A phase II trial of interferon alpha-2A plus fluorouracil in advanced renal cell carcinoma. A Hoosier Oncology Group study

Consensus interferon enhances the anti-proliferative effect of 5-fluorouracil on human hepatoma cells via downregulation of dihydropyrimidine dehydrogenase expression

BACKGROUND/AIMS

The effectiveness of 5-fluorouracil (5-FU) treatment is influenced by the activities of pyrimidine catabolic enzymes. The aim of this study was to investigate whether interferon (IFN)-alpha influences expression of 5-FU catabolic or target-related enzymes in human hepatoma cells.

METHODS

HepG2 cells were treated with 0, 0.15, 1.5, 15, and 150 ng/ml of consensus interferon (C-IFN). Expression of mRNAs encoding dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase, and thymidylate synthase was examined by reverse transcription-polymerase chain reaction before and after C-IFN treatment. To determine the effect of pretreatment with C-IFN on 5-FU+C-IFN combination therapy, we performed WST-1 cell proliferation assays.

RESULTS

A significant reduction in the level of DPD mRNA was observed when HepG2 cells were pretreated with C-IFN (P<0.05). This reduction occurred in a time-dependent manner. Cell proliferation was reduced most significantly when HepG2 cells were treated with 5-FU and C-IFN. Furthermore, when cells were pretreated with C-IFN for 3 days, the anti-proliferative effect of 5-FU+C-IFN combination therapy was augmented significantly (P<0.05).

CONCLUSIONS

C-IFN likely improves the anti-tumor effect of 5-FU via downregulation of DPD enzyme in hepatoma cells. Pretreatment with C-IFN may increase the anti-cancer effect of 5-FU+C-IFN combination therapy.

Chemotherapeutic strategies for renal cell carcinoma

Metastatic renal cell carcinoma (RCC) is a disease that is highly resistant to systemic chemotherapy. Responses to combination chemotherapy have been reported in patients with collecting duct carcinoma and the sarcomatoid variant of renal cancer. Clinical trials combining chemotherapy with biologic response modifiers have not resulted in significant advances in the treatment of RCC. Patients with advanced local or metastatic RCC should be offered investigational therapeutic options. The identification of novel agents with significantly improved antitumor activity remains a high priority in the treatment of this disease.

Pilot trial of infusional 5-fluorouracil, interleukin-2, and subcutaneous interferon-alpha for advanced renal cell carcinoma

The authors developed an outpatient, three-drug combination regimen for advanced renal cell carcinoma. Treatment was administered for 5 days each week for 4 weeks, followed by 2-week rests. Each weekly treatment consisted of 5-fluorouracil 1,750 mg/m2 continuous intravenous infusion for 24 hours followed by interleukin-2 6 mIU/m2 per day continuous intravenous infusion for 4 days, and interferon-alpha2b 6 mU/m2 subcutaneously on days 1, 2, and 5. This trial was undertaken to assess tolerability to this regimen and obtain a preliminary assessment of its effectiveness. Most patients required some dose adjustments (especially of cytokines), treatment interruptions, or both. Toxicities were as would be expected from individual drug profiles with only mild to moderate hematologic toxicities. Among 16 patients with renal cell carcinoma treated, four had major (clinical partial response) responses, one of which was demonstrated to be a pathologic clinical response after surgical resection of a residual mass. Estimated median survival time of all patients was 93 weeks. Response and survival were correlated with known clinical risk factors. Responding patients were noted to be significantly older in age (X = 61.75 years) than nonresponders (X = 48.92 years). There was no correlation between age and other clinical risk factors, treatment tolerance, or survival. The authors conclude that this three-drug regimen is a practical, tolerable, and promising regimen for further study in renal cell carcinoma.

Interferon-alpha and 5-fluorouracil therapy in patients with metastatic renal cell cancer: an open multicenter trial. The Japanese Study Group Against Renal Cancer

OBJECTIVES

Recent clinical trials have implied the cytotoxic and antiproliferative effects of combining 5-fluorouracil and interferon-alpha in the treatment of metastatic renal cell cancer. We therefore conducted an open multicenter trial to test the efficacy of such a combination on this cancer.

METHODS

Human lymphoblastoid interferon (3 MIU per patient) was administered subcutaneously three times weekly for 12 weeks, while 5-fluorouracil was administered (600 mg/m2/day) as a continuous infusion for the first 5 days, followed by an intravenous bolus infusion of 600 mg/m2 once a week from the 3rd week until the 12th week.

