First desmoid tumor drug

Desmoid tumors are soft tissue neoplasms arising from fascial and muscle-aponeurotic structure. These tumors are locally aggressive and have a high recurrence rate, even after complete resection. We present the case of a female with a giant intrathoracic desmoid tumor. She underwent complete surgical resection with no disease recurrence. Desmoid tumors’ natural history is not well defined and is often enigmatic, making these tumors difficult to manage. Currently, for intrathoracic desmoid tumors, medical treatment is the recommended approach, nevertheless, surgery can be considered in selected patients.

Purpose: To determine to the activity and safety of TGF-β inhibitor, vactosertib in combination with imatinib in patients with desmoid tumors.

Patients and methods: In this investigator-initiated, open-label, multicenter, phase Ib/II trial, patients with desmoid tumors not amendable to locoregional therapies (surgery and/or radiotherapy) or with disease progression following at least one treatment were enrolled. Participants were administered 400 mg imatinib daily in combination with vactosertib (5 days on and 2 days off, twice a day) every 28 days. In phase Ib, the vactosertib dose was set at 100 mg (level -1) and 200 mg (level 1) to determine the recommended phase II dose (RP2D). Phase II assessed the efficacy, with the primary endpoint being progression-free rate (PFR) at 16 weeks.

Results: No dose-limiting toxicities were observed during the phase Ib, therefore RP2D was defined at doses of 400 mg imatinib daily in combination with 200 mg vactosertib. Of the 27 patients evaluated, 7 (25.9%) achieved a confirmed partial response and 19 (70.4%) were stable. The PFR at 16 weeks and 1 year were 96.3% and 81.0%, respectively. The most toxicities were mild to moderate myalgia (n=10, 37%), anemia (n=10, 37%), and nausea (n=9, 33.3%). Common grade 3-4 toxicities included neutropenia (n=6, 22.2%) and anemia (n=5, 18.5%).

Conclusions: Vactosertib and imatinib combination was well-tolerated, with promising clinical activity in patients with progressive, locally advanced desmoid tumors. This is the first study investigating a novel target agent, a TGF-β inhibitor, in this rare and difficult-to-treat desmoid tumor.

Nirogacestat (OGSIVEO™) is an oral, selective, reversible, small molecule γ-secretase inhibitor developed by SpringWorks Therapeutics, Inc. γ-Secretase is a multi-subunit protease complex that cleaves multiple transmembrane protein complexes, including Notch and membrane-bound B-cell maturation antigen (BCMA). Inhibition of γ-secretase may result in growth inhibition of tumour cells overexpressing Notch, and preservation of membrane-bound BCMA may increase target density for BCMA-targeted therapy. In November 2023, nirogacestat was approved in the USA for use in adult patients with progressing desmoid tumours who require systemic treatment. This article summarizes the milestones in the development of nirogacestat leading to this first approval for the systemic treatment of desmoid tumours.

Background: Desmoid tumours (DTs) or deep fibromatosis are benign soft-tissue tumours, sometimes locally aggressive, requiring intervention on some cases. Surgery has been the gold standard, but new less invasive techniques such as percutaneous cryoablation have proved their effectiveness, reducing health resources and complications. The study aimed to compare the total cost of percutaneous cryoablation and conventional surgery for patients with extra-abdominal and/or abdominal wall DTs, candidates for local ablative treatment in Spain.

Methods: A cost-analysis model was developed. An expert panel provided data about resource consumption for the percutaneous cryoablation technique and validated the epidemiology used for target population estimation. Unitary resources cost (€ 2022) derived from local cost databases. A retrospective analysis of 54 surgical cases in 3 Spanish hospitals was performed to estimate the cost of conventional surgery based on the cost of the Diagnosis-Related group (DRG) codes identified on this patient sample, weighted by each DRG proportion. The total cost for each alternative included intervention cost and complications cost, considering debridement required in 4.5% of cases with percutaneous cryoablation and minor surgery for surgical site infection in 18.0% for conventional surgery.

Results: The total cost for percutaneous cryoablation (€ 5774.78/patient-year) was lower than the total cost for conventional surgery (€ 6780.98/patient-year), yielding cost savings up to € 80,002 in 1 year for the entire cohort of 80 patients with DTs eligible for intervention estimated in Spain. One-way sensitivity analyses confirmed the results’ robustness.

Conclusion: Percutaneous cryoablation versus conventional surgery would yield cost savings for the management of DT patients in Spain.

Critical relevance statement: This manuscript provides insight into the economic impact derived from the savings related to the use of percutaneous cryoablation for desmoid-type tumours from the perspective of the Spanish National Healthcare System, providing useful information for the health decision-making process.

Key points: • Desmoid tumours are locally aggressive and may require local therapy. • Percutaneous cryoablation procedure is less invasive than the conventional surgery. • Cost comparison shows savings associated to percutaneous cryoablation use.

CTNNB1 mutations play important roles in the development of soft tissue tumors, such as desmoid fibromatosis (DF), sinonasal tract angiofibroma, sinonasal glomangiopericytoma, intranodal palisaded myofibroblastoma, neuromuscular choristoma (NMC), and the recently reported pseudoendocrine sarcoma. Here, we report a unique hybrid soft tissue tumor with classic DF, unusual epithelioid component, and NMC in a 23-year-old female. The classic DF and NMC and the unusual epithelioid component and NMC were locally intermixed and closely related to each other. Immunohistochemically, the DF, unusual epithelioid component, and NMC exhibited nuclear positivity for β-catenin to varying degrees. More critically, all of the above components harbored identical CTNNB1 p.Ser45Pro missense mutations. To the best of our knowledge, this is the only reported CTNNB1 mutation-driven hybrid tumor with DF, unusual epithelioid component, and NMC. The present case further confirmed that CTNNB1-mutational soft tissue tumors are highly heterogeneous, but the morphological spectrum is wide and consecutive.