Sequential administration of recombinant human interleukin-2 and dacarbazine in metastatic melanoma: a multicenter phase II study

Whole genome and exome sequencing of melanoma: a step toward personalized targeted therapy

Melanoma has historically been refractive to traditional therapeutic approaches. As such, the development of novel drug strategies has been needed to improve rates of overall survival in patients with melanoma, particularly those with late stage or disseminated disease. Recent success with molecularly based targeted drugs, such as Vemurafenib in BRAF-mutant melanomas, has now made "personalized medicine" a reality within some oncology clinics. In this sense, tailored drugs can be administered to patients according to their tumor "mutation profiles." The success of these drug strategies, in part, can be attributed to the identification of the genetic mechanisms responsible for the development and progression of metastatic melanoma. Recently, the advances in sequencing technology have allowed for comprehensive mutation analysis of tumors and have led to the identification of a number of genes involved in the etiology of metastatic melanoma. As the methodology and costs associated with next-generation sequencing continue to improve, this technology will be rapidly adopted into routine clinical oncology practices and will significantly impact on personalized therapy. This review summarizes current and emerging molecular targets in metastatic melanoma, discusses the potential application of next-generation sequencing within the paradigm of personalized medicine, and describes the current limitations for the adoption of this technology within the clinic.

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.

Metastatic melanoma: is biochemotherapy the future?

Current treatment options in metastatic melanoma are of limited efficacy. Achievement of durable responses with biological agents, and the possibility to complement the higher response rate of chemotherapy and combined chemotherapy by prolonged duration of responses, led to development of biochemotherapy. Although a clear improvement in response rate (40-60% OR) resulted in some studies of the combined modality, several phase III studies had mixed results on the duration of survival. Various timeframes between the administration of chemotherapy and biologics have been tested, ranging between concurrent biochemotherapy, 1 d (immediately sequential), and up to 3 wk (long sequence or alternating). An analysis of the trend of responses and survival versus the duration of the chemobiotherapy sequence showed that, as the timeframe between chemo and bio components increases, the overall survival, survival of complete responders, and survival of partial responders appear to increase, but the effect is only present for the chemo-bio, and not for the bio-chemo sequence. Because there is no current explanation for this observation, it appears possible that the interaction between components of biochemotherapy results in a double effect: an increase in the immediate response reflected in the OR, CR, PR on one side, and an increase in survival on the other side. An analysis of mechanisms involved in the response leads us hypothesize that macrophage activation, as measured by the neopterin levels, may correlate with the survival of patients undergoing biochemotherapy, while the generation of nitric oxide, acting synergistically with chemotherapy in producing tumor cell killing, may be reflected in the overall response rate seen with the biochemotherapy combinations.

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

Pharmacy logbooks and clinical trial records were used to identify all 60 patients with metastatic melanoma who were treated as inpatients with intermediate-dose, continuous-infusion interleukin-2 (IL-2) in Hoag Hospital during 1987 to 1998. The hospital tumor registry was used to identify contemporary controls who had not received inpatient IL-2, matched for having distant metastatic melanoma, and by year and stage at original diagnosis, gender, and age. The mean time from original diagnosis to the documentation of distant metastatic disease was similar in both groups, 24 to 26 months. From the date of starting IL-2 therapy, patients had a median survival of 8.8 months, 38% 1-year survival, and 20% 5-year survival, with 8 patients alive beyond 5 years. However, there was no difference in survival from the first date of distant metastatic disease (median 25.8 months for IL-2 versus 31.5 months for controls, with survival rates 5 years after metastatic disease of 26% versus 31%). There was also no difference in overall survival from the date of original diagnosis (60.1 months for the IL-2 group versus 86.3 months for controls, with 5-year survival rates of 51% versus 64%, and 10-year survival rates of 29% versus 33%). This single-institution study failed to establish a survival advantage for patients with metastatic melanoma who received intermediate-dose, continuous-infusion IL-2 administered in the inpatient setting, compared to contemporary, matched-control patients who never received inpatient IL-2 therapy. However, the 5-year survival rates after a diagnosis of distant metastatic disease were a surprisingly high 26% to 31% in both groups. In the absence of a control group, the survival impact of IL-2 has probably been overestimated from single-arm phase II and III trials.

