pazopanib and Liver-Neoplasms

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Traditional chemotherapy drugs are hard to reach a satisfactory therapeutic effect since advanced HCC is highly chemo-resistant. Sorafenib is an oral multikinase inhibitor that can suppress tumor cell proliferation, angiogenesis and induce cancer cell apoptosis. However, the poor solubility, rapid metabolism and low bioavailability of sorafenib greatly restricted its further clinical application. During the past decade, numerous sorafenib derivatives have been designed and synthesized to overcome its disadvantages and improve its clinical performance. This article focuses on the therapeutic effects and mechanisms of various sorafenib derivatives with modifications on the N-methylpicolinamide group, urea group, central aromatic ring or others. More importantly, this review summarizes the current status of the structure-activity relationship (SAR) of reported sorafenib derivatives, which can provide some detailed information of future directions for further structural modifications of sorafenib to discovery new anti-tumor drugs with improved clinical performance.

Topics: Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Proliferation; Chemistry, Pharmaceutical; ErbB Receptors; Humans; Liver Neoplasms; Molecular Structure; Protein Kinase Inhibitors; Sorafenib

Gastrointestinal (GI) events have been described with sorafenib, sunitinib and pazopanib in cancer patients. We performed an up-to-date meta-analysis to determine the incidence and relative risk (RR) in patients with cancer treated with these agents. PubMed databases were searched for articles published till May 2013. Eligible studies were selected according to PRISMA statement. Summary incidence, RR, and 95% CIs were calculated using random-effects or fixed-effects models based on the heterogeneity of selected studies. A total of 6,447 patients were available for the meta-analysis; 2,260 had renal cell carcinoma (RCC) and 4,187, 1,691 non-small cell lung cancers, 599 hepatocellular cancers, 1,066 breast cancers, 165 neuroendocrine tumors, 304 gastrointestinal stromal tumors and 362 soft tissue sarcomas. Diarrhea was the most common GI event. When stratified by tumor type (RCC vs. non-RCC), the difference among the incidences of GI events was significant for diarrhea (p < 0.001) and vomiting (p = 0.006), that resulted higher in RCC patients. In RCC patients, sorafenib registered the lower incidence and RR of all grades GI events. The difference was statistically significant for sorafenib versus sunitinib-related all and high-grade events (p < 0.001) and for sorafenib versus pazopanib all grades GI events (p < 0.001) and high-grade anorexia (p < 0.001). Treatment with VEGFR TKIs sorafenib, sunitinib and pazopanib is associated with a significant increase in the risk of GI events in patients with cancer, and frequent clinical monitoring should be emphasized when managing these three and newer VEGFR TKIs.

Topics: Adverse Drug Reaction Reporting Systems; Carcinoma, Renal Cell; Clinical Trials as Topic; Diarrhea; Gastrointestinal Diseases; Gastrointestinal Tract; Humans; Incidence; Indazoles; Indoles; Liver Neoplasms; Neoplasms; Niacinamide; Phenylurea Compounds; Pyrimidines; Pyrroles; Sorafenib; Sulfonamides; Sunitinib; Vomiting

Angiogenesis is essential for tumor growth and metastasis. The main regulators of the process are the signaling cascades of VEGF-, PDGF- and FGF receptors. Inhibition of these pathways holds potential therapeutic benefit not only for cancer patients, but also for the treatment of other diseases. This paper summarizes the experimental and clinical results of studies available so far on the multi-target tyrosine kinase inhibitor nintedanib (BIBF 1120). According to these studies, nintedanib effectively inhibits VEGFR-, PDGFR- and FGFR signalization and thus the proliferation and survival of cell types which highly express these receptors (i.e. endothelial and smooth muscle cells and pericytes). In vitro studies and in vivo xenograft experiments have provided promising results. In the clinical setting, BIBF 1120 seems to be effective and well tolerated in various tumor types, such as lung, prostate, colorectal and hepatocellular carcinoma, as well as in gynecological tumors. The main adverse events are gastrointestinal toxicities and the reversible elevation of liver enzyme levels. Nintedanib might also be combined with paclitaxel, carboplatin, pemetrexed and docetaxel. There are several ongoing clinical trials testing the efficacy of BIBF 1120.

