Immunologic and therapeutic evaluation of a synthetic peptide vaccine for the treatment of patients with metastatic melanoma.

The cloning of the genes encoding cancer antigens has opened new possibilities for the treatment of patients with cancer. In this study, immunodominant peptides from the gp100 melanoma-associated antigen were identified, and a synthetic peptide, designed to increase binding to HLA-A2 molecules, was used as a cancer vaccine to treat patients with metastatic melanoma. On the basis of immunologic assays, 91% of patients could be successfully immunized with this synthetic peptide, and 13 of 31 patients (42%) receiving the peptide vaccine plus IL-2 had objective cancer responses, and four additional patients had mixed or minor responses. Synthetic peptide vaccines based on the genes encoding cancer antigens hold promise for the development of novel cancer immunotherapies.

Identification of dynamically distinct subpopulations of T lymphocytes that are differentially affected by HIV.

We examined the effects of human immunodeficiency virus infection on the turnover of CD4 and CD8 T lymphocytes in 17 HIV-infected patients by 30 min in vivo pulse labeling with bromodeoxyuridine (BrdU). The percentage of labeled CD4 and CD8 T lymphocytes was initially higher in lymph nodes than in blood. Labeled cells equilibrated between the two compartments within 24 h. Based on mathematical modeling of the dynamics of BrdU-labeled cells in the blood, we identified rapidly and slowly proliferating subpopulations of CD4 and CD8 T lymphocytes. The percentage, but not the decay rate, of labeled CD4 or CD8 cells in the rapidly proliferating pool correlated significantly with plasma HIV RNA levels for both CD4 (r = 0.77, P < 0.001) and CD8 (r = 0.81, P < 0.001) T cells. In six patients there was a geometric mean decrease of greater than 2 logs in HIV levels within 2 to 6 mo after the initiation of highly active antiretroviral therapy; this was associated with a significant decrease in the percentage (but not the decay rate) of labeled cells in the rapidly proliferating pool for both CD4 (P = 0.03) and CD8 (P < 0.001) T lymphocytes. Neither plasma viral levels nor therapy had an effect on the decay rate constants or the percentage of labeled cells in the slowly proliferating pool. Monocyte production was inversely related to viral load (r = -0.56, P = 0.003) and increased with therapy (P = 0.01). These findings demonstrate that HIV does not impair CD4 T cell production but does increase CD4 and CD8 lymphocyte proliferation and death by inducing entry into a rapidly proliferating subpopulation of cells.

Heterozygosity for a defective gene for CC chemokine receptor 5 is not the sole determinant for the immunologic and virologic phenotype of HIV-infected long-term nonprogressors.

HIV-1-infected long-term nonprogressors are a heterogeneous group of individuals with regard to immunologic and virologic markers of HIV-1 disease. CC chemokine receptor 5 (CCR5) has recently been identified as an important coreceptor for HIV-1 entry into CD4+ T cells. A mutant allele of CCR5 confers a high degree of resistance to HIV-1 infection in homozygous individuals and partial protection against HIV disease progression in heterozygotes. The frequency of CCR5 heterozygotes is increased among HIV-1- infected long-term nonprogressors compared with progressors; however, the host defense mechanisms responsible for nonprogression in CCR5 heterozygotes are unknown. We hypothesized that nonprogressors who were heterozygous for the mutant CCR5 gene might define a subgroup of nonprogressors with higher CD4+ T cell counts and lower viral load compared with CCR5 wild-type nonprogressors. However, in a cohort of 33 HIV-1-infected long-term nonprogressors, those who were heterozygous for the mutant CCR5 gene were indistinguishable from CCR5 wild-type nonprogressors with regard to all measured immunologic and virologic parameters. Although epidemiologic data support a role for the mutant CCR5 allele in the determination of the state of long-term nonprogression in some HIV-1- infected individuals, it is not the only determinant. Furthermore, long-term nonprogressors with the wild-type CCR5 genotype are indistinguishable from heterozygotes from an immunologic and virologic standpoint.

Phase I trial of recombinant human macrophage colony-stimulating factor administered by continuous intravenous infusion in patients with metastatic cancer.

