Targeted therapy for metastatic renal cell carcinoma

The discovery of a relationship for the VHL tumor suppressor gene, hypoxia inducible factor-1 alpha, and vascular endothelial growth factor in the growth of clear-cell renal cell carcinoma (RCC) has identified a pathway for novel targeted therapy. This study evaluated the impact of these agents on metastatic RCC (mRCC), and highlights recent phase II and III trials. A systematic review examined the clinical data for novel targeted agents in mRCC, with a focus on randomized phase II and III trials of the novel targeted agents sunitinib, temsirolimus, sorafenib, and bevacizumab. Several agents, including the small-molecule targeted inhibitors sunitinib, temsirolimus, sorafenib, and the monoclonal antibody bevacizumab, have demonstrated antitumor activity in randomized trials. Superior activity was found with sunitinib and temsirolimus versus cytokines in first-line therapy. Improved progression-free survival was reported with sorafenib and bevacizumab given second-line compared with placebo. Targeted therapies show promising activity in this disease, and they have been changing patient management. Sunitinib and sorafenib were recently approved by the US Food and Drug Administration for treatment of mRCC, These drugs are currently included in clinical practice.

[Palliative and supportive therapy in cases of renal cell carcinoma]

At the time of diagnosis, 25-30% of all patients with renal cell carcinoma already present with metastatic disease. Furthermore, 20-30% of patients with renal cell carcinoma will have progressive disease despite radical nephrectomy with complete tumor resection. In this review, we discuss the current therapeutic options for patients with metastatic renal cell carcinoma: These include palliative radical nephrectomy, surgery of metastasis, tumor embolisation and medical treatment options (e.g. immunotherapy, chemotherapy and targeted therapy), as well as supportive pain treatment.

Tyrosine kinase inhibitors of vascular endothelial growth factor receptors in clinical trials: current status and future directions

Angiogenesis plays a central role in the process of tumor growth and metastatic dissemination. The vascular endothelial growth factor (VEGF) family of peptide growth factors and receptors are key regulators of this process. Agents directed either against VEGF or VEGF receptors (VEGFRs) have been developed. The tyrosine kinase inhibitors of VEGFRs are low-molecular-weight, ATP-mimetic proteins that bind to the ATP-binding catalytic site of the tyrosine kinase domain of VEG-FRs, resulting in blockade of intracellular signaling. Several of these agents are currently in different phases of clinical development. Large randomized phase III trials have demonstrated the efficacy of sunitinib and sorafenib in the treatment of patients affected by gastrointestinal stromal tumors and renal cancer refractory to standard therapies, respectively. Positive results also have been reported with the combination of ZD6474 and chemotherapy in previously treated non-small cell lung cancer patients. For other agents, such as vatalanib, contrasting outcomes in metastatic colorectal cancer patients have been reported: the final results of these trials are expected in 2006. However, several key questions remain to be addressed, regarding the choice of an adequate dose or schedule, the presence of "off-target" effects, the safety of long-term administration, and the research of new clinical end points or methodological approaches for the optimal clinical development of these agents.

Anti-angiogenic drugs: from bench to clinical trials

Angiogenesis, the generation of new capillaries through a process of pre-existing microvessel sprouting, is under stringent control and normally occurs only during embryonic and post-embryonic development, reproductive cycle, and wound repair. However, in many pathological conditions (solid tumor progression, metastasis, diabetic retinopathy, hemangioma, arthritis, psoriasis and atherosclerosis among others), the disease appears to be associated with persistent upregulated angiogenesis. The development of specific anti-angiogenic agents arises as an attractive therapeutic approach for the treatment of cancer and other angiogenesis-dependent diseases. The formation of new blood vessels is a complex multi-step process. Endothelial cells resting in the parent vessels are activated by an angiogenic signal and stimulated to synthesize and release degradative enzymes allowing endothelial cells to migrate, proliferate and finally differentiate to give rise to capillary tubules. Any of these steps may be a potential target for pharmacological intervention. In spite of the disappointing results obtained initially in clinical trials with anti-angiogenic drugs, recent reports with positive results in phases II and III trials encourage expectations in their therapeutic potential. This review discusses the current approaches for the discovery of new compounds that inhibit angiogenesis, with emphasis on the clinical developmental status of anti-angiogenic drugs.

Small molecule tyrosine kinase inhibitors in the treatment of solid tumors: an update of recent developments

Small molecule tyrosine kinase inhibitors (TKIs) are developed to block intracellular signaling pathways in tumor cells, leading to deregulation of key cell functions such as proliferation and differentiation. Over 25 years ago, tyrosine kinases were found to function as oncogenes in animal carcinogenesis; however, only recently TKIs were introduced as anti cancer drugs in human cancer treatment. Tyrosine kinase inhibitors have numerous good qualities. First, in many tumor types they tend to stabilize tumor progression and may create a chronic disease state which is no longer immediately life threatening. Second, side effects are minimal when compared to conventional chemotherapeutic agents. Third, synergistic effects are seen in vitro when TKIs are combined with radiotherapy and/or conventional chemotherapeutic agents. In this article, we will give an update of the tyrosine kinase inhibitors that are currently registered for use or in an advanced stage of development, and we will discuss the future role of TKIs in the treatment of solid tumors. The following TKIs are reviewed: Imatinib (Gleevec/Glivec), Gefitinib (Iressa), Erlotinib (OSI-774, Tarceva), Lapatinib (GW-572016, Tykerb), Canertinib (CI-1033), Sunitinib (SU 11248, Sutent), Zactima (ZD6474), Vatalanib (PTK787/ZK 222584), Sorafenib (Bay 43-9006, Nexavar), and Leflunomide (SU101, Arava).

