Summary Background Tumour mutational status is an important determinant of the response of metastatic colorectal cancer to targeted treatments. However, the genotype of the tissue obtained at the ...time of diagnosis might not accurately represent tumour genotype after multiple lines of treatment. This retrospective exploratory analysis investigated the clinical activity of regorafenib in biomarker subgroups of the CORRECT study population defined by tumour mutational status or plasma protein levels. Methods We used BEAMing technology to identify KRAS, PIK3CA , and BRAF mutations in DNA obtained from the plasma of 503 patients with metastatic colorectal cancer who enrolled in the CORRECT trial. We quantified total human genomic DNA isolated from plasma samples for 503 patients using a modified version of human long interspersed nuclear element-1 (LINE-1) quantitive real-time PCR. We also measured the concentration of 15 proteins of interest—angiopoietin 2, interleukin 6, interleukin 8, placental growth factor, soluble TIE-1, soluble VEGFR1, VEGF-A, VEGF-C, VEGF-D, VEGF-A isoform 121, bone morphogenetic protein 7, macrophage colony-stimulating factor, stromal cell-derived factor-1, tissue inhibitor of metalloproteinase 2, and von Willebrand factor—in plasma samples from 611 patients. We did correlative analyses of overall survival and progression-free survival in patient subgroups based on mutational status, circulating DNA concentration, and protein concentrations. The CORRECT trial was registered with ClinicalTrials.gov , number NCT01103323. Findings Tumour-associated mutations were readily detected with BEAMing of plasma DNA, with KRAS mutations identified in 349 (69%) of 503 patients, PIK3CA mutations in 84 (17%) of 503 patients, and BRAF mutations in 17 (3%) of 502 patients. We did not do correlative analysis based on BRAF genotype because of the low mutational frequency detected for this gene. Some of the most prevalent individual hot-spot mutations we identified included: KRAS ( KRAS G12D, 116 28% of 413 mutations; G12V, 72 17%; and G13D, 67 16%) and PIK3CA ( PIK3CA E542K, 27 30% of 89 mutations; E545K, 37 42%; and H1047R, 12 14%). 41 (48%) of 86 patients who had received anti-EGFR therapy and whose archival tumour tissue DNA was KRAS wild-type in BEAMing analysis were identified as having KRAS mutations in BEAMing analysis of fresh plasma DNA. Correlative analyses suggest a clinical benefit favouring regorafenib across patient subgroups defined by KRAS and PIK3CA mutational status (progression-free survival with regorafenib vs placebo: hazard ratio HR 0·52, 95% CI 0·35–0·76 for KRAS wild-type; HR 0·51, 95% CI 0·40–0·65 for KRAS mutant KRAS wild type vs mutant, pinteraction =0·74; HR 0·50, 95% CI 0·40–0·63 for PIK3CA wild-type; HR 0·54, 95% CI 0·32–0·89 for PIK3CA mutant PIK3CA wild-type vs mutant, pinteraction =0·85) or circulating DNA concentration (progression-free survival with regorafenib vs placebo: HR 0·53, 95% CI 0·40–0·71, for low circulating DNA concentrations; HR 0·52, 95% CI 0·40–0·70, for high circulating DNA concentrations; low vs high circulating DNA, pinteraction =0·601). With the exception of von Willebrand factor, assessed with the median cutoff method, plasma protein concentrations were also not associated with regorafenib activity in terms of progression-free survival. In univariable analyses, the only plasma protein that was associated with overall survival was TIE-1, high concentrations of which were associated with longer overall survival compared with low TIE-1 concentrations. This association was not significant in multivariable analyses. Interpretation BEAMing of circulating DNA could be a viable approach for non-invasive analysis of tumour genotype in real time and for the identification of potentially clinically relevant mutations that are not detected in archival tissue. Additionally, the results show that regorafenib seems to be consistently associated with a clinical benefit in a range of patient subgroups based on mutational status and protein biomarker concentrations. Funding Bayer HealthCare Pharmaceuticals.
