Practical management of tyrosine kinase inhibitor-associated side effects in GIST

Using body composition to predict treatment-related adverse events and disease-free survival in patients with gastrointestinal stromal tumors treated with imatinib: a retrospective cohort study

Background

Imatinib (IM) is the primary treatment for Gastrointestinal stromal tumor (GIST), but it faces significant challenges with resistance and a high incidence of adverse events. This study aims to assess the predictive value of baseline body composition parameters on treatment-related adverse events and disease-free survival (DFS) in GIST patients treated with imatinib.

Materials and Methods

A single-center retrospective analysis was conducted on 107 moderate or high-risk stratification GIST patients diagnosed from 2014 to 2020 at the First Affiliated Hospital of Nanjing Medical University. Body composition parameters, including skeletal muscle index (SMI), myosteatosis, cachexia index (CXI), and Fat-Free Mass (FFM), etc. were obtained using abdominal CT images and clinical data. Logistic and COX regression models were used to analyze the relationship between these indicators and treatment-related adverse events and DFS.

Results

Multivariate analysis revealed that myosteatosis (OR=7.640, P<0.001) and drug dose (OR=1.349, P=0.010) were independent risk factors for adverse events, while a higher CXI (OR=0.983, P=0.017) was protective. Additionally, LAMA/SMA% (OR=1.072, P=0.028) was identified as an independent risk factor for dose-limiting toxicity (DLT). Independent predictors of DFS included sarcopenia (HR=3.067, P=0.013), myosteatosis (HR=6.985, P=0.024), risk stratification (HR=9.562, high-risk vs. moderate-risk, P=0.003), and C-KIT mutation (HR=3.615, C-KIT exon 9 mutation vs. 11, P=0.013).

Conclusions

Baseline body composition parameters, particularly myosteatosis, effectively predict the adverse events and DFS in patients taking imatinib. Personalized treatment, such as targeted nutritional and exercise interventions, and close monitoring of patients with myosteatosis or sarcopenia can enhance compliance and improve survival rates.

Impact of systemic steroids on the efficacy of first line imatinib treatment of patients with advanced gastrointestinal stromal tumors (GISTs)

BACKGROUND

Effective management of adverse events is required to maintain sufficient imatinib dosing when treating patients with gastrointestinal stromal tumors (GISTs). Skin rash is a common adverse event of imatinib, which can be effectively controlled by systemic steroid treatment without imatinib dose modification or interruption. However, the impact of the use of systemic steroids on the efficacy of imatinib treatment remains unclear.

METHODS

Between October 2014 and February 2022, 277 consecutive patients from a prospective registry of GIST patients were included as the study population. Patients who started systemic steroids due to grade ≥ 3 skin rash or grade 2 skin rash with grade 2 pruritis were classified as the steroid group, whereas patients who did not develop a skin rash or those who did not require steroids for a mild skin rash were classified as the control group. Efficacy outcomes were compared between the two groups.

RESULTS

Among the 277 patients, 30 (10.8%) were treated with systemic steroids for skin rash. There was no significant difference in progression free survival (PFS) or overall survival (OS) between the steroid and control groups (3-year PFS, 67.7% vs. 65.1%, p = 0.53; 3-year OS, 91% vs. 89.9%, p = 0.67, respectively). The use of systemic steroids was not an independent factor associated with PFS (hazard ratio 0.73, 95% confidence interval 0.36-1.49, p = 0.39) and OS (hazard ratio 0.37, 95% confidence interval 0.12-1.18, p = 0.09). In the steroid group, patients who successfully maintained the imatinib dosage showed a trend toward more favorable survival outcomes than those who did not (3-year PFS, 73.3% vs. 44.4%, p = 0.34; 3-year OS, 95.8% vs. 75.0%, p = 0.15, respectively).

CONCLUSIONS

The use of systemic steroids for the control of imatinib induced severe skin rash did not adversely affect the efficacy outcomes of imatinib in patients with advanced GIST.

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.

A real-world pharmacovigilance study of FDA adverse event reporting system (FAERS) events for sunitinib

Background

Sunitinib is approved for the treatment of metastatic renal cell carcinoma (mRCC), imatinib-resistant gastrointestinal stromal tumors (GIST), and advanced pancreatic neuroendocrine tumors (PNET). This study aims to investigate the safety profiles of sunitinib through data mining of the US Food and Drug Administration Adverse Event Reporting System (FAERS).

Methods

The individual case safety reports (ICSRs) on sunitinib from 2006 Q1 to 2024 Q1 were collected from the ASCII data packages in the Food and Drug Administration Adverse Event Reporting System (FAERS). After standardizing the data, a variety of disproportionality analyses, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the bayesian confidence propagation neural network (BCPNN), and the multi-item gamma Poisson shrinker (MGPS) were employed to identify the potential safety signals of sunitinib-associated AEs.

Results

A total of 35,923 ICSRs of sunitinib as the "primary suspected" drug were identified within the reporting period. The search detected 276 disproportionate preferred terms (PTs). The most common AEs, including diarrhea, asthenia, decreased appetite, hypertension, and dysgeusia, were consistent with the drug label and clinical trials. Unexpected significant AEs, such as uveal melanocytic proliferation, salivary gland fistula, yellow skin, eyelash discoloration, scrotal inflammation, were detected. The median onset time of sunitinib-related AEs was 57 days (interquartile range [IQR]16-170 days), with most of the ICSRs developing within the first month (n = 4,582, 39.73%) after sunitinib therapy as initiated.

Conclusion

The results of our study were consistent with routine clinical observations, and some unexpected AEs signals were also identified for sunitinib, providing valuable evidence for the safe use of sunitinib in the real-world and contributing to the clinical monitoring and risk identification of sunitinib.

A case-matched study of imatinib mesylate between different formulations on plasma trough concentration, adverse events, quality of life and outcomes in gastrointestinal stromal tumor patients

Genike, the imatinib (IM)-alpha form is widely used in the treatment of gastrointestinal stromal tumor (GIST) patients in China. We wanted to investigate whether there are differences in IM plasma concentrations, adverse events, health-related quality of life (QOL) and outcomes between patients treated with Genike and Glivec. Thirty included GIST patients receiving IM treatment were matched to either Genike or Glivec according to gastrectomy, body weight, body surface area and sex. There was no statistically significant difference in IM trough plasma levels between the two groups. There were no significant differences in very common adverse events of IM between the Genike and Glivec groups. IM was well tolerated, although it was associated with a significant change in cognitive function (P < 0.001), fatigue (P = 0.015), pain (P = 0.015), nausea/vomiting (P = 0.029), insomnia (P = 0.019), diarrhea (P = 0.003) and financial difficulties (P < 0.001). Physical functioning, financial burden and insomnia were significantly different between the two groups (P = 0.026). Until Aug. 2022, there was no significant difference in time to imatinib treatment failure (TTF) between the two groups. In conclusion, there was no difference in IM plasma concentration and adverse events between Genike and Glivec. Both Genike and Glivec could partially decrease the QOL of GIST patients. Physical functioning was worse in Genike group than in Glivec group, while the economic burden and symptoms of insomnia in Glivec patients were worse. There was no significant difference in TTF between the two groups.

