PDGFRA exon 18 mutation

Using a 73-gene panel, we characterized the molecular characteristics of GISTs and revealed a correlation with their clinical features. Moreover, KIT/PDGFRA-dependent and KIT/PDGFRA-independent mechanisms underlying resistance to imatinib were explored. Overall, our 73-gene panel is sufficient for clinical application in cases of GISTs.

P1, N=278, Recruiting, IDRx Inc. - A GSK Company | Trial primary completion date: Mar 2027 --> Nov 2027

P1, N=269, Recruiting, IDRx Inc. - A GSK Company | Trial completion date: Sep 2026 --> Nov 2027 | Trial primary completion date: Apr 2026 --> Mar 2027

Regorafenib was introduced but failed immediately owing to tumor penetration. Although based on a single case, this report demonstrates a significant metabolic response to pimitespib in PDGFRA-mutant GIST. More cases are required to fully elucidate the efficacy of this therapy against such rare tumors.

One model is characterized by a primary, imatinib-resistant PDGFRA exon 18 p.D842V mutation. Our established platform of well-characterized GIST PDX models, covering the most relevant driver mutations, serves as an excellent tool for preclinical drug testing and tumor biology studies.

P1, N=240, Recruiting, IDRx, Inc. | N=143 --> 240

One model is characterized by an imatinib-resistant PDGFRA exon 18 p.D842V mutation... We are expanding our established platform of well-characterized GIST PDX models, that were proven to serve as an excellent tool for preclinical drug testing and tumor biology studies. The platform is available for cooperative projects with academic and commercial partners.

Transarterial radioembolisation, followed by systemic gemcitabine/cisplatin therapy induced long-term remission...Therefore, due to the progressive hepatocellular component, the patient received atezolizumab/bevacizumab with induced tumor devascularization and AFP normalization. However, after six months, the therapy was changed to FOLFIRI due to progressive disease with lung, liver and lymph node involvement and an increase in CA19-9... In 2020, a 50-year-old male patient presented to our department with weight loss and pain in the right upper abdomen. CT and MRI imaging of the liver showed a 20-cm diffusely growing tumour involving all liver segments and multiple satellite lesions. Histologic examination confirmed the diagnosis of a poorly differentiated cHCC-CCA.

uPARAP is highly expressed in several GIST xenograft models across multiple passages of ex-mouse tumors. Considering its preferential expression in GIST and other mesenchymal tumors and the recycling character of this molecular target, uPARAP may serve as a powerful emerging target for systemic treatment of GIST beyond traditional kinase inhibitors or in combination with the latter. uPARAP positive xenograft models can be used for in vivo evaluation of such anti-uPARAP treatment.

If a patient progresses on imatinib, there are additional FDA-approved treatments (sunitinib, regorafenib, ripretinib), which are not currently available for those patients that progress on avapritinib. Our model has the potential to identify which PDGFRA exon 18 mutant GIST patients would benefit from front-line imatinib therapy, while subsequently identifying those that would require avapritinib treatment. Avapritinib was recently approved for first-line treatment for all PDGFRA exon 18 mutant GIST in the United States. Imatinib has been used clinically for over two decades, and is more cost-effective and has a superior safety and tolerability profile compared to avapritinib.

However, following initiation of first-line imatinib, a tyrosine kinase inhibitor (TKI), nearly all patients will develop resistance within 2 years through the emergence of secondary resistance mutations in KIT, typically in the Adenosine Triphosphate (ATP)-binding site or activation loop of the kinase domain...To target resistance, research efforts are primarily focused on developing next-generation inhibitors of KIT and/or PDGFRA, which can inhibit alternate receptor conformations or unique mutations, and compounds that impact complimentary pathogenic processes or epigenetic events. Here, we review the literature on the medical management of high-risk localized and advanced GIST and provide an update on clinical trial approaches to this disease.

DL models yielded comparable results to the Miettinen classification for relapse-free-survival prediction in localized GIST without adjuvant Imatinib (C-index=0.83 in cross-validation and 0.72 for independent testing)...Additionally, novel histological criteria predictive of patients' outcome and mutations were identified by reviewing the tiles selected by the models. As a proof of concept, our study showed the possibility of implementing DL with digitized WSI and may represent a reproducible way to improve tailoring therapy and precision medicine for patients with GIST.