Renal cell carcinoma treated with continuous-infusion interleukin-2 with ex vivo-activated killer cells

And Now for Something Completely Different: Immunotherapy Beyond Checkpoints in Melanoma

Advances in the understanding of biology and therapy of melanoma have occurred at an astonishing pace over the past approximately 15 years, and successful melanoma therapy has led the way for similar advances in many other solid tumors that are continuing to improve outcomes for all patients with cancer. Although the 2018 Nobel Prize was awarded to two investigators who discovered that therapeutic targeting of immune checkpoints held the key to major patient benefits, there are many additional immunotherapeutic strategies that warrant further study and discussion at scientific and medical meetings. This article provides the newest information on three areas of immunotherapy that have been successfully applied to melanoma and continue to pave the way for new developments: cytokines, adoptive cell therapies (ADTs), and intratumoral injection of immunomodulatory agents.

Standing on the shoulders of giants: a scientific journey from Singapore to stem cells

Cellular therapy was introduced in the early 1980s as adoptive immunotherapy for cancer and has now expanded to stem cell treatment for a wide variety of indications. During the same period, the concept of the fetus as a patient evolved from fantasy to everyday reality. The intersection of these two fields offers great potential for cures in childhood diseases. The fetal treatment of spina bifida is one such disease. Global surgery has also emerged as a cost effective approach to reducing the worldwide burden of childhood disease.

Continuous infusion interleukin-2 and famotidine in metastatic kidney cancer

Infusional interleukin-2 (IL-2) is able to elicit lymphokine-activated killer cell (LAK) cytotoxicity against kidney cancer in vitro and in vivo. Famotidine may be able to augment LAK cytotoxicity against neoplastic cells. Fifteen (15) patients were treated with continuous-infusion IL-2 (9-18 MIU/m2/24 hours) for 72 hours and famotidine 20 mg intravenously twice per day. Cycles were repeated every 3 weeks. These patients had a median age of 60 years (range, 29-72), had a median performance status of 1 (range, 0-1), and had metastatic sites, including lung, bone, lymph node, and liver. The most common toxicities of this regimen were hypophosphatemia, fever, nausea/emesis, rigors, elevated creatinine, and hypomagnesemia. One (1) complete and 6 partial responses have been seen (47% response rate). The median duration of response is 9 months. The median survival for all patients is 20 months. Five (5) patients are alive at a median of 36+ months. This combination of infusional IL-2 with famotidine is active in metastatic kidney cancer.

Lymphocyte therapy of renal cell carcinoma

During the past 20 years, there has been considerable interest in lymphocyte therapy as a treatment for renal cell carcinoma. There is no therapeutic role for B-lymphocyte therapy, but their products, monoclonal antibodies, now have widespread clinical applications. The major types of autologous lymphocyte therapy that have been explored in clinical trials are cytotoxic lymphokine-activated killer cells, which are natural killer cells and T-cells that have been stimulated in vitro by interleukin-2 or other similar cytokines; cytotoxic and noncytotoxic tumor infiltrating lymphocytes, which are T-cells derived from tumor tissue; other tumor antigen-stimulated T-lymphocytes derived from regional lymph nodes or peripheral blood; and noncytotoxic lymphocytes of the memory/helper phenotype. More recently, allogeneic immune therapy using nonmyeloablative hematopoietic stem cell transplant and/or donor lymphocyte therapy has also shown promise.

Administration of high-dose continuous infusion interleukin-2 to patients age 70 or over

High-dose bolus or continuous infusion interleukin-2-based therapy can cause capillary leak syndrome. Significant cardiovascular/hemodynamic events, including myocardial infarction, hypotension, pulmonary edema, and cardiac arrhythmia, have been described with such therapy. Concern over the toxicity of highdose interleukin-2 (IL-2) therapy has led to some clinicians excluding patients 70 years of age or over. We have treated 15 patients 70 years of age or over having an Eastern Conference Oncology Group (ECOG) performance status of 0 or 1, with therapy based on continuous infusion IL-2 18 MIU/sq m/24 hours for 72 hours. All patients underwent a pretreatment evaluation of cardiac status with a low-level stress or adenosine stress test. Cycles were typically repeated every 3 weeks for 4 cycles, then every 3-4 weeks thereafter. Patients were treated by oncology nurses in either the stem cell transplant (intermediate unit) or the oncology inpatient unit. Patient characteristics were: median age, 72 years (range, 70-83 years); tumor types: melanoma (10), kidney cancer (5); most common sites of disease: lung (11), lymph nodes (6), subcutaneous (3), liver (2); prior therapy included: none (8), outpatient IL-2 (5), other immunotherapy (4). Median number of cycles received: 3 (1-10). Most common toxicities were: fever, rigors, nausea, emesis, hypophosphatemia, and hypomagnesemia. Three patients required the use of dopamine for blood pressure support. Two patients declined further therapy. There were no treatment-related deaths. No patients required endotracheal intubation or transfer to an intensive care unit. One complete and 8 partial responses (60% response rate) have been seen. Responding sites include the lung, lymph node, intact kidney primary, and liver. Median survival has not been reached at over 14 months (range 3+-26+ months). Patients who are 70 years of age and older with an ECOG performance status of 0 or 1 are able to tolerate high-dose continuous infusion IL-2-based therapy and may respond to such treatment.