Targeted therapy for renal cell carcinoma: a new therapeutic paradigm

Renal cell carcinoma is the most common tumor of the kidney. It has an unpredictable behavior and poor response to systemic therapy. Developing newer therapy for this disease is a priority considering the high recurrence rate and the small subset of patients who benefit from the use of cytokines such as interferon-alpha or interleukin-2. Identifying molecular targets and targeting various biomarkers has revolutionized the therapeutic approach to advanced and metastatic renal cell carcinoma. Although some of the antiangiogenic agents and receptor tyrosine kinase inhibitors appear promising, further understanding of their mechanism of action and the patient population who would benefit most from such agents is still being explored. As numerous targeted agents are entering the clinical investigation arena in a relatively short period of time, newer challenges in renal cell carcinoma therapeutics are emerging. Some of the future challenges in using targeted antineoplastic agents in renal cell carcinoma will include evaluating their long-term safety and benefit, using the particular drug in the appropriate patient population after appropriate stratification and studying the combination of some of these drugs for synergy or additive effects.

Sorafenib

PURPOSE OF REVIEW

Sorafenib is an oral, multikinase inhibitor that was recently approved for use in metastatic renal cancer. It is currently undergoing investigation in locally advanced renal cancer and in other tumor types.

RECENT FINDINGS

Sorafenib was initially developed as an inhibitor of Raf kinase; however, it has broad spectrum activity against multiple tyrosine kinases, including angiogenic factors VEGFR and PDGFR. Common toxicities experienced with sorafenib include hypertension, hand-foot syndrome, rash, diarrhea and fatigue. Early clinical trials suggested that sorafenib acts as a cytostatic agent, as many patients experienced prolonged disease stabilization but insufficient tumor shrinkage to meet RECIST criteria for response. To assess whether sorafenib's growth inhibition translated into a clinical benefit, a phase II randomized discontinuation trial was designed. This trial demonstrated that sorafenib increased progression-free survival in patients with metastatic renal cell cancer; the phase II data were confirmed in a large international phase III trial.

SUMMARY

In this review, we will discuss the clinical development of sorafenib and its role in the treatment of renal cancer. Additionally, we will highlight critical methods of clinical trial design and biomarker development that contribute to the development of sorafenib.

Targeting VEGF-A to treat cancer and age-related macular degeneration

Inhibiting angiogenesis is a promising strategy to treat cancer and several other disorders, including intraocular neovascular syndromes. The identification of vascular endothelial growth factor (VEGF)-A as a major regulator of normal and pathological angiogenesis has enabled significant progress toward effective treatments for such disorders. Several VEGF inhibitors have been recently approved by the U.S. Food and Drug Administration for the treatment of cancer and the neovascular form of age-related macular degeneration. This review summarizes the basic biology of VEGF-A and illustrates the clinical progress in targeting this molecule.

Place de la néphrectomie dans la prise en charge des cancers du rein métastatiques

Metastatic kidney cancer is still a devastating disease but it represents a very heterogeneous situation. Some patients will have a median survival limited to some months, while others will live several years. If the initial diagnosis of kidney cancer at metastatic stage is quite uncommon, it raises the question of whether or not performing initial nephrectomy. The point was long debated as it was suggested that initial nephrectomy could result in a spontaneous metastase regression and protect against local complications (hematuria, local pain,...). Today, nephrectomy must not be systematic, as effective alternative treatments are often available. Furthermore spontaneous postoperative metastasis regression is unusual. Two recent prospective randomized trials clarified the impact of initial nephrectomy. It is now accepted that initial surgery prior to systemic immunotherapy results in 30% survival benefit. However this procedure should only be considered for highly selected cases: patients in otherwise good condition (ECOG 0-1), macroscopically complete local resection, no supra-hepatic caval thrombus, and patients suitable for systemic immunotherapy treatment. Several questions remain unanswered, such as lymph node dissection to be performed, and its real survival impact. Furthermore the definition of "suitable" patients for immunotherapy has to be clarified, based on the recent results from the Percy Quatro study. It would probably be more effective to consider only patients with an expected good survival benefit using immunotherapy, such as those classified as "good prognosis" based on the CRECY criteria. Finally the development of new drugs, targeting mainly the angiogenic pathway may lead to different future indications in this setting.