Topics: Animals; Antineoplastic Agents; Axitinib; Benzenesulfonates; Carcinoma, Hepatocellular; Clinical Trials as Topic; Colorectal Neoplasms; Digestive System; Enzyme Inhibitors; Female; Genital Neoplasms, Female; Humans; Imidazoles; Indazoles; Indoles; Liver Neoplasms; Lung Neoplasms; Male; Neoplasms; Niacinamide; Oligonucleotides; Phenylurea Compounds; Phthalazines; Piperidines; Prostatic Neoplasms; Protein-Tyrosine Kinases; Pyridines; Pyrimidines; Quinazolines; Receptors, Fibroblast Growth Factor; Receptors, Platelet-Derived Growth Factor; Receptors, Vascular Endothelial Growth Factor; Signal Transduction; Sorafenib; Sulfonamides; Xenograft Model Antitumor Assays

A phase I dose-escalating study of pazopanib was conducted to determine the maximum tolerated dose (MTD), pharmacokinetic/pharmacodynamic relationships, and clinical activity in patients with advanced hepatocellular carcinoma (HCC).. Asian patients (N = 28) were dose escalated on pazopanib (200-800 mg) once daily (QD) on 21-day cycles, with MTD as the primary endpoint using a modified 3 + 3 design. Changes in tumor vasculature were evaluated by dynamic contrast-enhanced MRI (DCE-MRI).. Two of five patients at the 800-mg dose level experienced dose-limiting toxicities [grade 3 aspartate aminotransferase (AST)/alanine aminotransferase (ALT) elevations and grade 3 malaise]. The MTD in patients with HCC (Child-Pugh class A) was 600 mg QD. Diarrhea, skin hypopigmentation, and AST elevation were the most commonly reported adverse events at the MTD. Mean C(max) and area under the concentration-time curve (AUC(0-6)) of pazopanib and its metabolites did not increase dose proportionally across the 200 to 800 mg range. Reductions in IAUGC and K(trans) were shown at all pazopanib doses evaluated, with the greatest reductions at 600 and 800 mg. Although larger DCE-MRI parameter decreases were associated with larger C(24) and C(max) values, there was no constant relationship between tumor perfusion decreases measured by DCE-MRI and plasma pazopanib pharmacokinetic parameters. Overall, 19 patients (73%) had either partial response or stable disease.. Pazopanib has a manageable safety profile in patients with advanced HCC, and 600 mg was chosen for further development of pazopanib in advanced HCCs. Moreover, pazopanib reduced tumor vessel leakage, as shown by DCE-MRI, indicating a direct effect on HCC vasculature that might be associated with its antitumor activity.

Topics: Adult; Aged; alpha-Fetoproteins; Angiogenesis Inhibitors; Carcinoma, Hepatocellular; Disease-Free Survival; Dose-Response Relationship, Drug; Female; Humans; Indazoles; Liver Neoplasms; Male; Middle Aged; Pyrimidines; Sulfonamides

PURPOSE Pazopanib is an oral angiogenesis inhibitor targeting vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit. This randomized, double-blind, placebo-controlled phase III study evaluated efficacy and safety of pazopanib monotherapy in treatment-naive and cytokine-pretreated patients with advanced renal cell carcinoma (RCC). PATIENTS AND METHODS Adult patients with measurable, locally advanced, and/or metastatic RCC were randomly assigned 2:1 to receive oral pazopanib or placebo. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, tumor response rate (Response Evaluation Criteria in Solid Tumors), and safety. Radiographic assessments of tumors were independently reviewed. Results Of 435 patients enrolled, 233 were treatment naive (54%) and 202 were cytokine pretreated (46%). PFS was significantly prolonged with pazopanib compared with placebo in the overall study population (median, PFS 9.2 v 4.2 months; hazard ratio [HR], 0.46; 95% CI, 0.34 to 0.62; P < .0001), the treatment-naive subpopulation (median PFS 11.1 v 2.8 months; HR, 0.40; 95% CI, 0.27 to 0.60; P < .0001), and the cytokine-pretreated subpopulation (median PFS, 7.4 v 4.2 months; HR, 0.54; 95% CI, 0.35 to 0.84; P < .001). The objective response rate was 30% with pazopanib compared with 3% with placebo (P < .001). The median duration of response was longer than 1 year. The most common adverse events were diarrhea, hypertension, hair color changes, nausea, anorexia, and vomiting. There was no evidence of clinically important differences in quality of life for pazopanib versus placebo. CONCLUSION Pazopanib demonstrated significant improvement in PFS and tumor response compared with placebo in treatment-naive and cytokine-pretreated patients with advanced and/or metastatic RCC.

