Phase II trial of subcutaneous interleukin-2, subcutaneous interferon-alpha, 5-fluorouracil and cis-retinoic acid in the treatment of renal cell carcinoma: final results of cancer biotherapy research group 94-10.

BACKGROUND

The treatment of metastatic renal cell cancer remains unsatisfactory despite encouraging results with biotherapy. Pilot studies from other investigators have suggested that combining cis-retinoic acid and 5-fluorouracil (5FU) with interleukin-2 (IL-2) and interferon-alpha (IFN) may improve outcomes for such patients.

METHODS

Eligible patients had metastatic renal cell cancer, were in good medical condition, and had not been treated previously with more than two of the study agents. A 56-day treatment cycle consisted of: interferon-alpha 2a 3.0 mu/m2 s.c. Monday, Wednesday, and Friday weeks 1-8, interleukin-2 11 mu/m2 s.c. Tuesday, Thursday and Saturday of weeks 1-4, cis-retinoic acid 1 mg/kg p.o. daily weeks 1-8, and 5-FU 750 mg/m2 i.v. weekly during weeks 5-8. Patients were evaluated for tumor response every 8 weeks, and in the absence of tumor progression, patients could receive treatment for up to one year. Survival was determined from the first date of treatment.

RESULTS

The 58 renal cell carcinoma patients included 41 men and 17 women, with a median age of 57 years with a range of 28-85 who were enrolled between October 1994 and July 1997. Thirty-seven percent were asymptomatic when treatment was initiated. Sites of disease at study entry included 62% lung, 34% bone, 31% lymph node, 22% kidney, 16% liver and 10% adrenal. There were only three patients with significant tumor responses (one complete, two partial) for a response rate of 5% (0-11% 95% CI) based on intent-to-treat analysis, and 6% (0-12%, 95% CI) for the 53 patients who were evaluable for response. The response rate among evaluable nephrectomized patients who had received no prior radiation or systemic treatment was 3/25 (12%). The median failure-free survival was 2.8 months; median overall survival was 10.9 months. The 1-year survival rate was 50% and 2-year survival rate was 33%. The most frequent toxicities were fatigue-81% (26% grade 3 or 4), nausea/vomiting-59%, and leukopenia/neutropenia 57% (16% grade 3 or 4).

CONCLUSIONS

Despite a disappointing objective response rate, survival in these patients who were treated entirely as outpatients was similar to that seen in our earlier trials of inpatient, intermediate dose continuous infusion IL-2-based therapy.