Antiangiogenetische Therapie beim Nierenzellkarzinom

Sunitinib and Sorafenib are both effective angiogenetic inhibitors for the treatment of renal cell carcinoma. With these drugs of a new class of chronic therapy is performed. During chronic treatment, the inherent side effects may necessitate stopping the application of these drugs thus preventing the required effective therapy. Most of the effects can be avoided or attenuated by prophylaxis. In this paper the published data are reviewed and added with our experience in 138 patients over up to two and a half years.

Therapeutic targets in melanoma: MAPKinase pathway

Recent progress in our understanding of the genetic alterations that occur in the pathogenesis of melanoma provides exciting opportunities for therapy. The most important signaling pathways in melanoma lie downstream of NRAS: the RAS-BRAF-MAPK pathway. A great deal of attention has been focused on the high mutation rate in the BRAF oncogene, which approaches 60%, because BRAF itself is an appealing drug substrate and because of the central contribution of BRAF function to melanoma development that the mutation rate signifies. Agents that specifically target BRAF, such as sorafenib, as well as new molecules that function both upstream and downstream of BRAF, are being actively investigated.

A phase II trial of continuous low-dose oral cyclophosphamide and celecoxib in patients with renal cell carcinoma

PURPOSE

The lack of effective systemic therapies for patients with advanced renal cell carcinoma (RCC) has stimulated interest in evaluating novel treatment strategies for this disease.

METHODS

This was a two-institution, two-stage, phase II trial of continuous low-dose oral cyclophosphamide (50 mg daily) in combination with celecoxib (400 mg twice daily) in patients with progressive, locally advanced or metastatic RCC. The primary endpoint was disease control rate (DCR) defined as the number of patients with complete (CR) or partial response (PR) or prolonged (> or =6 months) stable disease (SD). Secondary endpoints included time to progression and toxicity.

RESULTS

Between May 2001 and January 2003, 36 patients were enrolled onto the trial of which 32 were evaluable for response. One patient had a PR and three others had SD for longer than 6 months (DCR 12.5%, 95% CI 3.5-29.0%). The median progression free survival was 3.5 months (95% CI, 1.9-4.1 months) and the median overall survival was 14.5 months (95% CI, 8.4-20.8 months). One patient experienced grade five gastrointestinal bleeding. Otherwise, the treatment was well tolerated.

CONCLUSIONS

Although generally well tolerated, continuous therapy with low-dose cyclophosphamide and celecoxib had limited activity in RCC.

New developments in chemotherapy for advanced non-small cell lung cancer

PURPOSE OF REVIEW

The treatment of patients with advanced non-small cell lung cancer has changed considerably in the past decade. This paper reviews the most significant changes seen in chemotherapy and the most promising new agents in development for this disease.

RECENT FINDINGS

Chemotherapy prolongs survival and improves quality of life in patients with a good performance status and appears to alleviate disease-related symptoms in patients with a lower performance status. Platinum-based regimens became standard; none of the third-generation drug combinations seemed to be superior to the others. Nonplatinum combinations are reasonable alternatives now and offer a better toxicity profile in certain populations. Attempts to add molecular-targeted therapy to combination chemotherapy have failed except for bevacizumab. New compounds such as pemetrexed, bortezomib, TLK286, bevacizumab, and the epothilones are currently being evaluated in non-small cell lung cancer.

SUMMARY

Management of non-small cell lung cancer has improved considerably in the past decade. The overall benefit of chemotherapy over supportive care has been shown, platinum-based doublets have been established, nonplatinum regimens have been developed, chemotherapy has been used more broadly in subgroups of patients who have been previously neglected, and a shorter chemotherapy duration has been shown to be equally effective. After hitting a plateau in the benefit of chemotherapy, new drugs with novel action mechanisms such as the ones described here offer hope to improve therapy for this disease.

Cytotoxic synergy between the multikinase inhibitor sorafenib and the proteasome inhibitor bortezomibin vitro: induction of apoptosis through Akt and c-Jun NH2-terminal kinase pathways

This study was undertaken to characterize preclinical cytotoxic interactions for human malignancies between the multikinase inhibitor sorafenib (BAY 43-9006) and proteasome inhibitors bortezomib or MG132. Multiple tumor cell lines of varying histiotypes, including A549 (lung adenocarcinoma), 786-O (renal cell carcinoma), HeLa (cervical carcinoma), MDA-MB-231 (breast), K562 (chronic myelogenous leukemia), Jurkat (acute T-cell leukemia), MEC-2 (B-chronic lymphocytic leukemia), and U251 and D37 (glioma), as well as cells derived from primary human glioma tumors that are likely a more clinically relevant model were treated with sorafenib or bortezomib alone or in combination. Sorafenib and bortezomib synergistically induced a marked increase in mitochondrial injury and apoptosis, reflected by cytochrome c release, caspase-3 cleavage, and poly(ADP-ribose) polymerase degradation in a broad range of solid tumor and leukemia cell lines. These findings were accompanied by several biochemical changes, including decreased phosphorylation of vascular endothelial growth factor receptor-2, platelet-derived growth factor receptor-beta, and Akt and increased phosphorylation of stress-related c-Jun NH2-terminal kinase (JNK). Inhibition of Akt was required for synergism, as a constitutively active Akt protected cells against apoptosis induced by the combination. Alternatively, the JNK inhibitor SP600125 could also protect cells from apoptosis induced by the combination, indicating that both inhibition of Akt and activation of JNK were required for the synergism. These findings show that sorafenib interacts synergistically with bortezomib to induce apoptosis in a broad spectrum of neoplastic cell lines and show an important role for the Akt and JNK pathways in mediating synergism. Further clinical development of this combination seems warranted.