Topics: Adult; Aged; Aged, 80 and over; Bone Neoplasms; Carcinoma, Renal Cell; Double-Blind Method; Female; Humans; Indazoles; International Agencies; Kidney Neoplasms; Liver Neoplasms; Lung Neoplasms; Male; Middle Aged; Neoplasm Staging; Placebos; Prognosis; Pyrimidines; Sulfonamides; Survival Rate; Treatment Outcome; Young Adult

Angiosarcoma is a highly aggressive mesenchymal tumor. Although systemic chemotherapy is often considered for the inoperable or metastatic angiosarcoma, the outcome of such treatment is unsatisfactory and poorly delineated.. We reviewed electronic medical records of 75 patients with angiosarcoma who were treated with systemic chemotherapy for inoperable or metastatic disease. Patients were classified as having liver involvement if they had either primary or metastatic hepatic lesions.. Among the patients evaluated, 51 patients (68%) were male and 24 patients (32%) had primary cutaneous angiosarcoma. Liver involvement was present in 28 patients (37.3%). A total of 59 patients received first-line weekly paclitaxel (wPac) and showed an objective response rate (ORR) of 23.7% (n=14), a median progression-free survival (mPFS) of 4.0 months (95% confidence interval [CI], 3.0 to 6.1), and a median overall survival (mOS) of 10.2 months (95% CI, 7.0 to 14.6). Among patients without liver involvement, patients receiving wPac (n=35) had significantly prolonged mPFS (5.8 months vs. 3.2 months, respectively; p=0.014) with a tendency for prolonged mOS (13.8 months vs. 11.6 months, respectively; p=0.13) than those receiving other regimens (n=12). A total of 24 patients received second- or later-line pazopanib monotherapy and showed an ORR of 16.7% (n=4), a mPFS of 2.4 months (95% CI, 1.8 to 4.3) and a mOS of 5.4 months (95% CI, 3.5 to not available).. Treatment with first-line wPac and later-line pazopanib seems to provide survival benefit, especially for patients with advanced angiosarcoma without liver involvement.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Female; Follow-Up Studies; Hemangiosarcoma; Humans; Indazoles; Liver Neoplasms; Male; Middle Aged; Paclitaxel; Prognosis; Pyrimidines; Retrospective Studies; Skin Neoplasms; Sulfonamides; Survival Rate

Long-term follow-up reports of low-grade endometrial stromal sarcoma (LGESS) including its clinical course and pathological data are rare. We previously reported the case of a Japanese woman diagnosed with LGESS, who was treated with multidisciplinary therapy. She had been suffering from uterine cervical tumor diagnosed as cervical polyps, or fibroid in statu nascendi, since 24 years old. The patient had survived for 25 years with the disease. This report presents her progress and pathological change since the previous report.. At age 45, the patient experienced a relapse of the remnant LGESS tumor between the right diaphragm and liver. Although chemotherapy was not effective, the tumor was eliminated by proton therapy. At age 46 years, the remnant tumors outside the irradiated field were resected. The disease was originally diagnosed as "neuroendocrine carcinoma (NEC)" using the surgical specimen. Therefore, cisplatin and irinotecan combination chemotherapy were administered to treat the remnant dissemination. After 4 cycles of chemotherapy, the liver metastases had enlarged and were resected surgically. Consequently, no remnant tumor was visible in the abdominal cavity at the end of the surgery. To determine the origin of NEC, we examined the previously resected specimens obtained from her ileum at age 40 years. A boundary between the LGESS and neuroendocrine tumor grade 2 (NET G2)-like lesion was found in the tumor, indicating that the origin of these tumors was LGESS. After less than 2 years of chemotherapy and undergoing surgery, a relapse of the tumor in the liver induced biliary duct obstruction with jaundice, which was treated with endoscopic retrograde biliary drainage. Although pazopanib prolonged her life for 10 months, she died from sepsis at age 49 years, which was caused by the infection that spread to the liver metastatic tumor via the stented biliary ducts. Autopsy revealed adenocarcinoma-like differentiation of the tumor.. This LGESS patient has survived for a long time owing to multidisciplinary treatment including proton therapy. The LGESS tumor differentiated to NET G2-like tissue and then further to adenocarcinoma-like tissue during the long-term follow-up.