Effect of functionalization on the adsorption performance of carbon nanotube as a drug delivery system for imatinib: molecular simulation study

In this study, efficiency of functionalized carbon nanotube as a potential delivery system for imatinib anti-cancer drug was investigated. Accordingly, carboxyl and hydroxyl functionalized carbon nanotube were inspected as a notable candidate for the carriage of this drug in aqueous media. For this purpose, possible interactions of imatinib with pure and functionalized carbon nanotube were considered in aqueous media. The compounds were optimized in gas phase using density functional calculations. Solvation free energies and association free energies of the optimized structures were then studied by Monte Carlo simulation and perturbation method in water environment. Outcomes of quantum mechanical calculations presented that pure and functionalized carbon nanotubes can act as imatinib drug adsorbents in gas phase. However, results of association free energy calculations in aqueous solution indicated that only carboxyl and hydroxyl functionalized carbon nanotubes could interact with imatinib. Monte Carlo simulation results revealed that electrostatic interactions play a vital role in the intermolecular interaction energies after binding of drug and nanotube in aqueous solution. Computed solvation free energies in water showed that the interactions with functionalized carbon nanotubes significantly enhance the solubility of imatinib, which could improve its in vivo bioavailability.

Recent developments in antimalarial drug discovery

Although malaria remains a big burden to many countries that it threatens their socio-economic stability, particularly in the countries where malaria is endemic, there have been great efforts to eradicate this disease with both successes and failures. For example, there has been a great improvement in malaria prevention and treatment methods with a net reduction in infection and mortality rates. However, the disease remains a global threat in terms of the number of people affected because it is one of the infectious diseases that has the highest prevalence rate, especially in Africa where the deadly Plasmodium falciparum is still widely spread. Methods to fight malaria are being diversified, including the use of mosquito nets, the target candidate profiles (TCPs) and target product profiles (TPPs) of medicine for malarial venture (MMV) strategy, the search for newer and potent drugs that could reverse chloroquine resistance, and the use of adjuvants such as rosiglitazone and sevuparin. Although these adjuvants have no antiplasmodial activity, they can help to alleviate the effects which result from plasmodium invasion such as cytoadherence. The list of new antimalarial drugs under development is long, including the out of ordinary new drugs MMV048, CDRI-97/78 and INE963 from South Africa, India and Novartis, respectively.

The Application of Virtual Therapeutic Drug Monitoring to Assess the Pharmacokinetics of Imatinib in a Chinese Cancer Population Group

PURPOSE

Imatinib is used in gastrointestinal stromal tumours (GIST) and chronic myeloid leukaemia (CML). Oncology patients demonstrate altered physiology compared to healthy adults, e.g. reduced haematocrit, increased α-1 acid glycoprotein, decreased albumin and reduced glomerular filtration rate (GFR), which may influence imatinib pharmacokinetics. Given that Chinese cancer patients often report raised imatinib plasma concentrations and wider inter-individual variability reported in trough concentration when compared to Caucasian cancer patients, therapeutic drug monitoring (TDM) has been advocated.

METHOD

This study utilised a previously validated a Chinese cancer population and assessed the impact of imatinib virtual-TDM in Chinese and Caucasian cancer populations across a dosing range from 200-800 mg daily.

RESULTS

Staged dose titration to 800 mg daily, resulted in recapitulation to within the target therapeutic range for 50 % (Chinese) and 42.1% (Caucasian) subjects possessing plasma concentration < 550 ng/mL when dosed at 400 mg daily. For subjects with plasma concentrations >1500 ng/mL when dosed at 400 mg daily, a dose reduction to 200 mg once daily was able to recover 67 % (Chinese) and 87.4 % (Caucasian) patients to the target therapeutic range.

CONCLUSION

Virtual TDM highlights the benefit of pharmacokinetic modelling to optimising treatments in challenging oncology population groups.

Computational Investigation of 1, 3, 4 Oxadiazole Derivatives as Lead Inhibitors of VEGFR 2 in Comparison with EGFR: Density Functional Theory, Molecular Docking and Molecular Dynamics Simulation Studies

Vascular endothelial growth factor (VEGF) is an angiogenic factor involved in tumor growth and metastasis. Gremlin has been proposed as a novel therapeutic pathway for the treatment of renal inflammatory diseases, acting via VEGFR 2 receptor. To date, most FDA-approved tyrosine kinase (TK) inhibitors have been reported as dual inhibitors of EGFR and VEGFR 2. The aim of the present study was to find the potent and selective inhibitor of VEGFR 2 specifically for the treatment of renal cancer. Fourteen previously identified anti-inflammatory compounds i.e., 1, 3, 4 oxadiazoles derivatives by our own group were selected for their anti-cancer potential, targeting the tyrosine kinase (TK) domain of VEGFR2 and EGFR. A detailed virtual screening-based study was designed viz density functional theory (DFT) study to find the compounds' stability and reactivity, molecular docking for estimating binding affinity, SeeSAR analysis and molecular dynamic simulations to confirm protein ligand complex stability and ADMET properties to find the pharmacokinetic profile of all compounds. The DFT results suggested that among all the derivatives, the 7g, 7j, and 7l were chemically reactive and stable derivatives. The optimized structures obtained from the DFTs were further selected for molecular docking, and the results suggested that 7g, 7j and 7l derivatives as the best inhibitors of VEGFR 2 with binding energy values -46.32, -48.89 and -45.01 kJ/mol. The Estimated inhibition constant (IC50) of hit compound 7j (0.009 µM) and simulation studies of its complexes confirms its high potency and best inhibitor of VEGFR2. All the derivatives were also docked with EGFR, where they showed weak binding energies and poor interactions, important compound 7g, 7j and 7i exhibited binding energy of -31.01, -33.23 and -34.19 kJ/mol respectively. Furthermore, the anticancer potential of the derivatives was confirmed by cell viability (MTT) assay using breast cancer and cervical cancer cell lines. At the end, the results of ADMET studies confirmed these derivatives as drug like candidates. Conclusively, the current study suggested substituted oxadiazoles as the potential anticancer compounds which exhibited more selectivity towards VEGFR2 in comparison to EGFR. Therefore, the identified lead molecules can be used for the synthesis of more potent derivatives of VEGFR2, along with extensive in vitro and in vivo experiments, that can be used to treat various cancers, especially renal cancers, and to prevent angiogenesis due to aberrant expression of VEGFR2.

Symptoms reported by gastrointestinal stromal tumour (GIST) patients on imatinib treatment: combining questionnaire and forum data

PURPOSE

Treatment with the tyrosine kinase inhibitor (TKI) imatinib in patients with gastrointestinal stromal tumours (GIST) causes symptoms that could negatively impact health-related quality of life (HRQoL). Treatment-related symptoms are usually clinician-reported and little is known about patient reports. We used survey and online patient forum data to investigate (1) prevalence of patient-reported symptoms; (2) coverage of symptoms mentioned on the forum by existing HRQoL questionnaires; and (3) priorities of prevalent symptoms in HRQoL assessment.

METHODS

In the cross-sectional population-based survey study, Dutch GIST patients completed items from the EORTC QLQ-C30 and Symptom-Based Questionnaire (SBQ). In the forum study, machine learning algorithms were used to extract TKI side-effects from English messages on an international online forum for GIST patients. Prevalence of symptoms related to imatinib treatment in both sources was calculated and exploratively compared.

RESULTS

Fatigue and muscle pain or cramps were reported most frequently. Seven out of 10 most reported symptoms (i.e. fatigue, muscle pain or cramps, facial swelling, joint pain, skin problems, diarrhoea, and oedema) overlapped between the two sources. Alopecia was frequently mentioned on the forum, but not in the survey. Four out of 10 most reported symptoms on the online forum are covered by the EORTC QLQ-C30. The EORTC-SBQ and EORTC Item Library cover 9 and 10 symptoms, respectively.

CONCLUSION

This first overview of patient-reported imatinib-related symptoms from two data sources helps to determine coverage of items in existing questionnaires, and prioritize HRQoL issues. Combining cancer-generic instruments with treatment-specific item lists will improve future HRQoL assessment in care and research in GIST patients using TKI.

