Efficacy and safety of sunitinib in patients with advanced gastrointestinal stromal tumour after failure of imatinib: a randomised controlled trial

Adjuvant treatment of gastrointestinal stromal tumor: State of the art in 2025

The management of gastrointestinal stromal tumors (GISTs) has been revolutionized by the discovery of their sensitivity to imatinib. Most localized GISTs can be cured by surgery alone. The present overview aims to discuss the results of four recent randomized trials or updates assessing adjuvant imatinib. The duration of adjuvant treatments varied in these 4 trials (1 year versus zero, 2 years versus zero, 3 years versus 1 year and 6 years versus 3 years). All these trials showed that adjuvant imatinib improves disease/relapse-free survival in patients at high-risk of GIST relapse. Nevertheless, only one trial showed an overall survival improvement, in favor of 3-year treatment compared to 1-year treatment. But these randomized trials did not assess KIT or PDGFRA mutational status at study entry. Moreover, the definition of high-risk GIST differed across these trials. So, the patient subset that benefits the most from adjuvant imatinib therapy remains undetermined. The optimal duration of adjuvant imatinib therapy remain unclear.

Navigating Ongoing Challenges in GI Stromal Tumors

GI stromal tumors (GISTs) are mesenchymal neoplasms with variable natural histories, originating in the GI tract, most commonly in the stomach. They are frequently characterized by KIT or platelet-derived growth factor receptor alpha (PDGFRA) oncogenic mutations. Surgical resection remains the cornerstone treatment for localized GISTs. Clinical trials have demonstrated the benefits of adjuvant imatinib in patients selected on the basis of recurrence risk and gene mutations, although the optimal duration of therapy is yet to be established. Some data suggest that longer durations of adjuvant imatinib (>3 years) may provide additional benefit, which is being investigated in ongoing trials. Management of imatinib-related adverse effects is essential during treatment, and longitudinal abdominal imaging is mandatory both during and after adjuvant therapy. Once GISTs are more advanced and unresectable, KIT- and PDGFRA-directed tyrosine kinase inhibitors (TKIs) become the key treatment in most patients with KIT mutation. Several TKIs have regulatory approval for advanced GISTs, but in most patients, resistance to TKIs eventually emerges, mainly from secondary resistance mutations in KIT. Each TKI has different coverage of oncogenic KIT mutations, suggested by preclinical and clinical findings, which has given rationale to an ongoing clinical trial that includes molecular selection as eligibility criteria. Furthermore, novel treatment approaches, from TKI combinations to an antibody-drug conjugate, are being investigated. Despite the significant advance in managing GISTs with KIT mutations, those without KIT or PDGFRA mutation, which consists of 10%-15% of patients with GIST, can be a clinical challenge in the advanced setting. These non-KIT/PDGFRA GISTs could be driven by genomic or epigenomic alterations in SDHx, NF1 mutations, and other genomic alterations. Non-KIT/PDGFRA GISTs are less responsive to currently available TKIs than GISTs driven by KIT/PDGFRA mutations, and each subset of non-KIT/PDGFRA GIST has distinctive biology and clinical features. Therefore, individualized, multidisciplinary, biology-based management and consideration for clinical trial enrollment are critical for non-KIT/PDGRFA GISTs.

Cutting-edge technologies illuminate the neural landscape of cancer: Insights into tumor development

Neurogenesis constitutes a pivotal facet of malignant tumors, wherein cancer and its therapeutic interventions possess the ability to reconfigure the nervous system, establishing a pathologic feedback loop that exacerbates tumor progression. Recent strides in high-resolution imaging, single-cell analysis, multi-omics technologies, and experimental models have opened unprecedented avenues in cancer neuroscience. This comprehensive review summarizes the latest advancements of these emerging technologies in elucidating the biological mechanisms underlying tumor initiation, invasion, metastasis, and the dynamic heterogeneity of the tumor microenvironment(TME), with a specific focus on neuron-glial-tumor interactions in glioblastoma(GBM) and other neurophilic cancers. Moreover, we innovatively propose target screening processes based on sequencing technologies and database frameworks. It rigorously evaluates ongoing clinical trial drugs and efficacy while spotlighting characteristic cells in the central and peripheral TME, consolidating cancer biomarkers pivotal for future targeted therapies and management strategies. By integrating these cutting-edge findings, this review aims to offer fresh insights into tumor-nervous system interactions, establishing a robust foundation for forthcoming clinical advancements.

ESMO-Magnitude of Clinical Benefit Scale version 2.0 (ESMO-MCBS v2.0)

BACKGROUND

The ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated tool to assess the magnitude of clinical benefit from new cancer therapies, with planned updates based upon recognition of new needs and shortcomings. This paper describes the development of ESMO-MCBS v2.0.

METHODOLOGY

The revision process incorporates nine steps: (i) review of critiques and suggestions and identification of problems in the application of ESMO-MCBS v1.1; (ii) identification of shortcomings for revision in the upcoming version; (iii) drafting solutions addressing identified shortcomings; (iv) field-testing of solutions; (v) preparation of a near-final revised version for peer review for reasonableness by members of the ESMO Faculty and ESMO Guidelines Committee; (vi) amendments based on peer review for reasonableness; (vii) near-final review by members of the ESMO-MCBS Working Group; (viii) final amendments; (ix) final review and approval by members of the ESMO-MCBS Working Group and the ESMO Executive Board.

RESULTS

Seventeen issues for revision or amendment were considered, and 13 amendments were formulated to address identified shortcomings. In the curative setting, studies evaluated based on disease-free survival now credit improved time without treatment or disease even when overall survival is not significantly improved, and studies with small absolute gain in disease-free survival are credited more conservatively. Additionally, acute and persistent toxicity annotations are added. In the non-curative setting, the approach to crediting a difference in the tail of overall survival and progression-free survival curves is more statistically valid, and the toxicity evaluation has been revised. In peer review all amendments were found to be either reasonable or mostly reasonable. The amendments changed the scoring of 85/353 of evaluated studies.

CONCLUSIONS

The amendments incorporated into ESMO-MCBS v2.0 change the scores of 13.6% of evaluated studies (10.5% downgraded, 3.1% upgraded) and add toxicity annotations to 45.5% of the studies in the curative setting, and improve its discriminatory capacity and utility.

Gastrointestinal Stromal Tumor: Current Approaches and Future Directions in the Treatment of Advanced Disease

This review discusses the current and future landscape of advanced gastrointestinal stromal tumor (GIST) treatment. It covers the role of tyrosine kinase inhibitors (TKIs), specifically imatinib, and further treatment options, such as sunitinib, regorafenib, and ripretinib, as well as avapritinib for platelet-derived growth factor receptor alpha D842V mutations. In addition, this review emphasizes individualized treatment strategies within multidisciplinary expert teams, including surgery and other locoregional therapies, together with the importance of mutation-guided approaches, particularly for wild-type GISTs. Finally, it explores the potential of next-generation KIT inhibitors, combination therapies, and other investigational approaches.

Twenty-one-year report from the Danish Health Authority Expert Advisory Panel for review of treatment of 10 000 cancer patients

BACKGROUND

Patients with hard-to-treat or rare cancers and those not responding to standard-of-care (SoC) treatment have unmet needs. Limited access to novel drugs is an increasing additional challenge. In 2003, the Danish government adopted a Health Act to ensure that treatment of patients with life-threatening disease could be reevaluated by independent experts. The Danish Health Authority (DHA) set up an Expert Advisory Panel to provide advice on possibilities for further treatment of patients, including treatment not approved nationally. A few years later, clinical units were established that could offer unestablished treatment to patients by referral from the Panel. The treatment was first reimbursed by the Government and later by regional authorities.

MATERIALS AND METHODS

We present the structure, workflow, and impact of the Health Act for 21 years for patients with cancer. Annual reports from the DHA were the primary data source.

RESULTS

11 034 cases from 9603 cancer patients were evaluated by the Panel from 2003 to 2023, representing a median of 372 unique cases yearly. In 53%, the Panel advised on further treatment in Denmark, and of these, 56% were recommended nationally nonapproved treatment, 21% SoC treatment or workup, and 19% clinical trial participation. In 4.5% of cases, advice was given on treatment abroad. A significant decline in admissions to the Panel from a peak of 1167 patients in 2008 to 3-400 yearly from 2012 to 2017 followed the conversion of nonapproved treatments to SoC practice. A shift in drug reimbursement, independent of Panel advise, reduced the clinical impact and explained the further decline observed in admissions lately to only 51 patients in 2023.

