Capecitabine in the treatment of metastatic renal cell carcinoma

Druggable Biomarkers Altered in Clear Cell Renal Cell Carcinoma: Strategy for the Development of Mechanism-Based Combination Therapy

Targeted therapeutics made significant advances in the treatment of patients with advanced clear cell renal cell carcinoma (ccRCC). Resistance and serious adverse events associated with standard therapy of patients with advanced ccRCC highlight the need to identify alternative 'druggable' targets to those currently under clinical development. Although the Von Hippel-Lindau (VHL) and Polybromo1 (PBRM1) tumor-suppressor genes are the two most frequently mutated genes and represent the hallmark of the ccRCC phenotype, stable expression of hypoxia-inducible factor-1α/2α (HIFs), microRNAs-210 and -155 (miR_S), transforming growth factor-beta (TGF-ß), nuclear factor erythroid 2-related factor 2 (Nrf2), and thymidine phosphorylase (TP) are targets overexpressed in the majority of ccRCC tumors. Collectively, these altered biomarkers are highly interactive and are considered master regulators of processes implicated in increased tumor angiogenesis, metastasis, drug resistance, and immune evasion. In recognition of the therapeutic potential of the indicated biomarkers, considerable efforts are underway to develop therapeutically effective and selective inhibitors of individual targets. It was demonstrated that HIF_S, miR_S, Nrf2, and TGF-ß are targeted by a defined dose and schedule of a specific type of selenium-containing molecules, seleno-L-methionine (SLM) and methylselenocystein (MSC). Collectively, the demonstrated pleiotropic effects of selenium were associated with the normalization of tumor vasculature, and enhanced drug delivery and distribution to tumor tissue, resulting in enhanced efficacy of multiple chemotherapeutic drugs and biologically targeted molecules. Higher selenium doses than those used in clinical prevention trials inhibit multiple targets altered in ccRCC tumors, which could offer the potential for the development of a new and novel therapeutic modality for cancer patients with similar selenium target expression. Better understanding of the underlying mechanisms of selenium modulation of specific targets altered in ccRCC could potentially have a significant impact on the development of a more efficacious and selective mechanism-based combination for the treatment of patients with cancer.

Capecitabine induces hand-foot syndrome through elevated thymidine phosphorylase-mediated locoregional toxicity and GSDME-driven pyroptosis that can be relieved by tipiracil

BACKGROUND

Hand-foot syndrome (HFS) is a serious dose-limiting cutaneous toxicity of capecitabine-containing chemotherapy, leading to a deteriorated quality of life and negative impacts on chemotherapy treatment. The symptoms of HFS have been widely reported, but the precise molecular and cellular mechanisms remain unknown. The metabolic enzyme of capecitabine, thymidine phosphorylase (TP) may be related to HFS. Here, we investigated whether TP contributes to the HFS and the molecular basis of cellular toxicity of capecitabine.

METHODS

TP-/- mice were generated to assess the relevance of TP and HFS. Cellular toxicity and signalling mechanisms were assessed by in vitro and in vivo experiments.

RESULTS

TP-/- significantly reduced capecitabine-induced HFS, indicating that the activity of TP plays a critical role in the development of HFS. Further investigations into the cellular mechanisms revealed that the cytotoxicity of the active metabolite of capecitabine, 5-DFUR, was attributed to the cleavage of GSDME-mediated pyroptosis. Finally, we demonstrated that capecitabine-induced HFS could be reversed by local application of the TP inhibitor tipiracil.

CONCLUSION

Our findings reveal that the presence of elevated TP expression in the palm and sole aggravates local cell cytotoxicity, further explaining the molecular basis underlying 5-DFUR-induced cellular toxicity and providing a promising approach to the therapeutic management of HFS.

Non-Coding Micro RNAs and Hypoxia-Inducible Factors Are Selenium Targets for Development of a Mechanism-Based Combination Strategy in Clear-Cell Renal Cell Carcinoma-Bench-to-Bedside Therapy

Durable response, inherent or acquired resistance, and dose-limiting toxicities continue to represent major barriers in the treatment of patients with advanced clear-cell renal cell carcinoma (ccRCC). The majority of ccRCC tumors are characterized by the loss of Von Hippel⁻Lindau tumor suppressor gene function, a stable expression of hypoxia-inducible factors 1α and 2α (HIFs), an altered expression of tumor-specific oncogenic microRNAs (miRNAs), a clear cytoplasm with dense lipid content, and overexpression of thymidine phosphorylase. The aim of this manuscript was to confirm that the downregulation of specific drug-resistant biomarkers deregulated in tumor cells by a defined dose and schedule of methylselenocysteine (MSC) or seleno-l-methionine (SLM) sensitizes tumor cells to mechanism-based drug combination. The inhibition of HIFs by selenium was necessary for optimal therapeutic benefit. Durable responses were achieved only when MSC was combined with sunitinib (a vascular endothelial growth factor receptor (VEGFR)-targeted biologic), topotecan (a topoisomerase 1 poison and HIF synthesis inhibitor), and S-1 (a 5-fluorouracil prodrug). The documented synergy was selenium dose- and schedule-dependent and associated with enhanced prolyl hydroxylase-dependent HIF degradation, stabilization of tumor vasculature, downregulation of 28 oncogenic miRNAs, as well as the upregulation of 12 tumor suppressor miRNAs. The preclinical results generated provided the rationale for the development of phase 1/2 clinical trials of SLM in sequential combination with axitinib in ccRCC patients refractory to standard therapies.