In vitro Evaluation of Isatin derivatives as Potent Anti-Breast Cancer Agents against MCF-7, MDA MB 231, MDA-MB 435 and MDA-MB 468 Breast Cancers cell lines: A Review

INTRODUCTION

Breast cancer (BC) is one of the most frequent malignancy and most common reasons of impermanence in women. The backbone of therapy for BC is principally chemotherapy, but due to its non-specific nature between normal cells and cancer cells and severe side effects are the main barriers in its therapy. So, there is an intense requirement for the enlargement of more efficacious, more specific and safer anti-BC agents.

OBJECTIVE

Isatin (IST) is an endogenous molecule which is a principal class of heterocyclic compounds and exhibits a wide range of therapeutic activities which can be used as a starting material for the synthesis of several drug molecules. Many literatures were reported previously on different pharmacological activities of IST derivatives and particularly on anticancer activity but this review mainly focus on anti-BC activities of IST derivatives through MCF-7, MDA MB 231, MDA-MB 435 and MDA-MB 468 cell lines. Here in we mentioned, a total 33 IST derivatives (compound 24- 56) which shown good anti-BC activity. IST derived compounds are also available in market and are used for various cancer types like sunitinib for renal cell carcinoma (RCC) and Nintedanib used for the cryptogenic fibrosing alveolitis treatment but when evaluated for BC did not get much success.

CONCLUSION

This review mainly highlights anti-BC activities of various IST analogues using MCF-7, MDA MB 231, MDA-MB 435 and MDA-MB 468 cell lines, display the potent compound of the series and structure-activity relationships of compounds with molecular docking also. So, this study mainly shows the importance of IST as major sources for drug design and development of newer anti-BC drugs.

Epidermal growth factor receptor inhibitor-induced diarrhea: clinical incidence, toxicological mechanism, and management

The epidermal growth factor receptor (EGFR) family is a class of receptor tyrosine kinase playing a central role in carcinogenesis and cancer progression. The members of this family, particularly EGFR and human epidermal growth factor receptor 2 (HER2), are the most extensively studied drug targets for malignancy. Today, numerous tyrosine kinase inhibitors targeting EGFR family have been developed to combat non-small-cell lung cancer and breast cancer. However, severe gastrointestinal (GI) toxicity leading to dose reduction and treatment discontinuation hampers the therapeutic outcome of EGFR inhibitors. Diarrhea is one of the most frequent GI side effects, especially when it comes to second-generation EGFR inhibitors. Enterocytes apoptosis and increased inflammation accompany with many oral EGFR inhibitors. Loperamide and budesonide are the first-line treatment to manage such adverse effects. However, current prophylaxis and management are all empirical interventions to relieve the symptom. They do not specifically target the toxicological mechanism of EGFR inhibitors. Hereby, those anti-diarrhea agents do not work well when used in cancer patients experiencing EGFR inhibitor-induced diarrhea. On the other hand, the toxicological mechanism of EGFR inhibitor-induced diarrhea is poorly understood. Thus, determining the mechanism behind such diarrhea is urgently in need for developing genuinely effective anti-diarrhea agents. This review aims to call attention to EGFR inhibitor-induced diarrhea, a highly occurring and devastating cancer drug toxicity.

Gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GIST) have an incidence of ~1.2 per 10⁵ individuals per year in most countries. Around 80% of GIST have varying molecular changes, predominantly mutually exclusive activating KIT or PDGFRA mutations, but other, rare subtypes also exist. Localized GIST are curable, and surgery is their standard treatment. Risk factors for relapse are tumour size, mitotic index, non-gastric site and tumour rupture. Patients with GIST with KIT or PDGFRA mutations sensitive to the tyrosine kinase inhibitor (TKI) imatinib that are at high risk of relapse have improved survival with adjuvant imatinib treatment. In advanced disease, median overall survival has improved from 18 months to >70 months since the introduction of TKIs. The role of surgery in the advanced setting remains unclear. Resistance to TKIs arise mainly from subclonal selection of cells with resistance mutations in KIT or PDGFRA when they are the primary drivers. Advanced resistant GIST respond to second-line sunitinib and third-line regorafenib, as well as to the new broad-spectrum TKI ripretinib. Rare molecular forms of GIST with alterations involving NF1, SDH genes, BRAF or NTRK genes generally show primary resistance to standard TKIs, but some respond to specific inhibitors of the activated genes. Despite major advances, many questions in both advanced and localized disease remain unanswered.

Medication-Related Osteonecrosis of the Jaw Spontaneously Occurred in a Patient with Chronic Myelogenous Leukemia Only by Imatinib: A Report of a Rare Case

The prevalence of medication-related osteonecrosis of the jaw (MRONJ) associated with molecular-targeted therapies such as bevacizumab and sunitinib has been constantly increasing in recent years. MRONJ frequently occurs after invasive dental procedures such as tooth extraction in patients currently or with a previous history of receiving antiresorptive agents including bisphosphonates and/or denosumab. Here, we report a rare case of spontaneously occurring MRONJ of the mandible in a 52-year-old Japanese woman with chronic myelogenous leukemia (CML) who was administered imatinib for 9 years. She had never been treated with antiresorptive agents, and her MRONJ developed spontaneously. Although there have been few reports of MRONJ related to imatinib, our case reported here indicates that imatinib may be capable of causing spontaneous MRONJ.

Assessment of Adherence to Imatinib and Health-Related Quality of Life Among Patients with Gastrointestinal Stromal Tumor: A Cross-Sectional Study in an Oncology Clinic in Malaysia

PURPOSE

To evaluate the rate and predictors of non-adherence to imatinib in gastrointestinal stromal tumor (GIST) patients, as well as to compare the difference in health-related quality of life (HRQOL) between adherent and non-adherent patients.

PATIENTS AND METHODS

A cross-sectional study at the Oncology Clinic, Hospital Kuala Lumpur was conducted from March to August 2018. All patients with metastatic and/or unresectable GIST aged ≥18 years old and on at least 3 months of imatinib were included. Adherence to imatinib was assessed using the 10-item validated Medication Compliance Questionnaire, with a score of <100% indicating non-adherence. Non-adherence predictors were determined by multiple logistic regressions. HRQOL was evaluated by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). The difference in the mean HRQOL scores between adherent and non-adherent groups was determined by multivariate analysis of variance.

RESULTS

A total of 89 patients were enrolled, of which 49 (55.1%) were considered non-adherent. The significant predictors of non-adherence were age (adjusted odds ratio [OR] 0.93; CI 0.89-0.98; P = 0.007), presence of nausea and vomiting (OR 5.63; CI 1.25-25.27; P = 0.024), and presence of comorbidities (OR 4.56; CI 1.44-14.40; P = 0.010). Patients who were in the adherent group showed significantly better score in overall HRQOL, F (15, 73) = 2.09, P < 0.02; Pillai's trace = 0.3, partial eta squared = 0.30.

CONCLUSION

Non-adherence to long-term treatment with imatinib among patients with GIST should not be underestimated. Significant predictors of non-adherence among this population are younger age, presence of nausea and vomiting, as well as comorbidities. Patients with good adherence portrayed better HRQOL.

Systemic Steroid Treatment for Imatinib-Associated Severe Skin Rash in Patients with Gastrointestinal Stromal Tumor: A Phase II Study

BACKGROUND

To achieve optimal clinical outcomes in patients with gastrointestinal stromal tumor (GIST), it is crucial to maintain sufficient dosing of imatinib. Skin rash is a common imatinib-associated adverse event and may affect compliance. This phase II study was conducted to evaluate whether imatinib-associated severe skin rash can be managed with systemic steroids without dose reduction or interruption of imatinib. This study is registered at ClinicalTrials.gov, number NCT03440515.

