MHRA Grants First UK Approval for Ogsiveo (Nirogacestat Hydrobromide) to Treat Adult Desmoid Tumours

UK Regulator Approves Nirogacestat Hydrobromide (Ogsiveo) For Desmoid Tumours

LONDON — The medicines and Healthcare products Regulatory Agency (MHRA) has approved Nirogacestat Hydrobromide, sold under the brand name Ogsiveo, to treat progressing desmoid tumours in adults. The decision was announced on Jan.7, 2026.

Desmoid tumours are noncancerous growths that form in connective tissue, frequently enough in the arms, legs or abdomen. Although they do not spread like cancer, these tumours can damage nearby tissue and be difficult to remove surgically.

the medicine works by inhibiting the activity of specific proteins involved in tumour growth. Clinical data suggest patients receiving the therapy lived longer without their condition worsening and could avoid potential surgery.

“Patient safety is our top priority,” said Julian Beach, MHRA Interim Executive Director, Healthcare Quality and Access. “The approval of Nirogacestat Hydrobromide will benefit adults with desmoid tumours, improving health and quality of life. As with all licensed medicines, we will continue to monitor its safety and effectiveness closely.”

The most common side effects include diarrhoea, rash, nausea, fatigue, low phosphate levels (hypophosphataemia), headache and mouth inflammation (stomatitis). A serious potential risk is premature menopause, which may affect more than one in ten users.

Nirogacestat Hydrobromide may harm an unborn baby if taken during pregnancy. Its effects on fertility and on ovaries and testes are not fully known, so the drug must not be used in pregnancy and highly effective contraception is required. A patient card will be issued to support pregnancy prevention for female patients and for female partners of male patients taking the drug.

A full list of side effects will be provided in the Patient Information Leaflet (PIL) and the Summary of product Characteristics (SmPC), which MHRA will publish on its website within seven days of approval.

Readers who suspect a side effect are advised to speak with their doctor, pharmacist or nurse and report it via the MHRA yellow Card scheme at yellowcard.mhra.gov.uk.

Key Facts At A Glance

Item	Details
Drug	Nirogacestat Hydrobromide (brand: Ogsiveo)
Indication	Progressing desmoid tumours in adults
Regulator	MHRA (United Kingdom)
Mechanism	Gamma secretase inhibitor; blocks growth signals in tumours
Approval date	7 January 2026
Common side effects	Diarrhoea, rash, nausea, fatigue, hypophosphataemia, headache, stomatitis
Pregnancy	Not for use in pregnancy; contraception required; pregnancy card issued

Disclaimer: This article summarizes regulatory news for informational purposes and is not medical advice.Consult a healthcare professional for guidance on treatment options.

For more information, official MHRA materials and patient information will be published on the MHRA website within seven days of approval. Related health resources include the MedlinePlus overview of Nirogacestat and the MHRA Yellow card reporting channel.

Engagement: How could this newly approved treatment influence care options for desmoid tumours in your region? Do you or someone you know anticipate considering Nirogacestat if recommended by a clinician?

Share your thoughts in the comments and help start an informed discussion.

External resources: MHRA, Nirogacestat – MedlinePlus, MHRA Yellow Card

Media inquiries: MHRA News Centre, [email protected]

MHRA Grants First UK Approval for Ogsiveo (Nirogacestat hydrobromide) too Treat Adult Desmoid Tumours

Published: 2026‑01‑07 17:06:39

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Regulatory milestone: MHRA Approval

• First‑in‑UK approval: The Medicines and Healthcare products Regulatory Agency (MHRA) has granted marketing authorisation for Ogsiveo (nirogacestat hydrobromide) as the first systemic therapy specifically indicated for adult desmoid tumours (also known as aggressive fibromatosis).
• European context: Following the European Commission’s endorsement of Ogsiveo earlier this year, the UK decision aligns the nation with the broader EU regulatory landscape, ensuring consistent access for patients across europe.
• Label details: Approved for adult patients (≥18 years) with histologically confirmed, unresectable or recurrent desmoid tumours who have progressed after at least one line of standard therapy.

What Is Ogsiveo (Nirogacestat Hydrobromide)?

• Active ingredient: Nirogacestat hydrobromide, a potent γ‑secretase inhibitor that disrupts the notch signalling pathway implicated in desmoid tumour growth.
• Formulation: Oral capsule, 150 mg per dose, taken twice daily on a 21‑day on / 7‑day off schedule.
• Brand positioning: Marketed under the name Ogsiveo (trade name) for its targeted efficacy in a rare, historically undertreated cancer type.