Renal Cancer Treatment: A Review of the Literature

Renal carcinoma represents about 3% of all adult tumors, with an estimate of 31,900 new cases diagnosed in 2003 in the United States. In the early phase of its natural history, renal cancer is potentially curable by surgery, but if the disease presents any signs of metastasis, the chances of survival are remote, even though anecdotal cases characterized by long survival have been reported. In fact, the treatment of metastatic renal cancer remains unsatisfactory. Systemic treatment with single agents and with polychemotherapy, with or without cytokine-based immunotherapy, has not been successful, obtaining very low response rates without a significant benefit in overall survival. This review highlights the most interesting issues regarding conventional therapeutic strategies, in localized and in advanced disease. New approaches such as monoclonal antibodies, vaccines, gene therapy, angiogenesis inhibitors and allogeneic cell transplantation and their possible clinical applications are also discussed.

Efficacy of the oral fluorouracil pro-drug capecitabine in cancer treatment: a review

Capecitabine (Xeloda) was developed as a pro-drug of fluorouracil (FU), with the aim of improving tolerability and intratumor drug concentrations through its tumorspecific conversion to the active drug. The purpose of this paper is to review the available information on capecitabine, focusing on its clinical effectiveness against various carcinomas. Identification of all eligible English trails was made by searching the PubMed and Cochrane databases from 1980 to 2007. Search terms included capecitabine, Xeloda and cancer treatment. Nowadays, FDA has approved the use of capecitabine as a first line therapy in patients with metastatic colorectal cancer when single-agent fluoropyrimidine is preferred. The drug is also approved for use as a single agent in metastatic breast cancer patients who are resistant to both anthracycline and paclitaxel-based regimens or when further anthracycline treatment is contraindicated. It is also approved in combination with docetaxel after failure of prior anthracycline-based chemotherapy. In patients with prostate, pancreatic, renal cell and ovarian carcinomas, capecitabine as a single-agent or in combination with other drugs has also shown benefits. Improved tolerability and comparable efficacy, compared with the intravenous FU/LV combination, in addition to its oral administration, make capecitabine an attractive option for the treatment of several types of carcinomas.

Phase II trial of capecitabine and weekly docetaxel in metastatic renal cell carcinoma

OBJECTIVES

To evaluate the toxicity and efficacy of capecitabine and weekly docetaxel in a phase II clinical trial.

METHODS

Eligibility included metastatic renal cancer with a maximum of 2 prior regimens, performance status of 0-2, and adequate renal, hepatic, and bone marrow function. Docetaxel was administered intravenously at a dose of 36 mg/m(2) weekly on days 1, 8, and 15 of a 28- day cycle and capecitabine was administered orally at a dose of 1800 mg/m(2) from days 5-18. Toxicity was assessed on days 1, 8, and 15 of each cycle, and response was evaluated every 2 cycles.

RESULTS

Twenty-five patients, 19 white and 6 African American, were enrolled on this phase II trial. The median age was 60 years (range: 39-75 years). Eighteen patients had clear cell histology, 7 had papillary, sarcomatoid, or chromophobe histology. Thirteen had liver/bone metastases and 13 had >or=2 of the Memorial Sloan-Kettering Cancer Center prognostic risk factors. Twelve patients received prior immunotherapy. A total of 93 cycles were administered; median of 3 cycles and range from 0-10 cycles. The therapy was well tolerated. No treatment-related mortality was observed and 2 treatment-related hospitalizations for nausea, diarrhea, and dehydration occurred. Ten patients had stable disease. The median time to progression was 1.7 months and median survival was 11.1 months.

CONCLUSIONS

The combination of capecitabine and docetaxel was well tolerated in metastatic renal cancer. Clinical activity was predominantly noted in non-clear cell histology in which chemotherapy would be worthy of future investigation.

All-Trans Retinoic Acid and Interferon-α for Treatment of Human Renal Cell Carcinoma Multicellular Tumor Spheroids

INTRODUCTION

Conventional preclinical investigations have strongly recommended to combine interferon-alpha (IFN-alpha) with 13-cis retinoic acid (13-cRA, isotretinoin) for treatment of renal cell carcinoma (RCC). However, a recent randomized controlled trial on the drug combination ultimately failed to demonstrate an increased tumor-specific survival of patients with metastatic RCC (MRCC). All-trans retinoic acid (ATRA, tretinoin) was suggested to provide stronger antineoplastic properties than 13-cRA in different other tumors.

