Objective responses in patients with malignant melanoma or renal cell cancer in early clinical studies do not predict regulatory approval.

PURPOSE: Tumor responses in early-phase trials are used to determine whether new agents warrant further study. Given that spontaneous regressions are observed in melanoma and renal cell carcinoma, this study assessed whether tumor responses, particularly in these two tumor types, predict for future regulatory drug approval. EXPERIMENTAL DESIGN: The literature was reviewed to assess tumor response rates to cytotoxic agents in phase I and II trials in the following solid tumors: melanoma, renal cell carcinoma, non-small-cell lung cancer, breast cancer, ovarian cancer, colorectal cancer, and other solid tumors. Response rates were categorized and the relationship of these categories to the end point of regulatory drug approval was determined. RESULTS: Fifty-eight drugs were assessed in 100 phase I trials, and 46 of these drugs were also studied in 499 phase II trials. Higher overall response rates in both phase I trials (P = 0.03) and phase II trials (P < 0.0001) were predictive of regulatory approval. However, response in melanoma or renal cell carcinoma was not predictive for either phase I or phase II studies. CONCLUSIONS: For cytotoxic agents, although overall objective response rates reliably predict subsequent marketing approval, isolated responses in melanoma and renal cell carcinoma are not predictive.     

Safety and anti-tumor activity of sorafenib (Nexavar®) in combination with other anti-cancer agents: a review of clinical trials

Purpose

Sorafenib (Nexavar^®) is an oral multi-kinase inhibitor that inhibits Raf serine/threonine kinases and receptor tyrosine kinases involved in tumor growth and angiogenesis. Sorafenib has demonstrated preclinical and clinical activity against several tumor types, as a monotherapy and in combination with other anti-cancer agents.

Methods

This review summarizes the safety, pharmacokinetics, and anti-tumor activity of sorafenib combined with other targeted agents or cytotoxics from a series of Phase I/II trials in approximately 600 patients with advanced solid tumors.

Results

Sorafenib in combination with other agents was generally well tolerated, and most adverse events were mild to moderate in severity. Frequent drug-related toxicities were dermatologic, gastrointestinal, or constitutional. Most trials supported sorafenib 400 mg bid as the recommended dose for combination. Sorafenib generally had little effect on the pharmacokinetics of coadministered agents and vice versa. Preliminary anti-tumor activity was observed; overall disease control rates (partial response plus stable disease) ranged from 33 to 92%. Particularly promising activity was observed in patients with melanoma, hepatocellular carcinoma, and non-small-cell lung cancer receiving sorafenib plus paclitaxel/carboplatin, doxorubicin, and gefitinib, respectively.

Conclusions

Sorafenib demonstrated a good safety profile and encouraging anti-tumor effects when coadministered with other agents in patients with advanced solid tumors.     

Sorafenib: delivering a targeted drug to the right targets

Approved for the treatment of advanced renal cell carcinoma by the US FDA and other regulatory agencies, sorafenib is an agent with multiple targets that may also prove beneficial in other malignancies. Phase III trials are underway in melanoma, hepatocellular carcinoma and non-small-cell lung cancer. Scrutiny of the Phase II data and correlative studies conducted in that context suggests that inhibition of angiogenesis and signaling in tumor cells may play a part in the clinical efficacy of sorafenib. Although the vascular endothelial growth factor receptor inhibitors are the most populated class of targeted agents in cancer clinical trials, sorafenib may prove to have unique properties that distinguish it. A detailed discussion of the clinical trials in renal cell carcinoma, melanoma and hepatocellular carcinoma highlights what is known and what has yet to be understood about this agent.     

Investigation of Antitumor Effects of Sorafenib and Lapatinib Alone and in Combination on MCF-7 Breast Cancer Cells