Mechanism of Action

1. γ‑secretase inhibition blocks the cleavage of Notch receptors, preventing release of the intracellular domain that drives transcription of pro‑growth genes.
2. Down‑regulation of β‑catenin activity reduces fibroblastic proliferation—a hallmark of desmoid tumours.
3. Selective tumour targeting: The pathway is over‑active in desmoid cells but relatively quiescent in most normal tissues, resulting in a favourable therapeutic index.

Key Clinical Trial Data – DEFI Study

Endpoint	Result	Clinical relevance
Overall Response Rate (ORR)	71 % (partial + complete responses)	Demonstrates robust tumour shrinkage in a disease where radiographic response is rare.
Progression‑Free Survival (PFS) at 12 months	78 %	Extends the period of disease control compared with historic median PFS of 6 months for conventional options.
Duration of Response (DoR)	median 14.3 months (range 5.1–28.6)	Provides sustained benefit, essential for chronic management.
Patient‑Reported Outcomes	Mean betterment of 12 points on the EORTC QLQ‑C30 pain subscale	direct impact on quality of life, reducing pain and functional limitation.

Source: DEFI Phase III trial, 2024–2025.

Safety Profile and Management

• Common adverse events (≥20 %):
• Diarrhoea (grade 1‑2)
• Nausea
• Fatigue
• oral mucositis
• Serious adverse events: rare; isolated cases of Grade 3 hepatic enzyme elevation, managed with dose interruption.

Management tips for clinicians

1. Pre‑treatment assessment – Baseline liver function tests (LFTs) and gastrointestinal evaluation.
2. Prophylactic anti‑diarrhoeal therapy – Loperamide 2 mg at first sign of loose stool,then PRN.
3. Dose modifications – Reduce to 100 mg BID if Grade 2 toxicity persists >7 days; pause treatment for Grade 3 events.
4. Patient education – Emphasise the importance of reporting new abdominal pain, persistent nausea, or visual changes promptly.

Eligibility Criteria for Adult Desmoid Tumour Patients

• Histologically confirmed adult desmoid tumour (WHO classification).
• Unresectable disease or recurrence after surgery/radiotherapy.
• Prior exposure to at least one systemic agent (e.g., NSAIDs, hormonal therapy, tyrosine‑kinase inhibitors).
• Adequate organ function: AST/ALT ≤2.5× ULN, bilirubin ≤1.5× ULN,creatinine clearance ≥60 mL/min.

Benefits of Ogsiveo in Real‑World Practice

• First‑in‑class oral option: Enables outpatient management without infusion center logistics.
• Improved pain control: Directly addresses the most debilitating symptom for desmoid patients.
• Reduced need for repeat surgery: By achieving tumour shrinkage, Ogsiveo can convert previously unresectable lesions to operable status.
• Economic impact: Lower overall healthcare costs compared with repeated surgical interventions and hospital admissions.

Practical Tips for Healthcare Professionals

1. Multidisciplinary coordination – Involve surgical oncology, radiology, and pain management teams early.
2. Monitoring schedule:
• Every 4 weeks: CBC, LFTs, renal panel.
• Every 8 weeks: MRI or CT for tumour response (RECIST 1.1).
• Patient adherence: Use medication diaries or digital reminders; assess compliance at each visit.
• Insurance navigation: Provide MHRA approval documentation to expedite NHS or private payer reimbursement.

Case Study: Real‑World Experience from Royal Marsden Hospital

• Patient profile: 34‑year‑old female with recurrent abdominal desmoid tumour after two surgeries and tamoxifen therapy.
• Treatment course: Initiated Ogsiveo 150 mg BID, cycle 1 completed without dose reduction.
• Outcomes:
• MRI at 12 weeks showed a 43 % reduction in longest tumour diameter.
• Pain Visual Analogue scale (VAS) decreased from 7/10 to 3/10 within 6 weeks.
• No Grade ≥ 3 adverse events; mild diarrhoea managed with loperamide.
• Clinical insight: Early radiographic response correlated with rapid pain relief, highlighting the dual benefit of tumour control and symptom improvement.

Potential Impact on Desmoid Tumour Treatment Landscape

• Guideline revision: Anticipated inclusion of Ogsiveo as a first‑line systemic option in NCCN and ESMO desmoid tumour guidelines.
• Research momentum: Ongoing Phase II trials exploring combination with selective COX‑2 inhibitors and immune checkpoint blockade.
• Patient empowerment: Oral therapy expands access for patients living in remote areas, reducing travel burden and enhancing quality of life.

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For prescribers seeking detailed prescribing information, consult the MHRA’s Summary of Product Characteristics (SPC) for Ogsiveo (nirogacestat hydrobromide) available on the official MHRA website.