Five-year survival outcomes for patients with advanced melanoma treated with pembrolizumab in KEYNOTE-001.

BACKGROUND: Pembrolizumab demonstrated robust antitumor activity and safety in the phase Ib KEYNOTE-001 study (NCT01295827) of advanced melanoma. Five-year outcomes in all patients and treatment-naive patients are reported herein. Patients whose disease progressed following initial response and who received a second course of pembrolizumab were also analyzed. PATIENTS AND METHODS: Patients aged ≥18 years with previously treated or treatment-naive advanced/metastatic melanoma received pembrolizumab 2 mg/kg every 3 weeks, 10 mg/kg every 3 weeks, or 10 mg/kg every 2 weeks until disease progression, intolerable toxicity, or patient/investigator decision to withdraw. Kaplan-Meier estimates of overall survival (OS) and progression-free survival (PFS) were calculated. Objective response rate and PFS were based on immune-related response criteria by investigator assessment (data cut-off, September 1, 2017). RESULTS: KEYNOTE-001 enrolled 655 patients with melanoma; median follow-up was 55 months. Estimated 5-year OS was 34% in all patients and 41% in treatment-naive patients; median OS was 23.8 months (95% CI, 20.2-30.4) and 38.6 months (95% CI, 27.2-not reached), respectively. Estimated 5-year PFS rates were 21% in all patients and 29% in treatment-naive patients; median PFS was 8.3 months (95% CI, 5.8-11.1) and 16.9 months (95% CI, 9.3-35.5), respectively. Median response duration was not reached; 73% of all responses and 82% of treatment-naive responses were ongoing at data cut-off; the longest response was ongoing at 66 months. Four patients [all with prior response of complete response (CR)] whose disease progressed during observation subsequently received second-course pembrolizumab. One patient each achieved CR and partial response (after data cut-off). Treatment-related AEs (TRAEs) occurred in 86% of patients and resulted in study discontinuation in 7.8%; 17% experienced grade 3/4 TRAE. CONCLUSIONS: This 5-year analysis of KEYNOTE-001 represents the longest follow-up for pembrolizumab to date and confirms the durable antitumor activity and tolerability of pembrolizumab in advanced melanoma. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov, NCT01295827.

Pathologic features of response to neoadjuvant anti-PD-1 in resected non-small-cell lung carcinoma: a proposal for quantitative immune-related pathologic response criteria (irPRC).

Background: Neoadjuvant anti-PD-1 may improve outcomes for patients with resectable NSCLC and provides a critical window for examining pathologic features associated with response. Resections showing major pathologic response to neoadjuvant therapy, defined as ≤10% residual viable tumor (RVT), may predict improved long-term patient outcome. However, %RVT calculations were developed in the context of chemotherapy (%cRVT). An immune-related %RVT (%irRVT) has yet to be developed. Patients and methods: The first trial of neoadjuvant anti-PD-1 (nivolumab, NCT02259621) was just reported. We analyzed hematoxylin and eosin-stained slides from the post-treatment resection specimens of the 20 patients with non-small-cell lung carcinoma who underwent definitive surgery. Pretreatment tumor biopsies and preresection radiographic 'tumor' measurements were also assessed. Results: We found that the regression bed (the area of immune-mediated tumor clearance) accounts for the previously noted discrepancy between CT imaging and pathologic assessment of residual tumor. The regression bed is characterized by (i) immune activation-dense tumor infiltrating lymphocytes with macrophages and tertiary lymphoid structures; (ii) massive tumor cell death-cholesterol clefts; and (iii) tissue repair-neovascularization and proliferative fibrosis (each feature enriched in major pathologic responders versus nonresponders, P < 0.05). This distinct constellation of histologic findings was not identified in any pretreatment specimens. Histopathologic features of the regression bed were used to develop 'Immune-Related Pathologic Response Criteria' (irPRC), and these criteria were shown to be reproducible amongst pathologists. Specifically, %irRVT had improved interobserver consistency compared with %cRVT [median per-case %RVT variability 5% (0%-29%) versus 10% (0%-58%), P = 0.007] and a twofold decrease in median standard deviation across pathologists within a sample (4.6 versus 2.2, P = 0.002). Conclusions: irPRC may be used to standardize pathologic assessment of immunotherapeutic efficacy. Long-term follow-up is needed to determine irPRC reliability as a surrogate for recurrence-free and overall survival.

