The treatment of metastatic renal cell carcinoma by continuous intravenous infusion of recombinant interleukin-2

Long-Term Survival in Patients with Metastatic Renal Cell Carcinoma Treated with Continuous Intravenous Infusion of Recombinant Interleukin-2: The Experience of a Single Institution

Aim and background

Metastatic renal cell carcinoma is one of the few tumors for which a clear benefit of immunotherapy has been demonstrated. The aim of this study was to evaluate the long-term survival of patients with metastatic renal cell carcinoma, along with response rate and other prognostic and predictive factors.

Patients and methods

Between July 1989 and May 1995, 56 patients with metastatic renal cell carcinoma were treated in a single institution with high-dose recombinant interleukin-2 in continuous infusion. Survival was measured by the Kaplan and Meier method. Prognostic factors were assessed by univariate and multivariate analyses of survival (Cox proportional hazard ratio model).

Results

Of 56 patients, 15 had objective responses (26.8%), 16 stable disease (28.6%), 18 disease progressions (32.1%), and 7 (12.5%) were not valuable for response. Median overall survival was 20 months, and probability of 2- and 5-year survival was 41% and 21%, respectively. At multivariate analysis, the increased risk of death for: performance status ≥2 vs 0 (HR = 6.20), stable disease (HR = 1.87), disease progression (HR = 10.61) vs partial or complete remission, and for hypotension and oliguria toxicity, G3 + G4 vs G1 + G2 (HR = 2.19).

Conclusions

Our study confirms the activity of IL-2 based immunotherapy in renal cell carcinoma. Moreover, ECOG performance status, clinical response, hypotension and oliguria toxicity resulted as independent survival prognostic factors.

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.

Novel treatments for metastatic renal cell carcinoma

The mainstay of any curative treatment in renal cell carcinoma (RCC) is surgery. In case of metastatic disease at presentation a radical nephrectomy is recommended to good performance status patients prior to start of interferon-alfa treatment. Interferon-alpha (IFN-alpha) offers in a small but significant percentage of patients advantage in overall survival; interleukin-2 (IL-2) based therapy gives similar survival rates. To date hormonal and chemotherapy do not have a proven impact on survival. The recent new insights in the molecular biology of clear RCC has revealed a key-role for vascular endothelial growth factor (VEGF) in the stimulation of angiogenesis in this highly vascularized tumour. This opens interesting new treatment strategies including: blockage of VEGF with the monoclonal antibody bevacizumab and inhibition of VEGF receptor tyrosine kinases (with small oral molecules such as SU11248 or PTK787). Likewise, inhibition of the Raf kinase pathway (with oral Bay 43-9006) or inhibition of the mTOR pathway (with i.v. CCI-779) are under investigation. Preliminary clinical results with all these compounds are interesting and the results of ongoing phase III studies will become available in the next years.

Novel treatment strategies in clear-cell metastatic renal cell carcinoma

Metastatic renal-cell carcinoma (mRCC) is highly resistant to cytotoxic agents or hormones and is currently mainly treated with cytokine-based therapy. Transient responses and moderate survival advantages have been achieved in a subset of patients with these aspecific biological response modifiers. Side-effects are considerable, especially with high-dose interleukin (IL)-2. Efforts made in the field of specific immunotherapy have focused on optimization of dendritic cell vaccination and on administration of monoclonal antibodies, either cold (unconjugated) or hot (radioactively labeled). Furthermore, allogeneic bone marrow transplantation is able to induce remissions but, regrettably, is related to substantial morbidity and mortality. Neutralization of the biological activity of some immunosuppressive cytokines produced by RCC (IL-6 and tumor necrosis factor-alpha) with monoclonal antibodies is currently under investigation. Insights gained into the processes and pathways underlying carcinogenesis have led to the development of new treatment strategies. These treatments can be used for clear cell RCC, since they focus on blocking gene products that are upregulated by mutations in the von Hippel-Lindau gene. Specific strategies include anti-vascular endothelial growth factor monoclonal antibody (bevacizumab) or inhibition of its receptor kinases (oral SU11248 or PTK787), or targeting the Raf kinase pathway (by BAY 43-9006) or the mammalian target of rapamycin (mTOR) pathway (by CCI-779). Early clinical results are promising, but their place in the treatment of RCC has to be determined.