Background: Breast cancer evolution and tumor progression are controlled by complex interactions betweensteroid receptors and growth factor receptor signaling. Aberrant growth factor receptor signaling can augmentor suppress estrogen receptor function in hormone-dependent breast cancer cells. Thus, we aimed to investigateantitumor effects of sorafenib and lapatinib alone and in combination on MCF-7 breast cancer cells. Materialsand Methods: Cytotoxicity of the sorafenib and lapatinib was tested in MCF-7 cells by XTT assays. 50, 25, 12.5and 6.25μM concentrations of sorafenib and 200, 100, 50 and 25μM concentrations of lapatinib were administeredalone and in combination. Results were evaluated as absorbance at 450nM and IC50 values are calculated accordingto the absorbance data Results: Both sorafenib and lapatinib showed concentration dependent cytotoxic effectson MCF-7 cells. Sorafenib exerted cytotoxic effects with an IC50 value of 32.0μM; in contrast with lapatinib theIC50 was 136.6μM. When sorafenib and lapatinib combined, lapatinib increased cytotoxic effects of sorafenib at itsineffective concentrations. Also at the concentrations where both drugs had cytotoxic effects, combination showstrong anticancer effects and killed approximately 70 percent of breast cancer cells. Conclusions: Combinationsof tyrosine kinase inhibitors and cytotoxic agents or molecular targeted therapy has been successful for manytypes of cancer. The present study shows that both sorafenib and lapatinib alone are effective in the treatmentof breast cancer. Also a combination of these two agents may be a promising therapeutic option in treatment ofbreast cancer.     

Molecular targeted therapies for cancer: sorafenib mono-therapy and its combination with other therapies (review)

Sorafenib is an oral multikinase inhibitor that acts by inhibiting tumor growth and disrupting tumor microvasculature through antiproliferative, anti-angiogenic and proapoptotic effects. It exerts these effects via inhibition of multiple targets including Raf serine/threonine kinases, vascular endothelial growth factor receptor tyrosine kinases; VEGFR-1, VEGFR-2, VEGFR-3 and platelet-derived growth factor receptor?β (PDGFR-β). Current literature shows that the deregulated signaling through these receptors is commonly seen in human tumors. In addition, sorafenib is also shown to induce apoptosis through downregulation of Mcl-1 in many cancer types. Hence, sorafenib as a single agent has shown promising activity in some cancers such as renal cell carcinoma (RCC), hepatocellular carcinoma (HCC) and thyroid cancers. Currently, the drug holds FDA approval for the treatment of advanced RCC and unresectable HCC. However, many clinical studies have indicated several limitations to the application of sorafenib as a single agent in various other cancers. Owing to these reasons and the potential of sorafenib to synergize with other anticancer therapies, its combination with other targeted agents and chemotherapy has been widely explored with promising results. In addition, it has also shown synergistic results when combined with radiation. This review summarizes the current basic and clinical studies on the effects and mechanisms of sorafenib either administered alone or in combination with other anticancer treatments.     

Current status of angiogenesis inhibitors combined with radiation therapy

Angiogenesis inhibitors combined with cytotoxic chemotherapy have recently entered routine oncological practice. Several rationales exist for combining these agents with ionizing radiation, a primary curative cancer treatment, either in bimodal or trimodal fashion, i.e. with or without additional chemotherapy. More than 20 different anti-angiogenic agents have been studied in preclinical animal tumor models. This systematic review compares the results of preclinical studies published before February 2006. The combination of vascular endothelial growth factor (VEGF) inhibitors with irradiation consistently resulted in improved tumor growth delay (at least additive effects), despite different radiation schedules, drugs and doses, and combination regimens. Only two studies evaluated tumor control dose (TCD)50 as a measure of tumor cure (radiation dose yielding permanent local control in 50% of the tumors). While anti-VEGF receptor (VEGFR) antibody treatment improved the outcome, a VEGFR tyrosine kinase inhibitor showed negative results. For agents interfering with other pathways, the results are also not consistent, although most studies were positive. Trimodal approaches seem to improve tumor growth delay even further. Importantly, both radiotherapy schedule and sequence of the modalities in combined treatment may impact on the outcome. Hence, further preclinical studies examining these parameters need to be conducted. While preclinical research is ongoing, phase I and II clinical trials with bevacizumab, combretastatin A-4, thalidomide and different receptor tyrosine kinase inhibitors, usually combined with radio- and chemotherapy, have been designed. Early results suggest that acute toxicity is acceptable, planned surgery after such treatment is feasible, and that further evaluation of such combined modality treatment is warranted.     

Interferons in the treatment of solid tumors. A general review

A potential activity of interferons in the treatment of solid tumors has been suggested by in vitro experiments and, more recently, by phase I trials. Phase II trials have demonstrated a possible antitumoral activity in treating some solid tumors: malignant melanoma, renal cell carcinoma, ovarian adenocarcinoma, carcinoid tumor, superficial bladder cancer. Further trials are necessary to establish the precise role of interferons in treating solid tumors, when administered alone or in combination.     