MATERIALS AND METHODS

The present study aimed to compare ATRA with 13-cRA (0.1, 1, 10, 100 nM) alone or in combination with IFN-alpha (5, 400, 5,000, 25,000, 250,000 IU/ml) or 5-fluorouracil (5-FU; 0.1, 1, 10, 100 microg/ml). Multicellular tumor spheroids of human RCC cells (SN12C) were treated in order to facilitate the predictions of the model system.

RESULTS

ATRA decreased the mean volume of SN12C spheroids 10-20% more than 13-cRA. Both retinoids led to a super-additive growth inhibition in combination with IFN-alpha, but not with 5-FU. However, in this scenario the superior effect of ATRA compared to 13-cRA, although statistically significant, was not impressive (<10%).

CONCLUSIONS

ATRA provides a slightly stronger direct antineoplastic effect on human renal cancer cells than 13-cRA, and acts synergistically with IFN-alpha. However, ATRA, if at all, does not seem to be more suitable for treatment of patients with MRCC than 13-cRA.

Capecitabine as third-line treatment in patients with metastatic renal cell carcinoma after failing immunotherapy

The aim of this study was to evaluate the activity and toxicity of capecitabine as third-line treatment in patients with advanced renal cell carcinoma for whom immunotherapy had failed. Twenty-one patients with metastatic clear renal cell carcinoma were enrolled. Capecitabine was administered orally twice daily at a dosage of 2500 mg/m(2) for 14 days, followed by 7 days of rest. The median number of administered cycles was five (1-13). One patient (4.8%) achieved a remission after eight treatment cycles. Stable disease was observed in nine patients (42.8%), whereas 11 progressed (52.4%). The estimated median time to progression was 3.6 months (confidence interval: 1.4 to 5.2). The estimated median overall survival was 7.2 months (confidence interval: 4.6 to 8.8). The regimen was well tolerated and no unexpected toxic effects were observed. Capecitabine as third-line treatment showed a favourable toxicity profile, but exhibited low activity in patients with advanced renal cell carcinoma after failing immunotherapy.

Multicenter Phase II Study of Chemo-immunotherapy in the Treatment of Metastatic Renal Cell Carcinoma

The purpose of this study was to evaluate the potential efficacy of a chemo-immunotherapy regimen for the treatment of metastatic renal cell carcinoma (MRCC). Forty-one patients with progressing MRCC and with a median age of 63 years were recruited. Planned treatment consisted of 6 courses of capecitabine 1000 mg/m twice daily on days 1 to 14 every 4 weeks, pegylated alpha-interferon 2b 50 microg every week, interleukin-2 1.8 M IU subcutaneously, and oral 13-cis-retinoic acid 0.5 mg/kg, all given 5 days/wk, 3 weeks of each month. After 6 courses of concomitant biochemotherapy, biotherapy was continued in patients who had a clinical benefit. The primary end point was response; secondary end points were the evaluation of the immunologic parameters, toxicity, progression-free, and overall survival. The treatment was well-tolerated. Grade 3 and 4 neutropenia and thrombocytopenia occurred in 5% and 7% of patients, respectively. The overall response rate in the 41 evaluable patients was 53.6% (95% confidence interval 37%-69%). Median progression-free and overall survivals were 14.7 and 27.8 months, respectively. A sustained improvement in all evaluated immunologic parameters was observed in the 36 patients treated with maintenance biotherapy. Six cycles of biochemotherapy, being followed by maintenance immunotherapy is well-tolerated and shows significant activity in patients with MRCC.

Phase II trial of capecitabine and rHu-interferon-alpha-2a in patients with metastatic renal cell carcinoma, limited efficacy, and moderate toxicity

BACKGROUND

Capecitabine is an orally administered fluoropyrimidine that is converted to 5-fluorouracil by thymidine phosphorylase. In view of the recognized synergism of fluoropyrimidines with interferon-alpha (IFNalpha), a Phase II study to characterize the toxicity and efficacy of the combination of capecitabine and rHuIFNalpha-2a for the treatment of patients with renal cell carcinoma (RCC) was conducted.

PATIENTS AND METHODS

Eligible patients had metastatic RCC, measurable disease, and no prior systemic therapy. A total of 32 patients were entered into the study. Histologic subtypes included clear cell (n = 28) and nonclear cell (n = 2). Histology was unknown for 2 patients. The first 14 patients were treated with capecitabine 1,000 mg/m(2) twice daily on days 1-14 and 22-36, combined with IFNalpha-2a 3.0 MU/m(2) subcutaneously 3 times weekly. Because of toxicity requiring dose reductions during the first cycle, the capecitabine dose was reduced to 825 mg/m(2) twice daily on days 1-14 and 22-36 in the subsequent 18 patients.