PATIENTS AND METHODS

Between 2014 and 2016, 29 patients with imatinib-associated severe skin rash were enrolled. Skin rash of grade 2 with grade ≥2 pruritus or of grade 3 was considered severe. Oral prednisolone was administered 30 mg/day for 3 weeks, then tapered off over 12 weeks. The primary endpoint was treatment success rate (TSR). Treatment success was defined as maintaining imatinib for more than 15 weeks after completion of the steroid administration schedule without skin rash that led to additional steroid treatment or dose reduction or interruption of imatinib.

RESULTS

Of the 29 patients enrolled, 22 patients with skin rash were treated successfully (TSR, 75.8%), 2 (6.9%) were evaluated as treatment failures, and 5 (17.2%) were not evaluable. The 2-year rash-free and imatinib reduction-free interval rate was 67.2% with median follow-up of 22.0 months (range, 0.4-30.3). Recurrence of severe skin rash occurred in seven patients (24.1%). Systemic steroids were well tolerated except in one patient who experienced pneumocystis pneumonia.

CONCLUSION

This study demonstrated that imatinib-associated severe skin rash can be effectively controlled by systemic steroid treatment without interruption or dose reduction of imatinib in patients with GIST.

IMPLICATIONS FOR PRACTICE

Imatinib has been the standard treatment of gastrointestinal stromal tumor in both adjuvant and palliative settings. It is crucial to maintain sufficient dosing of imatinib to achieve optimal clinical outcomes. Imatinib commonly causes imatinib-associated skin rash, which may worsen drug compliance. This phase II study demonstrated that systemic steroids could help maintaining the efficacy of imatinib by preventing interruption or dose reduction of imatinib. The present study provides a new administration strategy of systemic steroids and its efficacy and safety data. Thus, this study can be a cornerstone to establish treatment guidelines for imatinib-associated skin rash.

Renal Clearable Theranostic Nanoplatforms for Gastrointestinal Stromal Tumors

Advances in molecular imaging modalities have accelerated the diagnosis and treatment of human diseases. However, tumors less than 1 cm in size still remain difficult to localize by conventional means because of the difficulty in specific targeting/delivery to the tumor site. Furthermore, high nonspecific uptake in the major organs and persistent background retention results in low tumor-to-background ratio. The targeting and therapy of gastrointestinal stromal tumors (GIST) using nonsticky and renal clearable theranostic nanoparticles (a.k.a. H-Dots) are demonstrated. H-Dots not only target GIST for image-guided surgery, but also tailor the fate of anticancer drugs such as imatinib (IM) to the tumor site resulting in efficient treatment of unresectable GIST. In addition, H-Dots can monitor targetability, pharmacokinetics, and drug delivery, while also showing therapeutic efficacy in GIST-bearing xenograft mice following surgical resection. More importantly, IM loaded H-Dots exhibit lower uptake into the immune system, improved tumor selectivity, and increased tumor suppression compared to free IM, which accumulates in the spleen/liver. Precisely designed H-Dots can be used as a promising theranostic nanoplatform that can potentially reduce the side effects of conventional chemotherapies.

Imatinib-induced hepatitis treated by corticosteroids in a patient with metastatic gastrointestinal stromal tumor

Imatinib mesylate is currently used as the first-line treatment for metastatic gastrointestinal stromal tumors (GISTs). Imatinib-induced hepatotoxicity in patients with GIST is very rare. Its features vary from subclinical elevation of serum aminotransferase to clinically apparent acute hepatitis, which is associated with immunologic reactions. Imatinib-induced hepatotoxicity with autoimmune-like features can be treated by the discontinuation of imatinib mesylate and the administration of oral steroids. Here, we report a case of late-onset imatinib-induced hepatitis with autoimmune-like features in a patient with metastatic GIST, which was improved by oral corticosteroids.

Impact of L-carnitine on imatinib-related muscle cramps in patients with gastrointestinal stromal tumor

Introduction Muscle cramps constitute one of the leading adverse events of imatinib, the standard first-line treatment for advanced gastrointestinal stromal tumor (GIST). This study aims to assess the impact of L-carnitine on relieving cramps in patients with GIST taking imatinib. Materials and methods We reviewed our prospective database for patients with GIST who took L-carnitine (500-mg tablet, 2-3 times daily) for muscle cramps in Asan Medical Center. The assessment tool included severity by the numeric rating scale (NRS), frequency, duration of cramps, and questionnaire for the disturbance in basic activities of daily living (ADL), instrumental ADL (iADL), outdoor activity, or sleeping before and after L-carnitine treatment. Results We examined 42 patients [median age: 60 (range: 17-81) years; males, 52.4%] who received L-carnitine for cramps on NRS ≥ 4 intensity during 2016-2017. In 83.3% of patients (n = 35), the NRS score declined to <4 points, with 8 patients (19.0%) experiencing complete disappearance of symptoms [median response time: 10 (range: 2-30) days]. Moreover, the median duration of each episode and frequency decreased from 5 to 2 min and from 30 to 3 times per month (P < 0.001), respectively. We observed substantial improvement in all quality-of-life aspects after L-carnitine (ADL, 73.2%-14.6%; iADL, 73.2%-17.1%; sleeping, 78.0%-22.0%; outdoor activity, 68.3%-17.1%; P < 0.001). ConclusionL-carnitine could effectively relieve imatinib-related muscle cramps in patients with GIST. Accordingly, a randomized phase 3 study is currently ongoing (NCT03426722).

Long-term efficacy of imatinib mesylate in patients with advanced Tenosynovial Giant Cell Tumor

Tenosynovial giant cell tumors (TGCT), are rare colony stimulating factor-1(CSF-1)-driven proliferative disorders affecting joints. Diffuse-type TGCT often causes significant morbidity due to local recurrences necessitating multiple surgeries. Imatinib mesylate (IM) blocks the CSF-1 receptor. This study investigated the long term effects of IM in TGCT. We conducted an international multi-institutional retrospective study to assess the activity of IM: data was collected anonymously from individual patients with locally advanced, recurrent or metastatic TGCT. Sixty-two patients from 12 institutions across Europe, Australia and the United States were identified. Four patients with metastatic TGCT progressed rapidly on IM and were excluded for further analyses. Seventeen of 58 evaluable patients achieved complete response (CR) or partial response (PR). One- and five-year progression-free survival rates were 71% and 48%, respectively. Thirty-eight (66%) patients discontinued IM after a median of 7 (range 1–80) months. Reported adverse events in 45 (78%) patients were among other edema (48%) and fatigue (50%), mostly grade 1–2 (89%). Five patients experienced grade 3–4 toxicities. This study confirms, with additional follow-up, the efficacy of IM in TGCT. In responding cases we confirmed prolonged IM activity on TGCT symptoms even after discontinuation, but with high rates of treatment interruption and additional treatments.

A Turn-On Optoacoustic Probe for Imaging Metformin-Induced Upregulation of Hepatic Hydrogen Sulfide and Subsequent Liver Injury

Metformin is currently the most prescribed oral agent for diabetes treatment; however the overdose or long-term use may cause some severe side effects such as liver injury. Researches indicate that metformin-induced liver injury is closely related to upregulation of hepatic H2S. Hence, monitoring hepatic H2S generation induced by metformin could be an effective approach for evaluating hepatoxicity of the drug. Methods: We present a novel turn-on and dual-mode probe for detecting and imaging metformin-induced liver injury by specifically tracking the upregulation of hepatic H2S with fluorescent and optoacoustic methods. After reaction with H2S, the strong electron-withdrawing group dinitrophenyl ether (which acts as both the recognition moiety and the fluorescence quencher) was cleaved and replaced by an electron-donating group hydroxyl. This correspondingly leads to the changes of the probe's electronic state and absorption red-shifting as well as the subsequent turn-on fluorescent and optoacoustic signals. Results: The probe was applied to the colon tumor-bearing mice model and the metformin-induced liver injury mice model to achieve tumor imaging and liver injury assessment. The biosafety of the probe was verified by histological analysis (hematoxylin and eosin staining) and serum biochemical assays. Conclusion: The probe responds quickly to H2S in tumors and the liver, and MSOT imaging with the probe offers cross-secitonal and 3D spatial information of liver injury. This study may provide an effective approach for accessing medication side effects by tracking drug-metabolism-related products.