Targeted Approaches for Treating Advanced Clear Cell Renal Carcinoma

The mainstay of any curative treatment in renal cell carcinoma (RCC) is surgery. In the case of metastatic disease at presentation, a radical nephrectomy is recommended to good performance status patients prior to the start of cytokine treatment. Interferon (IFN)-a offers in a small but significant percentage of patients advantage in overall survival. Interleukin (IL)-2-based therapy gives similar survival rates. To date, hormonal therapy and chemotherapy do not have a proven impact on survival. Recent insights demonstrate that the majority of clear cell RCC harbor abnormalities of the von Hippel-Lindau (VHL) gene. This gene plays a key role in the stimulation of angiogenesis by vascular endothelial growth factor (VEGF) in this highly vascularized tumor. This opens interesting new treatment strategies including blockade of VEGF with the monoclonal antibody bevacizumab (Avastin) and inhibition of VEGF receptor tyrosine kinases with small oral molecules such as sunitinib (SU11248, Sutent) or PTK787. Likewise, inhibition of the Raf kinase pathway with oral sorafenib (Bay 43-9006, Nexavar) or inhibition of the mTOR pathway with intravenous CCI-779 are under investigation. Preliminary clinical results with all these compounds are promising, and the results of ongoing first-line phase III studies will become available in the next years.

Treatment for renal cancer: are we beyond the cytokine era?

Cytokines have been the mainstay of treatment for metastatic renal cancer for the past 20 years. Response rates of patients treated with these agents are low, and toxicity is high, but there is evidence from large multicenter randomized trials that indicate that there are survival benefits with interferon-based immunotherapy. A large number of new small molecule inhibitors are emerging that have caused considerable interest in the oncology community. The evidence for benefit from these compounds is based on small studies, using progression-free survival as an end-point. New compounds may provide an improvement in survival for patients with metastatic renal cancer; however, any trial of these agents should be tested against established, standard cytokine therapy.

Phase II trial of interferon and thalidomide in metastatic renal cell carcinoma

OBJECTIVES

To evaluate the toxicity and efficacy of interferon and thalidomide combination in a phase II clinical trial.

PATIENTS AND METHODS

Eligibility included metastatic renal cancer with a maximum of two prior regimens, performance status of 0-2 and adequate renal, hepatic and bone marrow function.

RESULTS

Twenty patients were enrolled on this phase II trial. Median age was 60.5 years (Range: 39-75 years). 17 patients had visceral metastases (lung/liver/both) and 3 patients had lymph node only metastases. A total of 26 cycles of 4 weeks each were administered; median of 1 cycle and range from 0-9 cycles. The therapy was poorly tolerated with grade 3 adverse events noted in 12 (60%) of the 20 patients. No objective responses were noted. Of the 14 response evaluable patients, one had an unconfirmed response (38% decrease in size) and one had prolonged disease stabilization for 10 months. The median time to progression was 1.0 month and median survival was 2.8 months. Pre and post therapy PET scans were performed nine weeks apart on one patient. The mean standardized uptake values (SUV) declined from 1.45 (SUV min-max 0.89-1.76) to 1.12 (SUV min-max 0.55-1.47), denoting anti vascular effect. The patient did not have an objective response but had a disease stabilization sustained for 10 months.

CONCLUSION

The combination of interferon and thalidomide has minimal efficacy and considerable toxicity which makes this combination unworthy of future investigation in metastatic renal cancer.

Emerging role of tyrosine kinase inhibitors in the treatment of advanced renal cell cancer: a review

Advanced and metastatic renal cell cancer (RCC) is resistant to conventional chemotherapy. Only a very small number of patients survive long term after immunotherapy. However, any effect of interleukin-2 (IL-2) and/or interferon on median overall survival is small, and treatment-associated toxicities may be severe. The disease is therefore an area of high unmet medical need. Activation of the VEGF and EGF/RAS/RAF/MAP kinase pathways is frequent in solid tumours such as RCC. Such activation is implicated in tumour angiogenesis and proliferation. VEGF and EGF receptors and molecules (such as RAF kinase) involved in downstream signalling are therefore potential appropriate targets for drug therapy. Several antibodies and low molecular weight tyrosine kinase inhibitors (TKIs) have completed phase II clinical trials. Phase II studies of multitargeted agents, which include inhibition of VEGFR tyrosine kinase in their repertoire (sorafenib, sunitinib and AG 013736), show clear second-line activity in metastatic RCC. The same is true of the anti-VEGF antibody, bevacizumab. In a randomised phase III comparison against placebo in pretreated patients, sorafenib doubled median progression free survival (24 versus 12 weeks). Studies now in progress will determine whether benefits seen second-line will also be evident first-line, and whether the activity of novel agents can be increased by combining them with each other, with cytokines, or with chemotherapy.

Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis

The effects of sorafenib – an oral multikinase inhibitor targeting the tumour and tumour vasculature – were evaluated in patients with advanced melanoma enrolled in a large multidisease Phase II randomised discontinuation trial (RDT). Enrolled patients received a 12-week run-in of sorafenib 400 mg twice daily (b.i.d.). Patients with changes in bi-dimensional tumour measurements <25% from baseline were then randomised to sorafenib or placebo for a further 12 weeks (ie to week 24). Patients with ⩾25% tumour shrinkage after the run-in continued on open-label sorafenib, whereas those with ⩾25% tumour growth discontinued treatment. This analysis focussed on secondary RDT end points: changes in bi-dimensional tumour measurements from baseline after 12 weeks and overall tumour responses (WHO criteria) at week 24, progression-free survival (PFS), safety and biomarkers (BRAF, KRAS and NRAS mutational status). Of 37 melanoma patients treated during the run-in phase, 34 were evaluable for response: one had ⩾25% tumour shrinkage and remained on open-label sorafenib; six (16%) had <25% tumour growth and were randomised (placebo, n=3; sorafenib, n=3); and 27 had ⩾25% tumour growth and discontinued. All three randomised sorafenib patients progressed by week 24; one remained on sorafenib for symptomatic relief. All three placebo patients progressed by week-24 and were re-started on sorafenib; one experienced disease re-stabilisation. Overall, the confirmed best responses for each of the 37 melanoma patients who received sorafenib were 19% stable disease (SD) (ie n=1 open-label; n=6 randomised), 62% (n=23) progressive disease (PD) and 19% (n=7) unevaluable. The overall median PFS was 11 weeks. The six randomised patients with SD had overall PFS values ranging from 16 to 34 weeks. The most common drug-related adverse events were dermatological (eg rash/desquamation, 51%; hand-foot skin reaction, 35%). There was no relationship between V600E BRAF status and disease stability. DNA was extracted from the biopsies of 17/22 patients. Six had V600E-positive tumours (n=4 had PD; n=1 had SD; n=1 unevaluable for response), and 11 had tumours containing wild-type BRAF (n=9 PD; n=1 SD; n=1 unevaluable for response). In conclusion, sorafenib is well tolerated but has little or no antitumour activity in advanced melanoma patients as a single agent at the dose evaluated (400 mg b.i.d.). Ongoing trials in advanced melanoma are evaluating sorafenib combination therapies.

Targeted Therapies in Combination with Chemotherapy in Non–Small Cell Lung Cancer

With rare exceptions, attempts to combine so-called targeted agents with standard cytotoxic chemotherapy in advanced non-small cell lung cancer have yielded disappointing results. The reasons underlying these spectacular failures are not always fully understood, but certainly the lack of careful patient selection is a major contributing factor. In addition, recent preclinical and clinical studies indicate that antagonism may exist between the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and chemotherapy primarily in tumor cells with wild-type EGFR. By contrast, tumor cells harboring somatic mutations in EGFR experience massive apoptosis when exposed to the EGFR tyrosine kinase inhibitors. Therefore, in theory, mutant tumor cells should exhibit enhanced cell kill when treated with concomitant chemotherapy and EGFR tyrosine kinase inhibitors akin to what is observed with chemotherapy and trastuzumab in breast cancer. Clinical data from the recently completed TRIBUTE trial support the latter possibility. Ideally, future studies of EGFR tyrosine kinase inhibitors and other targeted drugs will use careful patient selection criteria based on well-characterized and validated predictive markers. However, in the absence of such biomarkers, clinical judgment, common sense, and innovative clinical trial design are necessary to avoid undue delay in drug development.

Adoptive Immunotherapy by Allogeneic Stem Cell Transplantation for Metastatic Renal Cell Carcinoma: A CALGB Intergroup Phase II Study

A graft-versus-tumor effect through nonmyeloablative allogeneic stem cell transplantation (N-SCT) in metastatic renal cell carcinoma (RCC) has been reported. An Intergroup phase II trial was undertaken to define further the feasibility, toxicity and efficacy of this approach in a multi-institutional setting, Patients with cytokine-refractory, metastatic RCC were treated with N-SCT. The conditioning regimen was fludarabine 30 mg . m(-2) . d(-1) on day (d) -7 through d -3 and cyclophosphamide 60 mg . kg(-1) . d(-1) on d -4 and d -3. Patients received 2-8 x 10(6) CD34+ cells/kg of granulocyte colony-stimulating factor mobilized stem cells from a 6/6 HLA-matched sibling donor. Immunosuppression after transplantation included tacrolimus and methotrexate. Twenty-two patients were enrolled at 14 institutions. Greater than 90% donor T-cell chimerism was observed in 17 of 19 evaluable patients (89%) by d +120. No objective response was observed. Acute graft-versus-host disease (GVHD) was observed in 11 patients (50%). Chronic GVHD was reported in 5 patients (23%). There was 1 patient death from liver failure secondary to chronic GVHD. Regimen-related mortality was 2 of 22 (9%; liver failure, sepsis). Median survival time was 5.5 months (95% confidence interval, 3.9-12.0 months) and the median time to progression was 3.0 months (95% confidence interval, 2.3-4.2 months). N-SCT for metastatic RCC is feasible in a multi-institutional setting. Adequate donor T-cell engraftment was achieved in most patients before disease progression. A graft-versus-tumor effect was not observed in this study despite acute and chronic GVHD, thus highlighting the need for further understanding of this approach. Allogeneic SCT remains investigational in RCC.

