A systematic review and network meta-analysis of the efficacy and safety of third-line and over third-line therapy after imatinib and TKI resistance in advanced gastrointestinal stromal tumor

Pimitespib in patients with advanced gastrointestinal stromal tumors in Japan: an expanded access program

BACKGROUND

Pimitespib, an oral heat shock protein 90 inhibitor, significantly prolonged progression-free survival in patients with advanced gastrointestinal stromal tumors (GIST) in CHAPTER-GIST-301 study. This expanded access program was conducted to evaluate the safety and efficacy of pimitespib in Japanese patients with advanced GIST.

METHODS

This multicenter, open-label, single-arm study was conducted in patients (≥ 20 years) with histologically confirmed GIST who had been previously treated with imatinib, sunitinib and regorafenib and had an Eastern Cooperative Oncology Group performance status of 0-1. Patients received pimitespib 160 mg/day for five days, followed by a 2-day rest, in 21-day cycles.

RESULTS

Between February and August 2022, 23 patients were enrolled (median age 59.0 years). Over a median pimitespib treatment duration of 81.0 days, adverse events occurred in 22 patients (95.7%). The most common adverse events were diarrhea (73.9%), nausea (39.1%) and increased blood creatinine (30.4%). Serious adverse events occurred in two patients (tumor hemorrhage and tumor pain); neither was related to pimitespib. One patient had grade 3 diarrhea that was considered treatment-related. Four patients (17.4%) had eye disorders, all of which were grade 1 and treatment-related. The median progression-free survival was 4.2 months (95% confidence interval [CI] 1.9-6.2), the overall response rate was 0% (95% CI 0-16.1) and the disease control rate was 66.7% (95% CI 43.0-85.4).

CONCLUSIONS

Pimitespib was well tolerated and effective in patients with advanced GIST in real-world practice in Japan. No new safety signals were identified.

TRIAL REGISTRATION

jRCT2031210526 registered 1 February 2022.

Case Report: Coexistence of an esophageal schwannoma disguised as a leiomyoma with a gastrointestinal stromal tumor of the gastric fundus

To our knowledge, this is the first reported case of coexisting esophageal schwannoma and gastric fundus gastrointestinal stromal tumor (GIST). This case report describes the diagnostic and treatment process of a patient with esophageal schwannoma who also had a concurrent gastric fundus GIST and was presented to Hebei General Hospital (Hebei, China) in October 2024. The association between the pathogenesis of the two types of submucosal gastrointestinal tumors is unclear, with limited existing evidence in the literature. The esophageal schwannoma was misdiagnosed as a leiomyoma preoperatively, which prompted us to seek new diagnostic modalities to differentiate gastrointestinal submucosal lesions (leiomyomas, GISTs, and schwannomas). Surgical resection is considered the optimal treatment for esophageal schwannoma. The patient underwent a right single-port thoracoscopic esophageal tumor resection and recovered well, subsequently being discharged smoothly from the hospital.

Exploring nanotechnology solutions for improved outcomes in gastrointestinal stromal tumors

Objectives

Gastrointestinal stromal tumors, the most prevalent mesenchymal tumors (80 %) of the gastrointestinal tract, comprise less than 1 % of all gastrointestinal neoplasms and about 5 % of all sarcomas. Despite their rarity, Gastrointestinal stromal tumors present diverse clinical manifestations, anatomic locations, histological subtypes, and prognostic outcomes.

Methods

This scoping review comprehensively explores the epidemiology, clinical characteristics, diagnostic and prognostic modalities, as well as new therapeutic options for Gastrointestinal stromal tumors.

Results

A particular focus is placed on the promising role of bio-nanomaterials as multifunctional agents for drug delivery and 3D tumor microenvironment modeling. Bio-nanomaterials offer promising opportunities for targeted drug delivery, overcoming treatment resistance, and improving therapeutic efficacy.