Topics: Adult; Autopsy; Drainage; Endometrial Neoplasms; Fatal Outcome; Female; Humans; Indazoles; Liver Neoplasms; Middle Aged; Neoplasm Metastasis; Neoplasm Recurrence, Local; Proton Therapy; Pyrimidines; Sarcoma, Endometrial Stromal; Sepsis; Sulfonamides; Young Adult

To test the hypothesis that cytoreductive nephrectomy (CN) improves overall survival (OS) of patients with synchronous metastatic renal cell carcinoma (mRCC), who subsequently receive targeted therapies (TT).. We identified 261 patients who received TT for synchronous mRCC with or without prior CN. To achieve balance in baseline characteristics between groups, we used the inverse probability of treatment weighting (IPTW) method. We conducted OS analyses, including IPTW-adjusted Kaplan-Meier curves, Cox regression models, interaction term, and landmark and sensitivity analyses.. Of the 261 patients, 97 (37.2%) received CN and 164 (62.8%) did not. IPTW-adjusted analyses showed a statistically significant OS benefit for patients treated with CN (HR 0.63, 95% CI 0.46-0.83, P = 0.0015). While there was no statistically significant difference in OS at 3 months (P = 0.97), 6 months (P = 0.67), and 12 months (P = 0.11) from diagnosis, a benefit for the CN group was noted at 18 months (P = 0.005) and 24 months (P = 0.004). On interaction term analyses, the beneficial effect of CN increased with better performance status (P = 0.06), in women (P = 0.03), and in patients with thrombocytosis (P = 0.01).. IPTW-adjusted analysis of our patient cohort suggests that CN improves OS of patients with synchronous mRCC treated with TT. On the whole, the survival difference appears after 12 months. Specific subgroups may particularly benefit from CN, and these subgroups warrant further investigation in prospective trials.

Topics: Aged; Anilides; Antibodies, Monoclonal; Antineoplastic Agents; Carcinoma, Renal Cell; Cohort Studies; Combined Modality Therapy; Cytoreduction Surgical Procedures; Female; Humans; Indazoles; Indoles; Kaplan-Meier Estimate; Kidney Neoplasms; Liver Neoplasms; Lung Neoplasms; Male; Middle Aged; Molecular Targeted Therapy; Neoplasm Metastasis; Nephrectomy; Nivolumab; Probability; Prognosis; Proportional Hazards Models; Pyridines; Pyrimidines; Pyrroles; Retrospective Studies; Sex Factors; Sulfonamides; Sunitinib; Survival Rate; Thrombocytosis

Primary hepatic angiosarcoma (PHA) is a rare and aggressive solid tumor, with high rates of local recurrence and distant metastasis, and poor prognosis. There are no established treatment guidelines for PHA.. A 78-year-old asymptomatic man with PHA that was successfully treated with pazopanib plus PD-1 inhibitor and RetroNectin-activated killer cells (RAK cells). After one month of treatment, there was a clear reduction in the size and number of the liver metastases; and after nearly 15 months, most of the lesions were stable, no new lesions had developed, and the side effect of treatment was minor.. Pazopanib, PD-1 inhibitor and RAK cells could serve as a potential option for the treatment of advanced PHA.

Topics: Aged; Antineoplastic Agents, Immunological; Antineoplastic Combined Chemotherapy Protocols; Biopsy; Cell Line, Tumor; Combined Modality Therapy; Hemangiosarcoma; Humans; Immunohistochemistry; Immunotherapy, Adoptive; Indazoles; Liver Neoplasms; Magnetic Resonance Imaging; Male; Neoplasm Metastasis; Neoplasm Staging; Programmed Cell Death 1 Receptor; Pyrimidines; Sulfonamides; Treatment Outcome

Hepatic epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor of endothelial origin with a highly variable clinical presentation and natural history. Given its vascular origin, new therapies with inhibitors of vascular endothelial growth factor (VEGF) have been introduced in the treatment of these patients and have shown promising results. Few reports have described the role of F-Fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography (F-FDG PET/CT) in the evaluation of this tumor after treatment with anti-angiogenic agents. Our case reports how F-FDG PET-CT scan was critical in the assessment of this tumor after treatment with an anti-angiogenic agent, Pazopanib, demonstrating complete metabolic response.. A 30-year-old man with no previous significant medical history presented with pain in the right upper quadrant for over a year.. Multiple hepatic masses were found on abdominal ultrasound. Liver biopsy confirmed the diagnosis of epithelioid hemangioendothelioma. F-FDG PET/CT was performed for staging. Multiple FDG-avid hepatic, splenic, and lymph nodes lesions were detected on F-FDG PET/CT. A subsequent spleen biopsy confirmed splenic involvement. Immunohistochemistry was positive for CD31, CD34, and ERG, supporting the diagnosis of epithelioid hemangioendothelioma.. A 1-year cyclophosphamide treatment was provided followed by Pazopanib for 17 months.. Six years after the first F-FDG PET/CT, F-FDG PET/CT performed for restaging demonstrated complete metabolic response to therapy. Follow-up CT demonstrated no interval changes in size of some of the treated lesions.. F-FDG PET/CT is useful for baseline assessment and posttreatment follow-up of this rare cancer.

