A long-term time course of colorimetric assessment of the effects of imatinib mesylate on skin pigmentation: a study of five patients

BACKGROUND: Imatinib mesylate (IM), the first-line treatment of chronic myeloid leukaemia (CML), is a tyrosine kinase inhibitor that targets those proteins involved in BCR-ABL signal transduction in CML, c-kit (KIT) and platelet-derived growth-factor (PDGFR) receptor. The use of IM has been associated with cutaneous reactions. In the last 2 years numerous studies have focused the attention on hypopigmentations, depigmentations and photosensitivity developing after the initiation of IM therapy. OBJECTIVE: The aim of this study is to evaluate the effects of IM therapy on the skin pigmentation of five patients affected by CML. METHODS: Skin pigmentation measurements were performed with a Minolta CR-200 Chromameter. results: All the studied patients show the gradual lightening of the skin on unexposed areas over the treatment with IM. In particular, this explorative colorimetric study indicates the association between IM and skin depigmentation with a significant increase of luminance value (L*) (P = 0.001) and a significant decrease of the pigmentation value (b*) (P = 0.028). CONCLUSION: Even if we do not know the clinical significance of the skin depigmentation caused by IM, the regulatory role of KIT and its ligand stem cell factor in melanocyte development and survival seems to suggest an objective mechanism of action for IM in the pathogenesis of this cutaneous depigmentation.     

Laparoscopic resection for a large gastrointestinal stromal tumor (GIST) with diaphragm invasion following preoperative imatinib treatment: A case report

IntroductionNeoadjuvant imatinib for large GISTs may prevent tumor rupture and the need for extended surgery by reducing tumor size. In this study, we present a case of large gastric GIST with diaphragm invasion, due to the patient receiving laparoscopic resection following preoperative imatinib treatment.Presentation of caseA 72-year-old woman was hospitalized with left hypochondriac pain for a month. Examinations revealed a large heterogeneous gastric mass measuring 80 mm in size, arising from the greater curvature of the corpus. The mass invaded the left thoracic diaphragm. Treatment with imatinib at an initial dosage of 400 mg/day was initiated. After a further two months of follow-up, the lesion had sustained reduction to 50 mm in size, however, the invasion to the diaphragm remained. The patient eventually underwent laparoscopic partial gastrectomy and partial resection of the diaphragm with curative intent. Adjuvant chemotherapy was initiated at one month after the surgery, however, was discontinued due to nausea. After one-year follow-up, no recurrence was noted.DiscussionNeoadjuvant imatinib may shrink tumor size remarkably and prevent tumor rupture during surgery, and thus lead to increased rates of complete resection. To date, several publications have directly compared the oncologic results between laparoscopic and open resection for GISTs. In the present case, the tumor was movable, and moderately fixed on diaphragm. It was favorable condition for laparoscopic surgery.ConclusionsThis is the first report of a large gastric GIST invading the diaphragm that was successfully treated by laparoscopic resection after tumor reduction by neoadjuvant imatinib.     

Anti-SARS-CoV-2 activity of targeted kinase inhibitors: Repurposing clinically available drugs for COVID-19 therapy

Coronavirus disease 2019 (COVID-19) remains a major public health concern, and vaccine unavailability, hesitancy, or failure underscore the need for discovery of efficacious antiviral drug therapies. Numerous approved drugs target protein kinases associated with viral life cycle and symptoms of infection. Repurposing of kinase inhibitors is appealing as they have been vetted for safety and are more accessible for COVID-19 treatment. However, an understanding of drug mechanism is needed to improve our understanding of the factors involved in pathogenesis. We tested the in vitro activity of three kinase inhibitors against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including inhibitors of AXL kinase, a host cell factor that contributes to successful SARS-CoV-2 infection. Using multiple cell-based assays and approaches, gilteritinib, nintedanib, and imatinib were thoroughly evaluated for activity against SARS-CoV-2 variants. Each drug exhibited antiviral activity, but with stark differences in potency, suggesting differences in host dependency for kinase targets. Importantly, for gilteritinib, the amount of compound needed to achieve 90% infection inhibition, at least in part involving blockade of spike protein-mediated viral entry and at concentrations not inducing phospholipidosis (PLD), approached a clinically achievable concentration. Knockout of AXL, a target of gilteritinib and nintedanib, impaired SARS-CoV-2 variant infectivity, supporting a role for AXL in SARS-CoV-2 infection and supporting further investigation of drug-mediated AXL inhibition as a COVID-19 treatment. This study supports further evaluation of AXL-targeting kinase inhibitors as potential antiviral agents and treatments for COVID-19. Additional mechanistic studies are needed to determine underlying differences in virus response.     

Renal cell carcinoma: review of novel single-agent therapeutics and combination regimens.