Conclusion

Despite significant advancements, Gastrointestinal stromal tumors remain a complex clinical entity with ongoing challenges. The integration of nanotechnology into Gastrointestinal stromal tumors management offers the potential to enhance patient outcomes. Future studies should prioritize the development and evaluation of nanomaterial-based therapies in clinical trials to facilitate the translation of laboratory discoveries into real-world clinical applications.

Pathologic diagnosis and molecular features of gastrointestinal stromal tumors: a mini-review

Gastrointestinal stromal tumors (GISTs) arise from the interstitial cells of Cajal, predominantly affecting the stomach and small intestine, with rare occurrences in the duodenum, rectum, and extraintestinal sites. Histologically, GISTs can present as spindle cells, epithelioid cells, or mixed morphologies, with immunohistochemical staining revealing expression of KIT (CD117) and discovered on GIST 1 (DOG1). Approximately 80% of GISTs harbor activating mutations in KIT or platelet derived growth factor receptor α (PDGFRA), which influence their clinical behavior and treatment response. SDH-deficient GISTs, associated with syndromes such as Carney triad and Carney-Stratakis syndrome, represent a distinct subgroup with unique characteristics and management challenges. The standard treatment includes surgery and imatinib for metastatic cases; however, resistance to tyrosine kinase inhibitors remains a significant hurdle, especially in pediatric and wildtype GISTs. This highlights the need for advanced therapeutic strategies and emphasizes the importance of molecular profiling in guiding treatment decisions and improving outcomes for GIST patients.

Evaluation of Systemic Treatment Options for Gastrointestinal Stromal Tumours

Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumours of the gastrointestinal tract. Surgical treatment is recommended for the majority of localised GIST, while systemic treatment is the cornerstone of management for metastatic or unresectable disease. While a three-year regimen of imatinib is the standard of care in the adjuvant setting, there is no precise recommendation for the duration of neoadjuvant treatment, where imatinib is usually given between 4 and 12 months. Continuous treatment with imatinib at a dose of 400 mg once per day is recommended for most patients with unresectable or metastatic GIST in the first line. An exception is represented by patients with tumours harbouring the imatinib-insensitive PDGFRA D842V mutation who would be better treated with avapritinib. Targeted therapies are also recommended in the presence of NTRK rearrangements and BRAF mutations, although limited data are available. While an increase in the dose of imatinib to 800 mg is an option for the second line, sunitinib is usually considered the standard of care. Similar outcomes were reported for ripretinib in patients with tumours harbouring KIT exon 11 mutation, with significantly fewer side effects. Regorafenib and ripretinib are the standards of care in the third and fourth lines, respectively. The recent development of various systemic treatment options allows for a more personalised approach based on the molecular profile of the GIST, patient characteristics, and the profile of medications' adverse events. A multidisciplinary approach is paramount since combining systemic treatment with locoregional treatment options and supportive care is vital for long-term survival.

Emerging Targeted Therapeutic Strategies to Overcome Imatinib Resistance of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common malignant mesenchymal neoplasms of the gastrointestinal tract. The gold standard for the diagnosis of GISTs is morphologic analysis with an immunohistochemical evaluation plus genomic profiling to assess the mutational status of lesions. The majority of GISTs are driven by gain-of-function mutations in the proto-oncogene c-KIT encoding the tyrosine kinase receptor (TKR) known as KIT and in the platelet-derived growth factor-alpha receptor (PDGFRA) genes. Approved therapeutics are orally available as tyrosine kinase inhibitors (TKIs) targeting KIT and/or PDGFRA oncogenic activation. Among these, imatinib has changed the management of patients with unresectable or metastatic GISTs, improving their survival time and delaying disease progression. Nevertheless, the majority of patients with GISTs experience disease progression after 2-3 years of imatinib therapy due to the development of secondary KIT mutations. Today, based on the identification of new driving oncogenic mutations, targeted therapy and precision medicine are regarded as the new frontiers for GISTs. This article reviews the most important mutations in GISTs and highlights their importance in the current understanding and treatment options of GISTs, with an emphasis on the most recent clinical trials.