Topics: Adult; Angiogenesis Inhibitors; Antineoplastic Agents; Fluorodeoxyglucose F18; Hemangioendothelioma, Epithelioid; Humans; Indazoles; Liver Neoplasms; Male; Positron Emission Tomography Computed Tomography; Pyrimidines; Radiopharmaceuticals; Sulfonamides; Treatment Outcome

To evaluate survival outcomes and prognostic factors for overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) who received sunitinib (SU) and pazopanib (PZ) as first-line therapy in real-world Korean clinical practice.. Data of 554 patients with mRCC who received SU or PZ at eight institutions between 2012 and 2016 were retrospectively reviewed. Based on the targeted therapy, the patients were divided into SU (n = 293) or PZ (n = 261) groups, and the clinicopathological variables and survival rates of the two groups were compared. A multivariable Cox proportional hazard model was used to determine the prognostic factors for OS.. The median follow-up was 16.4 months (interquartile range, 8.3-31.3). Patients in the PZ group were older, and no significant difference was observed in the performance status (PS) between the two groups. In the SU group, the dose reduction rate was higher and the incidence of grade 3 toxicity was more frequent. The objective response rates were comparable between the two groups (SU, 32.1% vs. PZ, 36.4%). OS did not differ significantly between the two groups (SU, 36.5 months vs. PZ, 40.2 months; log-rank,. Our real-world data of Korean patients with mRCC suggested that SU and PZ had similar efficacies as first-line therapy for mRCC. However, PZ was better tolerated than SU in Korean patients.

Topics: Aged; Bone Neoplasms; Carcinoma, Renal Cell; Female; Humans; Indazoles; Kaplan-Meier Estimate; Kidney Neoplasms; Liver Neoplasms; Male; Middle Aged; Prognosis; Proportional Hazards Models; Protein Kinase Inhibitors; Pyrimidines; Retrospective Studies; Sulfonamides; Sunitinib; Treatment Outcome

Topics: Adolescent; Angiogenesis Inhibitors; Bone Neoplasms; Child; Female; Humans; Indazoles; Liver Neoplasms; Lung Neoplasms; Male; Osteosarcoma; Pyrimidines; Sulfonamides

Malignant gastrointestinal neuroectodermal tumor (GNET) is an aggressive rare tumor, primarily occurring in young adults with frequent local-regional metastases and recurrence after local control. The tumor is characterized by the presence of EWSR1-ATF1 or EWSR1-CREB1 and immunohistochemical positivity for S-100 protein without melanocytic marker positivity. Due to poor responses to standard sarcoma regimens, GNET has a poor prognosis, and development of effective systemic therapy is desperately needed to treat these patients. Herein, we present a patient with a small bowel GNET who experienced recurrent hepatic and skeletal metastases after a primary resection. Comprehensive genomic profiling (CGP) in the course of clinical care with DNA and RNA sequencing demonstrated the presence of an exon 7 to exon 6 EWSR1-CREB1 fusion in the context of a diploid genome with no other genomic alterations. In a clinical trial, the patient received a combination of 250 mg crizotinib with 600 mg pazopanib quaque die and achieved partial response and durable clinical benefit for over 2.8 years, and with minimal toxicity from therapy. Using a CGP database of over 50,000 samples, we identified 11 additional cases that harbor EWSR1-CREB1 and report clinicopathologic characteristics, as these patients may also benefit from such a regimen.

Topics: Adolescent; Adult; Anaplastic Lymphoma Kinase; Antineoplastic Combined Chemotherapy Protocols; Bone Neoplasms; Crizotinib; Female; Humans; Indazoles; Intestinal Neoplasms; Liver Neoplasms; Male; Middle Aged; Neuroectodermal Tumors; Oncogene Proteins, Fusion; Proto-Oncogene Proteins c-met; Pyrazoles; Pyridines; Pyrimidines; Receptor Protein-Tyrosine Kinases; Response Evaluation Criteria in Solid Tumors; Sulfonamides; Vascular Endothelial Growth Factor A; Young Adult

Targeted therapy is the first line treatment for patients with recurrent/metastatic gastrointestinal stromal tumors(GIST). Sunitinib is effective for patients who have failed imatinib, specially with c-kit exon 9 gene mutation. Tyrosine kinase inhibitors combined with partial hepatectomy may increase the overall survival of GIST patients with liver metastasis. Selective patients with recurrent or metastatic GIST can benefit from surgical resection. Regorafenib and pazopanib can provide a significant improvement in progression-free survival in patients after failure of standard treatment.