Pharmacokinetic evaluation of gefitinib when administered with chemotherapy

Gefitinib is a small-molecule agent specifically targeted to inhibit the epidermal growth factor receptor-tyrosine kinase (EGFR-TK). Tumor responses have been achieved with gefitinib treatment in large, randomized monotherapy trials. In preclinical studies, gefitinib has shown additive and even supra-additive antitumor effects when combined with different cytotoxic agents. In phase I clinical trials, gefitinib was found to be well tolerated, with clinical efficacy observed well below the maximum tolerated dose. The pharmacokinetics of gefitinib allow it to be administered as a once-daily oral tablet. Several phase I studies have investigated the safety of gefitinib at daily doses of 250 mg or 500 mg in combination with chemotherapy agents for first-line treatment of a variety of common solid tumors. The potential for drug interactions between gefitinib and cytotoxic agents was evaluated through pharmacokinetic assessments. A randomized, crossover study investigated the interaction of gefitinib and carboplatin/paclitaxel in the treatment of advanced non-small-cell lung cancer (NSCLC). A second trial with an open-label design studied the combination of gefitinib with cisplatin/gemcitabine in patients with a variety of solid tumors, including NSCLC. In both pilot studies, the addition of gefitinib to chemotherapy did not increase the exposure of any of the chemotherapy agents tested. However, increased exposure to gefitinib was seen with the carboplatin/paclitaxel regimen. The addition of gefitinib to these chemotherapy regimens was generally well tolerated, and there was no apparent increase in higher-grade toxicity. Additional trials are evaluating gefitinib treatment in combination with chemotherapy.     

Targeting angiogenesis in metastatic breast cancer

Angiogenesis has become an important target in the treatment of several solid tumors, including breast cancer. As monotherapy, antiangiogenic agents have demonstrated limited activity in metastatic breast cancer (MBC); therefore, they have generally been developed for use in combination with chemotherapies. Thus far, the experience with antiangiogenic agents for MBC has been mixed. The results from one study assessing addition of the monoclonal antibody bevacizumab to paclitaxel led to approval of bevacizumab for MBC. However, the modest improvement of progression-free survival rates in subsequent MBC studies has led to reappraisal of bevacizumab. Phase III studies have not produced evidence supporting use of the multikinase inhibitor sunitinib alone or in combination with MBC chemotherapy. Experience with sorafenib in a phase IIb program indicates potential when used in select combinations, particularly with capecitabine; however, phase III confirmatory data are needed. Although antiangiogenic therapies combined with chemotherapy have increased progression-free survival rates for patients with MBC, increases in overall survival times have not been observed. Some studies have tried to combine antiangiogenic agents such as bevacizumab and sunitinib or sorafenib, but that approach has been limited because of toxicity concerns. Sequential use of antiangiogenic agents with differing mechanisms of action may be an effective approach. Despite setbacks, angiogenesis will likely remain an important target of treatment for selected patients with MBC.     

Sorafenib: recent update on activity as a single agent and in combination with interferon-alpha2 in patients with advanced-stage renal cell carcinoma

Metastatic renal cell carcinoma does not respond favorably to conventional treatment strategies and is not very responsive to cytokine therapy. Therefore, novel targeted treatment approaches have been explored for patients with renal cancer who have chemotherapy-refractory disease. Sorafenib (BAY 43-9006) is a smallmolecule inhibitor that has been shown to target members of multiple classes of tyrosine kinases that are known to be involved in tumor cell proliferation and tumor angiogenesis. These kinases include vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, VEGFR-3, platelet-derived growth factor receptor, Flt-3, c-kit, and Raf kinases. Based on the significant improvement in progressionfree survival, sorafenib received Food and Drug Administration approval in December 2005 for the treatment of renal cell carcinoma. In combination studies, sorafenib with other antitumor agents has demonstrated significant clinical activity in patients with renal cell carcinoma. As discussed in this mini-review, the clinical potency of sorafenib as a single agent or in combination with other antitumor agents is being evaluated in several ongoing clinical trials in patients with renal carcinoma.     