CONCLUSIONS

This unique national scheme provided early access to treatment for patients with no further SoC options and facilitated the introduction of new cancer treatments, initiation of clinical trials, and establishment of trial units in the country. The scheme may be adapted to other countries with a public healthcare system. Results of the current report indicate that impact is dependent on delivering clinical units and reimbursement associated with the recommended treatment.

Influence of fluctuations in fasting blood glucose on left ventricular function in patients with type 2 diabetes mellitus and coronary microcirculation dysfunction: a prospective cohort study

AIMS

To examine the effects of fluctuations in fasting blood glucose (FBG) levels on left ventricular function in patients with T2DM and coronary microcirculation dysfunction (CMD).

METHODS

A total of 290 patients with T2DM who received glucose-lowering therapy during hospitalization and were subsequently followed up for 18 months at the First Affiliated Hospital of Harbin Medical University, were enrolled in this study. 135 were diagnosed with CMD and were assigned to the CMD group, whereas 155 patients without CMD were allocated to the non-CMD group. The fasting blood glucose coefficient of variation (FBG-CV) was calculated for all participants. The CMD group was further stratified into three subgroups based on their FBG-CV values: CMD1 (FBG-CV > 25%), CMD2 (FBG-CV 15% ~ 25%), and CMD3 (FBG-CV < 15%). The left ventricular function, assessed by left ventricular ejection fraction (LVEF) and the E/e' ratio, was compared within each group before and after the follow-up period. This study was registered in the Chinese Clinical Trial Register, ChiCTR-ORC-16009800.

RESULTS

After the end of follow-up, the E/e' ratio in CMD1 was significantly higher than that in CMD2 and CMD3 (14.35 vs 8.57; p < 0.01; 14.35 vs 6.61; p < 0.01), and the E/e' ratio in CMD2 was significantly higher than that in CMD3 (8.57 vs 6.61; p < 0.01). Compared to the baseline measurements, the E/e' ratio in CMD1 showed a significant increase after an average 17.8 months of follow up (14.35 vs 8.44; p < 0.001). We found elevated E/e' ratio was associated with an increased FBG-CV level (odds ratio [OR]: 2.571; 95% CI 1.819-3.634; p < 0.001). In multivariate logistic analysis, course of diabetes (OR:1.062; 1.016-1.11; P = 0.007) and CMD (OR:2.231; 1.303-3.819; P = 0.003), were significantly associated with elevated E/e' ratio, while oral stains drugs (OR = 0.412 95% CI 0.237-0.715; P = 0.002) and insulin injections (OR = 0.536 95% CI 0.311-0.924; P = 0.025) behaved as a protective factor.

CONCLUSIONS

Our study clarified the association between FBG-CV levels and the E/e' ratio in a prospective cohort study. In T2DM patients with CMD, FBG-CV > 25% may adversely affect left ventricular diastolic function, whereas an optimal FBG-CV is considered to be less than 15%.

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.

Selective internal radiation with Y-90 resin microspheres (SIRT) for liver metastases of gastro-intestinal stromal tumors (GIST) resistant to tyrosine kinase inhibitor (TKI) therapy

BACKGROUND

Hepatic metastases of GIST might be the dominant site of progression and resistant to available tyrosine kinase inhibitors (TKIs). Selective internal radiation therapy (SIRT) offers treatment by intratumoral radiation up to 200 Gy. We analyzed the hepatic progression-free survival (H-PFS) in a consecutive patient cohort.

METHODS

Twenty-six patients (median age 57.6 years) with biopsy proven liver metastases of GIST were treated by SIRT. All had RECIST documented tumor progression, and 24/26 patients had up to four lines of pretreatment. Mutational status was 'quadruple wildtype' (q-wt, n = 5), KIT exon 11/9/13 in n = 15/4/1 cases and PDGFRα (n = 1). Median follow-up of this retrospective analysis of a prospectively kept database is 33.6 months.

RESULTS

Median H-PFS was 16 months (range, 4-54+ months, 95% CI 6.5-25.4 months) and OS after SIRT was 28 months (95% CI 17.2-28.7 months). Best H-PFS was observed in patients with 'q-wt' at 25 months (range, 6+-54 months, 95% CI 16.2-33.8 months). The worst outcome was for KIT exon 11 mutations plus secondary mutations with 7 months (range, 4-33 months, 95% CI, 4.2-9.8 months).

CONCLUSIONS

90Y-SIRT is a potent treatment for patients with liver metastases of GIST resistant to TKI therapy. In patients with 'q-wt' GIST, SIRT is an option for first-line use.

Targeting VEGF signaling for tumor microenvironment remodeling and metastasis inhibition: Therapeutic strategies and insights

The tumor microenvironment (TME) plays a pivotal role in cancer progression and metastasis, with vascular endothelial growth factor (VEGF) signaling serving as a key regulator of tumor angiogenesis and immune evasion. VEGF induces abnormal blood vessel formation, promoting tumor growth, immune suppression, and metastasis through epithelialmesenchymal transition (EMT). As a result, VEGF signaling has become a critical therapeutic target in cancer treatment. This review examines the molecular mechanisms driving VEGF-mediated tumor growth and angiogenesis, with a focus on the interaction between tumor and endothelial cells and the dual role of VEGF in fostering vascularization and immune suppression. Current anti-VEGF therapies, including monoclonal antibodies (e.g., bevacizumab) and tyrosine kinase inhibitors (TKIs), have demonstrated efficacy and have received FDA approval for various cancers; however, therapeutic resistance remains a significant challenge. Strategies to overcome resistance, such as novel VEGF inhibitors, vascular normalization approaches, and combination therapies with immune checkpoint inhibitors, have been explored. Additionally, future directions emphasize the need for personalized approaches to improve treatment efficacy and reduce metastasis. A comprehensive understanding of VEGF signaling in the TME may pave the way for more effective cancer therapies.

Potent Anti-Cancer Activity of Benzo[d]Thiazole-Isatin Conjugates: Induces S Phase Arrest and Cell Necrosis in A549 and HepG2 Cells

The search for new molecules in cancer therapeutics is essential for overcoming treatment limitations, targeting evolving cancer characteristics, minimizing side effects, and advancing scientific knowledge. In this context, a series of benzo[d]thiazole-isatin conjugates (6a-6m) has been synthesized successfully in three steps with excellent yields (>90%). The preliminary antiproliferative results demonstrate that these synthetic derivatives are comparable to the well-known tyrosine kinase inhibitor (TKI) sunitinib. Moreover, the evaluation of their cytotoxicity has revealed outstanding activity against various cancer cell lines, including A549, HePG2, MDA-MB-231, and SGC7901. This significant efficacy highlights their potential as effective anti-cancer agents. Mechanism of action (MoA) studies revealed that compound 6g arrests the A549 and HepG2 cells at S phase, and the compound 6g on HepG2 cells results in a large number of cell necroses. Binding affinity of 6g with EGFR and cyclin-dependent kinase 2 (CDK2) kinase gives better results than reference drugs gefitinib and roscovitine, respectively.

Case Report: Neoadjuvant therapy with ripretinib for gastrointestinal stromal tumor: a case report

Neoadjuvant therapy targeting genotype-specific gastrointestinal stromal tumors (GISTs) may be indicated in select cases. While the majority of patients respond to Imatinib with a reduction in tumor size, some exhibit either poor response or resistance, necessitating the exploration of alternative therapeutic strategies. This report describes a high-risk patient facing potential multiorgan resections whose tumor responded poorly after 14 months of Imatinib therapy. After 8 months of transitioning to Ripretinib treatment, there was a 26% reduction in the largest tumor diameter. This improvement allowed better delineation of the tumor from the surrounding tissues, which in turn made it possible to perform an R0 resection while preserving the possibly involved organs. To our knowledge, this is the first case report of Ripretinib as a neoadjuvant therapy for GIST with peripheral organ invasion to achieve complete resection. This case report may present the effectiveness of Ripretinib and introduce a relatively novel approach to clinical treatment.

