Standard versus personalized schedule of regorafenib in metastatic gastrointestinal stromal tumors: a retrospective, multicenter, real-world study

Regorafenib in patients with metastatic colorectal cancer in Spain: from clinical trials to real-world evidence

Aim: To describe the evolution of regorafenib use, since its approval, in patients with previously treated metastatic colorectal cancer (mCRC) in routine clinical practice in Spain.Methods: We extracted patient characteristics, dosing, safety and efficacy data for the Spanish cohorts of the CORRECT and CONSIGN trials, and the real-world CORRELATE study.Results: The Spanish cohorts represented 10.7-13.8% of the global cohorts. Efficacy and safety in the Spanish cohorts reflected findings from the global cohorts, with evidence of a flexible dosing approach being adopted in routine clinical practice.Conclusion: Regorafenib use in patients with mCRC has evolved in the real-world setting, emphasizing the need for further research evaluating dosing patterns that can optimize clinical outcomes in these patients.Clinical trial registration: The CORRECT trial is registered at ClinicalTrials.gov, number NCT01103323; the CONSIGN trial is registered at ClinicalTrials.gov, number NCT01538680; the CORRELATE study is registered at ClinicalTrials.gov, number NCT02042144.

KIT/PDGFRA Variant Allele Frequency as Prognostic Factor in Gastrointestinal Stromal Tumors (GISTs): Results From a Multi-Institutional Cohort Study

BACKGROUND

The patient selection for optimal adjuvant therapy in gastrointestinal stromal tumors (GISTs) is provided by nomogram based on tumor size, mitotic index, tumor location, and tumor rupture. Although mutational status is not currently used to risk assessment, tumor genotype showed a prognostic influence on natural history and tumor relapse. Innovative measures, such as KIT/PDGFRA-mutant-specific variant allele frequency (VAF) levels detection from next-generation sequencing (NGS), may act as a surrogate of tumor burden and correlate with prognosis and overall survival of patients with GIST, helping the choice for adjuvant treatment.

PATIENTS AND METHODS

This was a multicenter, hospital-based, retrospective/prospective cohort study to investigate the prognostic role of KIT or PDGFRA-VAF of GIST in patients with radically resected localized disease. In the current manuscript, we present the results from the retrospective phase of the study.

RESULTS

Two-hundred (200) patients with GIST between 2015 and 2022 afferent to 6 Italian Oncologic Centers in the EURACAN Network were included in the study. The receiver operating characteristic (ROC) curves analysis was used to classify "low" vs. "high" VAF values, further normalized on neoplastic cellularity (nVAF). When RFS between the low and high nVAF groups were compared, patients with GIST with KIT/PDGFRA nVAF > 50% showed less favorable RFS than patients in the group of nVAF ≤ 50% (2-year RFS, 72.6% vs. 93%, respectively; P = .003). The multivariable Cox regression model confirmed these results. In the homogeneous sub-population of intermediate-risk, patients with KIT-mutated GIST, the presence of nVAF >50% was statistically associated with higher disease recurrence.

CONCLUSION

In our study, we demonstrated that higher nVAF levels were independent predictors of GIST prognosis and survival in localized GIST patients with tumors harboring KIT or PDGFRA mutations. In the cohort of intermediate-risk patients, nVAF could be helpful to improve prognostication and the use of adjuvant imatinib.

Case Report: Should Regorafenib be prescribed as a continuous schedule in gastrointestinal stromal tumors? Three case reports on Regorafenib personalized schedule

Introduction

Regorafenib is a tyrosine kinase inhibitor (TKI) approved in metastatic gastrointestinal stromal tumor (GIST), colorectal cancer, and hepatocarcinoma. Anyway, the toxicity profile of Regorafenib standard schedule is associated with poor compliance and a high rate of discontinuation. For this reason, there is a growing need for a Regorafenib personalized schedule emerging from the scientific community.

Objective

The aim of this case series was to describe the experience of our sarcoma referral center with the continuous administration of Regorafenib as an alternative regimen to treat metastatic GIST patients.

Methods

We retrospectively collected clinical, pathological, and radiological data of patients with metastatic GIST treated with daily personalized Regorafenib at a single tertiary referral center from May 2021 to December 2022.

Results

We identified three patients fulfilling the inclusion criteria. The average follow-up since the start of Regorafenib was 19.1 months (12-25 months). All three patients had started a standard third-line Regorafenib schedule according to guidelines. The reasons for switching to a continuous schedule were as follows: exacerbation of symptoms during week-off treatment in the first patient, a serious adverse event (AE) in the second patient, and a combination of both conditions in the third. After switching, none of the patients reported severe AEs, and they improved control of tumor-related symptoms. Two of the patients experienced disease progression after 16 months (9 months of which is continuous schedule) and 12 months (8.1 months of which is continuous schedule) of Regorafenib, respectively; the third patient is still receiving continuous Regorafenib at the time of writing, with a progression-free survival of 25 months (14 months after the modified schedule start).

Conclusion

With a similar efficacy and lower toxicities, a daily, personalized Regorafenib schedule seems to be a promising alternative to the standard regimen for metastatic GIST patients, including the frail ones. Further prospective analyses are needed to confirm the safety and efficacy of such regimen.

Molecular Tailored Therapeutic Options for Advanced Gastrointestinal Stromal Tumors (GISTs): Current Practice and Future Perspectives

Gastrointestinal stromal tumors (GISTs) are one of the most common mesenchymal tumors characterized by different molecular alterations that lead to specific clinical presentations and behaviors. In the last twenty years, thanks to the discovery of these mutations, several new treatment options have emerged. This review provides an extensive overview of GISTs’ molecular pathways and their respective tailored therapeutic strategies. Furthermore, current treatment strategies under investigation and future perspectives are analyzed and discussed.