Chinese consensus on management of tyrosine kinase inhibitor-associated side effects in gastrointestinal stromal tumors

Tyrosine kinase inhibitors (TKIs) have improved the overall survival of patients with gastrointestinal stromal tumors (GISTs), but their side effects can impact dose intensity and, consequently, the clinical benefit. To date, no guideline or consensus has been published on the TKI-associated adverse reactions. Therefore, the Chinese Society of Surgeons for Gastrointestinal Stromal Tumor of the Chinese Medical Doctor Association organized an expert panel discussion involving representatives from gastrointestinal surgery, medical oncology, cardiology, dermatology, nephrology, endocrinology, and ophthalmology to consider the systemic clinical symptoms, molecular and cellular mechanisms, and treatment recommendations of GISTs. Here, we present the resultant evidence- and experience-based consensus to guide the management of TKI-associated side events in clinical practice.

Imatinib and liver toxicity

Imatinib is a specific tyrosine kinase inhibitor which has been approved for the treatment of Philadelphia chromosome-positive chronic myeloid leukaemia and c-KIT (CD117)-positive gastrointestinal stromal tumours. It has been associated with hepatotoxicity ranging from abnormal liver function tests to acute liver failure along with chronic hepatitis B reactivation. We report the case of a patient who was started on adjuvant treatment with imatinib following resection of a primary gastrointestinal stromal cell tumour of jejunum and developed severe hepatotoxicity. There was no history of risk factors for liver disease, and a search for the underlying causes of hepatotoxicity was unremarkable. Imatinib was stopped and she was treated with steroids which resulted in dramatic improvement of liver function tests. Liver biopsy in this case was not performed because liver function tests improved following discontinuation of imatinib and treatment with steroids. Repeat imaging did not reveal any evidence of tumour recurrence.

Prolonging Gastrointestinal-Stromal-Tumor-free life, an optimal suggestion of imatinib intervention ahead of operation

Background: Imatinib has been regarded as the first successful synthetic small molecule targeting at blocking tyrosine kinase. Its high efficacy stabilized disease in above 80% of chronic myeloid leukemia (CML) patients over 10 years survival. Due to the similar canceration of gastrointestinal stromal tumor (GIST) as to CML, imatinib has been approved to be used as first-line treatment. Study design: Our retrospective study was proposed to enroll 191 GIST patients with larger tumor size (≥8 cm) who preoperative accepted imatinib from those with direct operation. Analysis included demographics, cancer specific survival and relationship of their risk factors. Results: Male patients and gastrointestinal (GI) tract location took higher proportion in total cases, detection of KIT mutant took 89.7% among all traceable genetic testing. Patients with preoperative imatinib can achieve higher cancer specific survival (CSS) after both in 1 year and 3 years duration than their counterpart. Tumor size above its threshold of 8 cm would be a hazardous factor for poor prognosis. Conclusion: In conclusion, as for regressing tumor progression and creating operative chance, preoperative imatinib should be considered for the patients with high risk, although the precise duration of this intervention needs further validation.

Plasma cytokeratin-18 concentrations as noninvasive biomarker of early gastrointestinal toxicosis in dogs receiving toceranib

Background

No biomarkers for the early detection of gastrointestinal (GI) toxicosis secondary to antineoplastic treatment are recognized in veterinary medicine. Toceranib causes GI toxicosis in dogs.

Hypothesis/Objective

To assess if changes in plasma cytokeratin 18 (CK18) concentration, measured in dogs being treated with toceranib phosphate, can predict the onset of GI toxicosis. We hypothesize that an increase in CK18 concentrations will be detected before the development of GI toxicosis in dogs treated with toceranib phosphate.

Animals

Twenty healthy client‐owned dogs and 25 client‐owned dogs with surgically excised mast cell tumor (MCT).

Methods

Prospective cohort study. Dogs were treated with toceranib (2.75 mg/kg PO q48h). Plasma was collected weekly for 4 weeks. Plasma CK18 concentration was measured on days 0, 7, 14, 21, and 28. vascular endothelial growth factor was measured on days 0 and 28.

Results

Mean plasma CK18 concentration on day 0 in dogs with MCT was not significantly different than healthy controls (313.5 ± 592.8 pg/mL, 119.7 ± 76.9 pg/mL, mean ± SD P = 0.27). Mean plasma CK18 concentration decreased by 98.69 pg/mL from day 0 to day 28 (P < 0.001). Plasma CK18 concentration was not a significant predictor of the development of signs of GI toxicosis.

Conclusions and Clinical Importance

Plasma CK18 concentration was not a clinically useful biomarker for the early detection of GI toxicosis secondary to toceranib administration in dogs with MCTs.

Management of Acute Complications of Targeted Therapy in Patients With Cancer: A Review of Cases Managed in ICU

INTRODUCTION

Targeted therapies, molecules in full expansion, are not free of side effects that can lead patients to intensive care. We performed an extensive review of the published evidence and propose a management strategy for acute complications of targeted therapy in critically ill patients with cancer.

METHODS

The literature search was performed in August 2017 using the Ovid Medline system by a scientific librarian and physicians. We made a review of cases admitted in intensive care unit (ICU) and a review of toxicities of grades greater or equal to 3.

RESULTS

Our search selected 59 articles. The main cardiovascular side effects requiring ICU are heart failure, which is generally reversible, severe hypertension, thrombotic and ischemic events, and rhythm disturbances. The main pulmonary side effects are interstitial lung disease essentially caused by crizotinib, respiratory infections, pneumothorax, and alveolar hemorrhage. The main gastrointestinal side effects are fulminant hepatitis that may be fatal, colitis that may be complicated by hemorrhage, and perforation. The main neurological side effect is posterior reversible encephalopathy syndrome essentially caused by bevacizumab. The main other side effects are Steven-Johnson syndrome, necrotizing fasciitis, and anaphylactic reactions.

CONCLUSIONS

The side effects induced by targeted therapies may be fatal but are generally potentially reversible. The main treatment includes stopping current therapy and symptomatic management. Treatment rechallenge should be discussed on a case-by-case basis.

Imatinib rechallenge in patients with advanced gastrointestinal stromal tumors following progression with imatinib, sunitinib and regorafenib

BACKGROUND

Rechallenge with imatinib is an option in advanced gastrointestinal stromal tumor (GIST) patients following progression with standard tyrosine-kinase inhibitors (TKIs), imatinib, sunitinib and regorafenib. We retrospectively collected data from metastatic Italian GIST patients treated with imatinib resumption after progression to conventional TKIs.

METHODS

A total of 104 eligible advanced GIST patients, previously treated with imatinib, sunitinib and regorafenib, were collected from six referral Italian institutions. Mutational analysis was recorded and correlated with survival and response according to RECIST 1.1 or CHOI criteria.

RESULTS

Overall, 71 patients treated with imatinib 400 mg as rechallenge were included. Mutational status was available in all patients. The median follow up was 13 months. In patients who received a rechallenge therapy, the median time to progression (TTP) was 5.4 months [95% confidence interval (CI) 1.9-13.5] and overall survival (OS) was 10.6 months (95% CI 2.8-26.9). A correlation between mutational status, response rate, TTP and OS was not found but comparing deleted versus nondeleted KIT exon 11 patients, a significant difference was identified in terms of TTP and OS (p = 0.04 and p = 0.02, respectively).

