Long-Term Follow-Up of Desmoid Fibromatosis Treated with PF-03084014, an Oral Gamma Secretase Inhibitor
Abstract
Background
Desmoid fibromatosis is a fibroblastic neoplasm driven by aberrations within the WNT pathway, exhibiting mutations in β-catenin or APC. We review the long-term follow-up of patients in a phase I study treated with an oral gamma secretase inhibitor, PF-03084014.
Methods
PF-03084014 was administered orally at doses ranging from 20 to 330 mg twice daily. Tumor assessments were performed using computed tomography/magnetic resonance imaging (CT/MRI) within 4 weeks of study entry, and every other cycle through cycle 9. After cycle 9, patients were evaluated as clinically indicated.
Results
Seven patients with desmoid fibromatosis were treated between December 2009 and December 2016 at the University of Colorado. Five patients (71.4%, 95% confidence interval [CI] 29.0–96.3%) achieved a partial response (PR), with a mean time to achieving response of 11.9 months (95% CI 2.5–21.4 months). All patients who achieved a PR continue to maintain responses between 47.9 and 73+ months. Four patients stopped treatment yet remain free of progression between 11 and 53+ months. One patient had PFS of 42+ months, with a 17% decrease in the target lesion. A biopsy performed at the end of the study showed decreased tumoral cellularity compared with previous biopsies. Effective treatment doses ranged from 80 to 330 mg administered orally twice daily.
Conclusions
PF-03084014 was effective in treating desmoid tumors, with an objective response rate of 71.4% (95% CI 29.0–96.3%) in this small cohort of patients. PF-03084014 exhibits promising activity, even at relatively low doses (80 mg twice daily), with high tolerability leading to prolonged disease control even after therapy discontinuation.
Publisher URL: https://link.springer.com/article/10.1245/s10434-017-6082-1
DOI: 10.1245/s10434-017-6082-1
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.