RESULTS

Responses were seen in 4 of 32 patients (12%) (95% confidence interval 4% to 29%), with 1 complete response and 3 partial responses. There were 3 responses that occurred at the higher capecitabine starting dose level. Median response duration was 12 months (range 4.6-15.0). There were 12 patients (38%) who had stable disease for at least 2 cycles (duration 2.9 to 33.6+ months). One-year survival was 63%. Toxicity was moderate to severe and required dose reductions in 88% of patients. There were 23 patients who had grade > or =3 toxicity.

CONCLUSION

The combination of capecitabine and IFNalpha-2a has limited activity in metastatic RCC and is associated with moderate-to-severe toxicity.

C-reactive Protein in Patients with Metastatic Clear Cell Renal Carcinoma: An Important Biomarker for Tumor-associated Inflammation

Two consecutive multi-center phase II trials were designed to prove the hypothesis, whether therapeutic modeling of tumor-associated inflammatory processes could result in improved tumor response.Therapy in both trials consisted of low-dose capecitabine 1g/m2 twice daily p.o. for 14 days, every 3 weeks, day 1+, and rofecoxib 25 mg daily p.o., day 1+ (from 11/04 etoricoxib 60 mg daily instead) plus pioglitazone 60 mg daily p.o., day 1+. In study II low-dose IFN-alpha 4.5 MU sc. three times a week, week 1+, was added until disease progression.Eighteen, and 33 patients, respectively, with clear cell renal carcinoma and progressive disease were enrolled. Objective response (48%) was exclusively observed in study II (PR 35%, CR 13%), and paralleled by a strong CRP response after 4 weeks on treatment, p = 0.0005, in all 29 pts (100%) with elevated CRP levels. Median progression-free survival could be more than doubled from a median of 4.7 months (95% CI, 1.0 to 10.4) to 11.5 months (6.8 to 16.2) in study II, p = 0.00001. Median overall survival of population II was 26 months.Efficacious negative regulation of tumor-associated inflammation by transcription modulators may result in a steep increase of tumor response and survival.

Interleukin-2/interferon-alpha2a/13-retinoic acid-based chemoimmunotherapy in advanced renal cell carcinoma: results of a prospectively randomised trial of the German Cooperative Renal Carcinoma Chemoimmunotherapy Group (DGCIN)

We performed a prospectively randomised clinical trial to compare the efficacy of four subcutaneous interleukin-2-(sc-IL-2) and sc interferon-alpha2a (sc-IFN-alpha2a)-based outpatient regimens in 379 patients with progressive metastatic renal cell carcinoma. Patients with lung metastases, an erythrocyte sedimentation rate < or =70 mm h(-1) and neutrophil counts < or =6000 microl(-1) (group I) were randomised to arm A: sc-IL-2, sc-IFN-alpha2a, peroral 13-cis-retinoic acid (po-13cRA) (n=78), or arm B: arm A plus inhaled-IL-2 (n=65). All others (group II) were randomised to arm C: arm A plus intravenous 5-fluorouracil (iv-5-FU) (n=116), or arm D: arm A plus po-Capecitabine (n=120). Median overall survival (OS) was 22 months (arm A; 3-year OS: 29.7%) and 18 months (arm B; 3-year OS: 29.2%) in group I, and 18 months (arm C; 3-year OS: 25.7%) and 16 months (arm D; 3-year OS: 32.6%) in group II. There were no statistically significant differences in OS, progression-free survival, and objective response between arms A and B, and between arms C and D, respectively. Given the known therapeutic efficacy of sc-IL-2/sc-INF-alpha2a/po-13cRA-based outpatient chemoimmunotherapies, our results did not establish survival advantages in favour of po-Capecitabine vs iv-5-FU, and in favour of short-term inhaled-IL-2 in patients with advanced renal cell carcinoma receiving systemic cytokines.

C-reactive Protein in Patients with Metastatic Clear Cell Renal Carcinoma: An Important Biomarker for Tumor-associated Inflammation

Two consecutive multi-center phase II trials were designed to prove the hypothesis, whether therapeutic modeling of tumor-associated inflammatory processes could result in improved tumor response.

Therapy in both trials consisted of low-dose capecitabine 1g/m2 twice daily p.o. for 14 days, every 3 weeks, day 1+, and rofecoxib 25 mg daily p.o., day 1+ (from 11/04 etoricoxib 60 mg daily instead) plus pioglitazone 60 mg daily p.o., day 1+. In study II low-dose IFN-α 4.5 MU sc. three times a week, week 1+, was added until disease progression.