BACKGROUND: Macrophage colony-stimulating factor is a bone marrow-derived glycoprotein that can stimulate monocytes and macrophages, resulting in production of factors involved in immune response. In vitro and in vivo preclinical studies in animals have demonstrated that recombinant human macrophage colony-stimulating factor (rHuM-CSF) can have antitumor activity. PURPOSE: A phase I clinical trial was undertaken to evaluate the toxicity, pharmacokinetics, and immunologic effects of rHuM-CSF given by continuous intravenous infusion in patients with cancer. METHODS: Eighteen patients with metastatic solid tumors refractory to conventional therapy were treated with rHuM-CSF. Twelve patients received two 14-day cycles of rHuM-CSF by continuous infusion, with a 2-week interval. Dose escalation levels were 50, 100, and 150 micrograms/kg over 24 hours. Consecutive cohorts of three to six patients were planned at each dose level. Six patients received a modified regimen of four 7-day periods of infusion at 100 micrograms/kg over 24 hours, with 1-week intervals. RESULTS: Dose-limiting toxicity was grade 4 thrombocytopenia at a dose of 150 micrograms/kg over 24 hours in two patients receiving the 2-week regimen. Platelet count nadirs and concomitant monocytosis were seen on days 7-9, but recovery occurred during the treatment period. Macrophage colony-stimulating factor serum levels were maximal on day 1 and returned to near baseline on day 7 of infusion. Patients treated with four 7-day infusions had no treatment-limiting thrombocytopenia. There were no cumulative effects on platelet or monocyte counts or significant constitutional symptoms. Subclinical conjunctival injection was noted in five of 10 patients receiving screening ophthalmologic evaluation. Grade 2 episcleritis was diagnosed in one patient, and asymptomatic perilimbal and retinal hemorrhages were seen in two. Two patients developed sepsis caused by the intravenous line, which required cessation of therapy. No objective responses were documented. CONCLUSION: The maximum tolerated dose of rHuM-CSF given by continuous intravenous infusion for 14 days was 100 micrograms/kg over 24 hours, with rapidly reversible, dose-limiting thrombocytopenia at 150 micrograms/kg over 24 hours. A regimen alternating weekly cycles of infusion avoids dose-limiting toxicity and allows long-term treatment. IMPLICATIONS: The regimen of repeated 7-day infusions may be useful for future studies evaluating rHuM-CSF-activated monocytes in therapy for long-term infectious diseases or in investigation of new modes of cancer therapy using rHuM-CSF in conjunction with a tumor-specific antibody.

Immunizing patients with metastatic melanoma using recombinant adenoviruses encoding MART-1 or gp100 melanoma antigens.

BACKGROUND: The characterization of the genes encoding melanoma-associated antigens MART-1 or gp100, recognized by T cells, has opened new possibilities for the development of immunization strategies for patients with metastatic melanoma. With the use of recombinant adenoviruses expressing either MART-1 or gp100 to immunize patients with metastatic melanoma, we evaluated the safety, immunologic, and potential therapeutic aspects of these immunizations. METHODS: In phase I studies, 54 patients received escalating doses (between 10(7) and 10(11) plaque-forming units) of recombinant adenovirus encoding either MART-1 or gp100 melanoma antigen administered either alone or followed by the administration of interleukin 2 (IL-2). The immunologic impact of these immunizations on the development of cellular and antibody reactivity was assayed. RESULTS: Recombinant adenoviruses expressing MART-1 or gp100 were safely administered. One of 16 patients with metastatic melanoma receiving the recombinant adenovirus MART-1 alone experienced a complete response. Other patients achieved objective responses, but they had received IL-2 along with an adenovirus, and their responses could be attributed to the cytokine. Immunologic assays showed no consistent immunization to the MART-1 or gp100 transgenes expressed by the recombinant adenoviruses. High levels of neutralizing antibody were found in the pretreatment sera of the patients. CONCLUSIONS: High doses of recombinant adenoviruses could be safely administered to cancer patients. High levels of neutralizing antibody present in patients' sera prior to treatment may have impaired the ability of these viruses to immunize patients against melanoma antigens.

Treatment of patients with metastatic melanoma with autologous tumor-infiltrating lymphocytes and interleukin 2.

