Desmoid tumor management

OGSIVEO clinical trial results

OGSIVEO was evaluated in DeFi—the largest completed*
Phase 3 trial of an FDA-approved therapy in adult patients with desmoid tumors

OGSIVEO significantly improved progression-free survival³

OGSIVEO demonstrated a statistically significant improvement in objective response rate vs placebo

Objective response rate and tumor size reductions in a long-term analysis

Adverse reactions in the DeFi trial

OGSIVEO dosing

OGSIVEO offers convenient oral dosing¹

The recommended dosage of OGSIVEO is 150 mg administered orally twice a day until disease progression or unacceptable toxicity

OGSIVEO safety information

Setting expectations at treatment initiation may help patients stay on track with therapy

OGSIVEO dose modifications

Proactive monitoring and management can help support patients receiving OGSIVEO

OGSIVEO Use for Desmoid Tumors

Indication

IMPORTANT SAFETY INFORMATION

Patients with desmoid tumors may face uncontrollable growth and a high symptom burden1-4

Examples of desmoid tumors and potential symptoms

Desmoid tumor management

OGSIVEO clinical trial results

OGSIVEO was evaluated in DeFi—the largest completed* Phase 3 trial of an FDA-approved therapy in adult patients with desmoid tumors

OGSIVEO significantly improved progression-free survival3

OGSIVEO demonstrated a statistically significant improvement in objective response rate vs placebo

Objective response rate and tumor size reductions in a long-term analysis

Adverse reactions in the DeFi trial

OGSIVEO dosing

OGSIVEO offers convenient oral dosing1

The recommended dosage of OGSIVEO is 150 mg administered orally twice a day until disease progression or unacceptable toxicity

OGSIVEO safety information

Setting expectations at treatment initiation may help patients stay on track with therapy

OGSIVEO dose modifications

Proactive monitoring and management can help support patients receiving OGSIVEO

OGSIVEO Use for Desmoid Tumors

Indication

IMPORTANT SAFETY INFORMATION

Patients with desmoid tumors may face uncontrollable growth and a high symptom burden^1-4

OGSIVEO was evaluated in DeFi—the largest completed*
Phase 3 trial of an FDA-approved therapy in adult patients with desmoid tumors

OGSIVEO significantly improved progression-free survival³

OGSIVEO offers convenient oral dosing¹