Eighteen, and 33 patients, respectively, with clear cell renal carcinoma and progressive disease were enrolled. Objective response (48%) was exclusively observed in study II (PR 35%, CR 13%), and paralleled by a strong CRP response after 4 weeks on treatment, p = 0.0005, in all 29 pts (100%) with elevated CRP levels. Median progression-free survival could be more than doubled from a median of 4.7 months (95% CI, 1.0 to 10.4) to 11.5 months (6.8 to 16.2) in study II, p = 0.00001. Median overall survival of population II was 26 months.

Efficacious negative regulation of tumor-associated inflammation by transcription modulators may result in a steep increase of tumor response and survival.

A phase I study of the oral combination of CI-994, a putative histone deacetylase inhibitor, and capecitabine

BACKGROUND

This study was conducted to determine the toxicity profile, maximum tolerated dose (MTD) and pharmacokinetics of the putative histone deacetylase inhibitor CI-994 in combination with capecitabine.

PATIENTS AND METHODS

Fifty-four patients were treated according to three different dosing schemes in which the capecitabine dose was fixed and the CI-994 dose was escalated. Capecitabine was administered in twice daily divided doses, and CI-994 was given as a single daily dose. In schedule A, 26 patients were treated with capecitabine 1650 mg/m2/day and CI-994 for 2 weeks of a 3-week cycle. In schedule B, six patients received capecitabine 1650 mg/m2/day for two 3-week cycles and CI-994 for 5 of 6 weeks. In schedule C, 22 patients were treated with capecitabine 2000 mg/m2/day and CI-994 for 2 of 3 weeks.

RESULTS

At the MTD, the principal dose-limiting toxicity was thrombocytopenia. The pharmacokinetics of CI-994 were unaltered by capecitabine, and there was no correlation between body surface area and major pharmacokinetic parameters. Platelet count nadir was best predicted by the observed maximal concentration (C(max)) of CI-994.

CONCLUSIONS

The recommended phase II dose is 6 mg/m2 (or 10 mg) of CI-994 in combination with capecitabine 2000 mg/m2/day for 2 weeks of a 3-week cycle.

Capecitabine: a review

BACKGROUND

Fluorouracil (FU) is an antimetabolite with activity against numerous types of neoplasms, including those of the breast, esophagus, larynx, and gastrointestinal and genitourinary tracts. Systemic toxicity, including neutropenia, stomatitis, and diarrhea, often occur due to cytotoxic nonselectivity. Capecitabine was developed as a prodrug of FU, with the goal of improving tolerability and intratumor drug concentrations through tumor-specific conversion to the active drug.

OBJECTIVES

The purpose of this article is to review the available information on capecitabine with respect to clinical pharmacology, mechanism of action, pharmacokinetic and pharmacodynamic properties, clinical efficacy for breast and colorectal cancer adverse-effect profile, documented drug interactions, dosage and administration, and future directions of ongoing research.

METHODS

Relevant English-language literature was identified through searches of PubMed (1966 to August 2004), International Pharmaceutical Abstracts (1977 to August 2004), and the Proceedings of the American Society of Clinical Oncology (January 1995 to August 2004). Search terms included capecitabine, Xeloda, breast cancer, and colorectal cancer. The references of the identified articles were reviewed for additional sources. In addition, product information was obtained from Roche Pharmaceuticals. Studies from the identified literature that addressed this article's objectives were selected for review, with preference given to Phase II/III trials.

RESULTS

Capecitabine is an oral prodrug that is converted to its only active metabolite, FU, by thymidine phosphorylase. Higher levels of this enzyme are found in several tumors and the liver, compared with normal healthy tissue. In adults, capecitabine has a bioavailability of approximately 100% with a Cmax of 3.9 mg/L, Tmax of 1.5 to 2 hr, and AUC of 5.96 mg.h/L. The predominant route of elimination is renal, and dosage reduction of 75% is recommended in patients with creatinine clearance (CrCl) of 30 to 50 mL/min. The drug is contraindicated if CrCl is < 30 mL/min. Capecitabine has shown varying degrees of efficacy with acceptable tolerability in numerous cancers including prostate, renal cell, ovarian, and pancreatic, with the largest amount of evidence in metastatic breast and colorectal cancer. Single-agent capecitabine was compared with IV FU/leucovorin (LV) using the bolus Mayo Clinic regimen in 2 Phase III trials as first-line treatment for patients with metastatic colorectal cancer. Overall response rate (RR) favored the capecitabine arm (26% vs 17%, P < 0.001); however, this did not translate into a difference in time to progression (TTP) (4.6 months vs 4.7 months) or overall survival (OS) (12.9 months vs 12.8 months). In Phase II noncomparative trials, combinations of capecitabine with oxaliplatin or irinotecan have produced results similar to regimens combining FU/LV with the same agents in patients with colorectal cancer. In metastatic breast cancer patients who had received prior treatment with an anthracycline-based regimen, a Phase III trial comparing the combination of capecitabine with docetaxel versus docetaxel alone demonstrated superior objective tumor RR (42% vs 30%, P = 0.006), median TTP (6.1 months vs 4.2 months, P < 0.001), and median OS (14.5 months vs 11.5 months, P = 0.013) with the combination treatment. Noncomparative Phase II studies have also supported efficacy in patients with metastatic breast cancer pretreated with both anthracyclines and taxanes, yielding an overall RR of 15% to 29% and median OS of 9.4 to 15.2 months. The most common dose-limiting adverse effects associated with capecitabine monotherapy are hyperbilirubinemia, diarrhea, and hand-foot syndrome. Myelosuppression, fatigue and weakness, abdominal pain, and nausea have also been reported. Compared with bolus FU/LV, capecitabine was associated with more hand-foot syndrome but less stomatitis, alopecia, neutropenia requiring medical management, diarrhea, and nausea. Capecitabine has been reported to increase serum phenytoin levels and the international normalized ratio in patients receiving concomitant phenytoin and warfarin, respectively. The dose of capecitabine approved by the US Food and Drug Administration (FDA) for both metastatic colorectal and breast cancer is 1250 Mg/M2 given orally twice per day, usually separated by 12 hours for the first 2 weeks of every 3-week cycle.

