Immuno-Oncology Advances in Genitourinary Cancers

Immuno-oncology (IO) has made monumental gains in the past decade in the genitourinary space. In this review, we highlight advances with IO in renal cell carcinoma where it now has become standard-of-care frontline therapy in the metastatic setting but also discuss challenges with the initial approach. In urothelial carcinoma, we discuss the growing use of IO including exciting recent updates with IO-based regimens that may soon become the new standard of care. We further discuss difficulties with IO in prostate cancer, germ cell tumors, and penile squamous cell carcinoma. Finally, we highlight advances in IO approaches beyond checkpoint inhibition including the role of the gut microbiome and T-cell redirecting therapies.

Safety and tolerability of sorafenib in clear-cell renal cell carcinoma: a Phase III overview

This review summarizes the safety of sorafenib, an oral multikinase inhibitor, focusing on the randomized, placebo-controlled, Phase III Treatment Approaches in Renal Cancer Global Evaluation Trial (TARGET) in renal cell carcinoma, which formed the basis of the approval of sorafenib. Similar to other targeted agents, sorafenib acts primarily to induce disease stabilization, rather than tumor regression, suggesting that long-term administration is necessary. The tolerability of an agent is important in long-term treatment, and a predictable and manageable side-effect profile is advantageous. Although IL-2 and interferon have been standard care treatments for advanced renal cell carcinoma for over a decade, they are poorly tolerated. Targeted agents offer an alternative for patients with advanced renal cell carcinoma, as initial therapy or after failure of cytokine treatment.

Sorafenib tosylate in advanced kidney cancer: past, present and future

The objective of this paper was to review the development of sorafenib tosylate in kidney cancer. The MedLine database, the Proceedings of the Annual American Society of Clinical Oncology meeting, as well as those of other key international meetings were extensively searched to identify relevant publications. Furthermore, the authors' direct experience with the drug was taken into account when commenting on the results retrieved. Sorafenib is a multikinase inhibitor that targets VEGF and PDGF receptors, other kinases, as well as the serine-threonine kinase Raf. Following early signs of activity from phase I and II studies, it has been shown to improve survival of pretreated advanced kidney cancer patients within a placebo-controlled, randomized, phase III trial, leading to its approval both in the United States and in Europe. Its activity has been subsequently confirmed in a real-world population by two expanded access programs performed globally, but not in a first-line setting; it also proved to be non-cross-resistant with two other molecularly targeted agents. Finally, its toxicity profile, which is acceptable and highly predictable, makes sorafenib appealing for combination treatments, especially with other molecularly targeted agents. Despite having been already demonstrated to be active in kidney cancer, the exact role of sorafenib in the first-line setting, in patients who have failed other molecularly targeted agents, and especially in combination with other agents, deserves further, prospective, studies.

Cancer-specific survival outcomes among patients treated during the cytokine era of kidney cancer (1989-2005): a benchmark for emerging targeted cancer therapies

BACKGROUND

The management of renal cell carcinoma (RCC) is evolving toward less extirpative surgery and the use of targeted therapy. The authors set out to provide a benchmark against which emerging therapies should be measured.

METHODS

A prospective database including clinical and pathological variables for 1632 patients with RCC treated between 1989 and 2005 was queried. Patients were stratified using the University of California-Los Angeles Integrated Staging System (UISS) into low-, intermediate-, and high-risk groups. Disease-specific survival (DSS) was measured. Response to systemic therapy for patients with advanced disease was assessed.

RESULTS

Nephrectomy was performed in 1492 patients. Overall 5-, 10-, and 15-year DSS was 55%, 40%, and 29%. For localized disease, 5- and 10-year DSS for UISS low-, intermediate-, and high-risk groups was 97% and 92%, 81% and 61%, and 62% and 41%, respectively. For metastatic disease, 5- and 10-year DSS for UISS low-, intermediate-, and high-risk groups was 41% and 31%, 18% and 7%, and 8% and 0%, respectively. Patients with metastatic disease receiving immunotherapy (n=453) had complete response in 7% (median survival [MS], 120+ months), partial response in 15% (MS, 42.8 months), stable disease in 33% (MS, 38.6 months), and progressive disease in 45% (MS, 11.6 months).