Background
In the phase 3 GRID trial, regorafenib improved progression-free survival (PFS) independent of
KIT
mutations in exons 9 and 11. In this retrospective, exploratory analysis of the GRID ...trial, we investigated whether a more comprehensive
KIT
mutation analysis could identify mutations that impact treatment outcome with regorafenib and a regorafenib-induced mutation pattern.
Methods
Archived tumor samples, collected at any time prior to enrollment in GRID, were analyzed by Sanger sequencing (
n
= 102) and next-generation sequencing (FoundationONE;
n
= 47). Plasma samples collected at baseline were analyzed by BEAMing (
n
= 163) and SafeSEQ (
n
= 96).
Results
In archived tumor samples, 67% (68/102) had a
KIT
mutation; 61% (62/102) had primary
KIT
mutations (exons 9 and 11) and 12% (12/102) had secondary mutations (exons 13, 14, 17, and 18). At baseline, 81% of samples (78/96) had
KIT
mutations by SafeSEQ, including the M541L polymorphism (sole event in 6 patients). Coexisting mutations in other oncogenes were rare, as were mutations in
PDGFR
,
KRAS
, and
BRAF
. Regorafenib showed PFS benefit across all primary and secondary
KIT
mutational subgroups examined. Available patient-matched samples taken at baseline and end of treatment (
n
= 41; SafeSEQ), revealed heterogeneous
KIT
mutational changes with no specific mutation pattern emerging upon regorafenib treatment.
Conclusion
These data support the results of the GRID trial, and suggest that patients may benefit from regorafenib in the presence of
KIT
mutations and without the selection of particular mutation patterns that confer resistance. The study was not powered to address biomarker-related questions, and the results are exploratory and hypothesis-generating.
Mutant IDH1 (mIDH1) inhibitors have shown single-agent activity in relapsed/refractory AML, though most patients eventually relapse. We evaluated the efficacy and molecular mechanism of the ...combination treatment with azacitidine, which is currently the standard of care in older AML patients, and mIDH1 inhibitor BAY1436032. Both compounds were evaluated in vivo as single agents and in combination with sequential (azacitidine, followed by BAY1436032) or simultaneous application in two human IDH1 mutated AML xenograft models. Combination treatment significantly prolonged survival compared to single agent or control treatment (P<.005). The sequential combination treatment depleted leukemia stem cells (LSC) by 470-fold. Interestingly, the simultaneous combination treatment depleted LSCs by 33,150-fold compared to control mice. This strong synergy is mediated through inhibition of MAPK/ERK and RB/E2F signaling. Our data strongly argues for the concurrent application of mIDH1 inhibitors and azacitidine and predicts improved outcome of this regimen in IDH1 mutated AML patients.
The human HDAC (histone deacetylase) family, a well-validated anticancer target, plays a key role in the control of gene expression through regulation of transcription. While HDACs can be subdivided ...into three main classes, the class I, class II and class III HDACs (sirtuins), it is presently unclear whether inhibiting multiple HDACs using pan-HDAC inhibitors, or targeting specific isoforms that show aberrant levels in tumours, will prove more effective as an anticancer strategy in the clinic. To address the above issues, we have tested a number of clinically relevant HDACis (HDAC inhibitors) against a panel of rhHDAC (recombinant human HDAC) isoforms. Eight rhHDACs were expressed using a baculoviral system, and a Fluor de Lystrade mark (Biomol International) HDAC assay was optimized for each purified isoform. The potency and selectivity of ten HDACs on class I isoforms (rhHDAC1, rhHDAC2, rhHDAC3 and rhHDAC8) and class II HDAC isoforms (rhHDAC4, rhHDAC6, rhHDAC7 and rhHDAC9) was determined. MS-275 was HDAC1-selective, MGCD0103 was HDAC1- and HDAC2-selective, apicidin was HDAC2- and HDAC3-selective and valproic acid was a specific inhibitor of class I HDACs. The hydroxamic acid-derived compounds (trichostatin A, NVP-LAQ824, panobinostat, ITF2357, vorinostat and belinostat) were potent pan-HDAC inhibitors. The growth-inhibitory effect of the HDACis on HeLa cells showed that both pan-HDAC and class-I-specific inhibitors inhibited cell growth. The results also showed that both pan-HDAC and class-I-specific inhibitor treatment resulted in increased acetylation of histones, but only pan-HDAC inhibitor treatment resulted in increased tubulin acetylation, which is in agreement with their activity towards the HDAC6 isoform.