Medical management of melanoma

The treatment for malignant melanoma has undergone significant changes over the past few decades, with biological therapy playing an increasingly important role and replacing the traditional cytotoxic agents as the first-line therapy for this disease, both in advanced disease and adjuvant settings. Despite the developments of new modalities of therapy for melanoma, the outcome for patients with advanced disease remains poor. This article discusses the clinical studies that have shaped our current management of melanoma, both in the adjuvant setting, and in the metastatic setting. Additionally, successes and failures of clinical trials will be discussed, as they will guide the strategic development of future studies in the management of this aggressive disease.

Metastatic melanoma

The overall survival for patients with metastatic melanoma ranges from 4.7 to 11 months, with a median survival of 8.5 months. Standard treatment for patients with metastatic melanoma has not been defined. The range of treatment options includes close observation, surgical resection of isolated metastases, therapy with dacarbazine, combination chemotherapy, and participation in clinical trials. Numerous chemotherapeutic agents have shown activity in the treatment of malignant melanoma. Dacarbazine (DTIC-Dome; Bayer Corporation, West Haven, CT) has a response rate of 15% to 20% and remains the reference agent for the treatment of metastatic disease. Additional agents with single-agent activity include cisplatin, (Platinol-AQ; Bristol-Myers Oncology, Princeton, NJ); carmustine (BiCNU; Bristol-Myers Oncology, Princeton, NJ); paclitaxel (Taxol; Bristol-Myers Squibb, Princeton, NJ); and docetaxel (Taxotere; Rhone-Poulenc Rorer Pharmaceuticals, Collegeville, PA). Temozolomide (Temodar; Schering-Plough, Kenilworth, NJ), which is essentially an oral form of dacarbazine but with greater central nervous system penetrance, is associated with a response rate of 20%. Combination chemotherapy with or without tamoxifen has been extensively evaluated in patients with metastatic melanoma. Although the initial results with the Dartmouth regimen (dacarbazine, cisplatin, carmustine, and tamoxifen) were associated with overall response rates of 50% to 55% in single-institution studies, results from larger multicenter studies reveal responses rates ranging from 10% to 20%. Based on the results of several clinical trials, there is no evidence that the addition of tamoxifen improves the response rate. Another combination regimen is cisplatin, vinblastine, and dacarbazine (CVD), which is associated with a 20% to 25% response rate. There has been widespread interest in developing immunotherapies against metastatic melanoma. Interferon (IFN)-alfa and interleukin (IL)-2 as single agents have produced response rates in the 15% to 20% range. Biochemotherapy, which is a combination of immunotherapy and cytotoxic chemotherapy, has been studied in patients with metastatic melanoma. Multiple phase II studies have demonstrated high response rates but unclear impact on overall survival. Therapy is associated with significant toxicity. Ongoing randomized clinical trials will clarify the role of biochemotherapy in patients with metastatic melanoma. Ongoing new approaches to treatment include the therapeutic use of vaccines alone or in combination with cytokines.

Combined chemoimmunotherapy in metastatic melanoma--is there a need for the double?

The therapeutic benefit of adding immunotherapeutic agents such as interferon (IFN)-alpha and interleukin (IL)-2 to established single-agent or combination chemotherapy regimens for the treatment of metastatic melanoma has not been proven. On the contrary, recent studies indicate a significantly higher incidence of severe toxic side effects in patients treated with combined biochemotherapy. This article summarizes recent trials using either chemotherapy alone or chemotherapy plus the administration of IFN-alpha and/or IL-2 to evaluate the benefit of a combined biochemotherapy.

Therapeutic advances in melanoma

Therapy for melanoma continues to evolve, and with the expanding work in the basic pathophysiology, the continued development of biologic modifiers is expected. With new treatment regimens, the rate of remissions is improving for patients with metastatic disease. Much work has yet to be done, however, and there will be continued development in all areas.