CONCLUSIONS

Our retrospective data confirm that imatinib rechallenge is a reasonable option in advanced GIST. The prognostic value of the specific KIT mutations was confirmed in our series.

Ultra-performance LC–MS/MS study of the pharmacokinetic interaction of imatinib with selected vitamin preparations in rats

Aim: The growing interest of cancerous patients in using vitamins, while on imatinib (IMA) therapy, increased the risk of their pharmacokinetic interactions. Methodology: Ultra-performance LC–MS/MS method was developed and validated for the determination of IMA following oral administration of selected vitamin preparations (vitamin A, E, D3 and C) in rat plasma using a hybrid sample preparation technique of protein precipitation followed by SPE. Results: The method showed good linear response for IMA over the concentration range 1–500 ng/ml. Co-administered vitamin preparations could affect IMA pharmacokinetic profiling through either an increase (vitamin A and E) or a decrease (vitamin C) in IMA bioavailability. Vitamin D3 produced no significant effect on IMA bioavailability. Conclusion: Particular concern should be paid when vitamin preparations are administered with IMA.

Photoactivation of imatinib-antibody conjugate using low-energy visible light from Ru(ii)-polypyridyl cages

Ru(ii)-polypyridyl cages with sterically bulky bidentate ligands provide efficient photochemical release of the anticancer drug imatinib using low energy visible light, imparting spatiotemporal control over drug bioavailability. The light-activated drug release is maintained when the Ru(ii) cage is covalently coupled to an antibody, which is expected to localize selectively on the tumor.

Can therapeutic drug monitoring increase the safety of Imatinib in GIST patients?

Imatinib at 400 mg daily is the standard treatment for patients affected with CML and GIST. The intervariability in plasma concentration is very significant. In many reports, a good therapeutic effect is attributed to an adequate concentration of Imatinib. However, few studies have been conducted to investigate the association between plasma concentration and side effects. Besides, no upper concentration limit of Imatinib plasma concentration detection has been established. The correlation of Imatinib trough concentrations (Cmin ) with adverse effects (AEs) was described here. Plasma samples were obtained from patients after 3 months treatment with Imatinib (steady state, n = 122). Liquid chromatography/ tandem mass spectrometry was used to determine the concentration of Imatinib and its metabolite NDI. The incidence of myelosuppression was increased significantly with the increased Imatinib trough plasma concentration. The plasma level of Imatinib and NDI in patients who developed myelosuppression are 1698.3 ± 598.6 ng/mL and 242.1 ng/mL, respectively, which were significantly higher than those in patients who did not (1327.2 ± 623.4 ng/mL, P = 1.75 × 10-4 ; 206.3 ng/mL, P = 0.006). Estimated exposure thresholds of Imatinib and NDI were 1451.6 ng/mL with ROCAUC (95%CI) of 0.693 (0.597-0.789) and 207.1 ng/mL with ROCAUC (95%CI) of 0.646 (0.546-0.745), respectively. Multivariate regression confirmed the correlation of Imatinib Cmin with myelosuppression. Other side effects such as fluid retention and rash were not found to be correlated with Imatinib concentrations. These results suggest that trough concentration of Imatinib should be taken into consideration to increase the safety of Imatinib therapy in GIST patients.

Clinical implications of repeated drug monitoring of imatinib in patients with metastatic gastrointestinal stromal tumour

BACKGROUND

Imatinib mesylate (IM) is the preferred treatment for the majority of patients with metastatic gastrointestinal stromal tumour (GIST). Low trough IM concentration (C_min) values have been associated with poor clinical outcomes in GIST patients. However, there are few studies of repeated measurements of IM levels, and therapeutic drug monitoring is not yet a part of routine clinical practice. This study was conducted to reveal clinical scenarios where plasma concentration measurement of IM trough level (C_min) is advantageous.

METHODS

Patients with advanced GIST receiving IM were included from January 2011 to April 2015. Heparin plasma was collected at each follow-up visit. Ninety-six samples from 24 patients were selected for IM concentration measurement. Associations between IM plasma concentration and clinical variables were analyzed by Students' t test, univariate and multivariate linear regression analyses.

RESULTS

The mean IM C_min plasma concentrations for patients taking <400, 400 and >400 mg daily were 782, 1132 and 1665 ng/mL, respectively (p = 0.010). High IM C_min levels were correlated with age, low body surface area, low haemoglobin concentration, low creatinine clearance, absence of liver metastasis and no prior gastric resection in univariate analysis. In multivariate analysis age, gastric resection and liver metastasis were included in the final model. Eight patients had disease progression during the study, and mean IM levels were significantly lower at time of progression compared to the previous measurement for the same patients (770 and 1223 ng/mL, respectively; p = 0.020).

CONCLUSIONS

Our results do not support repeated monitoring of IM levels on a routine basis in all patients. However, we have revealed clinical scenarios where drug measurement could be beneficial, such as for patients who have undergone gastric resection, suspicion of non-compliance, subjectively reported side effects, in elderly patients and at the time of disease progression.

Leukocyte trafficking is not affected by multikinase inhibitors sunitinib or sorafenib in mice

Sunitinib and sorafenib are broad-spectrum tyrosine kinase inhibitors (TKI) targeting, for example, VEGF1-3, PDGFRb, RET, FLT3, CD117 (c-KIT) and CSF-1R cell membrane receptors thus suppressing tumor angiogenesis and cancer cell growth. Recently it has been suggested that the kinases targeted by Sunitinib and/or Sorafenib regulate leukocyte transmigration, which might in part be responsible for the often-observed reduction in tumor-associated myeloid derived suppressor cells and regulatory T cells. The aim of the current study is to determine whether sunitinib or sorafenib inhibit leukocyte extravasation. Sunitinib, sorafenib, or vehicle treated animals did not show any difference in leukocyte trafficking either in peritonitis or in vivo homing experiments, although sunitinib treatment effectively inhibited growth of B16 melanoma tumors in WT, SCID and SCID beige mice. Inhibition of tumor growth was associated with an increased number of infiltrating CD11b+ cells in the tumor, while the numbers of CD8, Gr-1 and F4/80 expressing cells were unchanged. In conclusion, the findings suggest that despite multiple targets with a potential role in leukocyte extravasation, neither sunitinib nor sorafenib effectively inhibits this process in vivo. Thus, the observed specific effect on CD11b cells among tumor infiltrating leukocytes is most likely an indirect effect.

European LeukemiaNet recommendations for the management and avoidance of adverse events of treatment in chronic myeloid leukaemia

Most reports on chronic myeloid leukaemia (CML) treatment with tyrosine kinase inhibitors (TKIs) focus on efficacy, particularly on molecular response and outcome. In contrast, adverse events (AEs) are often reported as infrequent, minor, tolerable and manageable, but they are increasingly important as therapy is potentially lifelong and multiple TKIs are available. For this reason, the European LeukemiaNet panel for CML management recommendations presents an exhaustive and critical summary of AEs emerging during CML treatment, to assist their understanding, management and prevention. There are five major conclusions. First, the main purpose of CML treatment is the antileukemic effect. Suboptimal management of AEs must not compromise this first objective. Second, most patients will have AEs, usually early, mostly mild to moderate, and which will resolve spontaneously or are easily controlled by simple means. Third, reduction or interruption of treatment must only be done if optimal management of the AE cannot be accomplished in other ways, and frequent monitoring is needed to detect resolution of the AE as early as possible. Fourth, attention must be given to comorbidities and drug interactions, and to new events unrelated to TKIs that are inevitable during such a prolonged treatment. Fifth, some TKI-related AEs have emerged which were not predicted or detected in earlier studies, maybe because of suboptimal attention to or absence from the preclinical data. Overall, imatinib has demonstrated a good long-term safety profile, though recent findings suggest underestimation of symptom severity by physicians. Second and third generation TKIs have shown higher response rates, but have been associated with unexpected problems, some of which could be irreversible. We hope these recommendations will help to minimise adverse events, and we believe that an optimal management of them will be rewarded by better TKI compliance and thus better CML outcomes, together with better quality of life.