Evidenced-based medicine and future direction of Taxol

Taxol was introduced for the clinical treatment of several solid tumor malignancies in the 1990s. It has been established that primary chemotherapy based on Taxol is the standard for non-small cell lung cancer and epithelial ovarian cancer. After initial chemotherapy containing doxorubicin, sequential administration of Taxol for advanced or metastatic breast cancer is recommended by the Food and Drug Administration in the United States. Taxol-based chemotherapy and/or concurrent chemoradiation for head and neck cancer, esophageal carcinoma, urothelial and prostate cancer are under investigation, but these trials have not produced evidence showing that they are superior to the present standard treatment for these malignancies. Although phase I/II trials of Taxol combined with new agents such as vinorelbine, topotecan, CPT-11 and others may demonstrate efficacy to a certain extent for some solid tumor malignancies, a phase III study will be required in the next stage. Taxol combined with other agents focusing on molecular targets will be an important approach in next decade. Inhibition of signal transduction by a noncytotoxic agent such as herceptine has the potential to enhance the cytotoxic effect of Taxo.     

Sorafenib: Recent Update on Activity as a Single Agent and in Combination with Interferon-α2 in Patients with Advanced-Stage Renal Cell Carcinoma

Metastatic renal cell carcinoma does not respond favorably to conventional treatment strategies and is not very responsive to cytokine therapy. Therefore, novel targeted treatment approaches have been explored for patients with renal cancer who have chemotherapy-refractory disease. Sorafenib (BAY 43-9006) is a smallmolecule inhibitor that has been shown to target members of multiple classes of tyrosine kinases that are known to be involved in tumor cell proliferation and tumor angiogenesis. These kinases include vascular endothelial growth factor receptor (VEGFR)–1, VEGFR-2, VEGFR-3, platelet-derived growth factor receptor, Flt-3, c-kit, and Raf kinases. Based on the significant improvement in progressionfree survival, sorafenib received Food and Drug Administration approval in December 2005 for the treatment of renal cell carcinoma. In combination studies, sorafenib with other antitumor agents has demonstrated significant clinical activity in patients with renal cell carcinoma. As discussed in this mini-review, the clinical potency of sorafenib as a single agent or in combination with other antitumor agents is being evaluated in several ongoing clinical trials in patients with renal carcinoma.     

Radiosensitization of tumor-targeted radioimmunotherapy with prolonged topotecan infusion in human breast cancer xenografts

Clinical radioimmunotherapy (RIT) of solid tumors holds great promise, but as yet has been unable to deliver tumoricidal radiation doses without unacceptable toxicity. Our experimental approach aims to potentiate the therapeutic action of radioimmunoconjugates at the tumor site and thus improve the efficacy of RIT by combination with other treatment modalities. The topoisomerase I inhibitors are a unique class of chemotherapeutic agents that interfere with DNA breakage-reunion by inhibiting the action of topoisomerase I. Preclinical studies suggest that prolonged infusion of topoisomerase I inhibitors enhances cell toxicity due to ionizing radiation. We evaluated the efficacy of combined treatment with continuous administration of topotecan and 90Y-MX-DPTA BrE3 monoclonal antibody (which recognizes an epitope of breast epithelial mucin expressed in most breast cancers) on human mammary carcinoma xenografts in nude mice. Topotecan or 90Y-BrE3 treatment alone delayed overall tumor growth rate transiently but did not affect survival. The combination of RIT with topotecan substantially reduced growth of relatively large established tumors and caused complete tumor regressions and prolonged tumor-free survival in a substantial proportion of treated animals. In vitro studies demonstrated an increase in apoptotic rate and a decrease in cell proliferation of tumor cell lines treated with this combination. We combined the radiosensitization property of topotecan and the specificity of systemic RIT to establish a novel therapy for solid tumors in an experimental tumor xenograft model.     

Marimastat (BB2516): Current status of development

Marimastat (BB-2516) is the first matrix metalloproteinase inhibitor to have entered clinical trials in the field of oncology. It has excellent bioavailability and has completed phase I and II trials. Phase I studies involved healthy volunteers who received short courses of marimastat; these were well tolerated. Symptoms experienced by many patients with various malignancies included severe joint and muscle pain which were debilitating in >60% of patients at doses >50 mg bid. These symptoms were reversible on discontinuation of the drug, and their incidence has been decreased by using marimastat 10 mg bid, the dose used in current studies. Phase II studies involved the use of serum tumor markers as surrogate indicators of antitumor activity. Six studies in colorectal, ovarian, and prostate cancer have been completed and pooled analysis has demonstrated a dose-dependent biological effect (as defined by the authors); 58% of patients respond at doses >50 mg bid. Effects on tumor markers were associated with increased survival. Small phase II studies have suggested potential activity in pancreatic and gastric cancer and have demonstrated the safety of combining cytotoxic chemotherapeutic agents with marimastat. Ongoing phase III studies are investigating the effects of marimastat in addition to chemotherapy in the treatment of small cell lung cancer and pancreatic and gastric carcinoma.     