Immunotherapy and experimental approaches for metastatic melanoma

This article reviews the clinical investigations involving recombinant cytokines (either alone or in combination with adoptive immunotherapy, toxicity reduction agents, or cytotoxic chemotherapy), vaccines, monoclonal antibodies or antibody conjugates, and gene therapy. These various approaches are reviewed for their current and potential roles in curing metastatic melanoma.

Systemic treatment of metastatic melanoma with chemotherapy

This article reviews the use of systemic chemotherapy for the treatment of metastatic melanoma, including single-agent chemotherapy, combination chemotherapy with and without tamoxifen, and biochemotherapy.

Randomized phase II trial of BCDT [carmustine (BCNU), cisplatin, dacarbazine (DTIC) and tamoxifen] with or without interferon alpha (IFN-alpha) and interleukin (IL-2) in patients with metastatic melanoma

The purpose of this study was to evaluate in a randomized phase II trial the efficacy and toxicity of combination biochemotherapy compared with chemotherapy alone in patients with metastatic melanoma. Sixty-five patients with metastatic melanoma (ECOG performance status 0 or 1) were randomized to receive intravenous BCNU 100 mg m(-2) (day 1, alternate courses), cisplatin 25 mg m(-2) (days 1-3), DTIC 220 mg m(-2) (days 1-3) and oral tamoxifen 40 mg (BCDT regimen) with (n = 35) or without (n = 30) subcutaneous interleukin 2 (IL-2) 18 x 10(6) iu t.d.s. (day - 2), 9 x 10(6) iu b.d. (day - 1 and 0) and interferon 2 alpha (IFN-alpha) 9 MU (days 1-3). Evidence for immune activation was determined by flow cytometric analysis of peripheral blood lymphocytes. Treatment was repeated every 4 weeks up to six courses depending on response. The overall response rate of BCDT with IL-2/IFN-alpha was 23% [95% confidence interval (CI) 10-40%] with one complete response (CR) and seven partial responses (PR), and for BCDT alone 27% (95% CI 12-46%) with eight PRs; the median durations of response were 2.8 months and 2.5 months respectively. Sites of response were similar in both groups. There was no difference between the two groups in progression-free survival or overall survival (median survival 5 months for BCDT with IL-2/IFNalpha and 5.5 months for BCDT alone). Although 3 days of subcutaneous IL-2 resulted in significant lymphopenia, evidence of immune activation was indicated by a significant rise in the percentage of CD56- (NK cells) and CD3/HLA-DR-positive (activated T cells) subsets, without any change in the percentage of CD4 or CD4 T-cell subsets. Toxicity assessment revealed a significantly higher incidence of severe thrombocytopenia in patients treated with combination chemotherapy than with chemotherapy alone (37% vs 13%, P = 0.03) and a higher incidence of grade 3/4 flu-like symptoms (20% vs 10%) and fatigue (26% vs 13%). The addition of subcutaneous IL-2 and IFNalpha to BCDT chemotherapy in a randomized phase II trial resulted in immune activation but did not improve response rates in patients with metastatic melanoma, and indeed may increase some treatment-related toxicity.

Comparison of patient characteristics and outcome between a single-institution phase II trial and a cooperative-group phase II trial with identical eligibility in metastatic melanoma

Differences in overall survival and response rates are often noted when promising single-institution phase II treatment regimens are evaluated in a cooperative group setting. One reason for this discrepancy may be the differences in patient characteristics at the time of registration. In the metastatic melanoma literature, the prognostic factors for survival that are most frequently identified are the number of metastatic sites, visceral involvement, performance status, liver involvement, and possibly the disease-free interval and gender. A prognostic factor for response appears to be sites of involvement. A comparison of patient characteristics and outcome was conducted for patients entered in similar phase II melanoma trials at a single institution versus those in a cooperative group. Sixty-four patients at Wayne State University (WSU) were compared with 96 patients who had nearly identical eligibility criteria and were registered in the Southwest Oncology Group (SWOG). All patients were receiving comparable phase II treatments for metastatic melanoma. Southwest Oncology Group patients were significantly older (p < 0.001), had worse performance status (p = 0.03), had more visceral involvement (p = 0.001), and were more likely to have two or more metastatic sites (p = 0.02). No significant differences in gender (p = 0.55), absence or presence of liver involvement (p = 0.12), or disease-free interval were noted. These disparities, despite similar eligibility, may partly explain the observed differences in survival (WSU median = 10 months, SWOG median = 7 months; p = 0.13) and response rates (WSU = 31%, SWOG = 15%; p = 0.02) between the two groups of patients. Investigators should report these important patient characteristics in treatment reports. These differences highlight the difficulty in comparing single-institution and cooperative-group phase II trials, even with comparable patient eligibility. This serves to emphasize the need for well-designed phase III trials when comparing treatment approaches and stratification for the prognostic factors identified.