RESULTS

Of the 63 patients entered into the trial, 55 were eligible and evaluable for systemic toxicities, and 53 were evaluable for their response. All patients had undergone a prior nephrectomy, and their European Cooperative Oncology Group (ECOG) performance status ranged from 0 to 3 (median 0). Three complete and eight partial responses were induced, with an overall response rate of 20.0%. The median time to progression and the median survival time were 11 and 33 months, respectively. World Health Organization grade 3 toxicities were observed in 8 patients; however, no grade 4 toxicities or toxicity-related deaths were noted.

CONCLUSIONS

Combination therapy of interferon-alpha plus 5-fluorouracil at the above-described dosage and schedule produced no better responses than interferon monotherapies. Prolongation of survival could be attributable to the fair performance status of the patients. This regimen has limited value for the treatment of patients with advanced renal cell cancer.

Antitumor effect of irinotecan hydrochloride (CPT-11) on human renal tumors heterotransplanted in nude mice

BACKGROUND

There has been a paucity of antitumor drugs that are active against renal tumors. Irinotecan hydrochloride (CPT-11), a DNA topoisomerase type 1 inhibitor, has demonstrated antitumor activity against human tumors, however, no antitumor effect of CPT-11 on renal tumors has been reported. The antitumor effect of CPT-11 was investigated on 2 human renal tumors (OUR-10 and OUR-20) heterotransplanted into nude mice.

METHODS

Tumor-bearing nude mice were given daily intraperitoneal injections of multiple anticancer drugs suspended in 0.2 mL of phosphate-buffered saline (PBS) 3 times at 3-day intervals. Control mice were injected with 0.2 mL of PBS. The antitumor effects were evaluated by calculating the T/C ratio (treated tumors/controls) of the tumor volume.

RESULTS

Among the 10 anticancer drugs tested, 50 mg/kg of CPT-11 showed an active antitumor effect on OUR-20 (T/C ratio 34). However, all drugs tested on OUR-10 failed to show antitumor activity.

CONCLUSION

Since CPT-11 was effective in 1 of 2 renal tumors examined without severe toxicity, this drug could be a candidate for chemotherapy of renal cell carcinoma.

Treatment of renal cell carcinoma with 5-fluorouracil and alfa-interferon

OBJECTIVES

Renal cell carcinoma is relatively resistant to both chemotherapy and immunotherapy. Response, survival, duration of response, and toxicity of treatment were evaluated in patients with advanced renal cell carcinoma receiving a continuous intravenous infusion of 5-fluorouracil (5-FU) and low dose subcutaneous alfa-2b-interferon.

METHODS

Between 1989 and 1994, 21 patients with advanced renal cell carcinoma underwent treatment with continuous intravenous infusion of 5-FU, 200 mg/m2/day, and subcutaneous injections of recombinant interferon alfa-2b (IFN-alpha), 1 x 10(6) U/day.

RESULTS

Objective response was observed in 9 patients (43%). Complete response occurred in 4 patients (19%): 2 with lung, 1 with bone, and 1 with liver metastasis. Partial response occurred in 5 patients (24%). Three of 4 complete responders remain alive without recurrence. Mean survival rate was 195 weeks among complete responders, 184 weeks among partial responders, and 88 weeks among nonresponders. The overall mean duration of response was 101 weeks. Responders developed progression of disease a mean of 62 weeks after the initial response to therapy. Mild dose-dependent toxicity was related to 5-FU infusion. Nearly all toxicities subsided with the temporary cessation of 5-FU infusion and/or decreasing the dose of the infusion. Few if any of the toxicities appear to be directly related to the low dose interferon injections.

CONCLUSIONS

Although this study is based on a small sample size, we believe that the encouraging complete and partial responses, apparent prolongation of survival, and manageable toxicity of this combination therapy warrant further investigation with larger randomized trials.

Natural history and therapy of metastatic renal cell carcinoma: the role of interleukin-2

BACKGROUND

Despite significant advances in understanding the biology of renal cell carcinoma (RCC) during the past decade, metastatic disease remains nearly incurable and a major medical challenge. Because RCC is known to be immunogenic, immunotherapeutic agents such as recombinant human interleukin-2 (rIL-2) and interferon-alpha (IFN-alpha) have represented encouraging treatment modalities.

METHODS

A review of the natural history of and therapeutic approaches to RCC was examined. Studies involving rIL-2 alone and in combination with other adjuvant therapies were critically evaluated.