A systematic review of the relation between interleukin-2 schedule and outcome in patients with metastatic renal cell cancer

In Europe, interleukin 2 (IL-2) is one of the two treatment modalities officially approved for patients with metastatic renal cell cancer. Traditionally, IL-2 has been administered by three different routes: intermittent bolus injection (BIV), continuous intravenous infusion (CIV) and subcutaneous injection (SC). There have been few randomized trials designed to compare these routes of administration. This paper describes a systematic review of the literature in which an attempt has been made to determine which schedule of administration is superior. Heterogeneity of the data makes firm conclusions difficult. It appears that the number of complete remissions (CR) is similar between BIV and SC routes and that these are higher than for CIV schedules. The durability of the CRs induced by BIV appeared superior to those induced by SC IL-2 and definitely higher than with CIV protocols. This analysis highlights some of the difficulties of using evidence-based medicine to determine standard of care when the clinical-trial data are heterogeneous. These data emphasize the importance of randomized clinical trials in determining what should be regarded as optimum therapy.

Safety and efficacy of subcutaneous and continuous intravenous infusion rIL-2 in patients with metastatic renal cell carcinoma

A retrospective analysis was conducted on data from four open-label, nonrandomised, phase II trials of recombinant interleukin-2 (rIL-2) in patients with metastatic renal cell carcinoma to compare the safety and efficacy of administration by subcutaneous (s.c.) and continuous intravenous (c.i.v.) infusion (n=103 s.c. and n=225 c.i.v.). No statistically significant differences were found between the cohorts in terms of overall response rate (s.c.: 13.6% vs c.i.v.: 12.4%, P=0.77), response duration (s.c.: 9.8 months vs c.i.v.: 10.1 months, P=0.99), and overall survival (P=0.08). Compared with c.i.v. administration, more patients in the s.c. cohort experienced stable disease (50.5 vs 29.8%) and fewer underwent disease progression (35.0 vs 43.6%). Subcutaneous administration was associated with a significantly lower incidence of grade 3 or 4 adverse events (46 vs 76%; P<0.001), and fewer s.c. patients required dose reductions because of toxicity (20 vs 82%). At the doses and within the schedules tested, this comparative analysis did not detect any difference in efficacy between s.c. and c.i.v. administration of rIL-2 in terms of overall survival, duration of response and response rate in patients with metastatic renal cell carcinoma. However, s.c. delivery of rIL-2 was associated with improved tolerability.

Prognostic and predictive factors of immunotherapy in metastatic renal cell carcinoma

Metastatic renal cell carcinoma has a poor prognosis. The value of immunotherapy with IFN-alpha and IL-2 both as single agent or as the combination is extensively investigated. The optimal dose and schedule is not known. In various studies response rates vary between 10 and 40%. The duration of response is variable. For a partial response a median duration between 10 and 12 months is given. Complete responses are sometimes long-lasting (a couple of years). The toxicity is drug, dose and schedule dependent. On the basis of a number of prognostic factors, such as performance score, time between the initial diagnosis and the treatment of metastases and the number of metastatic sites, patients can be divided in different prognostic groups. Patients who are classified in the good or intermediate prognostic group may have an improvement of their survival after immunotherapy and therefore they are candidates for immunotherapy.

Immunochemotherapy with interleukin-2, interferon-alpha and 5-fluorouracil for progressive metastatic renal cell carcinoma: a multicenter phase II study. Dutch Immunotherapy Working Party