Chemoimmunotherapy with bleomycin, vincristine, lomustine, dacarbazine (BOLD) plus interferon alpha for metastatic melanoma: a multicentre phase II study

High response rates in patients with metastatic melanoma have been achieved with combination chemoimmunotherapy. A response rate of 62% in 45 patients has been reported for treatment with dacarbazine, bleomycin, vincristine, lomustine (BOLD) plus interferon alpha (IFN-alpha). We conducted a multicentre phase II study to confirm these results. Melanoma patients with distant metastases were treated as outpatients with dacarbazine 200 mg m(-2) on days 1-5, vincristine 1 mg m(-2) on days 1 and 4, bleomycin 15 mg on days 2 and 5 i.v. and lomustine 80 mg orally on day 1, repeated every 4 weeks. IFN-alpha-2b was initiated s.c. on day 8 at 3 MU daily for 6 weeks, and 6 MU t.i.w. thereafter. Forty-three patients entered the study. The median number of metastatic sites was three (range 1-5), and 81% of patients had visceral metastases. Nine patients had brain metastases, and seven patients were systemically pretreated. Among the 41 patients that were evaluable for response, the response rate was 27% (95% CI 14-3%), with one complete and ten partial remissions. The response rate in 25 previously untreated patients without brain metastases was 40% (95% CI 21-61%). Median duration of response was 6 (range 2-14+) months; median overall survival was 5 (1-26) months. The main toxicity was malaise/fatigue. We confirm that BOLD plus IFN-alpha has activity in metastatic melanoma. The lower response rate in our study compared with the previous report is probably related to patient selection, as in the previous study 46% of patients had stage III disease, whereas all our patients had stage IV disease, which is associated with a worse prognosis.

Medical treatment of metastatic melanoma

The role of combination chemotherapy in the treatment of metastatic melanoma is still a matter of controversy because of the lack of prospective trials directly demonstrating increased response rates and improved survival compared with DTIC alone. Nevertheless, several three-drug regimens have reported response rates between 30% and 50% in single-institution studies. The duration of response medians of these regimens ranges between 6 and 9 months. However, the survival medians of 6 to 11 months are not substantially better than those of DTIC alone. However, survival at 1 and 2 years following initiation of therapy may more clearly demonstrate an impact of therapies for metastatic melanoma.

Cytokine therapy of malignant melanoma

Melanoma is a malignant neoplasia of melanocyte origin appearing mainly in the skin. About one third of all melanomas detected disseminate, with the metastatic spread occurring either via lymphatic or blood vessels. In the treatment of advanced melanoma the conventional chemotherapy or radiotherapy has not been very successful. Melanoma is known to have immunologically provocative features. In recent years immunological therapies, mainly cytokines, have been applied in the treatment of melanoma. The most widely used cytokines are Interferons and interleukin-2. These agents are used either alone or in combination with each other or with chemotherapeutics. Interferon and interleukin-2 therapies have yielded response rates of 15-20% on average, whereas combinations of immunotherapy and chemotherapy offer response rates as high as 50-60%. Unfortunately, average survival of patients with disseminated melanoma has been short, from 6 to 12 months. The immunotherapy approach has yielded some long-term responses and probably even a cure for a small proportion of patients. Understanding of basic mechanisms of tumour destruction by cytokines and new agents coming into clinical use will undoubtedly further improve treatment results.