Drug-induced hepatotoxicity in cancer patients - implication for treatment

INTRODUCTION

All anticancer drugs can cause idiosyncratic liver injury. Therefore, hepatoprotective agents assume particular importance to preserve liver function. Hepatic injury represents 10% of cases of acute hepatitis in adults; drug-related damage is still misjudged because of relative clinical underestimation and difficult differential diagnosis. Chemotherapeutic agents can produce liver toxicity through different pathways, resulting in different categories of liver injuries, but these drugs are not homogeneously hepatotoxic. Frequently, anticancer-induced hepatotoxicity is idiosyncratic and influenced by multiple factors.

AREAS COVERED

The aim of this paper is to perform a review of the literature regarding anticancer-induced liver toxicity. We described hepatotoxicity mechanisms of principal anticancer agents and respective dose reductions. Furthermore, we reviewed studies on hepatoprotectors and their optimal use. Tiopronin, magnesium isoglycyrrhizinate and S-Adenosylmethionine (AdoMet) demonstrated, in some small studies, a potential hepatoprotective activity.

EXPERT OPINION

Actually, in the literature only small experiences are reported. Even though hepatoprotective agents seem to be useful in the oncologic setting, the lack of well-designed prospective Phase III randomized controlled trials is a major limit in the introduction of hepatoprotectors in cancer patients and these kind of studies are warranted to support their use and to give further recommendations for the clinical practice.

Pazopanib plus best supportive care versus best supportive care alone in advanced gastrointestinal stromal tumours resistant to imatinib and sunitinib (PAZOGIST): a randomised, multicentre, open-label phase 2 trial

BACKGROUND

Gastrointestinal stromal tumours (GIST) are the most common mesenchymal neoplasms of the gastrointestinal tract. Imatinib followed by sunitinib and regorafenib is the standard sequence of treatment for advanced disease. Pazopanib is effective in soft tissue sarcomas but has never been assessed in advanced GIST in a randomised trial. We aimed to assess the efficacy and safety of pazopanib in patients with previously treated advanced GIST.

METHODS

In this randomised, open-label phase 2 study, we enrolled adults (aged ≥18 years) with advanced GIST resistant to imatinib and sunitinib from 12 comprehensive cancer centres or university hospitals in France and randomly assigned them 1:1 using an interactive web-based centralised platform to 800 mg oral pazopanib once daily in 4-week cycles plus best supportive care or best supportive care alone. Randomisation was stratified by the number of previous treatment regimens (2 vs ≥3); no-one was masked to treatment group allocation. Upon disease progression, patients in the best supportive care group were allowed to switch to pazopanib as compassionate treatment. The primary endpoint was investigator-assessed progression-free survival, analysed by intention-to-treat. All randomised participants who received at least one dose of pazopanib were included in the safety analysis. This study is registered with ClinicalTrials.gov, number NCT01323400.

FINDINGS

Between April 12, 2011, and Dec 9, 2013, 81 patients were enrolled and randomly assigned to pazopanib plus best supportive care (n=40) or best supportive care alone (n=41). The median follow-up was 26·4 months (IQR 22·0-37·8) in the pazopanib plus best supportive care group and 28·9 months (22·0-35·2) in the best supportive care group. 4-month investigator-assessed progression-free survival was 45·2% (95% CI 29·1-60·0) in the pazopanib plus best supportive care group versus 17·6% (7·8-30·8) in the best supportive care group (hazard ratio [HR] 0·59, 95% CI 0·37-0·96; p=0·029). Median progression-free survival was 3·4 months (95% CI 2·4-5·6) with pazopanib plus best supportive care and 2·3 months (2·1-3·3) with best supportive care alone (HR 0·59 [0·37-0·96], p=0·03). 36 (88%) of the patients originally assigned to the best supportive care group switched to pazopanib following investigator-assessed disease progression; these patients had a median progression-free survival from pazopanib initiation of 3·5 months (95% CI 2·2-5·2). 55 (72%) of the 76 pazopanib-treated patients had pazopanib-related grade 3 or worse adverse events, the most common of which was hypertension (15 [38%] in the pazopanib plus best supportive care group and 13 [36%] in the best supportive care group). 20 (26%) patients had pazopanib-related serious adverse events (14 [35%] in the pazopanib plus best supportive care group and six [17%] in the best supportive care group), including pulmonary embolism in eight (9%) patients (five [13%] in the pazopanib plus best supportive care group and three [7%] in the best supportive care group). Three pazopanib-related deaths occurred (two pulmonary embolisms [one in each group] and one hepatic cytolysis [in the best supportive care group]). Three adverse event-related but not pazopanib-related deaths occurred in the best supportive care group after switch to pazopanib; these deaths were from hyperammonaemic encephalopathy, pneumopathy, and respiratory failure.

INTERPRETATION

Pazopanib plus best supportive care improves progression-free survival compared with best supportive care alone in patients with advanced GIST resistant to imatinib and sunitinib, with a toxicity profile similar to that reported for other sarcomas. This trial provides reference outcome data for future studies of targeted inhibitors in the third-line setting for these patients.

FUNDING

GlaxoSmithKline, French National Cancer Institute, EuroSARC (FP7-278742), Centre Léon Bérard.

A successful approach to overcome imatinib-induced skin toxicity in a GIST patient

Since the introduction of tyrosine kinase inhibitors in gastrointestinal stromal tumor patients, the median survival of patients has increased from less than 1 to more than 5 years. The chronic use of a tyrosine kinase inhibitor has an impact on quality of life because of its toxicity. Adequate supportive therapy is therefore important. We describe a female patient with a metastatic gastrointestinal stromal tumor. During treatment with the c-KIT inhibitor imatinib, she developed severe therapy-limiting skin toxicity. After several different supportive attempts, the combination of doxycycline and clemastine proved to be the solution, enabling successful chronic treatment with imatinib. Chronic use of doxycycline and clemastine is useful in the management of skin toxicity caused by c-KIT inhibitors, enabling the needed long-term use of these kind of anticancer drugs without hampering the quality of life.

A safety evaluation of imatinib mesylate in the treatment of gastrointestinal stromal tumor

INTRODUCTION

For the last 15 years, imatinib mesylate has been the first line treatment of choice for advanced (metastatic) GIST.

AREAS COVERED

This review describes key efficacy data on imatinib for the treatment of GIST, and focuses on safety and tolerability of imatinib, with emphasis on common adverse events management and long term toxicity profile.

EXPERT OPINION

Imatinib has been the standard of care for metastatic GIST and probably will continue to be so for the next few years. Still, despite dramatic responses initially, imatinib drug resistance continues to be the major factor for treatment discontinuation. The toxicity profile of imatinib has been well characterized, and although the majority of patients experience an adverse event during treatment with imatinib, these side effects are usually mild and manageable, with the majority of patients continuing treatment uninterruptedly. Early concerns regarding imatinib related cardiotoxicity in GIST have not been confirmed in large prospective randomized trials, with reports indicating a low incidence of approximately 0.2%-0.4%. Future strategies for treatment of imatinib resistant GIST will probably include novel tyrosine kinase inhibitors, combination therapies or immunotherapy.