Antibody-mediated thyroid dysfunction during T-cell checkpoint blockade in patients with non-small-cell lung cancer.

Background: Programmed cell death protein-1 (PD-1) blockade therapies have demonstrated durable responses and prolonged survival in a variety of malignancies. Treatment is generally well tolerated although immune-related adverse events (irAEs) can occur. Autoimmune thyroid dysfunction is among the most common irAE, but an assessment of the clinical, mechanistic, and immunologic features has not been previously described. Patient and methods: Patients with advanced non-small-cell lung cancer (NSCLC) treated with pembrolizumab at Memorial Sloan Kettering Cancer Center (n = 51) as part of KEYNOTE-001 (NCT01295827) were included. Thyroid function test and anti-thyroid antibodies were assessed prospectively at each study visit, beginning before the first treatment. Frequency of development of thyroid dysfunction, association with anti-thyroid antibodies, clinical course, and relationship with progression-free survival and overall survival to treatment with pembrolizumab was evaluated. Results: Of 51 patients treated, 3 were hypothyroid and 48 were not at baseline. Ten of 48 [21%, 95% confidence interval (CI) 10% to 35%] patients developed thyroid dysfunction requiring thyroid replacement. Anti-thyroid antibodies were present in 8 of 10 patients who developed thyroid dysfunction, compared with 3 of 38 who did not (80% versus 8%, P < 0.0001). Thyroid dysfunction occurred early (median, 42 days) in the pembrolizumab course, and a majority (6 of 10 patients) experienced brief, transient hyperthyroidism preceding the onset of hypothyroidism; no persistent hyperthyroidism occurred. Both hyperthyroidism and hypothyroidism were largely asymptomatic. Overall survival with pembrolizumab was significantly longer in subjects who developed thyroid dysfunction (hazard ratio, 0.29; 95% CI 0.09-0.94; P = 0.04). Conclusions: Thyroid dysfunction during pembrolizumab treatment of NSCLC is common and is characterized by early-onset, frequently preceded by transient hyperthyroidism, closely associated with anti-thyroid antibodies, and may be associated with improved outcomes. The presence of antibody-mediated toxicity in T-cell-directed therapy suggests an under-recognized impact of PD-1 biology in modulating humoral immunity.

Toxicities of the anti-PD-1 and anti-PD-L1 immune checkpoint antibodies.

Immune checkpoint antibodies that augment the programmed cell death protein 1 (PD-1)/PD-L1 pathway have demonstrated antitumor activity across multiple malignancies, and gained recent regulatory approval as single-agent therapy for the treatment of metastatic malignant melanoma and nonsmall-cell lung cancer. Knowledge of toxicities associated with PD-1/PD-L1 blockade, as well as effective management algorithms for these toxicities, is pivotal in order to optimize clinical efficacy and safety. In this article, we review selected published and presented clinical studies investigating single-agent anti-PD-1/PD-L1 therapy and trials of combination approaches with other standard anticancer therapies, in multiple tumor types. We summarize the key adverse events reported in these studies and their management algorithms.

Poultry enteric inflammation model with dextran sodium sulfate mediated chemical induction and feed restriction in broilers.

Gut inflammation is a cardinal event occurring in various gastrointestinal diseases regardless of etiology. A potential mechanism of action for antibiotic growth promoters and probiotics is alleviation or attenuation of such inflammation. In vivo inflammation models and markers to quantify changes in inflammation, such as paracellular leakage and tight junction function, are necessary tools in the search for methods to reduce enteric inflammation. Dextran sodium sulfate (DSS) and feed restriction (FRS), and fluorescein isothiocyanate dextran (FITC-d; 3 to 5 kDa) marker were evaluated for induction and assessment of enteric inflammation in broilers. Three independent experiments were conducted where birds received an inflammation inducer treatment and an oral gavage of FITC-d (2.2 mg/bird) 2.5 h before killing on d 4, followed by measurement of serum FITC-d levels and release of FITC-d from different regions of gastrointestinal tract (GIT) to evaluate tight junction function. Experiment 1 tested control (CON) and DSS; Experiments 2 and 3 evaluated CON, DSS, and FRS. In all experiments DSS, as well as FRS in Experiments 2 and 3, showed higher (P<0.05) leakage of FITC-d into serum than CON, but FRS was not different from DSS. The amount of FITC-d retained in duodenal and cecal tissue was affected (P<0.05) by FRS in Experiments 2 and 3, and DSS affected FITC-d retention in duodenum only, suggesting differences in gut passage or absorption/adsorption. In conclusion, DSS oral gavage and FRS could induce leaky gut, with changes in serum FITC-d and migration of FITC-d from GIT.