Designing Macrocyclic Kinase Inhibitors Using Macrocycle Scaffold Hopping with Reinforced Learning (Macro-Hop)

Macrocycles have gained significant attention in drug discovery, with over 70 macrocyclic compounds currently in clinical use. Despite this progress, the effective methods for designing macrocycles remain elusive. In this study, we present Macro-Hop, a reinforced learning framework designed to rapidly and comprehensively explore the macrocycle chemical space. Macro-Hop efficiently generates novel macrocyclic scaffolds that not only align with predefined physicochemical properties but also exhibit 3D structural similarities to a specified reference compound. As a proof of concept, we applied Macro-Hop to design a new series of macrocycle inhibitors targeting PDGFRαD842 V kinase. The representative compound L7 exhibited high potency against PDGFRαD842 V in both biochemical and cellular assays with IC50 values of 23.8 and 2.1 nM, respectively. L7 effectively inhibited clinically relevant secondary mutants PDGFRαD842 V/G680R (IC50 = 64.1 nM) and PDGFRαD842 V/T674I (IC50 = 27.6 nM), highlighting the rapid effectiveness of wet-leb validation with Macro-Hop.

A real-world disproportionality analysis of ripretinib data mining of the public version of FDA adverse event reporting system

Background

Tyrosine kinase inhibitors (TKIs) are the preferred targeted therapy for advanced gastrointestinal stromal tumors (GIST). Ripretinib, the first tyrosine kinase switch control inhibitor, has not yet been extensively studied for long-term safety in large populations. This study evaluates Ripretinib-related adverse events (AEs) in real-world applications by analyzing data from the FDA's Adverse Event Reporting System (FAERS).

Methods

To quantify signals of AEs, we employed several disproportionality analyses: the Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-item Gamma Poisson Shrinker (MGPS).

Results

In the FAERS database, out of 7,064,646 reports, 3,161 were identified as related to Ripretinib AEs, with 438 significant disproportionality in preferred terms. The most common adverse reactions were tiredness, hair loss, nausea, constipation, diarrhea, loss of appetite, palmar-plantar erythrodysesthesia syndrome, and vomiting. These reactions align with the medication instructions and reports from corresponding clinical trials. Notably, the label includes unexpected and significant AEs such as "hepatic neoplasm", "hair texture abnormal", "metastases to liver" and "red blood cell count decreased". The median onset time for Ripretinib-related AEs was 99 days, with an interquartile range of 27-245 days. Most cases (26.74%, n = 165) occurred within the first month of Ripretinib administration.

Conclusion

Our findings align with clinical observations. We identified novel and unexpected AEs signatures of Ripretinib, indicating that prospective clinical studies are necessary to confirm these findings and clarify their implications. These results could provide valuable evidence to guide further safety studies on Ripretinib.

Management of subepithelial esophageal tumors

Subepithelial esophageal tumors (SET) are normally benign intramural esophageal lesions of mesenchymal origin. Although rare, the incidence of SET has increased in recent decades due to the more widespread use of endoscopy and diagnostic imaging. The current review aims to provide an overview of the histopathologic spectrum and the most frequent entities including leiomyoma and gastrointestinal stromal tumor (GIST), diagnostic workup, and multidisciplinary treatment options. Staging for SET should include endoscopy, endoscopic ultrasonography (EUS), and tissue sampling. Current consensus guidelines recommend that SET suggestive of gastrointestinal stromal tumor (GIST) larger than 20 mm or lesions with high-risk stigmata should undergo tissue sampling. Most SET have an excellent long-term outcome, but malignancy may be present in certain subtypes. Asymptomatic SET without high-risk stigmata discovered incidentally usually do not require specific treatment. However, depending on the size and location of the lesion symptoms may occur. Therapeutic interventions range from endoscopic interventional resections to major surgical procedures. Enucleation via minimally invasive or robotic-assisted access remains the standard of care for most SET sub-entities.

Gastrointestinal Stromal Tumors

PURPOSE OF REVIEW

This review aims to outline the current understanding of the molecular drivers and treatment paradigms of gastrointestinal stromal tumors, with a focus on recent developments in treatment in the advanced disease setting.

RECENT FINDINGS

There have been recent advancements in our understanding of the molecular biology of gastrointestinal stromal tumors, including the identification of new genetic drivers and complex resistance mechanisms. We review the most recent findings in these areas, focusing on how new research insights are reshaping treatment strategies. Recent advancements in our understanding of the biology and treatment of GIST are paving the way for more personalized and effective therapeutic options. As knowledge of rare molecular subtypes, resistance mechanisms, and novel genomic techniques grows, new approaches are emerging in an effort to improve patient outcomes.

Identification and multi-omics analysis of essential coding and long non-coding genes in colorectal cancer

Essential genes are indispensable for the survival of cancer cell. CRISPR/Cas9-based pooled genetic screens have distinguished the essential genes and their functions in distinct cellular processes. Nevertheless, the landscape of essential genes at the single cell levels and the effect on the tumor microenvironment (TME) remains limited. Here, we identified 396 essential protein-coding genes (ESPs) by integration of 8 genome-wide CRISPR loss-of-function screen datasets of colorectal cancer (CRC) cell lines and single-cell RNA sequencing (scRNA-seq) data of CRC tissues. Then, 29 essential long non-coding genes (ESLs) were predicted using Hypergeometric Test (HT) and Personalized PageRank (PPR) algorithms based on ESPs and co-expressed network constructed from scRNA-seq. CRISPR/Cas9 knockout experiment verified the effect of several ESPs and ESLs on the survival of CRC cell line. Furthermore, multi-omics features of ESPs and ESLs were illustrated by examining their expression patterns and transcription factor (TF) regulatory network at the single cell level, as well as DNA mutation and DNA methylation events at bulk level. Finally, through integrating multiple intracellular regulatory networks with cell-cell communication network (CCN), we elucidated that CD47 and MIF are regulated by multiple CRC essential genes, and the anti-cancer drugs sunitinib can interfere the expression of them potentially. Our findings provide a comprehensive asset of CRC ESPs and ESLs, sheding light on the mining of potential therapy targets for CRC.

A Review of FDA-Approved Multi-Target Angiogenesis Drugs for Brain Tumor Therapy

Neovascularization is an important process in brain tumor development, invasion and metastasis. Several research studies have indicated that the VEGF signaling target has potential for reducing angiogenesis in brain tumors. However, targeting VEGF signaling has not met the expected efficacy, despite initial enthusiasm. This is partly because tumors cleverly use alternative growth factor pathways, other than VEGF signaling, to restore angiogenesis. Multi-target inhibitors have been developed to inhibit several receptor kinases that play a role in the development of angiogenesis. By simultaneously affecting various receptor kinases, these treatments can potentially obstruct various angiogenic pathways that are involved in brain cancer advancement, often offering a more holistic strategy than treatments focusing on just one kinase. Since 2009, the FDA has approved a number of multi-kinase inhibitors that target angiogenic growth factor receptors (e.g., VEGFR, PDGFR, FGFR, RET, c-KIT, MET, AXL and others) for treatment of malignant diseases, including brain cancer. Here, we present some recent results from the literature regarding the preclinical and clinical effects of these inhibitors on brain tumors.

Characterizing Cardiotoxicity of FDA-Approved Soft Tissue Sarcoma Targeted Therapies and Immune Checkpoint Inhibitors: A Systematic Review

Background: Soft tissue sarcomas (STS) are aggressive cancers that show increasing response to novel targeted-therapies and immune-checkpoint-inhibitors. Despite anecdotal reports of cardiovascular adverse events (AEs) and major adverse cardiovascular events (MACE) potentially hindering their utility, the true cardiotoxic profile of these novel-therapies in STS has been largely understudied. Methods: We assessed the incidence and severity of AEs and MACE of contemporary FDA-approved targeted and immune-based therapies for STS, using data from landmark clinical trials supporting FDA-approval. We also analyzed data from the FDA adverse-event-reporting-system-(FAERS) for FDA-approved STS targeted and immune-based therapies for comparative real-world validation. Results: Overall, 12 clinical trials supporting FDA-approval of STS targeted-therapies and immune-checkpoint-inhibitors, incorporating 1249 patients, were identified. These clinical trials revealed 751 AEs including, hypertension (382, 50.87%), atrial fibrillation (3, 0.40%), myocardial infarction (2, 0.27%), cardiac failure (congestive included) (9, 1.20%), and cardiac failure (heart failure included) (7, 0.93%). Compared to placebo, those treated saw higher MACE (OR: 3.27, p < 0.001). The FAERS data showed 489 reported AEs including hypertension (275, 56.24%), atrial fibrillation (31, 6.34%), myocardial infarction (15, 3.07%), and cardiac failure (congestive included) (30, 6.13%). Programmed death-ligand 1 (PD-L1) inhibitors had the highest probability of AEs (0.65, 1.17), followed by tyrosine kinase inhibitors (0.66, 0.11), tropomyosin receptor kinase inhibitors (0.25, 0.13), mammalian target of rapamycin inhibitors (0.21, 0.09), and enhancer of zeste homologue 2 inhibitors (0.11, 0.06). Proportions were calculated from the samples in clinical trials supporting FDA-approval and FAERS, respectively. Conclusions: In this investigation, contemporary FDA-approved therapies for STS are associated with increased risk of AEs.