Subcutaneous recombinant interleukin-2 plus chemotherapy with cisplatin and dacarbazine in metastatic melanoma

The aim of our study was to verify the efficacy and tolerability of subcutaneous low doses of interleukin-2 with cisplatin and dacarbazine for malignant melanoma. 24 patients were included. The following schedule was used: cisplatin (CDDP) 100 mg/m2 day 1; darcarbazine (DTIC) 375 mg/m2 days 1-5; recombinant interleukin-2 (rIL-2) 4.5 million IU x 2/day days 13-17 and 20-24. The therapy was recycled every 28 days. 10 patients obtained clinical remission (42%), with 2 complete responses (8%) persisting for 12 and 15+ months, and 8 partial responses (35.5%) with a median duration of 5 months. Median survival of all 24 patients was 8 months, 13 months for responders and 6 months for non-responders. Responses were seen predominantly in lymph nodes (48%) and skin-soft tissue (38%), but were also seen in the liver (29%) and lung (14%). Treatment was relatively well tolerated and toxicity was mainly related to chemotherapy.

Direct gene transfer of a plasmid carrying the herpes simplex virus-thymidine kinase gene (HSV-TK) in transplanted murine melanoma: in vivo study

The aim of the study was to use a virus-free system to transfer the Herpes Simplex Virus-thymidine kinase (HSV-TK) gene in mice bearing melanoma tumours. B16 F1 murine melanoma cells were injected subcutaneously. On days 11 and 14, an intratumoral injection of either naked plasmid containing the HSV-TK gene (pAG0) or pAG0-lipofectamine complexes was given. Ganciclovir (120 mg/kg/day) was given for 5 days starting on day 14. Tumour weight reduction (40-50%) was observed in treated animals versus different control groups. Moreover, histopathological analysis on tumours showed large areas of cavitary necrosis (85%) in treated groups compared to controls (10%). Using a simple and safe method, the results presented here demonstrated that virus-free mediated delivery of the HSV-TK gene is efficient in vivo in murine malignant melanoma.

A multicenter phase II clinical trial using dacarbazine and continuous infusion interleukin-2 for metastatic melanoma. Clinical data and immunomonitoring

BACKGROUND

Treatment of patients with metastatic melanoma with either dacarbazine or recombinant interleukin-2 (rIL-2) resulted in a response rate of approximately 15%. This study investigates the possible synergism of this chemoimmunotherapy combination.

METHODS

Fifty-seven patients with metastatic malignant melanoma received 135 treatment cycles. Treatment consisted of dacarbazine (Days 1-5) at 250 mg/m2 by a 30-minute slow infusion, and interleukin-2 by constant intravenous infusion (Days 21-25 and 28-32) at 18 x 10(6) IU/m2/24 hours. After this treatment cycle, a 1-week rest was scheduled, and in the absence of undue toxicity or tumor progression, patients received a second cycle as described. Maximum treatment consisted of two induction and four maintenance cycles. In a subgroup of patients, immunoparameters were analyzed to identify prognostic factors. Standard supportive care was given.

RESULTS

Common toxicities included fever, hypotension, nausea/vomiting, anemia, leukopenia, thrombocytopenia, an increase in serum lactic dehydrogenase levels and diarrhea. The objective response rate was 15.8% (one complete response and eight partial responses). In 14 patients, the disease stabilized. For patients who had an objective response, median response duration was 13.9 months (6.3-39.0+), and median survival was 19.0 months (6.3-39.0+); overall survival was 9.3 months (0.8-39.0+). Immunomonitoring did not reveal any relevant prognostic factors for overall response.

CONCLUSIONS

Sequential treatment with dacarbazine and rIL-2 is feasible and produces long-lasting responses in a minority of patients.

Cardiotoxicity as a dose-limiting factor in a schedule of high dose bolus therapy with interleukin-2 and alpha-interferon. An unexpectedly frequent complication

BACKGROUND

In a group of patients with metastatic melanoma treated with high dose immunotherapy, there was an unexpectedly high incidence of severe cardiac adverse effects.