Immune modulation for cancer therapy.

BACKGROUND: Immune modulation in cancer refers to a range of treatments aimed at harnessing a patient's immune system to achieve tumour control, stabilisation, and potential eradication of disease. A novel therapeutic drug class called immune checkpoint-blocking antibodies modulate T-cell pathways that regulate T cells and have the potential to reinvigorate an antitumour immune response. Ipilimumab was the first FDA-approved immune checkpoint antibody licensed for the treatment of metastatic melanoma (MM) and blocks a checkpoint molecule called cytotoxic T-lymphocyte antigen 4 (CTLA-4). METHODS: Herein we review the preclinical and clinical development of ipilimumab. We outline the mode of action of these agents and other immune checkpoint inhibitors, the management of their toxicities, and how to adequately assess response to treatment. RESULTS: As a result of these data, a number of other antibodies that block novel checkpoint molecules including programmed death-1 (PD-1), and corresponding ligands such as programmed death ligand-1 (PD-L1) are under preclinical and clinical development, and have demonstrated activity in multiple tumour types. CONCLUSIONS: This review will summarise the mechanism of action and clinical development of immune checkpoint antibodies, as well as lessons learned in the management and assessment of patients receiving these agents.

Survival follow-up and ipilimumab retreatment of patients with advanced melanoma who received ipilimumab in prior phase II studies.

BACKGROUND: This report provides a survival update at a follow-up of >5 years (5.5-6 years) for patients with advanced melanoma who previously received ipilimumab in phase II clinical trials. Safety and efficacy data following ipilimumab retreatment are also reported. PATIENTS AND METHODS: Patients who previously received ipilimumab 0.3, 3, or 10 mg/kg in one of six phase II trials (CA184-004, CA184-007, CA184-008, CA184-022, MDX010-08, and MDX010-15) were eligible to enroll in the companion study, CA184-025. Upon enrollment, patients initially received ipilimumab retreatment, extended maintenance therapy, or were followed for survival only. Overall survival (OS) rates were evaluated in patients from studies CA184-004, CA184-007, CA184-008, and CA184-022. Safety and best overall response during ipilimumab retreatment at 10 mg/kg were assessed in study CA184-025. RESULTS: Five-year OS rates for previously treated patients who received ipilimumab induction at 0.3, 3, or 10 mg/kg were 12.3%, 12.3%-16.5%, and 15.5%-28.4%, respectively. Five-year OS rates for treatment-naive patients who received ipilimumab induction at 3 or 10 mg/kg were 26.8% and 21.4%-49.5%, respectively. Little to no change in OS was observed from year 5 up to year 6. The objective response rate among retreated patients was 23%. Grade 3/4 immune-related adverse events occurred in 25%, 5.9%, and 13.2% of retreated patients who initially received ipilimumab 0.3, 3, and 10 mg/kg, with the most common being observed in the skin (4.2%, 2.9%, 3.8%) and gastrointestinal tract (12.5%, 2.9%, 3.8%), respectively. CONCLUSIONS: At a follow-up of 5-6 years, ipilimumab continues to demonstrate durable, long-term survival in a proportion of patients with advanced melanoma. In some patients, ipilimumab retreatment can re-establish disease control with a safety profile that is comparable with that observed during ipilimumab induction. Further studies are needed to determine the contribution of ipilimumab retreatment to OS. CLINICALTRIALSGOV: NCT00162123.

Four-year survival rates for patients with metastatic melanoma who received ipilimumab in phase II clinical trials.