CONCLUSIONS

Capecitabine is currently approved by the FDA for use as first-line therapy in patients with metastatic colorectal cancer when single-agent fluoropyrimidine therapy is preferred. The drug is also approved for use as (1) a single agent in metastatic breast cancer patients who are resistant to both anthracycline- and paclitaxel-based regimens or in whom further anthracycline treatment is contra indicated and (2) in combination with docetaxel after failure of prior anthracycline-based chemotherapy. Single-agent and combination regimens have also shown benefits in patients with prostate, pancreatic, renal cell, and ovarian cancers. Improved tolerability and comparable efficacy compared with IV FU/LV in addition to oral administration make capecitabine an attractive option for the treatment of several types of cancers as well as the focus of future trials.

Chemotherapy in metastatic renal cell cancer

Currently, there is no standard treatment for patients with advanced renal cell carcinoma (RCC) who do not respond to or progress after transient remission to first-line immunotherapy. At the end of the 1990s, no single chemotherapeutic drug, alone or in combination with interleukin-2 (IL-2) or interferon-alfa (IFN), had shown activity beyond the one expected by immunotherapy alone. New drugs on the market such as the pyrimidine analog gemcitabine or taxane-based chemotherapeutics may show promising tumor activity in combination with targeted therapy, but this has to be substantiated in upcoming trials. There is a great need to develop effective systemic therapy for advanced MRCC and to evaluate the efficacy of new drugs in clinical trials.

Phase II clinical trial of capecitabine and gemcitabine chemotherapy in patients with metastatic renal carcinoma

We report a single institution phase II study of gemcitabine 1200 mg m⁻² i.v. on days 1 and 8 and capecitabine 1300 mg m⁻² twice daily on days 1–14 of each 3-week cycle in patients with metastatic renal carcinoma. Patients had a WHO performance status of 0, 1 or 2. Of the 21 enrolled patients, 19 had received prior immunotherapy or chemoimmunotherapy. All had progressive disease at study entry. In all,19 patients had multiple sites of disease. The median duration of metastatic disease was 12.3 months (range 1.2–78.1 months). Three of the 19 evaluable patients achieved a partial response to treatment, with no complete responses, producing an objective overall response rate of 15.8% (95% CI, 3.4–39.6%). The median time to disease progression was 7.6 months, and median overall survival was 14.2 months. Treatment was reasonably well-tolerated, neutropenia being the most frequently observed grade 3 or 4 toxicity, occurring in 57% of patients. Other side effects were consistent with the established toxicity profile of the two drugs, including diarrhoea, palmar-plantar erythema, fatigue, nausea, vomiting and infection. This combination of gemcitabine and capecitabine has modest activity in immunotherapy-refractory metastatic renal carcinoma with manageable toxicity.

Combination therapy with capecitabine and interferon alfa-2A in patients with advanced renal cell carcinoma: A phase II study