METHODS

Sixteen patients with metastatic melanoma were treated with high dose interleukin-2 (IL-2) and alpha-interferon (alpha-IFN). Each treatment cycle consisted of IL-2 at a dose of 12 MIU/m2 and alpha-IFN at a dose of 3 MIU/m2, given as intravenous bolus injections every 8 hours on Days 1-5, every 3 weeks for a total of three cycles. Before treatment, careful cardiologic screening was performed, including electrocardiogram (ECG), stress test, cardiac multiple uptake-gated acquisition (MUGA) scan, and echocardiography. During therapy, patients were monitored with daily ECG and creatine phosphokinase measurements. Once cardiac damage was suspected, IL-2 and alpha-IFN were discontinued, and echocardiography, stress test and MUGA-scan were repeated. If indicated, cardiac catheterization with endomyocardial biopsies was performed.

RESULTS

Despite pretreatment cardiac screening, seven patients (44%) exhibited myocardial injury. Acute myocardial infarction occurred in one patient, cardiomyopathy developed in four, asymptomatic ECG changes appeared in one, and 1 patient died of acute cardiac arrest. Echocardiography showed hypokinesis and decreased left ventricular ejection fraction. These abnormalities disappeared within 6 months. Cardiac catheterization in four affected patients revealed normal coronary arteries, but endomyocardial biopsies showed interstitial edema, vacuolation, and degeneration of myocytes. Electron-microscopic examination showed fragmentation of myofibrils, swelling of mitochondria and loss of mitochondrial cristae.

CONCLUSIONS

This intensive treatment schedule of IL-2 and alpha-IFN is prohibited by severe and life-threatening cardiac toxicity.

Biochemotherapy with thymosin alpha 1, interleukin-2 and dacarbazine in patients with metastatic melanoma: clinical and immunological effects

BACKGROUND

DTIC and interleukin-2 (IL-2), as single agents, have a limited anti-tumor activity in patients with metastatic melanoma. Experimentally, thymosin alpha 1 (TA1) may modulate the action of IL-2. We investigated the clinical and immunological effects of a combination with these three agents.

PATIENTS AND METHODS

Forty-six patients with measurable metastatic melanoma were treated with DTIC 850 mg IV on day 1, TA1 2 mg s.c. on days 4 to 7, and IL-2 18 MU/m2/d by continuous intravenous infusion on days 8 to 12. Cycles were repeated every 3 weeks.

RESULTS

Objective responses were obtained in 15 (36%) of 42 evaluable patients (CI at 95%: 22%-50%). Two patients experienced complete responses, and stable disease was observed in five. The median time to progression was 5.5 months and median survival was 11 months. Side effects were predominantly caused by IL-2. Treatment was tolerated reasonably well, and there was no overlapping toxicity or interference between chemotherapy and biotherapy. Baseline sCD4 levels seem to correlate to tumor burden. Patients benefiting from treatment had lower sCD4 and higher sCD8 than did progressing patients.

CONCLUSIONS

The combination of DTIC + TA1 + IL-2 is active in the treatment of advanced melanoma, with acceptable toxicity. However, even more active regimens are needed, and the interactions between thymic hormones and cytokines should be further explored.

Chemotherapy-induced modulation of natural killer and lymphokine-activated killer cell activity in euthymic and athymic mice