BACKGROUND: This analysis was carried out to evaluate the long-term survival of patients with metastatic melanoma who received ipilimumab, a fully human monoclonal antibody that binds to cytotoxic T-lymphocyte antigen-4, in clinical trials. PATIENTS AND METHODS: Patients received ipilimumab in one of three completed phase II clinical trials (CA184-008, CA184-022, and CA184-007). Previously treated patients were enrolled in all studies, and treatment-naïve patients were also included in study CA184-007. Patients received ipilimumab at a dose of 10 mg/kg in studies CA184-008 and CA184-007, and at doses of 0.3, 3, or 10 mg/kg in study CA184-022. Ipilimumab was given every 3 weeks for four doses, and eligible patients could receive ipilimumab maintenance therapy every 12 weeks. In study CA184-022, patients could cross over to be retreated with ipilimumab at 10 mg/kg upon disease progression. Ongoing survival follow-up is conducted in a companion study, CA184-025. RESULTS: Four-year survival rates [95% confidence interval (95% CI)] for previously treated patients who received ipilimumab at 0.3, 3, or 10 mg/kg were 13.8% [6.1-22.5], 18.2% [9.5-27.6], and 19.7% [13.4-26.5] to 28.4% [13.9-44.2], respectively. In treatment-naïve patients who received ipilimumab at 10 mg/kg, 4-year survival rates were 37.7% [18.6-57.4] to 49.5% [23.8-75.4]. CONCLUSIONS: These results demonstrate durable survival in a significant proportion of patients with metastatic melanoma who received ipilimumab therapy.

Coupling and uncoupling of tumor immunity and autoimmunity.

Self-antigens, in the form of differentiation antigens, are commonly recognized by the immune system on melanoma and other cancers. We have shown previously that active immunization of mice against the melanocyte differentiation antigen, a tyrosinase-related protein (TRP) gp75(TRP-1) (the brown locus protein) expressed by melanomas, could induce tumor immunity and autoimmunity manifested as depigmentation. In this system, tumor immunity and autoimmunity were mediated by autoantibodies. Here, we characterize immunity against another tyrosinase family glycoprotein TRP-2 (the slaty locus protein), using the same mouse model and method of immunization. As observed previously for gp75(TRP-1), immunity was induced by DNA immunization against a xenogeneic form of TRP-2, but not against the syngeneic gene, and depended on CD4(+) cells. Immunization against TRP-2 induced autoantibodies and autoreactive cytotoxic T cells. In contrast to immunization against gp75(TRP-1), both tumor immunity and autoimmunity required CD8(+) T cells, but not antibodies. Only autoimmunity required perforin, whereas tumor immunity proceeded in the absence of perforin. Thus, immunity induced against two closely related autoantigens that are highly conserved throughout vertebrate evolution involved qualitatively different mechanisms, i.e., antibody versus CD8(+) T cell. However, both pathways led to tumor immunity and identical phenotypic manifestations of autoimmunity.

Phase II trial of neoadjuvant temozolomide in resectable melanoma patients.

BACKGROUND: We treated melanoma patients with temozolomide (TMZ) in the neoadjuvant setting and collected cryopreserved tumor samples before and after treatment. The primary objective was to determine whether the response proportion was higher than previously reported in widely metastatic patients. A secondary objective was to test the feasibility of obtaining adequate tissue before and after treatment for genetic testing. MATERIALS AND METHODS: Chemotherapy-naive melanoma patients who were candidates for surgical resection were eligible. TMZ was administered orally at 75 mg/m(2)/day for 6 weeks of every 8-week cycle. Cycles were repeated until complete response (CR), progression, or stable disease (SD) for two cycles. RESULTS: Of 19 assessable patients, 2 had CRs and 1 had partial response. Four patients had SD; 12 progressed. Tumor O-6-methylguanine-DNA methyltransferase (MGMT) promoter was unmethylated in all nine patients analyzed including from the two CR patients. Pretreatment tumor microarray results were obtained in 16 of 19 patients. CONCLUSIONS: The response proportion to TMZ in the neoadjuvant setting was 16%, not different than in the metastatic setting. Responses were seen even in tumors with a methylated MGMT promoter. Pretreatment cryopreserved tumor adequate for microarray analysis could be obtained in most, but not all, patients. Post-treatment tumor was unavailable in complete responders.

Efficacy and safety of ipilimumab monotherapy in patients with pretreated advanced melanoma: a multicenter single-arm phase II study.