Design, Synthesis, and SAR of Covalent KIT and PDGFRA Inhibitors─Exploring Their Potential in Targeting GIST

Gastrointestinal stromal tumors (GIST), driven by KIT and PDGFRA mutations, are the most common mesenchymal tumors of the gastrointestinal tract. Although tyrosine kinase inhibitors (TKIs) have advanced treatment, resistance mutations and off-target toxicity limit their efficacy. This study develops covalent TKIs targeting drug-resistant GIST through structure-based design, synthesis, and biological evaluation. SAR studies provided key insights into mutant KIT and PDGFRA interactions, and the first crystal structure of PDGFRA bound to a covalent inhibitor is reported. These findings highlight the promise of covalent inhibitors for overcoming resistance and advancing safer, more effective therapies for advanced GIST.

SOCS2 inhibits the tumorigenesis of GISTs and increases the sensitivity of GISTs to imatinib by suppression of KIT activation

The suppressors of cytokine signaling 2 (SOCS2) inhibits growth hormone receptor (GHR) signaling by negative feedback in the regulation of metabolism. In this study, we found that GHR upregulates SOCS2 expression, whereas KIT mutations, the key driver mutations of gastrointestinal stromal tumors (GISTs), inhibits SOCS2 expression in GISTs. Furthermore, SOCS2 associated and inhibited the activation of KIT mutations, but not wild-type KIT, in addition to its inhibition of GHR signaling, suggesting that KIT mutations may promote their activation by downregulation of SOCS2 expression. Accordingly, SOCS2 inhibited GIST cell survival and proliferation in vitro. In KITV558A/WT mice, knockout of SOCS2 expression increased the tumorigenesis of GISTs and decreased the life span of the mice. In addition, the presence of SOCS2 increased the inhibition of KIT signaling and GIST cell survival and proliferation by imatinib in vitro, and imatinib treatment further reduced tumor growth in KITV558A/WT mice compared with that in KITV558A/WT/SOCS2-/- mice, indicating the key role of SOCS2 in the sensitivity of GISTs to the targeted therapy. Taken together, our data revealed the key role of SOCS2 in the tumorigenesis of GISTs and the sensitivity of GISTs to the targeted therapy, providing a better basis for the improved treatment strategy.

Patient-derived xenograft models of gastrointestinal stromal tumors provide a ready-to-use platform for translational research

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal malignancy of the gastrointestinal tract. Most GISTs harbor mutations in oncogenes, such as KIT, and are treated with tyrosine kinase inhibitors (TKIs), such as imatinib. Most tumors develop secondary mutations, inducing drug resistance against the available TKIs, requiring novel therapies. We established a GIST patient-derived xenograft (PDX) platform of GIST that can be used for preclinical drug testing. Tumor tissue from consenting GIST patients was transplanted subcutaneously to NMRI nu/nu mice. Once tumor growth was observed, the tumor was re-transplanted to a next generation of mice. Tumors were characterized histopathologically and molecularly at every re-transplantation and compared with the original patient tumor. We transplanted 112 tumor samples from 99 GIST patients, resulting in 12 established and well-characterized GIST models with different mutations and TKI sensitivity. Three models harbor secondary KIT mutations. 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.

Comprehensive review of signaling pathways and therapeutic targets in gastrointestinal cancers

Targeted therapy, the milestone in the development of human medicine, originated in 2004 when the FDA approved the first targeted agent bevacizumab for colorectal cancer treatment. This new development has resulted from drug developers moving beyond traditional chemotherapy, and several trials have popped up in the last two decades with an unprecedented speed. Specifically, EGF/EGFR, VEGF/VEGFR, HGF/c-MET, and Claudin 18.2 therapeutic targets have been developed in recent years. Some targets previously thought to be undruggable are now being newly explored, such as the RAS site. However, the efficacy of targeted therapy is extremely variable, especially with the emergence of new drugs and the innovative use of traditional targets for other tumors in recent years. Accordingly, this review provides an overview of the major signaling pathway mechanisms and recent advances in targeted therapy for gastrointestinal cancers, as well as future perspectives.

Gene therapy for intracranial aneurysms: systemic review

Treatment of intracranial aneurysms is currently limited to invasive surgical and endovascular modalities, and some aneurysms are not treatable with these methods. Identification and targeting of specific molecular pathways involved in the pathogenesis of aneurysms may improve outcomes. Low frequency somatic variants found in cancer related genes have been linked to intracranial aneurysm development. In particular, mutations in the PDGFRB gene lead to constitutively activated ERK and nuclear factor κB signaling pathways, which can be targeted with tyrosine kinase inhibitors. In this review, we describe how low frequency somatic variants in oncogenic and other genes affect the pathogenesis of aneurysm development, with a focus on gene therapy applications, such as endovascular in situ delivery of chemotherapeutics.

Probing structural requirements for thiazole-based mimetics of sunitinib as potent VEGFR-2 inhibitors

Novel thiazole analogs 3a, 3b, 4, 5, 6a-g, 8a, 8b, 9a-c, 10a-d and 11 were designed and synthesized as molecular mimetics of sunitinib. In vitro antitumor activity of the obtained compounds was investigated against HepG2, HCT-116, MCF-7, HeP-2 and HeLa cancer cell lines. The obtained data showed that compounds 3b and 10c are the most potent members toward HepG2, HCT-116, MCF-7 and HeLa cells. Moreover, compounds 3a, 3b, 6g, 8a and 10c were assessed for their in vitro VEGFR-2 inhibitory activity. Results proved that compound 10c exhibited outstanding VEGFR-2 inhibition (IC50 = 0.104 μM) compared to sunitinib. Compound 10c paused the G0-G1 phase of the cell cycle in HCT-116 and MCF-7 cells and the S phase in HeLa cells. Additionally, compound 10c elevated caspase-3/9 levels in HCT-116 and HeLa cells, leading to cancer cell death via apoptosis. Furthermore, compound 10c showed a significant reduction in tumor volume in Swiss albino female mice as an in vivo breast cancer model. Docking results confirmed the tight binding interactions of compound 10c with the VEGFR-2 binding site, with its binding energy surpassing that of sunitinib. In silico PK studies predicted compound 10c to have good oral bioavailability and a good drug score with low human toxicity risks.

Correlation between Efficacy and Cardiovascular Adverse Events in Patients with Advanced Solid Cancer Who Received VEGF Pathway Inhibitors: Hypertension within the First Eight Weeks Is Associated with Favorable Outcomes of Patients Treated with VEGF Pathway Inhibitors

Objective Many vascular endothelial growth factor (VEGF) pathway inhibitors are used in the treatment of patients with various advanced cancers; however, treatments induce cardiovascular adverse events (CVAEs), such as hypertension, heart failure, arrhythmia, arterial or venous embolism, and hemorrhage. Some studies have suggested a correlation between efficacy and CVAEs; however, further evidence is required. This study evaluated real-world data concerning the frequency and degree of CVAEs and possible associations between CVAEs and efficacy in such patients. Methods We analyzed CVAEs observed in 294 patients with advanced cancer who were treated with ramucirumab, regorafenib, pazopanib, sunitinib, or sorafenib. Results CVAEs of any grade and proteinuria within 8 weeks after the initiation of VEGF pathway inhibitors (early) or during the treatment period (total period) were observed in 72-85% and 77-92% of the patients, respectively. The progression-free survival (PFS) of patients with a CVAE of grade ≥1 in the early period was favorable compared with the PFS of those who had no CVAE (median, 4.9 vs. 3.5 months, p=0.016, log-rank test). Furthermore, the PFS of patients with a CVAE grade ≥3 in the early period was favorable compared to that of those with CVAEs of grades 0-2. Taken together, a higher degree of CVAE was correlated with favorable patient outcomes. Conclusion This study revealed the frequency and degree of CVAEs in patients with solid cancers who received VEGF pathway inhibitors in a real-world setting and added evidence regarding the correlation between CVAEs and efficacy of VEGF pathway inhibitors.