CONCLUSIONS

Most patients with localized RCC do well with surgery alone, but effective adjuvant therapy is needed for patients identified as at high risk for recurrence. For advanced disease, newer targeted and potentially less toxic treatments should be at least as effective as those achieved with aggressive surgical resection and immunotherapy.

Treatment options in renal cell carcinoma: past, present and future

Cytokine therapies have been the standard of care in metastatic renal cell carcinoma (RCC). However, these agents only provide clinical benefit to a small subset of patients and are associated with significant toxicity. A better understanding of the molecular biology of RCC has identified the vascular endothelial growth factor (VEGF) and platelet-derived growth factor signalling pathways as rational targets for anticancer therapy. The multitargeted receptor tyrosine kinase inhibitors sunitinib and sorafenib have both demonstrated improved efficacy as second-line therapy in patients with RCC. Sunitinib has also been shown to be effective in the first-line setting, and has recently received European Union approval as first-line treatment for advanced and/or metastatic RCC. There is also recent evidence that temsirolimus (an inhibitor of the mammalian target of rapamycin) and bevacizumab (a mAb targeted against VEGF) may provide benefits in the first-line treatment setting. These results confirm that inhibiting these tumour targets is a feasible approach to treatment and provides a more positive outlook for the future management of metastatic RCC.

Renal cell carcinoma: new developments in molecular biology and potential for targeted therapies

Renal cell carcinoma (RCC) affects 38,000 individuals in the U.S. yearly. Seventy-five percent of cases are clear-cell carcinomas, and a majority is driven by dysfunction of the von Hippel-Lindau (VHL) gene. VHL loss of function and other non-VHL pathways leading to RCC share aberrant activation of the hypoxic response, such as upregulation of vascular endothelial growth factor (VEGF) and consequent neoangiogenesis. Metastatic RCC has been notoriously resistant to therapy. For decades, its treatment has been based on nephrectomy and limited use of toxic and often inefficient immunotherapy with interleukin-2 or interferon-alpha. However, new biologic agents are beginning to break the resistance barrier. Small-molecule multikinase inhibitors that target VEGF receptors (sunitinib and sorafenib) have a favorable toxicity profile and can prolong time to progression and preserve quality of life when used in newly diagnosed or previously treated patients. The anti-VEGF antibody bevacizumab enhances the response rate and prolongs disease control when added to interferon-alpha. Temsirolimus, a mammalian target of rapamycin inhibitor, prolongs the survival duration of patients with poor-risk disease. Despite three new drugs being approved for RCC in the past 2 years, responses are mostly partial and of limited duration. Multiple new drugs and drug combinations are undergoing clinical trials and will likely impact the treatment of RCC in future years. Compounds found to be active in the metastatic setting are now being tried in earlier stage disease in an attempt to improve curability. However, no method has yet been validated to predict patient response to these newer treatments.

Sorafenib and sunitinib: novel targeted therapies for renal cell cancer

Renal cell cancer (RCC) is a relatively uncommon malignancy, with 51,190 cases expected to be diagnosed in 2007. Localized disease is curable by surgery; however, locally advanced or metastatic disease is not curable in most cases and, until recently, had a limited response to drug treatment. Historically, biologic response modifiers or immunomodulating agents were tested in clinical trials based on observations that some cases of RCC can spontaneously regress. High-dose aldesleukin is approved by the United States Food and Drug Administration as a treatment for advanced RCC; however, the drug is associated with a high frequency of severe adverse effects. Responses have been observed with low-dose aldesleukin and interferon alfa, but with little effect on overall survival. Sorafenib and sunitinib are novel therapies that target growth factor receptors known to be activated by the hypoxia-inducible factor and the Ras-Raf/MEK/ERK pathways. These pathways are important in the pathophysiology of RCC. Sorafenib and sunitinib have shown antitumor activity as first- and second-line therapy in patients with cytokine-refractory metastatic RCC who have clear-cell histology. Although complete responses are not common, both drugs promote disease stabilization and increase progression-free survival. This information suggests that disease stabilization may be an important determinant for response in RCC and possibly other cancers. Sorafenib and sunitinib are generally well tolerated and are considered first- and second-line treatment options for patients with advanced clear cell RCC. In addition, sorafenib and sunitinib have shown promising results in initial clinical trials evaluating antitumor activity in patients who are refractory to other antiangiogenic therapy. The most common toxicities with both sorafenib and sunitinib are hand-foot syndrome, rash, fatigue, hypertension, and diarrhea. Research is directed toward defining the optimal use of these new agents.