Cytokine-based therapy for metastatic renal cell cancer

The use of recombinant gene technology to produce commercially available amounts of cytokines heralded an era of clinical applications of immunotherapy. Although the response rates to cytokine therapies are modest and sometimes occur at the expense of great cost and toxicity, they are proof of the principal that even large tumor burdens can be overcome by purely immune modulation. The interleukins and the interferons have been used in various phases of clinical trials in RCC. The maturation and final results of phase III trials are needed to guide clinical practice. In the meantime, the knowledge gained clinically and in the laboratory should lead to continued improvements and outcomes in immunotherapy for RCC.

Generation of chimeric bispecific G250/anti-CD3 monoclonal antibody, a tool to combat renal cell carcinoma

The monoclonal antibody (MAb) G250 binds to a tumour-associated antigen, expressed in renal cell carcinoma (RCC), which has been demonstrated to be a suitable target for antibody-mediated immunotherapy. A bispecific antibody having both G250 and anti-CD3 specificity can cross-link G250 antigen-expressing RCC target cells with T cells and can mediate lysis of such targets. Therapy studies with murine antibodies are limited by immune responses to the antibodies injected (HAMA response), which can be decreased by using chimeric antibodies. We generated a chimeric bispecific G250/anti CD3 MAb by transfecting chimeric genes of heavy and light chains for both the G250 MAb and the anti-CD3 MAb into a myeloma cell line. Cytotoxicity assays revealed that the chimeric bispecific MAb was capable of mediating lysis of RCC cell lines by cloned human CD8+T cells or by IL-2-stimulated peripheral blood lymphocytes (PBLs). Lysis mediated by the MAb was specific for target cells that expressed the G250 antigen and was effective at concentrations as low as 0.01 microgram ml-1. The chimeric bispecific G250/anti-CD3 MAb produced may be an effective adjuvant to the currently used IL-2-based therapy of advanced renal cell arcinoma.

Phase III randomized trial of interleukin-2 with or without lymphokine-activated killer cells in the treatment of patients with advanced renal cell carcinoma

BACKGROUND

Treatment with interleukin-2 (IL-2) and lymphokine-activated killer cells (LAK) resulted in responses in some patients with advanced renal cell carcinoma (RCC). However, the relative therapeutic benefit of the addition of LAK to IL-2 was unknown.

METHODS

A randomized Phase III trial was conducted in patients with RCC comparing continuous intravenous infusion (CI) IL-2 alone with CI IL-2 plus LAK. Interleukin-2 was administered at 3 x 10(6) U/m2/day on days 1-5, 13-17, 21-24, and 28-31. Patients on the LAK treatment arm underwent leukapheresis on days 8-10 and LAK cell reinfusion on days 13-15. The results are reported with long-term follow-up. The published experience with IL-2 alone or with the addition of LAK was investigated in a quantitative literature survey. The response proportions were studied by schedule (high dose bolus, moderate dose, low dose) and by concomitant administration of LAK.

RESULTS

Seventy-one patients were treated, 36 on the IL-2 arm and 35 on the IL-2 plus LAK arm. Four patients (6%) had major responses (two complete, two partial). The median survival of all patients was 13 months (95% confidence interval [CI], 9-18 months). There were no differences between treatment arms with regard to response (P = 0.61) and survival (P = 0.67). More patients on the LAK arm experienced pulmonary toxicity (P = 0.008). The overall weighted response proportion was 16% (95% CI, 8%-24%) for the 39 published series of 1291 patients treated with IL-2. The 95% confidence intervals for response proportion overlapped when compared by schedule and by administration of LAK.

CONCLUSIONS

The dose and schedule of IL-2 used in this study resulted in a low level of antitumor activity and the addition of LAK did not improve the response rate against RCC. Given the infrequent, but reproducible, responses with IL-2 and interferon-based regimens, continued investigation of these agents is warranted as is the study of new cytokines. Alternative treatment strategies should be studied in RCC and new agents and treatment regimens that appear promising in Phase II studies must be studied in randomized trials.

The clinical experience with interleukin-2 in cancer therapy

In May 1992, interleukin-2 (IL-2) was formally approved by the U.S. Food and Drug Administration for use in cancer treatment based on its activity in metastatic renal cell carcinoma. IL-2 alone or in combination with activated lymphocytes or other cytokines has significant anti-tumor activity against renal cell carcinoma and melanoma with response rates of 15-20%, some of which are quite durable. Limited anti-tumor effects have been noted in some patients with colorectal cancer and lymphoma. Too few patients have been studied to establish the level of activity in most other specific tumor types. The mechanism of this anti-tumor effect appears to be entirely mediated by the immunostimulatory effects of IL-2. Toxicities are dose related, but are substantial and similar regardless of the schedule of administration. Randomized trials have failed to establish (1) the superiority of high-dose bolus over continuous infusion IL-2, (2) the superiority of IL-2 plus interferon over IL-2 alone, or (3) the superiority of IL-2 plus LAK cells versus IL-2 alone. Further investigation is needed to determine the optimum dose and schedule from the standpoint of cost:benefit and risk:benefit, and to determine the role of IL-2 in the therapy of other malignant diseases.