Gastrointestinal stromal tumour (GIST): British Sarcoma Group clinical practice guidelines

BACKGROUND

British Sarcoma Group guidelines for the management of GIST were initially informed by those published by the European Society of Clinical Oncology. This update was written by a group of experts to includes a discussion of the highlight improvements in our knowledge of the disease and recent treatment developments. The guidelines include sections on Incidence, Aetiology, Diagnosis, including risk assessment, Treatment and Follow-up.

METHODS

A careful review of the literature was performed to ensure that wherever possible recommendations are supported by the results of clinical trials or substantive retrospective reports. Areas of uncertainty are indicated appropriately.

CONCLUSION

Guidelines represent a consensus view of current best clinical practice. Where appropriate, key recommendations are given and the levels of evidence and strength of recommendation gradings are those used by the European Society for Medical Oncology (ESMO).

Comparative Analysis of Traditional and Pharmacometric-Based Pharmacoeconomic Modeling in the Cost-Utility Evaluation of Sunitinib Therapy

BACKGROUND

Cost-utility analyses (CUAs) increasingly use models to predict long-term outcomes and translate trial data to real-world settings. Model structure uncertainty affects these predictions. This study compares pharmacometric against traditional pharmacoeconomic model evaluations for CUAs of sunitinib in gastrointestinal stromal tumors (GIST).

METHODS

A two-arm trial comparing sunitinib 37.5 mg daily with no treatment was simulated using a pharmacometric-based pharmacoeconomic model framework. Overall, four existing models [time-to-event (TTE) and Markov models] were re-estimated to the survival data and linked to logistic regression models describing the toxicity data [neutropenia, thrombocytopenia, hypertension, fatigue, and hand-foot syndrome (HFS)] to create traditional pharmacoeconomic model frameworks. All five frameworks were used to simulate clinical outcomes and sunitinib treatment costs, including a therapeutic drug monitoring (TDM) scenario.

RESULTS

The pharmacometric model framework predicted that sunitinib treatment costs an additional 142,756 euros per quality adjusted life year (QALY) compared with no treatment, with deviations - 21.2% (discrete Markov), - 15.1% (continuous Markov), + 7.2% (TTE Weibull), and + 39.6% (TTE exponential) from the traditional model frameworks. The pharmacometric framework captured the change in toxicity over treatment cycles (e.g., increased HFS incidence until cycle 4 with a decrease thereafter), a pattern not observed in the pharmacoeconomic frameworks (e.g., stable HFS incidence over all treatment cycles). Furthermore, the pharmacoeconomic frameworks excessively forecasted the percentage of patients encountering subtherapeutic concentrations of sunitinib over the course of time (pharmacoeconomic: 24.6% at cycle 2 to 98.7% at cycle 16, versus pharmacometric: 13.7% at cycle 2 to 34.1% at cycle 16).

CONCLUSIONS

Model structure significantly influences CUA predictions. The pharmacometric-based model framework more closely represented real-world toxicity trends and drug exposure changes. The relevance of these findings depends on the specific question a CUA seeks to address.

Identification of D842V mutation in gastrointestinal stromal tumors based on CT radiomics: a multi-center study

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Recent advent of tyrosine kinase inhibitors (TKIs) has significantly improved the prognosis of GIST patients. However, responses to TKI therapy can vary depending on the specific gene mutation. D842V, which is the most common mutation in platelet-derived growth factor receptor alpha exon 18, shows no response to imatinib and sunitinib. Radiomics features based on venous-phase contrast-enhanced computed tomography (CECT) have shown potential in non-invasive prediction of GIST genotypes. This study sought to determine whether radiomics features could help distinguish GISTs with D842V mutations.

METHODS

A total of 872 pathologically confirmed GIST patients with CECT data available from three independent centers were included and divided into the training cohort ( n = 487 ) and the external validation cohort ( n = 385 ). Clinical features including age, sex, tumor size and location were collected. Radiomics features on the largest axial image of venous-phase CECT were analyzed and a total of two radiomics features were selected after feature selection. Random forest models trained on non-radiomics features only (the non-radiomics model) and on both non-radiomics and radiomics features (the combined model) were compared.

RESULTS

The combined model showed better average precision (0.250 vs. 0.102, p = 0.039) and F1 score (0.253 vs. 0.155, p = 0.012) than the non-radiomics model. There was no significant difference in ROC-AUC (0.728 vs. 0.737, p = 0.836) and geometric mean (0.737 vs. 0.681, p = 0.352).

CONCLUSIONS

This study demonstrated the potential of radiomics features based on venous-phase CECT images to identify D842V mutation in GISTs. Our model may provide an alternative approach to guide TKI therapy for patients inaccessible to sequence variant testing, potentially improving treatment outcomes for GIST patients especially in resource-limited settings.

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.

Prospective evaluation of quantitative response parameter in patients with Gastrointestinal Stroma Tumor undergoing tyrosine kinase inhibitor therapy-Impact on clinical outcome

The purpose of this study was to determine if dual-energy CT (DECT) vital iodine tumor burden (ViTB), a direct assessment of tumor vascularity, allows reliable response assessment in patients with GIST compared to established CT criteria such as RECIST1.1 and modified Choi (mChoi). From 03/2014 to 12/2019, 138 patients (64 years [32-94 years]) with biopsy proven GIST were entered in this prospective, multi-center trial. All patients were treated with tyrosine kinase inhibitors (TKI) and underwent pre-treatment and follow-up DECT examinations for a minimum of 24 months. Response assessment was performed according to RECIST1.1, mChoi, vascular tumor burden (VTB) and DECT ViTB. A change in therapy management could be because of imaging (RECIST1.1 or mChoi) and/or clinical progression. The DECT ViTB criteria had the highest discrimination ability for progression-free survival (PFS) of all criteria in both first line and second line and thereafter treatment, and was significantly superior to RECIST1.1 and mChoi (p < .034). Both, the mChoi and DECT ViTB criteria demonstrated a significantly early median time-to-progression (both delta 2.5 months; both p < .036). Multivariable analysis revealed 6 variables associated with shorter overall survival: secondary mutation (HR = 4.62), polymetastatic disease (HR = 3.02), metastatic second line and thereafter treatment (HR = 2.33), shorter PFS determined by the DECT ViTB criteria (HR = 1.72), multiple organ metastases (HR = 1.51) and lower age (HR = 1.04). DECT ViTB is a reliable response criteria and provides additional value for assessing TKI treatment in GIST patients. A significant superior response discrimination ability for median PFS was observed, including non-responders at first follow-up and patients developing resistance while on therapy.

Overall survival of patients with KIT-mutant metastatic GIST in the era of multiple kinase inhibitor availability

PURPOSE

The prognosis of patients with metastatic GIST and imatinib-sensitive primary mutations has significantly improved. However, limited data are available to inform patients about outcomes across different lines of treatment. This retrospective analysis aims to evaluate patient outcomes at a large German GIST referral center over the past 15 years.

PATIENTS AND METHODS

Overall survival (OS) and progression-free survival (PFS) were analyzed in patients with metastatic GIST, with diagnosis of metastases between 2008 and 2021, when at least three lines of treatment were available in Germany (n = 174).

RESULTS

The median overall survival far exceeds historical data for patients with primary exon 11 and exon 9 mutations (median OS in palliative treatment with imatinib: 7.1 years; median OS in second-line palliative treatment with sunitinib: 2.9 years; median OS in third-line palliative treatment with regorafenib: 1.9 years). Among those patients who received palliative imatinib treatment, no significant difference in median OS survival was observed between those who had received perioperative imatinib for localized disease and those who did not. Furthermore, the location of metastases significantly impacted survival, whereas the time between the initial diagnosis and the diagnosis of metastases had no significant effect on survival.

CONCLUSION

In conclusion, this study provides a novel, real-world reference for survival outcomes in patients with metastatic GIST.