Multiple targeted tyrosine kinase inhibition in the clinic: all for one or one for all?

Recent insight into the role of receptor tyrosine kinase function in cancer cells culminated in the design of highly selective tyrosine kinase inhibitors. After proof of concept for the clinical efficacy and tolerability of selective tyrosine kinase inhibitors, it was conceived that most tumours will depend on more than one signalling pathway for their growth and survival. As a consequence, different strategies were pursued to inhibit multiple signalling pathways or multiple steps in the same pathway either by the development of multi-targeted agents or the combination of single targeted drugs. The use of a combination of different compounds will be less convenient to the patient, may result in dosing mistakes and drug-drug interaction should be anticipated. However, this approach will enable the titration of the dose of either agent to optimize target inhibition. The use of multi-targeted agents will circumvent several of the problems of combination therapy. Clinical activity resulting in FDA approval for both BAY 43-9006 and SU11248 has been noted. However, optimal inhibition of several targets might not be feasible at a dose with acceptable toxicity.

Antiangiogenic cancer therapies get their act together: current developments and future prospects of growth factor- and growth factor receptor-targeted approaches

Targeting the vascular endothelial growth factor (VEGF) in combination with standard chemotherapy has recently proved successful in the treatment of different types of advanced cancer. The achievements of combinatorial anti-VEGF monoclonal antibody bevacizumab (BEV) renewed the confidence in targeted antiangiogenic approaches to constitute a complementary therapeutic modality in addition to surgery, radiotherapy and chemotherapy. While several second-generation multitargeted tyrosine kinase inhibitors show promise in defined tumor entities, these novel antiangiogenic compounds have yet to meet or exceed the efficacy of combinatorial BEV therapy in ongoing clinical trials. Current developments of targeted antiangiogenic agents include their use in the adjuvant setting and the combination of different antiangiogenesis inhibitors to take a more comprehensive approach in blocking tumor angiogenesis. The identification of surrogate markers that can monitor the activity and efficacy of antiangiogenic drugs in patients belongs to the most critical challenges to exploit the full potential of antiangiogenic therapies. The opportunities and obstacles in further development of growth factor- and growth factor receptor-targeted antiangiogenic approaches for advanced cancer, including malignant melanoma, will be discussed herein with particular reference to selected ongoing clinical trials.

Phase II Placebo-Controlled Randomized Discontinuation Trial of Sorafenib in Patients With Metastatic Renal Cell Carcinoma

Purpose

This phase II randomized discontinuation trial evaluated the effects of sorafenib (BAY 43-9006), an oral multikinase inhibitor targeting the tumor and vasculature, on tumor growth in patients with metastatic renal cell carcinoma.

Patients and Methods

Patients initially received oral sorafenib 400 mg twice daily during the initial run-in period. After 12 weeks, patients with changes in bidimensional tumor measurements that were less than 25% from baseline were randomly assigned to sorafenib or placebo for an additional 12 weeks; patients with ≥ 25% tumor shrinkage continued open-label sorafenib; patients with ≥ 25% tumor growth discontinued treatment. The primary end point was the percentage of randomly assigned patients remaining progression free at 24 weeks after the initiation of sorafenib.

Results

Of 202 patients treated during the run-in period, 73 patients had tumor shrinkage of ≥ 25%. Sixty-five patients with stable disease at 12 weeks were randomly assigned to sorafenib (n = 32) or placebo (n = 33). At 24 weeks, 50% of the sorafenib-treated patients were progression free versus 18% of the placebo-treated patients (P = .0077). Median progression-free survival (PFS) from randomization was significantly longer with sorafenib (24 weeks) than placebo (6 weeks; P = .0087). Median overall PFS was 29 weeks for the entire renal cell carcinoma population (n = 202). Sorafenib was readministered in 28 patients whose disease progressed on placebo; these patients continued on sorafenib until further progression, for a median of 24 weeks. Common adverse events were skin rash/desquamation, hand-foot skin reaction, and fatigue; 9% of patients discontinued therapy, and no patients died from toxicity.

Conclusion

Sorafenib has significant disease-stabilizing activity in metastatic renal cell carcinoma and is tolerable with chronic daily therapy.