BACKGROUND: Studies of human tumor-infiltrating lymphocytes (TILs) derived from patients with a variety of histologic types of cancer have demonstrated that cellular immune reactions against established malignancy exist in humans. PURPOSE: We report the results of using autologous TILs plus high-dose bolus interleukin 2 (IL-2), with or without the concomitant administration of cyclophosphamide, in the treatment of 86 consecutive patients with metastatic melanoma. METHODS: From May 1987 through December 1992, 86 patients (38 female and 48 male) with metastatic melanoma were treated (145 courses) with autologous TILs plus high-dose intravenous bolus IL-2 (720,000 IU/kg every 8 hours). TILs plus IL-2 were administered in two cycles separated by approximately 2 weeks. Two treatment cycles constituted one treatment course. Patients received a maximum of 15 doses of IL-2 per cycle given every 8 hours until grade 3 or 4 toxicity was reached that could not easily be reversed by standard supportive measures. All patients received concomitant medications to abrogate some of the side effects of IL-2 administration: acetaminophen (650 mg every 4 hours), indomethacin (50 mg every 8 hours), and ranitidine (150 mg every 12 hours). Fifty-seven of the 86 patients received a single intravenous dose of 25 mg/kg cyclophosphamide approximately 36 hours before receiving the first intravenous infusion of TILs plus IL-2. Six weeks after treatment, all known sites of disease were evaluated. RESULTS: The overall objective response rate in these patients was 34% and was similar in patients receiving TILs and IL-2 alone (31%) or in conjunction with cyclophosphamide (35%). There was no significant difference in the objective response rate in patients whose therapy with high-dose IL-2 had failed (32%) compared with patients not previously treated with IL-2 (34%). The frequency of response to treatment was greater in those patients who were treated with TILs from younger cultures (P = .0001), TILs with shorter doubling times (P = .03), and TILs that exhibited higher lysis against autologous tumor targets (P = .0008). Patients who received TILs generated from subcutaneous tumor deposits had higher response rates (49%) compared with those receiving TILs from lymph nodes (17%; P = .006). There was one treatment-related death due to respiratory insufficiency. CONCLUSIONS: Treatment with TILs and IL-2 with or without cyclophosphamide can result in objective responses in about one third of patients with metastatic melanoma. The side effects of treatment are transient in most patients, and this treatment can be safely administered. These results illustrate the potential value of immune lymphocytes for the treatment of patients with melanoma.

Prospective randomized trial of high-dose interleukin-2 alone or in conjunction with lymphokine-activated killer cells for the treatment of patients with advanced cancer.

BACKGROUND: Treatment using interleukin-2 (IL-2) alone or in conjunction with lymphokine-activated killer (LAK) cells has been shown to mediate disease regression in selected patients with advanced cancer. PURPOSE: This prospective randomized trial was designed to determine whether the administration of LAK cells in conjunction with high-dose IL-2 alters response and survival rates, compared with those for IL-2 alone, in patients with advanced cancer. METHODS: The 181 patients who had metastatic cancer that had failed to respond to standard therapy or who had disease for which no effective therapy existed received treatment with high-dose IL-2 alone or with LAK cells plus IL-2. Both treatment groups were to receive the same dose of IL-2 administered according to the same schedule. IL-2 doses were omitted depending on the tolerance of the patient. Of the 181 patients, 97 had renal cell cancer and 54 had melanoma. RESULTS: Median potential follow-up was 63.2 months. There were 10 complete responses among the 85 assessable patients who received IL-2 plus LAK cells, compared with four among the 79 who received IL-2 alone. There were 14 and 12 partial responses, respectively. Complete response continues in seven patients at 50-66 months. The 36-month actuarial survival with IL-2 plus LAK cells was 31%, compared with 17% with IL-2 alone (two-sided P value [P2] = .089). A trend toward improved survival was seen for patients with melanoma who received IL-2 plus LAK cells, compared with those who received IL-2 alone (24-month survival: 32% versus 15%; 48-month survival: 18% versus 4%; P2 = .064 [corrected]). None of 26 patients with melanoma who received IL-2 alone are alive; five of 28 who received IL-2 plus LAK cells are alive, and three continue in complete response. No difference in survival was seen in patients with renal cell cancer in the two treatment groups. There were six treatment-related deaths (3.3%); three were due to myocardial infarction. Other toxic effects resolved by discontinuation of IL-2. Many toxic effects were related to increased vascular permeability induced by IL-2. CONCLUSIONS: Some patients with metastatic cancer have prolonged remission when they are treated with high-dose IL-2 alone or in conjunction with LAK cells. Our results suggest a trend toward increased survival when IL-2 is given with LAK cells in patients with melanoma, but no trend was observed for patients with renal cell cancer. IMPLICATIONS: As these studies continue, efforts are underway to develop improved immunotherapies using tumor-infiltrating lymphocytes (TIL) and gene-modified TIL.