Phase I trial of PEG-interferon and recombinant IL-2 in patients with metastatic renal cell carcinoma

PURPOSE

Pegylated interferon alpha-2b (PEG-Intron) is a conjugate of polyethylene glycol (PEG) and interferon alpha-2b, has a prolonged half-life, and an increased area under the curve (AUC) for interferon alpha-2b. The combination of PEG-Intron with recombinant interleukin-2 (rIL-2) was investigated in a phase 1 trial. To determine the maximal tolerable dose (MTD) and preliminary efficacy of concurrent subcutaneous (SC) administration of PEG-Intron and rIL-2 in patients with metastatic renal cell carcinoma (RCC).

METHODS

Cohorts of 3-6 patients received escalating doses of PEG-Intron (I-1.5, II- 1.5, III-3.0, IV-3.0, V-4.5 microg/kg SC) given weekly in combination with rIL-2 administered three times weekly (TIW) for 6 weeks. rIL-2 dose levels were escalated in weeks 1 and 4 (I-10.0, II-15.0, III-15.0, IV-20.0, V-20.0 MIU/m(2) SC), and 5.0 MIU/m(2) SC TIW was administered during weeks 2, 3, 5 and 6.

RESULTS

Thirty-four patients (24 men; 10 women) were accrued at dose levels I (n = 4), II (n = 4), III (n = 6), IV (n = 14), and V (n = 6) between October 2000 and October 2002. All but one patient had prior nephrectomy (n = 33) and all but one patient (97%) had received no prior systemic therapy. Patients received a median of four cycles of treatment (range 1-9). Dose limiting toxicity occurred at dose level V and included grade 4 neutropenia and hypoxemia. A partial response was found in 5 pts (15%). Median progression-free and overall survival were 9.0 (95% C.I. 5.6-13.1 months) and 31.9 months (95% C.I. 17.2-61.9 months), respectively.

CONCLUSION

The combination of PEG-Interferon and SC rIL-2 can be administered with acceptable toxicity.

Phase II trial of sorafenib plus interferon alfa-2b as first- or second-line therapy in patients with metastatic renal cell cancer

PURPOSE

We undertook this study to determine the activity and tolerability of sorafenib administered with interferon alfa-2b (IFN-alpha-2b) as first- or second-line therapy in metastatic renal cell cancer (RCC).

PATIENTS AND METHODS

Between November 2004 and October 2006, 40 patients at two sites were enrolled onto a phase II trial of sorafenib plus IFN-alpha-2b. Treatment consisted of 8-week cycles of sorafenib 400 mg orally bid plus IFN-alpha-2b 10 million U subcutaneously three times a week followed by a 2-week break. Patients were eligible to receive additional cycles of therapy until disease progression. Dose reduction of both drugs by 50% was permitted once for toxicity.

RESULTS

The response rate was 33% (95% CI, 19% to 49%; 13 of 40 patients), including 28% partial responses (n = 11) and 5% complete responses (n = 2). Responses were seen in treatment-naïve and interleukin-2 (IL-2) -treated patients within the first two cycles. The median duration of response was 12 months. With a median follow-up time of 14 months, median progression-free survival time was 10 months (95% CI, 8 to 18 months), and median overall survival time has not yet been reached. Fatigue, anorexia, anemia, diarrhea, hypophosphatemia, rash, nausea, and weight loss were the most common toxicities. Grade 3 toxicities were uncommon but included hypophosphatemia, neutropenia, rash, fatigue, and anemia. Dose reductions were required in 65% of patients.