In patients with metastatic renal cell carcinoma response rates of 7-26% have been achieved with immunotherapy. A high response rate of 48% in 35 patients has been reported for treatment with the combination of interferon-alpha (IFN-alpha), interleukin-2 (IL-2) and 5-fluorouracil (5-FU) (Atzpodien et al (1993a) Eur J Cancer29A: S6-8). We conducted a multicentre phase II study to confirm these results. Metastatic renal cell carcinoma patients were treated as outpatients with an 8-week treatment cycle. Recombinant human IL-2 20 MU m(-2) was administered subcutaneously (s.c.) three times a week (t.i.w) in weeks 1 and 4 and 5 MU m(-2) t.i.w. in weeks 2 and 3. Recombinant human IFN-alpha 2a 6 MU m(-2) was administered s.c. once in weeks 1 and 4 and t.i.w. in weeks 2 and 3, and 9 MU m(-2) t.i.w. in weeks 5-8. 5-FU (750 mg m(-2)) was given as a bolus injection intravenous once a week in weeks 5-8. The treatment cycle was repeated once in case of response or minor response. Fifty-two patients entered the study. All had undergone a nephrectomy and had progressive metastatic disease. The median WHO-performance status was 1, the median number of metastatic sites was 2 (range 1-5) and the median time between the diagnosis of the primary tumour and the start of treatment was 12.9 months (range 1-153). Among the 51 patients, including four patients with early progressive disease, who were evaluable for response, the response rate was 11.8% (95% confidence interval (CI) 2.9-20.7%), with no complete responses. Median duration of response was 8.3 (range 3.8-22.4+) months. Median survival was 16.5 (range 1.8-30.5+) months. Grade 3/4 toxicity (WHO) occurred in 29/52 (55.8%) of the patients in cycle 1 and in 6/16 (37.5%) of the patients in cycle 2. It consisted mainly of anorexia, fatigue, nausea, fever and leucocytopenia. We cannot confirm the high response rate in patients with metastatic renal cell carcinoma treated with the combination of IFN-alpha, IL-2 and 5-FU, as described by Atzpodien et al.

A randomised dose escalation study of subcutaneous interleukin 2 with and without levamisole in patients with metastatic renal cell carcinoma or malignant melanoma

We have examined the efficacy, toxicity and host immunological response of two different dose schedules of interleukin 2 (IL-2) given subcutaneously, daily for 3 months in patients with renal cell carcinoma (RCC) or metastatic melanoma (MM). We also examined the effect of adding the immune modulator levamisole to the two different schedules of IL-2. Thirty-nine patients were entered into two sequential phase I/II studies. Eighteen patients entered study 1 and were randomised to receive IL-2, 3 x 10(6) IU m-2 day-1, subcutaneously for 3 months with or without levamisole 50 mg t.d.s. p.o. on days 1-3 on alternate weeks. Twenty-one patients entered study 2 and were randomised to receive 5.4 x 10(6) IU m-2 day-1 subcutaneously for 3 months with or without levamisole 50 mg t.d.s. p.o. on days 1-3 on alternate weeks. Blood was taken for peripheral blood lymphocyte (PBL) phenotype analysis, and measurement of IL-2, soluble IL-2 receptor (sIL-2R) and neopterin concentration. Two patients with metastatic melanoma, one in each study, responded (11.8%); both received IL-2 alone. Observations of immunological parameters showed that treatment with subcutaneous IL-2 resulted in a significant rise in the percentage of PBLs bearing CD25, CD3/HLA-DR, CD56 and levels of IL-2 receptor and neopterin. The total white blood cell count (WBC) and total lymphocyte count rose significantly on day 18 compared with pretreatment levels. The addition of levamisole to either IL-2 schedule resulted in no significant changes in any immunological parameters. This study illustrates that prolonged subcutaneous IL-2 can be given safely in the outpatient setting. There was no evidence that levamisole acts as an immunomodulator in this study.

High-dose, continuous infusion Interleukin-2 in the treatment of metastatic renal cell carcinoma: Experience of the C.R.O., Aviano

Interleukin-2 (IL-2, Proleukin, Chiron Therapeutics Inc., Emeryville, CA) has been approved in Italy for the therapy of patients affected by metastatic renal cell carcinoma (RCC) with a good performance status. The basis for approval in the USA and Europe was a series of clinical trials demonstrating that high-dose IL-2, although significantly toxic, can obtain approximately 20% objective responses and improve survival. Between July 1988 and September 1993, 50 patients were treated with high-dose IL-2 in continuous infusion (according to the West protocol), first as part of a European multicentric study, and subsequently as standard treatment. Responses were seen in 9 of the 45 evaluable patients, and, at the last control (December 1995), an improvement in the survival of responding or unchanged patients was clear. This statement may seem excessive but is based on clinical evidence showing a change in the natural history of some of our patients, which is unusual in patients with solid tumors, and in particular RCC patients.