Combinations of chemotherapy and interleukin-2 (IL-2) aimed at improving therapeutic efficacy in cancer patients have generally proved disappointing. Although chemotherapy blocks tumor growth and sometimes boosts immune functions, most drugs are immunosuppressive, at least transiently. Therefore, it is reasonable to assume that maximal exploitation of the immunostimulatory and antitumor activity of both modalities requires careful coordination of chemotherapy and IL-2 timing. We analyzed the temporal effect of 5-fluorouracil (5-FU, 100-120 mg/kg), cyclophosphamide (CY, 100 mg/kg), Adriamycin (8 mg/kg) and dacarbazine (100 mg/kg) on the activation of natural killer/lymphokine-activated killer (NK/LAK) cells by IL-2 in several strains of euthymic mice and in athymic nude mice. Following in vivo or in vitro exposure to IL-2 1-15 days after chemotherapy, the total lytic activity of the spleen and the number of LAK precursors (LAK-p) were measured. In euthymic mice injected with IL-2 (5 x 10(4) Cetus units twice daily for 4-5 days), 5-FU augmented (up to 37-fold, days 1-9) and CY reduced (up to day 6) LAK activity, as compared with that in the IL-2 control. In bulk cultures containing IL-2 (1000 CU/ml, 3-4 days), both 5-FU and CY reduced LAK activity of euthymic mice splenocytes for up to 6 days after chemotherapy, which was followed on day 9 by full recovery. In splenocytes of nude mice, 5-FU increased and CY diminished LAK activation in bulk cultures, starting 3 days after chemotherapy. In athymic mice, 5-FU markedly augmented the total number of LAK-p/spleen (up to 30-fold, days 3-9), as determined by limiting-dilution cultures with IL-2 (for 7-8 days). In euthymic mice, in contrast, LAK-p levels decreased for up to 6-9 days after treatment with 5-FU, Adriamycin or decarbazine, later recovering to pretreatment levels, whereas CY markedly increased LAK-p (up to 15-fold) when administered 6-12 days before limiting-dilution culture initiation. The effect of chemotherapy on LAK and NK activity was essentially similar. In other experiments, a subset of asialoGM1- LAK-p was found in the spleens of 5-FU-treated mice, but not in untreated mice. Our results suggest that the immunomodulatory effect of chemotherapy on NK/LAK activity in mice is variable and largely depends on the drug itself, the interval between chemotherapy and IL-2 administration, the strain of mice and the assay used.

A phase II study of dacarbazine and cisplatin in combination with outpatient administered interleukin-2 in metastatic malignant melanoma

BACKGROUND

Based on prior experience with dacarbazine (DTIC) and an outpatient interleukin-2 (IL-2) regimen, the current study was conducted to improve the antitumor efficacy and assess the immunologic interactions between chemotherapy and IL-2.

METHODS

Thirty-two patients were registered onto a treatment program, which included DTIC 750 mg/m2 with cisplatin 100 mg/m2, each by intravenous bolus on day 1. Recombinant IL-2 was administered on an outpatient basis intravenously by 15-30-minute infusion (24.0 x 10(6) IU/m2) daily on days 12-16 and 19-23 of a 28-day cycle for three cycles and then every 42 days for responding patients.

RESULTS

There were responses in 13 of the 32 registered patients (41% response rate), including five complete and eight partial remissions. Responses in the liver, lung, spleen, lymph nodes, and soft tissue sites were noted. The median duration of response was 8.0 months (range, 3.0-20.0+ months), and the overall median survival duration was 10.2 months. Three patients (9%) are alive, free of disease, without any treatment at 32.0+, 36.0+, and 42.0+ months after initiation of treatment. Only minor nephrotoxicity was observed, and treatment delays were rare.

CONCLUSIONS

Additional chemotherapeutic, hormonal, or biologic agents may be added to enhance efficacy further if they have toxicities that do not overlap.

Chemoimmunotherapy of metastatic malignant melanoma. The Salpétrière Hospital (SOMPS) experience

Optimistic results were obtained in the treatment of 39 patients with surgically incurable metastatic malignant melanoma using a regimen including 2 to 3 monthly induction cycles of cis-diamminedichloroplatinum (CDDP), recombinant interleukin-2 (rIL-2) and interferon alpha-2a (IFN alpha-2a). 33 of 39 patients were pretreated with chemotherapy (dacarbazine and/or fotemustine:31, CDDP:6) and 17 of 39 with IFN alpha-2a. Overall response rate was 54% with 13% achieving a complete response for up to 59+ weeks. Moderate to severe side-effects were reversible on rIL-2 cessation and toxicity was manageable in a routine inpatient setting. These results are especially encouraging as they were seen in previously treated patients, classically low responders, including 3 who were resistant to cisplatin or other platinum complexes. The question remains if this regimen bypasses traditional mechanisms of drug resistance.