CONCLUSION

The combination of sorafenib and IFN-alpha-2b has substantial activity in treatment-naïve and IL-2-treated patients with RCC. The toxicity exceeded that of either drug alone, but dose reductions and breaks between cycles allowed for chronic therapy. A larger, randomized trial would determine whether there is any advantage to this regimen compared with sorafenib alone.

Drug Insight: advances in renal cell carcinoma and the role of targeted therapies

In metastatic renal cell carcinoma (RCC) immunotherapy results in a small but important improvement in overall survival, but a need exists to develop more-effective systemic therapies. Recent developments in our understanding of the molecular biology of RCC have identified several pathways associated with the development of the disease. A number of strategies designed specifically to target these pathways have resulted. Initial studies have shown marked clinical benefits of so-called 'targeted therapies'. Sunitinib, sorafenib and axitinib are kinase inhibitors that inhibit the VEGF, platelet-derived growth factor and c-kit receptor tyrosine kinases. Bevacizumab is a monoclonal antibody that is directed against VEGF. Temsirolimus inhibits the mammalian target of rapamycin. These agents have all shown considerable activity with manageable toxicity in phase II and III studies in both previously treated and untreated patients. In phase III studies, sorafenib and bevacizumab have been associated with prolonged progression-free survival compared with placebo. Phase III data have shown improvements in progression-free and overall survival with sunitinib and temsirolimus, respectively, compared with interferon alfa. Additional studies are needed to determine the optimum utilization of these agents at the appropriate stage of disease and in the best combinations for maximal clinical benefit.

Vascular endothelial growth factor-targeted therapy in renal cell carcinoma: current status and future directions

Renal cell carcinoma is a highly vascular tumor associated with expression of vascular endothelial growth factor (VEGF). Recently, VEGF-targeted therapies have been identified as a promising therapeutic approach. Three agents targeting the VEGF pathway have shown clinical activity as monotherapy in metastatic renal cell carcinoma: the anti-VEGF monoclonal antibody, bevacizumab, and small-molecule VEGF receptor tyrosine kinase inhibitors, sorafenib and sunitinib. This article explores these agents in terms of their mechanisms of action, clinical efficacy, and toxicity profiles. This article also reviews future development strategies, including combination regimens and drug sequencing, trial design considerations, and patient selection opportunities.

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.

Wirksamkeit von Multikinaseinhibitoren in der Therapie des fortgeschrittenen Nierenzellkarzinoms

Due to the chemoresistance of renal cell cancer, cytokine-based therapeutic approaches were considered the standard treatment for patients with metastatic disease. At present, data that are available from a few phase II/III studies, dealing both with the first- and second-line treatment of patients suffering from systemic progression of RCC, indicate the significantly higher clinical efficacy of multikinase inhibitors when compared with cytokine-based therapeutic regimens. In this context, sorafenib (Nexavar, BAY 43-9006) and sunitinib (Sutent, SU 011248) are the most frequently applied and most intensively investigated substances. In Germany, with regard to a phase III study reported at the ASCO congress in 2006, sunitinib received approval for the first-line therapy of metastatic RCC. The application of multikinase inhibitors follows the principle of targeting such mediators that are considered to be substantially involved in the pathogenesis and particularly progression of renal cell cancer within relatively well-defined molecular pathways. The aim of the present paper is to address and to critically discuss the clinical data that are currently available regarding the therapeutic efficacy of kinase inhibitors during the treatment of metastatic RCC.

Anti-angiogenic therapy in the treatment of advanced renal cell cancer

Metastatic renal cell cancer is associated with a poor prognosis and is resistant to traditional chemotherapy agents. The majority of tumours are associated with inactivation of the von Hippel-Lindau gene and subsequent overexpression of proangiogenic factors, including vascular endothelial growth factor (VEGF). Drugs targeting these pathways have undergone clinical testing in renal cell cancer with encouraging results. This type of therapy is set to revolutionise the treatment of renal cell cancer and this review outlines recent evidence from clinical trials investigating the most promising of these agents.

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.