Summary Background Regorafenib inhibits VEGF receptors 1, 2, and 3 and PDGF receptors like other anti-angiogenic tyrosine-kinase inhibitors approved for treatment of advanced renal-cell cancer. ...Regorafenib also inhibits other potentially important angiogenic kinases like TIE2, activation of which is thought to be important in tumour escape mechanisms. This phase 2, open-label, non-randomised study assessed the safety and efficacy of the multikinase inhibitor regorafenib for treatment of renal-cell carcinoma. Methods Patients were recruited from 18 academic oncology centres across Europe and USA. Patients with previously untreated metastatic or unresectable clear-cell renal-cell carcinoma received oral regorafenib (160 mg per day) in repeating cycles of 3 weeks on, 1 week off until disease progression or until patients met the criteria for removal from study. The primary efficacy endpoint was the proportion of patients who achieved an objective overall response, assessed in all patients who were evaluable for response. The trial has finished. This trial is registered with ClinicalTrials.gov , number NCT00664326. Findings The study was done between April 30, 2008, and June 1, 2011. We screened 64 patients, of whom 49 received regorafenib. Median duration of treatment was 7·1 months (range 0·7–34·4, IQR 2·5–18·0) and at the time of data cutoff, six patients (12%) were still receiving treatment. 48 patients were assessable for tumour response. 19 patients (39·6%, 90% CI 27·7–52·5) had an objective response, all of which were partial responses. Drug-related adverse events occurred in 48 patients (98%) and drug-related serious adverse events in 17 (35%). Grade 3 drug-related adverse events were common, most frequently hand and foot skin reaction (16 patients, 33%), diarrhoea (five patients, 10%), renal failure (five patients, 10%), fatigue (four patients, 8%), and hypertension (three patients, 6%). Two patients had grade 4 treatment-related adverse events: two cardiac ischaemia or infarction, one hypomagnesaemia, and one pain in the chest or thorax. Four patients died during study treatment or within 30 days of last dose, of which two were deemed likely to be related to the study drug. Interpretation Regorafenib has antitumour activity as first-line treatment for metastatic or unresectable renal-cell carcinoma. The drug's safety profile requires close monitoring. Funding Bayer HealthCare Pharmaceuticals.
Introduction: Mucosa-associated lymphoid tissue lymphoma (MALT lymphoma or MALToma) is a prevalent type of primary pulmonary lymphoma. Typically, the primary therapeutic approaches involve surgery or ...chemotherapy, although there have been instances of radiation therapy being employed. Case Report: We present a case of pulmonary MALToma that exhibited progression despite rituximab therapy. Subsequently, the patient demonstrated a positive response to radiation therapy. Conclusion: This case highlights the potential efficacy of radiation therapy as a treatment option for pulmonary MALToma, especially in cases where other conventional treatments like rituximab have proven ineffective. Further research and studies are warranted to better understand the role of radiation therapy in managing pulmonary MALToma and to determine optimal treatment strategies for patients with this condition.
This study investigated Theileria orientalis following outbreaks of oriental theileriosis in cattle in the state of Victoria, Australia, from September 2010 to January 2012, using traditional and ...molecular methods of diagnosis. A questionnaire was used to collect epidemiological information from cattle farms. Blood samples (n=301), collected from individual symptomatic and asymptomatic cattle from 19 cattle farms, were examined for the presence of Theileria on stained blood smears and tested using a PCR-based approach, employing a region within the major piroplasm surface protein (MPSP) gene as a marker. The microscopic examination of stained blood smears detected stages consistent with Theileria piroplasms in 28.1% (79/281) of the samples. PCR products were amplified from 70.8% (213/301) of the samples. Mutation scanning analysis of all amplicons displayed seven distinct profiles. Following the direct sequencing of representative amplicons, the genotypes ikeda, chitose, buffeli and type 5 were detected in 91.1%, 32.9%, 2.4% and 1.4% of 213 blood samples, respectively. The distribution of these four genotypes varied among the 19 farms; genotype ikeda was detected on all farms, whereas genotypes chitose, buffeli and type 5 were detected on 14, 3 and 2 farms, respectively. Mix infections with genotypes ikeda and chitose were common (21.6%). Survey results revealed that oriental theileriosis affected mainly beef cows of more than two years of age, prior to calving, and disease was associated with abortion and cow deaths. Future investigations should focus on developing improved tools for investigating and managing oriental theileriosis.