Chemo-immunotherapy in patients with metastatic melanoma using sequential treatment with dacarbazine and recombinant human interleukin-2: evaluation of hematologic and immunologic parameters and correlation with clinical response

We have treated 18 patients with metastatic malignant melanoma (MM) with high-dose IL-2 administered by continuous iv infusion in combination with dacarbazine (DTIC), and correlated the clinical response with various hematologic and immunologic parameters. Two regimens differing in the sequence of treatment were employed, and 1-6 treatment cycles were given, depending on patient response. Two patients had a complete response (CR, 46+m, 14m), two patients a partial response (PR, 16m,6m), one a minimal response and four had a stable disease lasting 2-7 months, thus the response rate (CR+PR) was 22%. None of the following parameters, tested prior to initiation of the therapy and 1-2 days after termination of each course of IL-2, correlated with the clinical response: WBC counts (total and differential), levels of blood CD4 and CD8 T cells, NK cells, monocytes and B cells, production of IL-1 and IL-1 inhibitor by monocytes, responsiveness to 3 mitogens, NK/LAK cell activity, and serum levels of IL-1 alpha, IL-2, soluble IL-2 receptor, and TNF alpha. The only prognostic parameter was the greater increase in the level of IL-2 receptor (Tac)-bearing lymphocytes in the responding patients after 1-3 cycles of IL-2. The data suggests that non-specific immune parameters have no prognostic value for patients undergoing IL-2-based immunotherapy.

Chemo-adoptive immunotherapy of nude mice implanted with human colorectal carcinoma and melanoma cell lines

The antitumor effects of chemotherapy, recombinant human interleukin-2 (IL-2), recombinant human interferon alpha A/D (IFN alpha), allogeneic human lymphokine-activated killer (LAK) cells, and antitumor monoclonal antibody (mAb), administered alone and in various combinations, were tested in athymic nude mice carrying human tumor xenografts. Treatment began 6-18 days after i.v. or i.p. inoculation of colorectal carcinoma or melanoma cell lines, when macroscopic growths were evident. Chemotherapy consisted of two or three courses of 5-fluorouracil (5-FU) or dacarbazine. IL-2 and/or IFN alpha were administered three to five times weekly for 1-3 weeks, usually starting 2-5 days after chemotherapy. Human LAK cells were infused once or twice weekly for 2 or 3 weeks concurrently with IL-2. In some experiments, murine anticolorectal carcinoma mAb (SF25) was administered. In both tumor systems, chemotherapy alone or immunotherapy alone (IL-2, IL-2 + LAK cells, IFN alpha, IL-2 + IFN alpha +/- LAK cells) had little or no therapeutic effects. Additive effects were obtained by combining chemotherapy with IL-2 and LAK cells or with IL-2 and IFN alpha. In the majority of the experiments, the most effective combination was chemotherapy + IL-2 + IFN alpha + LAK cells. Treatment with mAb was beneficial in the colorectal carcinoma system when combined with 5-FU + IL-2 or 5-FU + IL-2 + IFN alpha. Homing experiments with radiolabeled human and mouse LAK cells injected i.v. showed increased early accumulation in the liver and lungs, whereas freshly explanted mouse splenocytes localized mostly in the spleen and liver. The tissue distribution pattern of human LAK cells was similar in normal and tumor-bearing mice (with lung metastases). These findings suggest that combination of chemotherapy with cytokines and LAK cells can be partially effective for advanced solid human tumors even in the absence of the host's T-cell immune response. Preliminary experiments showed that tumor-specific, anti-melanoma T-cell clones were effective in local (s.c.) tumor growth inhibition (Winn assay) following coinjection with the autologous tumor cells.

Clinical applications of interleukin-2

Interleukin-2 (IL-2) is a cytokine with potent immunomodulating properties which has shown considerable antitumour activity in preclinical models. In clinical trials, the effects of IL-2 given by various routes and schedules have been investigated. IL-2 has been administered either as single drug or in combination with other cytokines and immunomodulating agents, chemo therapeutic agents, or reinfusions of ex vivo activated autologous cytotoxic effector cells. The results of published clinical studies with IL-2 based immunotherapy are reviewed in this paper.