A search of the Medline database and ASCO 2003 conference proceedings was conducted to identify clinical trials currently underway using single-agent therapy for renal cell carcinoma (RCC). Combination trials were identified using the ASCO 2003 conference proceedings. Fourteen single-agent therapies employing different mechanisms of action were identified in the published literature: imatinib mesylate (Gleevec); bevacizumab (Avastin); thalidomide (Thalomid); gefitinib (ZD1839) (Iressa); cetuximab (IMC-C225) (Erbitux); bortezomib (PS-341) (Velcade); HSPPC-96 (Oncophage); BAY 59-8862; ABT-510; G250; CCI-779; SU5416; PTK/ZK; and ABX-EGF. Six distinct fields of clinical research have emerged: monoclonal antibodies, small molecules, vaccines, second-generation taxanes, nonapeptides and immunomodulators. Five combination regimens, primarily biological response modifiers (interleukin-2 or interferon-alpha), chemotherapy- or thalidomide-based, were identified. All therapies demonstrated acceptable toxicity profiles. Clinical benefit was assessed based on each study's reported criteria: antitumor response (regression or stability) ranged from 5% to 71%. In the past several years, significant advances in the underlying biological mechanisms of RCC, particularly the role of tumor angiogenesis, have permitted the design of molecularly targeted therapeutics. Based on preliminary and limited studies, combination therapies offer the greatest clinical benefit in the management of this malignancy, although additional basic research is still warranted.     

Imatinib accelerates progenitor cell‐mediated liver regeneration in choline‐deficient ethionine‐supplemented diet‐fed mice

Severe chronic hepatic injury can induce complex reparative processes. Ductular reaction and the appearance of small hepatocytes are standard components of this response, which is thought to have both adverse (e.g. fibrosis, carcinogenesis) and beneficial (regeneration) consequences. This complex tissue reaction is regulated by orchestrated cytokine action. We have investigated the influence of the tyrosine kinase inhibitor imatinib on a regenerative process. Ductular reaction was induced in mice by the widely used choline‐deficient ethionine‐supplemented diet (CDE). Test animals were treated daily with imatinib. After 6 weeks of treatment, imatinib successfully reduced the extent of ductular reaction and fibrosis in the CDE model. Furthermore, the number of small hepatocytes increased, and these cells had high proliferative activity, were positive for hepatocyte nuclear factor 4 and expressed high levels of albumin and peroxisome proliferator‐activated receptor alpha. The overall functional zonality of the hepatic parenchyma (cytochrome P450 2E1 and glucose 6 phosphatase activity; endogenous biotin content) was maintained. The expression of platelet‐derived growth factor receptor beta, which is the major target of imatinib, was downregulated. The anti‐fibrotic activity of imatinib has already been reported in several experimental models. Additionally, in the CDE model imatinib was able to enhance regeneration and preserve the functional arrangement of hepatic lobules. These results suggest that imatinib might promote the recovery of the liver following parenchymal injury through the inhibition of platelet‐derived growth factor receptor beta.     

Poor responses to tyrosine kinase inhibitors in a child with precursor B‐cell acute lymphoblastic leukemia with SNX2‐ABL1 chimeric transcript

In addition to BCR, various rare fusion partners for the ABL1 gene have been reported in leukemia. We have identified the fusion gene SNX2‐ABL1 in a pediatric case of acute lymphoblastic leukemia (ALL), which has only once previously been reported in an adult patient. Cytogenetic analysis detected this fusion gene arising from a t(5;9)(q22;q34) translocation. ALL cells carrying a SNX2‐ABL1 fusion exhibited a BCR‐ABL1+ ALL‐like gene expression profile. The patient poorly responded to dasatinib but partially responded to imatinib. Treatment using tyrosine kinase inhibitors requires further investigation to optimize the genotype‐based treatment stratification for patients with SNX2‐ABL1 fusion.     

Tyrosine kinase inhibitor imatinib (STIS71) as an anticancer agent for solid tumours

Imatinib mesylate, also known as ST1571 or CGP57148, is a competitive inhibitor of a few tyrosine kinases, including BCR-ABL, ABL, KIT, and the platelet-derived growth factor receptors (PDGF-R). It binds to the ATP-binding site of the target kinase and prevents the transfer of phosphate from ATP to the tyrosine residues of various substrates. At oral doses of 300 mg or greater, the vast majority of patients with chronic myeloid leukaemia achieve a haematological response and this is usually associated with limited toxicity. Imatinib also has substantial activity in Philadelphia chromosome-positive acute lymphoblastic leukaemia expressing the BCR-ABL fusion protein. Gastrointestinal stromal tumours (GISTS) have also been evaluated for clinical activity of imatinib. About 90% of malignant GISTs harbour a mutation in c-kit leading to KIT receptor autophosphorylation and ligand-independent activation. According to initial clinical studies, more than 50% of GISTs respond to therapy within a few months, and only about 10-15% progress. The potential for cure and the optimal length of treatment are currently not known. Several other human cancers may over-express KIT or PDGF-R, and clinical trials to evaluate the role of imatinib in the treatment of such cancers are currently ongoing. Imatinib is an example of a specifically designed, highly targeted cancer therapy, which poses novel requirements for both pathology laboratories and clinicians in terms of identifying the major molecular mechanisms involved in tumour growth.