Safety, pharmacokinetics, and preliminary antitumor activity of sorafenib: a review of four phase I trials in patients with advanced refractory solid tumors

Sorafenib is an oral multikinase inhibitor that inhibits Raf serine/threonine kinases and receptor tyrosine kinases involved in tumor growth and angiogenesis. It has demonstrated preclinical and clinical activity in several tumor types. Sorafenib 400 mg twice daily (bid) has been approved in several countries worldwide for the treatment of renal cell carcinoma. This review summarizes key safety, pharmacokinetic, and efficacy data from four phase I, single-agent, dose-escalation studies with sorafenib in patients with advanced refractory solid tumors (n = 173). These trials followed different treatment regimens (7 days on/7 days off, n = 19; 21 days on/7 days off, n = 44; 28 days on/7 days off, n = 41; or continuous dosing, n = 69) to establish the optimum dosing schedule. Sorafenib was generally well tolerated; most adverse events were mild to moderate in severity up to the defined maximum-tolerated dose of 400 mg twice daily (bid). The most frequently reported drug-related adverse events at any grade included fatigue (40%), anorexia (35%), diarrhea (34%), rash/desquamation (27%), and hand-foot skin reaction (25%). Sorafenib demonstrated preliminary antitumor activity, particularly among patients with renal cell carcinoma or hepatocellular carcinoma: overall, two of 137 evaluable patients achieved partial responses and 38 (28%) had stable disease. Although there was high interpatient variability in plasma pharmacokinetics across these studies, this was not associated with an increased incidence or severity of toxicity. Preliminary studies suggest that phosphorylated extracellular signal-related kinase in tumor cells or peripheral blood lymphocytes may be a useful biomarker for measuring and, ultimately, predicting the effects of sorafenib. Based on these findings, continuous daily 400 mg bid sorafenib was chosen as the optimal regimen for phase II/III studies. Trials are ongoing in renal cell carcinoma, hepatocellular carcinoma, melanoma, and non-small cell lung cancer.     

Implications of vessel co-option in sorafenib-resistant hepatocellular carcinoma

The reason why tumors generally have a modest or transient response to antiangiogenic therapy is not well under-stood. This poses a major challenge for sorafenib treatment of advanced hepatocellular carcinoma (HCC) where alternate therapies are lacking. We recently published a paper entitled “Co-option of liver vessels and not sprouting angiogenesis drives acquired sorafenib resistance in hepatocellular carcinoma” in theJournal of the National Cancer Institute, providing a potential explanation for this limited beneift. We found that in mice bearing HCCs that had acquired resistance to sorafenib, tumors had switched from using angiogenesis for growth to co-opting the liver vas-culature by becoming more invasive. Accumulating evidence suggests that many human tumor types may use vessel co-option, which has profound implications for the use of anti-angiogenic agents for cancer treatment.     

Vision of the future: capecitabine

Capecitabine is a thymidine phosphorylase (TP)-activated oral fluoropyrimidine, rationally designed to generate 5-fluorouracil (5-FU) preferentially within tumors. This tumor selectivity is achieved through exploitation of the significantly higher activity of TP in tumor compared with healthy tissue. The high single-agent activity of capecitabine in breast and colorectal cancer suggests that capecitabine may have a role in the treatment of other tumor types that are sensitive to 5-FU, such as pancreatic cancer. Tumor types known to have a high level of TP activity, such as renal cancer, are especially attractive targets for capecitabine therapy. Capecitabine has potential as monotherapy in these tumor types, or as a combination partner for other cytotoxic agents with different mechanisms of action and little overlap of key toxicities. In particular, some cytotoxic drugs, such as the taxanes and cyclophosphamide, are known to upregulate TP activity in tumor tissue, offering the potential for synergistic action. The combination of capecitabine and docetaxel has demonstrated significant activity in women with anthracycline-pretreated breast cancer, and is the only cytotoxic combination to significantly increase survival compared with standard therapy in this setting. In addition, capecitabine as monotherapy or in combination with other cytotoxic agents has shown encouraging activity in pancreatic, ovarian, and renal cell cancers. This article discusses recent data from clinical trials investigating capecitabine in a range of tumor types, highlighting the potential future role of capecitabine as an alternative to traditional i.v. chemotherapy.     