RESULTS

Overall response rates for metastatic RCC patients treated with rIL-2 were similar (i.e., in the range of 15-20%), regardless of whether rIL-2 was administered as monotherapy or in combination with IFN-alpha. Recombinant IL-2 monotherapy response rates were similar to those of IFN-alpha, but with an increased frequency of complete responses and enhanced response duration. Subcutaneous administration generally resulted in lower toxicity than intravenous administration. The roles of chemotherapy or adoptive immunotherapy in combination with rIL-2 and IFN-alpha therapy remain unclear and require further study. The importance of patient performance status as a predictor of response and survival in rIL-2 therapy was demonstrated.

CONCLUSIONS

The use of rIL-2 with or without IFN-alpha may represent the most useful therapeutic approach currently available for patients with good performance status. In patients with borderline performance status or severe comorbid disease, therapeutic approaches depend on patient factors and outcome expectation and may involve cytokine therapy. However, regardless of performance status, palliative measures and/or observation are important choices, because the majority of patients with metastatic RCC are incurable.

A phase II trial of interferon-alpha and 5-fluorouracil in patients with advanced renal cell carcinoma. A Southwest Oncology Group study

BACKGROUND

Renal cell carcinoma is a common neoplasm that is often refractory to treatment. It is occasionally responsive to immunomodulating agents including interferon-alpha, which enhances the effects of 5-fluorouracil upon cells. Combinations of these two drugs have been most frequently tested in patients with gastrointestinal cancers, with some promising results. Because interferon-alpha has activity for renal cell carcinoma, a trial of this combination in patients with this malignancy was undertaken.

METHODS

The Southwest Oncology Group performed a Phase II clinical trial of the combination of 5-fluorouracil and interferon-alpha for recurrent or metastatic renal cell carcinoma. Eligibility criteria included no prior treatment with medications for cancer, a performance status of 2 or better, and bidimensionally measurable disease. The regimen studied consisted of 5-fluorouracil, 750 mg/M2/day, by continuous intravenous infusion on Days 1-5, and interferon-alpha-2b (Intron A), 5 x 10(6)U/M2/day, subcutaneously on Days 1, 3, and 5, repeated every 21 days.

RESULTS

Forty eligible patients were treated; twenty of the 40 underwent a nephrectomy. The regimen was tolerable: 3 patients had Grade 4, and 17 had Grade 3 toxicity. There were 5 partial responses (13% with 95% confidence limits of 4-27%). Median progression free survival for all 40 patients was 4 months and median overall survival was 15 months from the time of registration.

CONCLUSIONS

The combination of 5-fluorouracil and interferon-alpha given by this schedule, although tolerable and occasionally yielding responses, is not an improvement over existing therapies.

Treatment of metastatic renal cell carcinoma with constant-rate floxuridine infusion plus recombinant alpha 2b-interferon

BACKGROUND

Floxuridine (FUDR) and alpha-interferon (IFN) are active agents in advanced renal cell carcinoma, with different dose-limiting toxic effects and antitumor synergism in experimental models. The main purpose of this phase II study was to assess the activity and toxic effects of a combination of FUDR and alpha 2b-IFN in metastatic renal cell carcinoma.

PATIENTS AND METHODS

Metastatic renal cell carcinoma patients with measurable disease entered the study. FUDR was administered as a constant-rate continuous infusion for 14 days every 28 days at a starting daily dose of 0.1 mg/kg and with dose escalations of 0.025 mg/kg/day at each subsequent cycle if WHO > or = 2 toxicity had not occurred. IFN-alpha 2b 10 x 10(6) I.U. was administered intramuscularly 3 times per week.

RESULTS

Forty-two patients entered the study and a total of 272 cycles of FUDR + alpha 2b-IFN were administered. In 41 evaluable patients WHO grade III-IV toxic effects included nausea and vomiting (22%), diarrhea (32%), stomatitis (12%), fatigue (27%) and anorexia (12%). It was possible to increase the initial FUDR does in 21 (50%) patients; the median FUDR dose intensity was 0.35 mg/kg/week (range 0.18-0.54). Among 39 evaluable patients, 3 (7.5%) complete and 10 (25.5%) partial responses were observed (response rate 33%, 95% confidence interval (CI) 19%-50%) which lasted a median of 13 months (5.5-40+). Responses also occurred in liver (2), in patients pretreated with systemic therapy (5) and in patients who had other unfavourable prognostic characteristics (7). Median progression-free and survival times were 9 and 16 months, respectively.

CONCLUSIONS

In this study FUDR + alpha 2b-IFN demonstrated interesting activity in metastatic renal cell carcinoma, showing promise also in patients with unfavourable prognostic characteristics. The antitumor activity of FUDR and alpha 2b-IFN seems to be cumulative, but cumulative toxicity is also observed. These results require confirmation in randomised trials.