[Therapy strategies for advanced renal cell carcinoma]

The therapeutic regimen for metastatic renal cell cancer has changed substantially in the last years. Formerly, metastatic disease was regarded as being inoperable and had a disastrous prognosis. Nowadays, radical nephrectomy is the accepted urologic-oncologic standard therapy in metastatic primaries, if technically feasible. A complete resection of metastases may be curative, or can achieve a substantial palliative benefit. A better understanding of prognostic parameters helps in the selection of patients with a chance of benefiting from systemic immunochemotherapy. For patients with rapidly progressing tumors or sarcomatoid dedifferentiation, new effective chemotherapy regimens are available. New angiogenesis inhibitors such as sutent, avastin or sorafenib can potentially be effectively used in future therapeutic regimens.

[Renal cancer study activities in Germany. Drug therapy]

Drug therapy of advanced renal cell carcinoma underwent rapid changes. Monotherapeutic, placebo-controlled protocols -- and more recently combinations of different targeted drugs -- dominated the global clinical studies in the past 2 years. The preliminary results are almost encouraging and international investigators, supported by the pharmaceutical industry, were most successful in enrolling patients quickly. The present article reviews the recent German drug study activities and indicates potential future projects.

The place of VEGF inhibition in the current management of renal cell carcinoma

Vascular endothelial growth factor (VEGF) is overexpressed in around 80% of patients with clear cell carcinoma of the kidney owing to the inactivation of von Hippel Lindau gene activity. VEGF stimulates angiogenesis and acts as an autocrine growth factor. A number of different agents are now available which target VEGF and its signalling pathways. A significant body of evidence has accumulated demonstrating that antagonism of VEGF and its downstream pathways is clinically useful in a significant proportion of patients with metastatic clear cell carcinoma of the kidney. Enough data is now available to recommend that patients with metastatic clear cell carcinoma of the kidney should at some point during the course of their disease be offered entry into a clinical trial enabling exposure to a targeted inhibitor of VEGF or its signalling pathways. Assuming early clinical trial data is substantiated by ongoing registration studies, efforts should be made to minimise the time taken between licensing and general availability of these active agents.

Zukunft der Chemotherapie

The future development of chemotherapy is derived based upon recent advances. With regard to adjuvant therapy a trend towards standardized prediction of recurrence risk using all available prognostic markers (e.g., nomograms) is observed. Furthermore, in some tumors major progress has been made regarding the development of "molecular classifiers" defining tumor biology (predicting clinical outcome) by analysis of molecular changes. In adjuvant therapy considerable advances may be achieved by use of new chemotherapeutic agents as well as sequential, dose-dense and dose-intensified regimens. However, in metastatic disease no breakthrough can be expected at least with regard to survival suggesting that quality of life needs to be addressed with more emphasis. Using targeted drugs alone or in combination with chemotherapy advances concerning adjuvant therapy as well as metastatic disease are observed. Further targeted drugs have entered clinical development. However, clarification of the relation between detection of the target(s) and drug activity will fundamentally change current treatment concepts.

Renal cell carcinoma

PURPOSE OF REVIEW

In this review we will highlight the recent novel contributions to the treatment of renal cell carcinoma in the fields of anti-angiogenesis, immunotherapeutics, and surgical management. In addition, this review will update recent advances in diagnostic and imaging modalities for renal cell carcinoma and dietary and environmental relationships to the epidemiology of this growing disease.

RECENT FINDINGS

Advancements in the use of innovative treatment strategies for the management of localized renal cell carcinoma and the introduction of new targeted therapeutics with benefit in the metastatic setting has produced a major impact on the treatment of this disease.

SUMMARY

The management of metastatic renal cell carcinoma has undergone a revolution in the past year with groundbreaking treatment strategies encompassing a broad range of therapeutic modalities. At the other end of the spectrum, emerging data is beginning to change our perspective about the management of small, localized renal tumors that are being discovered with increasing frequency. This review will update recent findings supporting diet and tobacco exposure as etiologic factors in the development of renal cell carcinoma, the molecular concepts that underlie the disease and the targeted therapeutics designed to inhibit specific kinase activities, and emerging use of minimally invasive therapies for localized disease.

Systemische Therapie des metastasierten Nierenzellkarzinoms

Cytokine-based immunotherapy was the only viable option in metastatic, nonresectable renal cell carcinoma (RCC) for many years. Systemic immunotherapy has become increasingly established as a standard therapy during the last 15 years. In this context, interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) turned out to be the most effective single agents in RCC. Subsequently, the approved subcutaneous application of these compounds was the preferred administration route in Germany. Response rates with cytokine combination therapy were almost similar to those of more aggressive concepts using additional chemotherapeutic agents.Currently, new compounds targeting specific signaling pathways are readily available and have passed clinical testing. Such small molecules like tyrosine kinase inhibitors, monoclonal antibodies, or the mTOR inhibitor CCI-779 may dramatically change the established concepts of systemic RCC treatment. This paper gives an overview of established, current, and evolving concepts of systemic therapy in RCC.