Neoadjuvant sunitinib plus exemestane in post-menopausal women with hormone receptor-positive/HER2-negative early-stage breast cancer (SUT_EXE-08): a phase I/II trial

Neoadjuvant endocrine therapy (NET) for hormone receptor-positive (HR+) breast cancer might be as effective as chemotherapy, with a better toxicity profile. Blocking a crucial process such as angiogenesis with sunitinib may have a synergistic effect with NET. We aimed to assess the efficacy and safety of neoadjuvant sunitinib plus exemestane in early-stage HR+/HER2-negative breast cancer. In this phase I/II study, postmenopausal women with HR+/HER2- stage II-III breast cancer received neoadjuvant exemestane at conventional dose of 25mg plus sunitinib in a 3 + 3 design at 25mg (3/1weeks scheme) or 37.5mg continuous dose, for 6 months. Coprimary endpoints were the recommended dose of sunitinib combined with exemestane and objective response. Secondary endpoints included safety and biomarkers of early response. For 15 months, 18 patients were enrolled, 15 at sunitinib 25mg and 3 at 37.5mg. Median age was 73, 77% of patients had T2 tumors and 67% node-positive disease. The most common grade 2 toxicity was asthenia (44%), as was hypertension (22%) for grade 3. No grade 4-5 were reported. Twelve patients (66%) achieved an objective response. VEGFR-2 levels significantly decreased after one month of treatment. Differential gene expression analysis showed downregulation of ESR1, PGR and NAT1 in post-treatment samples and upregulation of EGFR, MYC, SFRP1, and FOXC1. PAM50 analysis on 83% of patients showed a prevalence of luminal A subtype, both in pre-treatment (63.6%) and post-treatment tumors (54.5%). Sunitinib plus exemestane was associated with substantial yet reversible toxicities, providing safety, efficacy and biological impact insights of combining an antiangiogenic drug with hormone therapy in early-stage breast cancer.Trial registration: Registered with ClinicalTrials.gov, NCT00931450. 02/07/2009.

Intratumoral microbiome promotes liver metastasis and dampens adjuvant imatinib treatment in gastrointestinal stromal tumor

Understanding the determinants of long-term liver metastasis (LM) outcomes in gastrointestinal stromal tumor (GIST) patients is crucial. We established the feature selection model of intratumoral microbiome at the surgery, achieving robust predictive accuracies of 0.953 and 0.897 AUCs in discovery (n = 74) and validation (n = 34) cohorts, respectively. Notably, despite the significant reduction in LM occurrence with adjuvant imatinib (AI) treatment, intratumoral microbiome exerted independently stronger effects on post-operative LM. Employing both 16S and full-length rRNA sequencing, we pinpoint intracellular Shewanella algae as a foremost LM risk factor in both AI- and non-AI-treated patients. Experimental validation confirmed S. algae's intratumoral presence in GIST, along with migration/invasion-promoting effects on GIST cells. Furthermore, S. algae promoted LM and impeded AI treatment in metastatic mouse models. Our findings advocate for incorporating intratumoral microbiome evaluation at surgery, and propose S. algae as a therapeutic target for LM suppression in GIST.

Anti-tumor effect of antibody-drug conjugate targeting cell adhesion molecule 1 on GIST cells representing small intestinal GIST

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the alimentary tract. The prognosis depends on the primary site, and small intestinal GISTs have a worse prognosis than gastric GISTs. Molecularly targeted drugs to inhibit tyrosine kinase activity of KIT were used for unresectable or recurrent GISTs. However, secondary resistance to the drugs is often acquired, and treatments based on other mechanisms are needed. Previously, we reported that cell adhesion molecule 1 (CADM1) was highly expressed in most of small intestinal GISTs but not in most of gastric GISTs. In the present study, we examined whether the antibody-drug conjugate (ADC) with anti-CADM1 antibody and monomethyl auristatin E (anti-CAD-ADC) shows anti-tumor effect on CADM1-expressing human GIST cells. The ADC adhibited in this study was previously used for CADM1-expressing human mesothelioma cells and showed anti-tumor effect for them in vitro. GIST-T1 cell line of gastric origin which scarcely expresses CADM1 and GIST-T1 cells transfected with CADM1 cDNA (GIST-T1-CAD cells) which highly expresses CADM1 and represents small intestinal GIST were used. In vitro, anti-CAD-ADC showed remarkable cytotoxic activity on GIST-T1-CAD cells, but control ADC did not. Both anti-CAD-ADC and control ADC did not show anti-tumor effect on original GIST-T1 cells. When GIST-T1-CAD cells were subcutaneously injected to the nude mice, intravenous administration of anti-CAD-ADC showed inhibitory effect for tumor enlargement. Tumor of GIST-T1 cells grew even after anti-CAD-ADC injection. When GIST-T1-CAD cells were injected into peritoneal cavity of the SCID mice, intraperitoneal administration of anti-CAD-ADC showed reduction of the peritoneal tumor. On the other hand, peritoneal tumor grew after control ADC administration. Tissue and organ damage due to administration of anti-CAD-ADC was not apparent by macroscopic and histological examinations in mice. These results indicate that anti-CAD-ADC could have apparent anti-tumor effect on CADM1-expressing human GIST cells both in in vitro and in vivo mouse models.

Targeting the RAS upstream and downstream signaling pathway for cancer treatment

Cancer often involves the overactivation of RAS/RAF/MEK/ERK (MAPK) and PI3K-Akt-mTOR pathways due to mutations in genes like RAS, RAF, PTEN, and PIK3CA. Various strategies are employed to address the overactivation of these pathways, among which targeted therapy emerges as a promising approach. Directly targeting specific proteins, leads to encouraging results in cancer treatment. For instance, RTK inhibitors such as imatinib and afatinib selectively target these receptors, hindering ligand binding and reducing signaling initiation. These inhibitors have shown potent efficacy against Non-Small Cell Lung Cancer. Other inhibitors, like lonafarnib targeting Farnesyltransferase and GGTI 2418 targeting geranylgeranyl Transferase, disrupt post-translational modifications of proteins. Additionally, inhibition of proteins like SOS, SH2 domain, and Ras demonstrate promising anti-tumor activity both in vivo and in vitro. Targeting downstream components with RAF inhibitors such as vemurafenib, dabrafenib, and sorafenib, along with MEK inhibitors like trametinib and binimetinib, has shown promising outcomes in treating cancers with BRAF-V600E mutations, including myeloma, colorectal, and thyroid cancers. Furthermore, inhibitors of PI3K (e.g., apitolisib, copanlisib), AKT (e.g., ipatasertib, perifosine), and mTOR (e.g., sirolimus, temsirolimus) exhibit promising efficacy against various cancers such as Invasive Breast Cancer, Lymphoma, Neoplasms, and Hematological malignancies. This review offers an overview of small molecule inhibitors targeting specific proteins within the RAS upstream and downstream signaling pathways in cancer.

A disproportionality analysis of sunitinib in the FDA adverse event reporting system (FAERS)

Objective

This study aimed to analyze the FAERS database to identify adverse event associated with sunitinib to offer valuable insights for the judicious utilization of medication in clinical settings.

Methods

Various disproportionality analysis techniques, such as the reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPN), and multi-gamma Poisson shrinkage (MGPS), were employed to analyze adverse drug reaction (ADR) reports pertaining to sunitinib in the FAERS database from its market introduction up to the first quarter of 2023. Subsequently, a secondary screening process was conducted to identify reliable positive signals.

Results

The analysis of sunitinib adverse event signals at the system-organ classification level encompassed 27 organ systems, with gastrointestinal and endocrine disorders emerging as the predominant SOCs. A total of 237 significant adverse events meeting all four algorithms were detected. Notably, this study revealed previously unreported adverse events, including pleural effusion and ascites, while potential adrenal toxicity-related adverse events, highlighted in the drug's specification, were not identified in this analysis. The study examined the relationship between the duration of sunitinib dosing and the onset of adverse events, revealing a median onset of 48 days (IQR, 15-160 days). The findings indicated that a majority of adverse events manifested early in the dosing period, with tumor progression, disease progression, and mortality becoming more prevalent after one year of treatment.

Conclusion

In the clinical utilization of sunitinib, vigilant monitoring of potential adverse reactions is imperative during the initial phase of drug administration. In addition to the documented adverse reactions outlined in the drug specification, healthcare providers should remain attentive to potential adverse reactions such as pleural effusion, ascites, and tumor development.