MHC class I-restricted recognition of a melanoma antigen by a human CD4+ tumor infiltrating lymphocyte.

It is generally considered that MHC class I-restricted antigens are recognized by CD8+ T cells, whereas MHC class II-restricted antigens are recognized by CD4+ T cells. In the present study, we report an MHC class I-restricted CD4+ T cell isolated from the tumor infiltrating lymphocytes (TILs) of a patient with metastatic melanoma. TIL 1383 I recognized HLA-A2+ melanoma cell lines but not autologous transformed B cells or fibroblasts. The antigen recognized by TIL 1383 I was tyrosinase, and the epitope was the 368-376 peptide. Antibody blocking assays confirmed that TIL 1383 I was MHC class I restricted, and the CD4 and CD8 coreceptors did not contribute significantly to antigen recognition. TIL 1383 I was weakly cytolytic and secreted cytokines in a pattern consistent with it being a Th1 cell. The avidity of TIL 1383 I for peptide pulsed targets is 10-100-fold lower than most melanoma-reactive CD8+ T cell clones. These CD4+ T cells may represent a relatively rare population of T cells that express a T-cell receptor capable of cross-reacting with an MHC class I/peptide complex with sufficient affinity to allow triggering in the absence of the CD4 coreceptor.

The use of interleukin-2 and lymphokine-activated killer cells for the treatment of patients with non-Hodgkin's lymphoma.

PURPOSE: The study was undertaken to assess whether immunotherapy regimens with bolus high-dose interleukin-2 (IL-2) alone or with lymphokine-activated killer (LAK) cells are active in previously treated, relapsed patients with non-Hodgkin's lymphoma. PATIENTS AND METHODS: Nineteen patients with low- or intermediate-grade lymphomas were treated with bolus high-dose IL-2 alone (11 patients) or IL-2 with LAK cells (eight patients). IL-2 was administered by intravenous bolus infusion at 720,000 IU/kg every 8 hours. Eight patients had low-grade histologies; 11 patients were intermediate-grade. Eighteen patients had received second- or third-generation combination chemotherapy, and eight had also received radiation. All 19 relapsed after a median of two chemotherapy regimens. RESULTS: Four responses were observed, three partial and one complete, in patients with follicular histologies who received IL-2 with LAK cells. Response durations were 10, 16, 16, and 26 months, and three responders were re-treated after relapse with subsequent disease control for an additional 16, 39+, and 2+ months, respectively. CONCLUSION: High-dose, bolus IL-2-based immunotherapy with LAK cells may be an effective treatment for patients with non-Hodgkin's lymphoma and merits further testing with larger numbers of patients in phase II trials.

In vitro predictors of therapeutic response in melanoma patients receiving tumor-infiltrating lymphocytes and interleukin-2.

PURPOSE: To correlate in vitro characteristics of tumor-infiltrating lymphocytes (TIL) with clinical response to TIL immunotherapy in patients with metastatic melanoma. PATIENTS AND METHODS: Forty-one melanoma patients undergoing 43 separate treatment courses with TIL and interleukin-2 (IL-2) from December 1990 through November 1992 were studied prospectively. Multiple patient and treatment characteristics were evaluated for response correlates. In addition, TIL were assayed within 7 days of infusion for characteristics such as doubling time, cell-surface phenotype, autologous tumor lysis in 4-hour chromium-51 release assays, and cytokine secretion following autologous tumor stimulation. RESULTS: Nine patients experienced complete or partial tumor regressions. Clinical parameters such as age, sex, sites of disease, performance status, and prior therapies were similar in responders and nonresponders. Treatment variables such as the cumulative IL-2 dose and concomitant administration of cyclophosphamide or interferon (IFN)-alpha were not predictive of response, although responders received 33% more TIL. However, statistically significant differences in favor of clinical response were noted for extranodal source of TIL (v lymph node), shorter culture duration (mean, 38 v 47 days), shorter TIL doubling time (2.6 v 3.7 days), greater autologous tumor lysis by TIL (30% v 15%; effector-to-target [E:T], 40:1), and secretion of granulocyte-macrophage colony-stimulating factor (GM-CSF) by TIL following autologous tumor stimulation (six of nine responders v eight of 32 nonresponders). CONCLUSION: The associations of TIL lysis of autologous tumor and younger TIL age with clinical response observed in this study are supportive of previous reports, and these findings will be useful in designing future clinical trials. The new observation correlating GM-CSF secretion by TIL with clinical response is interesting and needs further substantiation.