Neuropsychiatric Adverse Drug Reactions with Tyrosine Kinase Inhibitors in Gastrointestinal Stromal Tumors: An Analysis from the European Spontaneous Adverse Event Reporting System

Tyrosine kinase inhibitors (TKIs) are widely used in gastrointestinal stromal tumors (GISTs). The aim of this study is to evaluate the reporting frequency of neuropsychiatric adverse drug reactions (ADRs) for TKIs through the analysis of European individual case safety reports (ICSRs). All ICSRs collected in EudraVigilance up to 31 December 2021 with one TKI having GISTs as an indication (imatinib (IM), sunitinib (SU), avapritinib (AVA), regorafenib (REG), and ripretinib (RIP)) were included. A disproportionality analysis was performed to assess the frequency of reporting for each TKI compared to all other TKIs. The number of analyzed ICSRs was 8512, of which 57.9% were related to IM. Neuropsychiatric ADRs were reported at least once in 1511 ICSRs (17.8%). A higher reporting probability of neuropsychiatric ADRs was shown for AVA. Most neuropsychiatric ADRs were known, except for a higher frequency of lumbar spinal cord and nerve root disorders (reporting odds ratio, ROR 4.46; confidence interval, CI 95% 1.58–12.54), olfactory nerve disorders (8.02; 2.44–26.33), and hallucinations (22.96; 8.45–62.36) for AVA. The analyses of European ICSRs largely confirmed the safety profiles of TKIs in GISTs, but some ADRs are worthy of discussion. Further studies are needed to increase the knowledge of the neuropsychiatric disorders of newly approved TKIs.

Exploring the Dynamic Crosstalk between the Immune System and Genetics in Gastrointestinal Stromal Tumors

Gastrointestinal Stromal Tumors (GISTs) represent a paradigmatic model of oncogene addiction. Despite the well-known impact of the mutational status on clinical outcomes, we need to expand our knowledge to other factors that influence behavior heterogeneity in GIST patients. A growing body of studies has revealed that the tumor microenvironment (TME), mostly populated by tumor-associated macrophages (TAMs) and lymphocytes (TILs), and stromal differentiation (SD) have a significant impact on prognosis and response to treatment. Interestingly, even though the current knowledge of the role of immune response in this setting is still limited, recent pre-clinical and clinical data have highlighted the relevance of the TME in GISTs, with possible implications for clinical practice in the near future. Moreover, the expression of immune checkpoints, such as PD-L1, PD-1, and CTLA-4, and their relationship to the clinical phenotype in GIST are emerging as potential prognostic biomarkers. Looking forward, these variables related to the underlying tumoral microenvironment in GIST, though limited to still-ongoing trials, might lead to the potential use of immunotherapy, alone or in combination with targeted therapy, in advanced TKI-refractory GISTs. This review aims to deepen understanding of the potential link between mutational status and the immune microenvironment in GIST.

The Role of Regorafenib in the Management of Advanced Gastrointestinal Stromal Tumors: A Systematic Review

Regorafenib, a multi-kinase inhibitor, has been widely used to treat patients with gastrointestinal stromal tumors (GIST) who failed the initial treatment with imatinib and sunitinib. This systematic review aims to demonstrate the efficacy and safety of regorafenib for patients with metastatic and/or unresectable GIST. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to perform this systematic review. We searched PubMed, Science Direct, and Cochrane databases to identify relevant articles based on predefined selection criteria. The implication of the search strategy results in 776 records from all databases. We excluded conference abstracts, discussion articles, case reports, case series, systematic reviews, and other observational non-intervention studies from the study, along with the articles published in languages other than English. After the screening and quality assessment, 10 studies were selected for final review - two randomized controlled trials and eight non-randomized prospective and retrospective review articles of intervention. Regorafenib improved the survival rates of patients after the failure of imatinib and sunitinib treatment, with an acceptable safety profile. Close monitoring of the patients may be needed to detect and manage the grade 4 or higher adverse events.

Efficacy and safety of regorafenib in Japanese patients with advanced gastrointestinal stromal tumors

BACKGROUND

Regorafenib is an oral multi-kinase inhibitor that has been established as third-line treatment for patients after the failure of imatinib and sunitinib. However, since clinical data of regorafenib in the Japanese population are still lacking, the management of regorafenib is mainly based on the clinical experience of each oncologist. The aim of this study was to evaluate the efficacy and safety of regorafenib in a Japanese population.

METHODS

Thirty-three patients treated with regorafenib for metastatic and recurrent gastrointestinal stromal tumors were retrospectively enrolled. This study investigated the anti-tumor effect, including overall survival, progression-free survival, and safety, which was evaluated based on the incidence of adverse events.

RESULTS

The median overall survival of patients treated with regorafenib was 23.8 months and the 1-year overall survival rate was 80.0%, the median progression-free survival was 7.1 months and the 1-year progression-free survival rate was 40.2%. The responses to regorafenib were partial response in 3 cases (9.1%), stable disease in 17 (51.5%), progressive disease in 10 (30.3%), and non-evaluable in 3 (9.1%). The disease control rate was 54.0%. Treatment-related adverse events were reported in all patients, with the most common being hand-foot syndrome (72.7%), followed by liver damage (36.4%) and diarrhea (27.3%), and six patients (20.0%) were discontinued due to adverse events.

CONCLUSION

This is the first report of Japanese patients with gastrointestinal stromal tumors treated with regorafenib. Regorafenib showed efficacy and a manageable safety profile in Japanese patients with advanced gastrointestinal stromal tumors, which was comparable with previous studies.