Fibroblast Growth Factor 2 (FGF2) Activates Vascular Endothelial Growth Factor (VEGF) Signaling in Gastrointestinal Stromal Tumors (GIST): An Autocrine Mechanism Contributing to Imatinib Mesylate (IM) Resistance

We showed previously that the autocrine activation of the FGFR-mediated pathway in GIST lacking secondary KIT mutations was a result of the inhibition of KIT signaling. We show here that the FGF2/FGFR pathway regulates VEGF-A/VEGFR signaling in IM-resistant GIST cells. Indeed, recombinant FGF2 increased the production of VEGF-A by IM-naive and resistant GIST cells. VEGF-A production was also increased in KIT-inhibited GIST, whereas the neutralization of FGF2 by anti-FGF2 mAb attenuated VEGFR signaling. Of note, BGJ 398, pan FGFR inhibitor, effectively and time-dependently inhibited VEGFR signaling in IM-resistant GIST T-1R cells, thereby revealing the regulatory role of the FGFR pathway in VEGFR signaling for this particular GIST cell line. This also resulted in significant synergy between BGJ 398 and VEGFR inhibitors (i.e., sunitinib and regorafenib) by enhancing their pro-apoptotic and anti-proliferative activities. The high potency of the combined use of VEGFR and FGFR inhibitors in IM-resistant GISTs was revealed by the impressive synergy scores observed for regorafenib or sunitinib and BGJ 398. Moreover, FGFR1/2 and VEGFR1/2 were co-localized in IM-resistant GIST T-1R cells, and the direct interaction between the aforementioned RTKs was confirmed by co-immunoprecipitation. In contrast, IM-resistant GIST 430 cells expressed lower basal levels of FGF2 and VEGF-A. Despite the increased expression VEGFR1 and FGFR1/2 in GIST 430 cells, these RTKs were not co-localized and co-immunoprecipitated. Moreover, no synergy between FGFR and VEGFR inhibitors was observed for the IM-resistant GIST 430 cell line. Collectively, the dual targeting of FGFR and VEGFR pathways in IM-resistant GISTs is not limited to the synergistic anti-angiogenic treatment effects. The dual inhibition of FGFR and VEGFR pathways in IM-resistant GISTs potentiates the proapoptotic and anti-proliferative activities of the corresponding RTKi. Mechanistically, the FGF2-induced activation of the FGFR pathway turns on VEGFR signaling via the overproduction of VEGF-A, induces the interaction between FGFR1/2 and VEGFR1, and thereby renders cancer cells highly sensitive to the dual inhibition of the aforementioned RTKs. Thus, our data uncovers the novel mechanism of the cross-talk between the aforementioned RTKs in IM-resistant GISTs lacking secondary KIT mutations and suggests that the dual blockade of FGFR and VEGFR signaling might be an effective treatment strategy for patients with GIST-acquired IM resistance via KIT-independent mechanisms.

The INSIGHT study: a randomized, Phase III study of ripretinib versus sunitinib for advanced gastrointestinal stromal tumor with KIT exon 11 + 17/18 mutations

Somatic KIT activating mutations drive most gastrointestinal stromal tumors (GISTs). Disease progression eventually develops with first-line imatinib, commonly due to KIT secondary mutations, and different kinase inhibitors have various levels of treatment efficacy dependent on specific acquired resistance mutations. Ripretinib is a broad-spectrum switch-control KIT/PDGFRA tyrosine kinase inhibitor for patients with advanced GIST who received prior treatment with three or more kinase inhibitors, including imatinib. Exploratory baseline circulating tumor DNA analysis from the second-line INTRIGUE trial determined that patients with advanced GIST previously treated with imatinib harboring primary KIT exon 11 mutations and secondary resistance mutations restricted to KIT exons 17/18 had greater clinical benefit with ripretinib versus sunitinib. We describe the rationale and design of INSIGHT (NCT05734105), an ongoing Phase III open-label study of ripretinib versus sunitinib in patients with advanced GIST previously treated with imatinib exclusively harboring KIT exon 11 + 17/18 mutations detected by circulating tumor DNA.Clinical Trial Registration: NCT05734105 (ClinicalTrials.gov).

Case report: Male genital system, soft tissue and myocardial metastases in a patient with exon 11-mutated GIST of unknown origin

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract, usually arising in the stomach or in the small bowel. Most GISTs are diagnosed early due to the presence of symptoms (e.g., abdominal discomfort/pain, anemia, etc.); at times, diagnosis could be incidental (e.g., ultrasound or endoscopic examinations performed for other reasons, surgical intervention for a different disease, etc.). Diagnosis occurs when the tumor is already metastatic in 10-20% of cases. The most common metastatic sites are liver, peritoneum, and loco-regional lymph nodes. Here, we present the case of a male patient with an atypical presentation of disease: as a matter of fact, during his oncological history, he developed metastases in unlikely sites, such as penis, scrotum, myocardium, and soft tissues.

Discontinuation versus continuation of imatinib in patients with advanced gastrointestinal stromal tumours (BFR14): exploratory long-term follow-up of an open-label, multicentre, randomised, phase 3 trial

BACKGROUND

The long-term impact of tyrosine kinase inhibitor (TKI) discontinuation on resistance and survival in patients with advanced gastrointestinal stromal tumours (GIST) is unclear. We report the exploratory long-term outcomes of patients with advanced GIST stopping imatinib in the BFR14 trial.

METHODS

BFR14, an open-label, randomised, phase 3 trial, was done in 17 comprehensive cancer centres or hospitals across France. Patients with advanced GIST aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-3, no previous treatment with imatinib, and no previous malignancy were eligible. Patients were treated with oral imatinib 400 mg daily. Patients with a complete or partial response, or stable disease, according to Response Evaluation Criteria in Solid Tumours (1.0) at 1 year, 3 years, and 5 years from the start of treatment were randomly assigned (1:1) to treatment discontinuation until progression (interruption group) or treatment continuation until progression (continuation group). Randomisation was done centrally with computer-generated permuted blocks of two and six patients stratified by participating centre and presence or absence of residual disease on CT scan. The primary endpoint was progression-free survival. Secondary endpoints included time to imatinib resistance and overall survival. Analyses were conducted on an intention-to-treat basis in all randomly assigned patients who were not lost to follow-up. This trial is registered with ClinicalTrial.gov, NCT00367861.

FINDINGS

Between May 12, 2003, and March 16, 2004, after 1 year of imatinib, 32 patients were randomly assigned to the interruption group and 26 to the continuation group. Between June 13, 2005, and May 30, 2007, after 3 years of imatinib, 25 patients were randomly assigned to the interruption group and 25 to the continuation group. Between Nov 9, 2007, and July 12, 2010, after 5 years of imatinib, 14 patients were randomly assigned to the interruption group and 13 to the continuation group. Median follow-up was 235·2 months (IQR 128·8-236·6) after the 1-year randomisation, 200·9 months (190·2-208·4) after the 3-year randomisation, and 164·5 months (134·4-176·4) after the 5-year randomisation. Median progression-free survival in the interruption group versus the continuation group after 1 year of imatinib was 6·1 months (95% CI 2·5-10·1) versus 27·8 months (19·5-37·9; hazard ratio [HR] 0·36 [95% CI 0·20-0·64], log-rank p=0·0003), after 3 years of imatinib was 7·0 months (3·5-11·7) versus 67·0 months (48·8-85·6; 0·15 [0·07-0·32], log-rank p<0·0001), and after 5 years of imatinib was 12·0 months (9·0-16·6) versus not reached (NR; NR-NR; 0·13 [0·03-0·58], log-rank p=0·0016). The median time to imatinib resistance after 1 year of imatinib was 28·7 months (95% CI 18·1-39·1) versus 90·6 months (25·3-156·1; HR 0·93 [95% CI 0·51-1·71], log-rank p=0·82), after 3 years was 66·2 months (43·0-89·6) versus 127·3 months (15·0-239·7; 0·35 [0·17-0·72, log-rank p=0·0028), and after 5 years was 58·6 months (0·0-167·4) versus NR (NR-NR; 0·24 [0·05-1·12], log-rank p=0·049). Median overall survival after 1 year of imatinib was 56·0 months (95% CI 30·3-82·9) versus 105·0 months (20·6-189·6; HR 0·84 [95% CI 0·46-1·54], log-rank p=0·57), after 3 years was 104·0 months (90·7-118·7) versus 134·0 months (89·7-178·3; 0·40 [0·20-0·82], log-rank p=0·0096), and after 5 years was NR (NR-NR) versus 110·4 months (82·7-154·1; 1·28 [0·41-3·99]; log-rank p=0·67), INTERPRETATION: Imatinib interruption in patients with GIST without progressive disease is not recommended. Imatinib interruption in non-progressing patients with GIST was associated with rapid progression, faster resistance to imatinib, and shorter overall survival in the long-term follow-up when compared with imatinib continuation in patients after 3 years and 5 years of imatinib.

FUNDING

Centre Léon Bérard, INCa, CONTICANET, Ligue Contre le Cancer, and Novartis.