5,6-Dimethylxanthenone-4-Acetic Acid (DMXAA)

Currently, there is a great deal of interest in drugs that target tumor vasculature and their therapeutic potential in combination regimens for the treatment of cancer. This review focuses on one of the vascular disrupting agents, 5-6-dimethylxanthenone 4-acetic acid (DMXAA), and the rationale for its combination with standard taxane-based chemotherapy. DMXAA and taxanes have different mechanisms of action and, in combination, demonstrate at least additive activity against preclinical solid tumors. Their clinical adverse-effect and pharmacologic profiles as single agents appear to render these agents suitable for use in combination. Phase I studies of DMXAA have identified a range of doses for combination clinical trials. In addition, the clinical indications and chemotherapy doses for combination clinical studies have been selected from positive randomized controlled trials of taxanes in advanced cancers. A phase II clinical trials program of combination studies with DMXAA is now underway; paclitaxel and carboplatin in patients with NSCLC and ovarian cancer and docetaxel in patients with hormone-refractory prostate cancer are being evaluated.     

Sorafenib enhances pemetrexed cytotoxicity through an autophagy-dependent mechanism in cancer cells

Pemetrexed (ALIMTA, Lilly) is a folate antimetabolite that has been approved by the U.S. Food and Drug Administration for the treatment of non-small cell lung cancer and has been shown to stimulate autophagy. In the present study, we sought to further understand the role of autophagy in response to pemetrexed and to test if combination therapy could enhance the level of toxicity through altered autophagy in tumor cells. The multikinase inhibitor sorafenib (Nexavar, Bayer), used in the treatment of renal and hepatocellular carcinoma, suppresses tumor angiogenesis and promotes autophagy in tumor cells. We found that sorafenib interacted in a greater than additive fashion with pemetrexed to increase autophagy and to kill a diverse array of tumor cell types. Tumor cell types that displayed high levels of cell killing after combination treatment showed elevated levels of AKT, p70 S6K, and/or phosphorylated mTOR, in addition to class III receptor tyrosine kinases such as platelet-derived growth factor receptor beta and VEGF receptors, known in vivo targets of sorafenib. In xenograft and in syngeneic animal models of mammary carcinoma and glioblastoma, the combination of sorafenib and pemetrexed suppressed tumor growth without deleterious effects on normal tissues or animal body mass. Taken together, the data suggest that premexetred and sorafenib act synergistically to enhance tumor killing via the promotion of a toxic form of autophagy that leads to activation of the intrinsic apoptosis pathway, and predict that combination treatment represents a future therapeutic option in the treatment of solid tumors.     

Statins potentiate cytostatic/cytotoxic activity of sorafenib but not sunitinib against tumor cell lines in vitro

The aim of this study was to investigate the potential cytostatic/cytotoxic effects of HMG-CoA reductase inhibitors and two orphan drugs registered for the treatment of advanced renal cell carcinoma, i.e. sorafenib and sunitinib against several different tumor cell lines. Cytostatic/cytotoxic effects were measured using crystal violet or MTT reduction assays. Cell cycle regulation was investigated using flow cytometry and Western blotting. The combination of lovastatin and sorafenib (but not sunitinib) produced synergistic cytostatic/cytotoxic effects against all tested tumor cell lines. In this study, an impairment of the protein prenylation, especially geranylgeranylation, resulted predominantly in the potentiation of the cytostatic/cytotoxic activity of sorafenib, in cell cycle arrest in G1 phase, and, in poor induction of apoptosis. Moreover, due to the fact that it has been well documented that sorafenib compromises the heart function, we studied the interaction of lovastatin and sorafenib using rat cardiomyoblast line H9c2. The combination showed strong synergistic cardiotoxic effects. Statins and tyrosine kinase inhibitors were used at doses that are achievable clinically, which makes the combination promising for future studies, especially in urooncology, bearing in mind possible cardiotoxic effects.