Capecitabine is a fluoropyrimidine carbamate capable of exploiting the high concentrations of thymidine phosphorylase in tumor tissue to achieve activation preferentially at the tumor site. Thymidine phosphorylase activity is high in renal cell carcinoma tissue. Interferon alfa has been proved to be the agent for standard therapy in metastatic renal cell carcinoma. The purpose of the study was to assess the efficacy and toxicity of combining capecitabine and interferon alfa-2A in patients with advanced renal cell carcinoma. Twenty-five patients with advanced renal cell carcinoma and no prior systemic therapy were treated with the combination of capecitabine at a dose of 1,250 mg/m2 twice daily for 2 weeks after every 21 days and interferon alfa-2A 6 million U three times a week. The overall response rate was 24.0% (95% CI, 9.4-45.1%), from 6 responded patients 5 had partial responses and 1 complete response. Stable disease status was achieved in 9 patients (36.0% with 95% CI 18.0-57.5%). The median survival time was 248 days (95% CI, 173-265 days). The median time to progression was 126 days (95% CI, 49-165 days). Grade 3-4 toxicities occurred in 12 patients and included fatigue (33.3%), nausea, hand-foot syndrome (both 12.5%), anorexia (8.3%), vomiting, anemia and neutropenia (all 4.2%). The capecitabine and interferon alfa-2A combination has clinical activity and an acceptable toxicity profile in patients with metastatic renal cell carcinoma. The importance of adding capecitabine to interferon alfa needs to be confirmed in a randomized trial.

Interferon-alpha 2a up-regulated thymidine phosphorylase and enhanced antitumor effect of capecitabine on hepatocellular carcinoma in nude mice

PURPOSE

To investigate the antitumor effect of interferon-alpha 2a (IFN-alpha2a) combined with capecitabine on hepatocellular carcinoma (HCC) in nude mice in relation to thymidine phosphorylase (TP) expression.

METHODS

Thirty nude mice bearing orthotopic xenografts of a human HCC tumor (LCI-D20) were divided into control, capecitabine, IFN-alpha2a, and combination (capecitabine plus IFN-alpha2a) groups. Tumor growth was determined by measuring the tumor volume. An enzyme-linked immunosorbent assay (ELISA) was used to study the TP expression in the cancer tissues of the liver.

RESULTS

IFN-alpha2a enhanced the sensitivity of the LCI-D20 tumor response to capecitabine treatment. The tumor volume was significantly reduced in the capecitabine (455+/-236 mm(3)), IFN-alpha2a (248 +/- 114 mm(3)) or combination (46 +/- 29 mm(3)) treatment groups as compared to the control (1,033 +/- 146 mm(3)) (P < 0.01). A significant difference was also found between the single treatment (capecitabine or interferon) and combination treatment group (P < 0.01 and P < 0.05, respectively). IFN-alpha2a up-regulated TP expression in LCI-D20 tumor. An approximate 1.5-fold increase in TP expression was observed in the mice which received IFN-alpha2a treatment compared to the control mice.

CONCLUSION

IFN-alpha2a enhanced the antitumor effect of capecitabine on HCC in nude mice, which might be ascribed to the up-regulation of TP expression in liver cancer tissues by IFN-alpha2a.

Capecitabine treatment results in increased mean corpuscular volume of red blood cells in patients with advanced solid malignancies

Capecitabine is a novel fluoropyrimidine carbamate which is selectively activated after oral administration to 5-fluorouracil (5-FU) by a sequential triple enzyme pathway in liver and tumor cells. The cytotoxic activity of the metabolized 5-FU depends on thymidylate synthase (TS) inhibition, leading to defective DNA synthesis. Capecitabine has shown promising activity in all tumor types sensitive to 5-FU and is therefore investigated in many clinical trials. Since we observed an increase of mean corpuscular volume (MCV) of red blood cells under therapy with capecitabine, the current investigation aimed to quantitate this effect and to elucidate the underlying mechanisms. A total of 154 patients suffering from advanced cancer received capecitabine (2500 mg/m2/day for 14 days every 21 days) either as monotherapy, or in combination with other antineoplastic agents or biological response modifiers. During 3 consecutive cycles of therapy a complete blood cell count including the red cell indices MCV, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration was performed before each application of capecitabine. In addition, vitamin B12, folic acid and homocysteine were determined to define their role in increasing MCV. Restaging was performed after 9 weeks. Within 9 weeks, a statistically significant increase of MCV (without other hematologic abnormalities or clinical symptoms) could be observed (p<0.0001). Vitamin B12, folic acid and homocysteine levels did not change significantly during the observation period. When comparing the different increases of MCV during 9 weeks (deltaMCV) with respect to tumor response, deltaMCV tended to higher values in patients with tumor remission or stable disease than in patients with tumor progression. We conclude that serum levels within the normal range rule out severe deficiencies of vitamin B12, folic acid or homocysteine as an account of macrocytemia. We therefore hypothesize that an increased MCV (without concomitant anemia) in patients receiving capecitabine might be due to the 5-FU-induced TS inhibition also in erythroid precursor cells. Whether this increase in MCV might serve as a surrogate marker for tumor response has to be evaluated in further investigations.