A Case of Disseminated Intra-abdominal Gastrointestinal Stromal Tumor Managed with Low Dose Imatinib

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Imatinib mesylate is recommended as adjuvant therapy for GIST after surgical resection. However, drug-related adverse events are common. A 74-year-old female with metastatic GIST who was managed with imatinib experienced severe adverse events, including skin rashes, tremor, and alopecia, etc. The imatinib dose was reduced and the size of the metastatic GIST continued to decrease and adverse events showed significant improvement.

Fluid retention associated with imatinib treatment in patients with gastrointestinal stromal tumor: quantitative radiologic assessment and implications for management

Objective

We aimed to describe radiologic signs and time-course of imatinib-associated fluid retention (FR) in patients with gastrointestinal stromal tumor (GIST), and its implications for management.

Materials and Methods

In this Institutional Review Board-approved, retrospective study of 403 patients with GIST treated with imatinib, 15 patients with imaging findings of FR were identified by screening radiology reports, followed by manual confirmation. Subcutaneous edema, ascites, pleural effusion, and pericardial effusion were graded on a four-point scale on CT scans; total score was the sum of these four scores.

Results

The most common radiologic sign of FR was subcutaneous edema (15/15, 100%), followed by ascites (12/15, 80%), pleural effusion (11/15, 73%), and pericardial effusion (6/15, 40%) at the time of maximum FR. Two distinct types of FR were observed: 1) acute/progressive FR, characterized by acute aggravation of FR and rapid improvement after management, 2) intermittent/steady FR, characterized by occasional or persistent mild FR. Acute/progressive FR always occurred early after drug initiation/dose escalation (median 1.9 month, range 0.3-4.0 months), while intermittent/steady FR occurred at any time. Compared to intermittent/steady FR, acute/progressive FR was severe (median score, 5 vs. 2.5, p = 0.002), and often required drug-cessation/dose-reduction.

Conclusion

Two distinct types (acute/progressive and intermittent/steady FR) of imatinib-associated FR are observed and each type requires different management.

Current management of patients with gastrointestinal stromal tumor receiving the multitargeted tyrosine kinase inhibitor sunitinib

BACKGROUND

Gastrointestinal stromal tumor (GIST), a form of soft tissue sarcoma, is often detected incidentally or at an advanced stage. The tyrosine kinase inhibitor sunitinib malate (Sutent * ) is established as second-line treatment for the management of GIST after disease progression on, or intolerance to, first-line imatinib treatment. Several published reviews give guidance on management of side effects in patients with advanced renal cell carcinoma treated with sunitinib, but fewer publications cover side-effect management in patients with GIST.

SCOPE

Using published articles and abstracts, prescribing information, and personal experience in managing patients with GIST at a specialized center of excellence for cancer care, I review side-effect management recommendations for patients with GIST treated with sunitinib and provide an overview of GIST.

FINDINGS

Sunitinib has a well described side-effect profile: most side effects occurring in patients with GIST can be easily managed by standard medical intervention and/or dose modification.

CONCLUSION

Care of patients with GIST can be enhanced through communication, support, knowledge, and education, with the goal of providing effective therapy and optimal symptom control.

Alternative schedules or integration strategies to maximise treatment duration with sunitinib in patients with gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumour of the gastrointestinal tract. The advent of targeted kinase-inhibitors has revolutionised treatment strategies and clinical outcomes for patients with advanced GIST. In the majority of countries, sunitinib is the only approved second-line treatment option for advanced GIST patients, who are resistant or intolerant to imatinib. However, sunitinib is associated with various adverse events, which often result in a reduction of the dosage, and interruption or suspension of therapy. Effective therapy management is essential to obtain the maximum clinical benefit, and includes adequate side effect management as well as optimization of dosing and treatment duration. In the current study, examples of maximization of treatment with sunitinib are presented, describing three clinical cases in which therapy with sunitinib was continued via the adoption of alternative reduced schedules or an additional loco-regional treatment, in order to manage toxicities or overcome progressive disease.

Masitinib in advanced gastrointestinal stromal tumor (GIST) after failure of imatinib: a randomized controlled open-label trial

BACKGROUND

Masitinib is a highly selective tyrosine kinase inhibitor with activity against the main oncogenic drivers of gastrointestinal stromal tumor (GIST). Masitinib was evaluated in patients with advanced GIST after imatinib failure or intolerance.

PATIENTS AND METHODS

Prospective, multicenter, randomized, open-label trial. Patients with inoperable, advanced imatinib-resistant GIST were randomized (1 : 1) to receive masitinib (12 mg/kg/day) or sunitinib (50 mg/day 4-weeks-on/2-weeks-off) until progression, intolerance, or refusal. Primary efficacy analysis was noncomparative, testing whether masitinib attained a median progression-free survival (PFS) (blind centrally reviewed RECIST) threshold of >3 months according to the lower bound of the 90% unilateral confidence interval (CI). Secondary analyses on overall survival (OS) and PFS were comparative with results presented according to a two-sided 95% CI.

RESULTS

Forty-four patients were randomized to receive masitinib (n = 23) or sunitinib (n = 21). Median follow-up was 14 months. Patients receiving masitinib experienced less toxicity than those receiving sunitinib, with significantly lower occurrence of severe adverse events (52% versus 91%, respectively, P = 0.008). Median PFS (central RECIST) for the noncomparative primary analysis in the masitinib treatment arm was 3.71 months (90% CI 3.65). Secondary analyses showed that median OS was significantly longer for patients receiving masitinib followed by post-progression addition of sunitinib when compared against patients treated directly with sunitinib in second-line [hazard ratio (HR) = 0.27, 95% CI 0.09-0.85, P = 0.016]. This improvement was sustainable as evidenced by 26-month follow-up OS data (HR = 0.40, 95% CI 0.16-0.96, P = 0.033); an additional 12.4 months survival advantage being reported for the masitinib treatment arm. Risk of progression while under treatment with masitinib was in the same range as for sunitinib (HR = 1.1, 95% CI 0.6-2.2, P = 0.833).

CONCLUSIONS

Primary efficacy analysis ensured the masitinib treatment arm could satisfy a prespecified PFS threshold. Secondary efficacy analysis showed that masitinib followed by the standard of care generated a statistically significant survival benefit over standard of care. Encouraging median OS and safety data from this well-controlled and appropriately designed randomized trial indicate a positive benefit-risk ratio. Further development of masitinib in imatinib-resistant/intolerant patients with advanced GIST is warranted.

Systematic review of the side effects associated with tyrosine kinase inhibitors used in the treatment of gastrointestinal stromal tumours on behalf of the EORTC Quality of Life Group

Tyrosine kinase inhibitors (TKIs) have revolutionised the treatment of advanced gastrointestinal stromal tumours (GISTs). Imatinib is approved as first line therapy and sunitinib is used in cases of imatinib resistance or intolerance. Compared with conventional treatments, TKIs are delivered over longer periods of time and are more specific in their targets (i.e., molecularly targeted), thus presenting different side effect profiles. We review the safety profiles of imatinib and sunitinib, documenting a total of 95 side effects including patient based as well as medically defined outcomes. Gastrointestinal complaints, particularly diarrhoea and nausea, oedema, fatigue and haematological disorders, notably anaemia, are amongst the most prevalent side effects. While there is overlap between the side effect profiles of imatinib and sunitinib, important differences emerge in the frequencies of oedema, hypertension, thyroid functioning, muscle and joint pains, as well as skin and oral conditions. Awareness of potential side effects is informative to both clinician and patient in terms of treatment decision making and can have important implications for treatment adherence and clinical outcome.