Ripretinib for the treatment of advanced, imatinib-resistant gastrointestinal stromal tumors

Discovery of constitutive activation of KIT/PDGFRA tyrosine kinases in gastrointestinal stromal tumors (GISTs) leads to the development of the targeted drug imatinib. However, the inevitable development of imatinib resistance remains a major issue. Ripretinib is a novel targeted drug that inhibits the activities of a broad spectrum of drug-resistant KIT/PDGFRA mutants. It was approved in 2020 and is currently recommended by major international guidelines as the fourth-line and beyond therapy for advanced GISTs. Emerging evidence shows that ripretinib is superior to sunitinib as a second-line treatment for KIT exon 11-mutated GISTs due to its activity against highly heterogeneous frequently occurring secondary mutations. This review summarizes current data on the use of ripretinib to treat advanced imatinib-resistant GISTs. We also propose future research directions to improve the targeted GIST treatment.

Glycolysis in gastrointestinal stromal tumor: a brief overview

Gastrointestinal stromal tumor (GIST) is the most prevalent mesenchymal tumor of the digestive tract. Its growth is primarily influenced by mutations in KIT or PDGFRA. Surgery is the primary treatment option for GIST; however, KIT inhibitors, such as imatinib, are used for inoperable cases. Resistance to imatinib is an upcoming challenge, especially because the effectiveness of alternative drugs is limited. Enhancement of the glycolysis pathway in cancer cells has been identified as a key feature in cancer. This unique metabolic activity has implications on tumor growth, prognosis, and resistance to therapy, even in GIST. Members of the glucose transporter (GLUT) family (particularly GLUT-1) play a significant role in GIST progression and response to treatment. Diagnostic imaging using 18F-fluorodeoxyglucose positron emission tomography/computed tomography, which enables visualization of glucose metabolism, can aid in GIST diagnosis and risk assessment. The interplay between glycolysis and GIST can lead to the development of various therapeutic strategies, especially those involving glycolysis-related molecules, such as hexokinase and lactate dehydrogenase. However, further research is required to understand the full spectrum of glycolysis in GIST and its therapeutic potential. Herein, we present an exhaustive overview and analysis of the role of glycolysis in GIST, especially as a therapeutic target.

Effect and safety of ripretinib in the treatment of advanced gastrointestinal stromal tumor: A systematic review and meta-analysis

BACKGROUND

Imatinib (IMA) has received approval as the primary treatment for gastrointestinal stromal tumors (GIST). Nonetheless, approximately half of the patients with advanced GIST show disease advancement following IMA treatment. Presently, the efficacy of secondary and tertiary medications in addressing various GIST secondary mutations is somewhat restricted. Consequently, there is a significant medical demand for the creation of kinase inhibitors that extensively block secondary drug-resistant mutations in advanced GIST. Ripretinib (RPT) is a new, switch-control tyrosine kinase inhibitors that can suppress different mutations of KIT and PDGFRA via a dual mechanism of action.

AIM

To investigate the literature on RPT to assess an effective, safe, and successful treatment strategy against advanced GIST.

METHODS

The present systematic review and meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase, Cochrane, Web of Science and ClinicalTrials.gov databases were screened from January 1, 2003 to May 1, 2024.

RESULTS

A total of 4 studies were included, with a total of 507 patients enrolled. The objective response rate (ORR) of the RPT-treated advanced GIST was 17% (95%CI: 0.11-0.27), while the disease control rate (DCR) was 66% (95%CI: 0.59-0.73). The overall occurrence of adverse events with varying degrees was 97% (95%CI: 0.93-1), whereas that of grade ≥ 3 adverse reactions was 42% (95%CI: 0.28-0.63). The sensitivity analysis revealed that omitting some studies did not yield statistically notable variances in the aggregate data regarding the ORR, DCR, and the occurrence of adverse events of grade 3 or higher. The publication bias was absent because no significant asymmetry was observed in Begg's funnel plot in all studies.

CONCLUSION

RPT has favorable efficacy profiles in GIST patients, but the adverse reactions are obvious, and patient management needs to be strengthened to achieve better safety and tolerability.

A PDE3A-SLFN12 Molecular Glue Exhibits Significant Antitumor Activity in TKI-Resistant Gastrointestinal Stromal Tumors

PURPOSE

Gastrointestinal stromal tumor (GIST), the most common mesenchymal tumor with KIT or PDGFRA driver mutations, is typically treated with tyrosine kinase inhibitors (TKI). However, resistance to TKIs due to secondary mutations is a common challenge in advanced GISTs. In addition, there are currently no effective therapies for several other molecular subtypes, such as succinate dehydrogenase-deficient GISTs. Therefore, novel therapeutic strategies are needed.

EXPERIMENTAL DESIGN

To address this need, we tested the efficacy of a novel non-TKI compound, OPB-171775, using patient-derived xenograft models of GISTs. In parallel, we sought to elucidate the mechanism of action of the compound.

RESULTS

Our study revealed that OPB-171775 exhibited significant efficacy against GISTs regardless of their KIT mutation status by inducing complex formation between phosphodiesterase 3A (PDE3A) and Schlafen family member 12 (SLFN12), which are highly expressed in GISTs, leading to SLFN12 RNase-mediated cell death. Furthermore, we identified the activation of general control non-derepressible 2 and its downstream response as an effector pathway of SLFN12 in mediating anticancer activity and revealed potential pharmacodynamic markers.

CONCLUSIONS

These findings suggest that OPB-171775, with its significant efficacy, could potentially serve as a novel and effective treatment option for advanced GISTs, particularly those resistant to TKIs.

First Description of the Clinical Activity of Avapritinib in Sporadic Mesenteric Desmoid Tumor

Desmoid tumors (DTs) are rare and locally aggressive with a high rate of local recurrence even with optimal surgical resection. Systemic treatments are often utilized for desmoid cases with high risk of surgical morbidity or for local and symptomatic control of recurrent disease. However, the systemic treatment options for DTs are limited with limited responses. Avapritinib is a tyrosine kinase inhibitor (TKI) approved in 2020 for adults with unresectable or metastatic gastrointestinal (GI) stromal tumors (GISTs) harboring a platelet-derived growth factor receptor alpha (PDGFRA) Exon 18 mutation, including D842V mutations. In this case report, we describe a 55-year-old man with a history of D842V-mutant gastric GIST who presented several years after complete resection of the GIST with an enlarging soft tissue mass in the small intestine. After a nondiagnostic biopsy, the patient was started on avapritinib due to concerns for recurrent D842V-mutant GIST. The tumor had a partial response to treatment by RECIST 1.1 criteria, and the patient underwent surgical resection. The final pathology report revealed a sporadic DT. To our knowledge, this is the first known description of the activity of avapritinib in the treatment of a sporadic mesenteric DT, which is relevant given the limited treatment options for patients with this diagnosis. This clinical finding may be worth exploring in a dedicated clinical trial.

Pan-Canadian consensus recommendations for GIST management in high- and low-throughput centres across Canada

Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours that originate from the interstitial cells of Cajal. GISTs are mainly driven by gain-of-function mutations in receptor tyrosine kinase or platelet-derived growth factor receptor alpha. Surgical resection is the only curative treatment for localized tumours and all currently approved medical GIST treatments are based on orally available tyrosine kinase inhibitors. Recent discoveries in the molecular and clinical features of GISTs have greatly impacted GIST management. Due to the provincially rather than nationally administered Canadian healthcare system, there have been inconsistencies in the treatment of GISTs across the country. Therefore, guidance on the latest knowledge, clinical management and treatment of GIST is needed to standardize the approach to GIST management nationwide. To establish pan-Canadian guidance, provide up-to-date data and harmonize the clinical practice of GIST management in high- and low-throughput centres across Canada; a panel of 20 physicians with extensive clinical experience in GIST management reviewed relevant literature. This included radiologists, pathologists, interventional radiologists, surgeons and medical oncologists across Canada. The structured literature focused on seven key domains: molecular profiling, radiological techniques/reporting, targeted localized therapy, intricacies of systemic treatments, emerging tests, multidisciplinary care and patient advocacy. This literature review, along with clinical expertise and opinion, was used to develop this concise and clinically relevant consensus paper to harmonize the knowledge and clinical practice on GIST management across Canada. The content presented here will help guide healthcare providers, especially in Canada, in terms of approaching and managing GIST.

Efficacy of Trametinib in Neurofibromatosis Type 1-Associated Gastrointestinal Stromal Tumors: A Case Report

Trametinib, an MEK inhibitor, may offer a new therapeutic option for patients with NF1-related GIST.