The role of rational immunotherapy for renal cell carcinoma

Metastases to distant organs are the principal cause of death from renal cell carcinoma (RCC). No commonly accepted therapy is available for disseminated RCC at present. The rationale for immunotherapy of RCC is based on the fact that there is no other therapy for advanced cases. Biologic therapies are the only current treatment modalities that have produced promising therapeutic results in metastatic RCC (mRCC). Therapy with cytokines usually has typical and sometimes severe side effects. Response rates and toxicity were higher with combined therapy. The administration of cytokines that augment the function of the immune system can be accomplished safely and without toxicity, provided a rational approach is used. The toxic effects that are frequently observed with combined therapy emphasize the need for careful selection of patients.

Capecitabine: fulfilling the promise of oral chemotherapy

Capecitabine is a synthetic oral fluoropyrimidine carbamate that is sequentially activated in a three-step process, which results in the preferential production of 5-fluorouracil in tumours, rather than in the normal surrounding tissue. Capecitabine is proven to be as effective as the combination of 5-fluorouracil and leucovorin administered on the Mayo clinic schedule in patients with metastatic colorectal cancer. It has also been proven to be effective in patients with metastatic breast cancer that has progressed despite prior anthracyclines and taxoids. More recently, it has also been shown to increase survival in combination with docetaxel in patients with metastatic breast cancer in comparison to docetaxel alone. This article reviews the pharmacology and clinical activity of capecitabine, as well as combinations of capecitabine with other chemotherapeutic agents and future directions of investigation with this convenient and widely active antitumour therapy.

Cancer immunotherapy: the interferon-alpha experience

Interferons are agents with antiviral, antiproliferative, and immunomodulatory properties. Interferon-alfa (IFN-alpha) is used in the treatment of hematologic malignancies and solid tumors. IFN-alpha has shown antitumor and antiviral efficacy that are not correlated, one with another. Approval by the US Food and Drug Administration was granted early for the treatment of patients with hairy cell leukemia, acquired immune deficiency syndrome-related Kaposi's sarcoma, and condylomata acuminata. Although IFNs are effective as single agents in certain clinical pathologic entities, increasing experience with these cytokines suggests that their greatest therapeutic potential may be realized in combination with other biological response modifiers, cytotoxics, or antiviral agents. For example, trials combining IFN-alpha with 5-fluorouracil to treat colorectal carcinoma or IFN-alpha with zidovudine to treat acquired immune deficiency disorder showed increased efficacy over IFN-alpha alone. While IFN-alpha appears to be moderately effective in certain diseases, the flu-like syndrome associated with its use is a major limiting factor for its clinical application. Further studies are needed to determine the underlying mechanism of action for IFNs and the most effective combinations and appropriate preclinical models, or intermediate endpoints that will then facilitate the rational use of this agent in combinations based on the mechanisms of action of IFN-alpha.

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.

Capecitabine in the treatment of metastatic renal cell carcinoma failing immunotherapy

Capecitabine is a novel fluoropyrimidine carbamate, orally administered and selectively activated to fluorouracil by a sequential triple-enzyme pathway in liver and tumor cells. This prospective trial aims to evaluate the therapeutic effects and systemic toxicities of capecitabine in patients with metastatic renal cell carcinoma in which immunotherapy failed. Twenty-six patients (median age, 58 years; range, 47 to 76 years) with disease in which first- or second-line immunotherapy treatment failed entered the trial. Median time of observation was 13+ months (range, 3 to 25+ months). Capecitabine was administered in the outpatient setting orally at a dose of 2,500 mg/m2/d divided into two daily doses for 14 days, followed by 7 days of rest. This schedule was repeated in 3-week intervals. Twenty-six patients are now assessable for toxicity, and 23 patients, for response. We observed a partial response to treatment in 2 patients (8.7%), minor response in 5 patients (21.7%), stable disease in 13 patients (56.5%), and continued disease progression despite treatment in only 3 patients (13.1%). Outpatient capecitabine therapy was well tolerated, and World Health Organization (WHO) grade III toxicity in these 26 patients consisted of hand-foot syndrome in 2 patients (7.7%) and anemia in 1 patient (3.8%). We did not observe WHO grade IV toxicity. Oral capecitabine appears to be a promising treatment with a favorable toxicity profile in patients with advanced renal cell carcinoma and should be evaluated in first- and second-line treatment schedules as monotherapy, as well as in combination with immunotherapy agents.

Renal cell carcinoma

Several renal cell carcinoma (RCC) prognostic factors show promise, including K1-67, p53/mdm-2, and vascular endothelial growth factor. The combination of increased incidence of RCC and diagnosis during earlier stages has generated interest in local therapeutic options. Nephron-sparing surgery and laparoscopic nephrectomy continue to gain support and may become the standard of care in select patients. Standard therapy for metastatic disease continues to be cytokine-based therapy with little benefit gained from adding granulocyte-macrophage-colony-stimulating factor, retinoic acid, or adoptive immunotherapy. The addition of chemotherapy, such as capecitabine, floxuridine, and vinblastine, may increase the effectiveness of immunotherapy; nonmyeloablative stem cell transplantation has shown early promise in metastatic disease.