Does continuous-infusion interleukin-2 increase survival in metastatic melanoma?

High-dose IL2 in metastatic melanoma: better survival in patients immunized with antigens from autologous tumor cell lines

Abstract Various published data show that in patients with metastatic melanoma, high-dose interleukin-2 (IL2) is associated with 5-year survival rates of 15% from treatment initiation. We previously reported a median survival of 15.6 months, and a 20% 5-year survival rate for 150 patients who were treated with inpatient IL2 (Cancer Biother Radiopharm 2012;27:337). In the current study, we sought to determine whether treatment with active specific immunotherapy (ASI) with patient-specific tumor stem cell vaccines derived from autologous tumor cell (TC) lines contributed to the survival result. Existing databases revealed that 32/149 IL2-treated patients also received ASI, while 117 did not. ASI was given within 12 months of IL2 therapy in 19/32 patients. Patients who received IL2 plus ASI had better overall survival (p<0.001) with longer median survival (39.5 vs. 12.0 months) and a higher 5-year survival rate (39% vs. 13%). Survival was better even after exclusion of 55 IL2-alone patients who died before 12 months of follow-up (p=0.12). In subset analyses, survival was longer for 25 patients who received ASI after IL2 than for 7 who received ASI before IL2 (5-year survival 46% vs. 14%, p<0.001) and for 16 patients who received a dendritic cell/TC-based ASI compared with 16 injected with irradiated TC (p=0.17). This retrospective study suggests that receipt of IL2 followed by a patient-specific melanoma stem cell vaccine is associated with better survival than IL2 alone.

Antigen-specific versus antigen-nonspecific immunotherapeutic approaches for human melanoma: the need for integration for optimal efficacy?

Due to its immunogenecity and evidence of immune responses resulting in tumor regression, metastatic melanoma has been the target for numerous immunotherapeutic approaches. Unfortunately, based on the clinical outcomes, even the successful induction of tumor-specific responses does not correlate with efficacy. Immunotherapies can be divided into antigen-specific approaches, which seek to induce T cells specific to one or several known tumor associated antigens (TAA), or with antigen-nonspecific approaches, which generally activate T cells to become nonspecifically lytic effectors. Here the authors critically review the different immunotherapeutic approaches in melanoma.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Initial clinical response predicts outcome and is associated with dose schedule in metastatic melanoma and renal cell carcinoma patients treated with high-dose interleukin 2

BACKGROUND

High-dose interleukin (IL)-2 is an effective agent for the treatment of metastatic malignant melanoma and renal cell carcinoma. This study evaluated the outcomes of patients receiving two commonly used intravenous IL-2 schedules that have never been directly compared.

METHODS

Forty-seven metastatic malignant melanoma and renal cell carcinoma patients were identified from a prospective database who underwent high-dose IL-2 therapy (720,000 or 600,000 IU/kg) during 1999 to 2003. Disease-specific survival (DSS) was calculated by the Kaplan-Meier method with the log-rank test on an intention-to-treat basis. Multivariate Cox regression analysis of prognostic variables associated with outcome was performed. Factors associated with initial response and prevention of disease progression were determined.

RESULTS

Objective response (5 partial and 5 mixed) or disease stabilization was noted in 9 (20%) and 10 (22%), respectively, of 46 assessable patients after 1 course of therapy. Four patients (22%) achieved disease-free status after the third course of IL-2 (n = 1) or surgical resection of confined metastatic disease (n = 3). At 19.1 months' median follow-up, factors associated with improved DSS included an initial clinical response to IL-2 therapy (P < .001) and a higher administered dose (P = .04). Patients who received 720,000 IU/kg were more likely to experience an initial major objective response (P = .03) and disease stabilization (P = 0.03) independent of the tumor treated. Objective response early in the course of therapy was the only independent predictor of tumor-related mortality (P = .004).

CONCLUSIONS

The initial clinical response to IL-2 therapy is an independent predictor of improved outcome associated with DSS and the 720,000 IU/kg dose. These results support further prospective trials with increased IL-2 dose schedules in a larger cohort of patients.