Measuring response in a post-RECIST world: from black and white to shades of grey

The unprecedented pace of therapeutic development in oncology has created a climate in which the traditional methods of evaluating agent activity might no longer be adequate. How is the field transitioning to new endpoints in early drug development and what are the difficulties in this transition? Here, we will explore the historical context for the current criteria for tumour response evaluation and some of the pitfalls in using these standards when testing newer anticancer agents for activity. We will argue that the current drug development environment dictates different outcome measurements and therefore more imaginative and rigorous early-phase trial designs.

Targeted therapy for metastatic renal cell carcinoma

Metastatic renal cell carcinoma (RCC) has historically been refractory to cytotoxic and hormonal agents; only interleukin 2 and interferon alpha provide response in a minority of patients. We reviewed RCC biology and explored the ways in which this understanding led to development of novel, effective targeted therapies. Small molecule tyrosine kinase inhibitors, monoclonal antibodies and novel agents are all being studied, and phase II studies show promising activity of sunitinib, sorafenib and bevacizumab. The results of phase III studies will determine the role of these agents in metastatic RCC.

Understanding the Importance of Smart Drugs in Renal Cell Carcinoma

OBJECTIVE

To understand the mode of action of the currently most investigated new drugs in renal cell carcinoma (RCC) and ultimately to analyze what should be the role of the urologist in this new therapeutic era.

METHODS

A comprehensive review of the peer-reviewed literature was performed on the topic of molecular pathways involved in RCC angiogenesis, vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR) and targeted molecular therapy for RCC.

RESULTS

Von Hippel-Lindau (VHL) disease has provided a model for understanding that the early inactivation of the VHL gene was responsible for accumulation of hypoxia-inducible factor and therefore activation of hypoxia-inducible genes such as VEGF, platelet-derived growth factor, erythropoietin, carbonic anhydrase IX and tumor growth factor alpha. The fact that such VHL inactivation also was found in up to 70% of sporadic RCC has been the rationale for developing new drugs targeting VEGF, VEGFR, platelet-derived growth factor receptor and tyrosine kinase receptors that are required for intracellular transduction.

CONCLUSION

Initial results from phase 2 trials in metastatic disease are very promising. There is a strong rationale for initiating adjuvant trials with those kind of agents in patients with high-risk localised tumors. Urologists who have a good understanding of prognostic parameters in localised RCC particularly should be involved in such new approaches.

Phase II study of vinflunine in patients with metastatic renal cell carcinoma

PURPOSE

An open-label, multicentre, non-comparative phase II trial to determine the response rate of intravenous vinflunine as first line chemotherapy in patients with metastatic renal cell carcinoma (RCC).

PATIENTS AND METHODS

Patients with metastatic RCC were treated with vinflunine 350 mg/m2 (n = 11) or 320 mg/m2 (n = 22) administered intravenously every 21 days.

RESULTS

Out of 33 patients included in this study, one partial response was observed in the group treated at 350 mg/m2 and none in the group receiving 320 mg/m2 resulting in a response rate in this population of 9.1% (95% CI: 0.2-41.3). Median progression free survival was 5.6 months (95% CI: 2.8-14.4) for patients treated at 350 mg/m2, and 3.3 months (95% CI: 1.6-6.4) for those treated at 320 mg/m2.The median survival time was 10.4 months (95% CI: 6.8-12.4) for the whole study population. The principal toxicities were grade 3/4 neutropaenia -90.9% at 350 mg/m2 and 68.1% at 320 mg/m2, febrile neutropaenia was recorded in 3 patients (27.3%) at 350 mg/m2 and in 5 patients (22.7%) at 320 mg/m2. One episode of thromboembolic event was reported in 1 patient at each dose level.

CONCLUSION

Vinflunine given intravenously once every 3 weeks has not shown any clinically relevant activity in the management of patients with metastatic renal cell carcinoma; tolerance of the treatment was better at a dose of 320 mg/m2 than at 350 mg/m2.

Molecularly targeted therapy in renal cell carcinoma

Recent developments in the molecular biology of renal cell carcinoma have identified multiple pathways associated with the development of this cancer. Multiple strategies have been investigated targeting these pathways, with significant clinical benefits shown in early studies. This review aims to overview the findings of recent clinical trials and clarify the development of these compounds for use in renal cell carcinoma. The authors also aim to clarify the molecular pathways implicated in renal cell carcinoma and the clinical results in metastatic renal cell carcinoma with agents targeting these pathways. The relevant literature was reviewed concerning pathways implicated in the pathophysiology of renal cell carcinoma including pathways activated secondary to von Hippel-Lindau gene inactivation and PI-3 kinase/Akt/mammalian target of rapamycin pathway activation. Therapeutic targeting based upon underlying molecular biology in renal cell carcinoma has strong rationale. Substantial clinical activity has been reported with various agents targeting these pathways, most notably with vascular endothelial growth factor-targeted therapy. However, investigation is needed to optimally utilize these agents at the appropriate stage of disease and in the best combinations for maximal clinical benefit.