Topics: Benzamides; Disease-Free Survival; Gastrointestinal Neoplasms; Gastrointestinal Stromal Tumors; Hepatectomy; Humans; Imatinib Mesylate; Indazoles; Indoles; Liver Neoplasms; Phenylurea Compounds; Piperazines; Pyridines; Pyrimidines; Pyrroles; Recurrence; Sulfonamides; Sunitinib

Significant progress has been made in the identification of molecular targets and targeted therapy is becoming a realistic option for patients with tumors for which potential driver mutations are identified. We present a case that highlights that the identification of a potential driver mutation does not confirm it as a key mutational event in every case and emphasizes the need for ongoing research to enable therapy to be more accurately directed for the benefit of patients.

Topics: Adenocarcinoma; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Pancreatic Ductal; Fatal Outcome; Female; Humans; Indazoles; Liver Neoplasms; Microtubule-Associated Proteins; Middle Aged; Molecular Targeted Therapy; Mutation; Oncogenes; Pancreatic Neoplasms; Paraneoplastic Syndromes; Pyrimidines; Radiography; Receptor, Fibroblast Growth Factor, Type 3; Sulfonamides

Increasing studies implicate cancer stem cells (CSCs) as the source of resistance and relapse following conventional cytotoxic therapies. Few studies have examined the response of CSCs to targeted therapies, such as tyrosine kinase inhibitors (TKIs). We hypothesized that TKIs would have differential effects on CSC populations depending on their mechanism of action (anti-proliferative vs. anti-angiogenic).. We exposed human sarcoma cell lines to sorafenib, regorafenib, and pazopanib and assessed cell viability and expression of CSC markers (ALDH, CD24, CD44, and CD133). We evaluated survival and CSC phenotype in mice harboring sarcoma metastases after TKI therapy. We exposed dissociated primary sarcoma tumors to sorafenib, regorafenib, and pazopanib, and we used tissue microarray (TMA) and primary sarcoma samples to evaluate the frequency and intensity of CSC markers after neoadjuvant therapy with sorafenib and pazopanib. Parametric and non-parametric statistical analyses were performed as appropriate.. After functionally validating the CSC phenotype of ALDHbright sarcoma cells, we observed that sorafenib and regorafenib were cytotoxic to sarcoma cell lines (P < 0.05), with a corresponding 1.4 - 2.8 fold increase in ALDHbright cells from baseline (P < 0.05). In contrast, we observed negligible effects on viability and CSC sub-populations with pazopanib. At low doses, there was progressive CSC enrichment in vitro after longer term exposure to sorafenib although the anti-proliferative effects were attenuated. In vivo, sorafenib improved median survival by 11 days (P < 0.05), but enriched ALDHbright cells 2.5 - 2.8 fold (P < 0.05). Analysis of primary human sarcoma samples revealed direct cytotoxicity following exposure to sorafenib and regorafenib with a corresponding increase in ALDHbright cells (P < 0.05). Again, negligible effects from pazopanib were observed. TMA analysis of archived specimens from sarcoma patients treated with sorafenib demonstrated significant enrichment for ALDHbright cells in the post-treatment resection specimen (P < 0.05), whereas clinical specimens obtained longitudinally from a patient treated with pazopanib showed no enrichment for ALDHbright cells (P > 0.05).. Anti-proliferative TKIs appear to enrich for sarcoma CSCs while anti-angiogenic TKIs do not. The rational selection of targeted therapies for sarcoma patients may benefit from an awareness of the differential impact of TKIs on CSC populations.

Topics: Aldehyde Dehydrogenase 1 Family; Angiogenesis Inhibitors; Animals; Antigens, CD; Cell Line, Tumor; Cell Proliferation; Cell Survival; Female; Humans; Indazoles; Isoenzymes; Liver Neoplasms; Lung Neoplasms; Mice, Inbred NOD; Neoadjuvant Therapy; Neoplastic Stem Cells; Niacinamide; Phenylurea Compounds; Protein Kinase Inhibitors; Pyrimidines; Retinal Dehydrogenase; Sarcoma; Sorafenib; Sulfonamides; Tissue Array Analysis; Xenograft Model Antitumor Assays