Hepatocyte growth factor (HGF) is a ligand of the receptor tyrosine kinase encoded by the c-Met protooncogene. HGF/Met signaling has multifunctional effects on various cell types. We sought to ...determine the role of HGF/Met in apoptosis and identify signal transducers involved in this process. In experiments with human SK-LMS-1 leiomyosarcoma cells, we show that the Akt kinase is activated by HGF in a time- and dose-dependent manner by phosphatidylinositol 3-kinase (PI3-kinase). Akt is also activated by active tumorigenic forms of Met, i.e., ligand-independent Tpr-Met, a truncated and constitutively dimerized form of Met, and a mutationally activated version of Met corresponding to that found in human hereditary papillary renal carcinoma. In NIH 3T3 cells transfected with wild-type Met, HGF inhibits apoptosis induced by serum starvation and UV irradiation. HGF-induced survival correlates with Akt activity and is inhibited by the specific PI3-kinase inhibitor LY294002, indicating that HGF inhibits cell death through the PI3-kinase/Akt signal transduction pathway. Furthermore, transiently transfected Tpr-Met activates Akt (both Akt1 and Akt2) and protects cells from apoptosis. Mitogen-activated protein kinase (MAPK) also is activated by HGF and rescues cells from apoptosis, although the cytoprotective effect is less marked than for PI3-kinase/Akt. Blocking MAPK with the specific MAPK kinase inhibitor PD098059 impairs the ability of HGF to promote cell survival. Similar results were obtained with NIH 3T3 cells expressing the fusion protein Trk-Met and stimulated with nerve growth factor, the Trk ligand. These results demonstrate that HGF/Met is capable of protecting cells from apoptosis by using both PI3-kinase/Akt and, to a lesser extent, MAPK pathways.
Hepatocyte growth factor (HGF) is a ligand of the receptor tyrosine
kinase encoded by the c-
Met
protooncogene.
HGF/Met signaling has multifunctional effects on various cell
types. We sought to ...determine the role of HGF/Met in
apoptosis and identify signal transducers involved in this
process. In experiments with human SK-LMS-1 leiomyosarcoma cells, we
show that the Akt kinase is activated by HGF in a time- and
dose-dependent manner by phosphatidylinositol 3-kinase (PI3-kinase).
Akt is also activated by active tumorigenic forms of Met, i.e.,
ligand-independent Tpr-Met, a truncated and constitutively dimerized
form of Met, and a mutationally activated version of Met corresponding
to that found in human hereditary papillary renal carcinoma. In NIH 3T3
cells transfected with wild-type Met, HGF inhibits apoptosis
induced by serum starvation and UV irradiation. HGF-induced survival
correlates with Akt activity and is inhibited by the specific
PI3-kinase inhibitor LY294002, indicating that HGF inhibits cell death
through the PI3-kinase/Akt signal transduction pathway.
Furthermore, transiently transfected Tpr-Met activates Akt (both Akt1
and Akt2) and protects cells from apoptosis. Mitogen-activated
protein kinase (MAPK) also is activated by HGF and rescues cells from
apoptosis, although the cytoprotective effect is less marked
than for PI3-kinase/Akt. Blocking MAPK with the specific MAPK
kinase inhibitor PD098059 impairs the ability of HGF to promote cell
survival. Similar results were obtained with NIH 3T3 cells expressing
the fusion protein Trk-Met and stimulated with nerve growth factor, the
Trk ligand. These results demonstrate that HGF/Met is capable of
protecting cells from apoptosis by using both
PI3-kinase/Akt and, to a lesser extent, MAPK pathways.
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