BACKGROUND: This phase II study evaluated the safety and activity of ipilimumab, a fully human mAb that blocks cytotoxic T-lymphocyte antigen-4, in patients with advanced melanoma. PATIENTS AND METHODS: Patients with previously treated, unresectable stage III/stage IV melanoma received 10 mg/kg ipilimumab every 3 weeks for four cycles (induction) followed by maintenance therapy every 3 months. The primary end point was best overall response rate (BORR) using modified World Health Organization (WHO) criteria. We also carried out an exploratory analysis of proposed immune-related response criteria (irRC). RESULTS: BORR was 5.8% with a disease control rate (DCR) of 27% (N = 155). One- and 2-year survival rates (95% confidence interval) were 47.2% (39.5% to 55.1%) and 32.8% (25.4% to 40.5%), respectively, with a median overall survival of 10.2 months (7.6-16.3). Of 43 patients with disease progression by modified WHO criteria, 12 had disease control by irRC (8% of all treated patients), resulting in a total DCR of 35%. Adverse events (AEs) were largely immune related, occurring mainly in the skin and gastrointestinal tract, with 19% grade 3 and 3.2% grade 4. Immune-related AEs were manageable and generally reversible with corticosteroids. CONCLUSION: Ipilimumab demonstrated clinical activity with encouraging long-term survival in a previously treated advanced melanoma population.

Tumor immunity and autoimmunity induced by immunization with homologous DNA.

The immune system can recognize self antigens expressed by cancer cells. Differentiation antigens are prototypes of these self antigens, being expressed by cancer cells and their normal cell counterparts. The tyrosinase family proteins are well characterized differentiation antigens recognized by antibodies and T cells of patients with melanoma. However, immune tolerance may prevent immunity directed against these antigens. Immunity to the brown locus protein, gp75/ tyrosinase-related protein-1, was investigated in a syngeneic mouse model. C57BL/6 mice, which are tolerant to gp75, generated autoantibodies against gp75 after immunization with DNA encoding human gp75 but not syngeneic mouse gp75. Priming with human gp75 DNA broke tolerance to mouse gp75. Immunity against mouse gp75 provided significant tumor protection. Manifestations of autoimmunity were observed, characterized by coat depigmentation. Rejection of tumor challenge required CD4(+) and NK1.1(+) cells and Fc receptor gamma-chain, but depigmentation did not require these components. Thus, immunization with homologous DNA broke tolerance against mouse gp75, possibly by providing help from CD4(+) T cells. Mechanisms required for tumor protection were not necessary for autoimmunity, demonstrating that tumor immunity can be uncoupled from autoimmune manifestations.

Characterisation and management of dermatologic adverse events to agents targeting the PD-1 receptor.

BACKGROUND: Dermatologic adverse events (AEs) are some of the most frequently observed toxicities of immune-checkpoint inhibitor therapy, but they have received little attention. The drugs, pembrolizumab and nivolumab are recently approved inhibitors of the programmed death (PD)-1 receptor that have overlapping AE profiles however, the incidence, relative risk (RR), and clinico-morphological pattern of the associated dermatologic AEs are not known. METHODS: We conducted a systematic review of the literature, and performed a meta-analysis of dermatologic AEs observed with the use of pembrolizumab and nivolumab in cancer patients. An electronic search was conducted using the PubMed, and Web of Science, and on the American Society of Clinical Oncology and European Society for Medical Oncology meeting abstracts' libraries for potentially relevant oncology trials, that employed the drugs at Food and Drug Administration-approved doses and reported dermatologic AEs. The incidence, RR and 95% confidence intervals were calculated using either random- or fixed-effects models based on the heterogeneity of included studies. The clinical presentation, histology of affected skin areas, and management strategies (based on institutional experience), are also presented. RESULTS: Rash, pruritus and vitiligo were found to be the most frequently reported dermatologic AEs. The calculated incidence of all-grade rash with pembrolizumab and nivolumab was 16.7% (RR = 2.6) and 14.3% (RR = 2.5), respectively. Other significant all-grade AEs included pruritus (pembrolizumab: incidence, 20.2% [RR = 49.9]; nivolumab: incidence, 13.2% [RR = 34.5]) and vitiligo (pembrolizumab: incidence, 8.3% [RR = 17.5]; nivolumab: 7.5% [RR = 14.6]). Interestingly, all the vitiligo events were reported in trials investigating melanoma. The RR for developing dermatologic AEs in general, was 2.95 with pembrolizumab, and 2.3 with nivolumab. CONCLUSION: We found that pembrolizumab and nivolumab are both associated with dermatologic AEs, primarily low-grade rash, pruritus, and vitiligo, which are reminiscent of those seen with ipilimumab. Knowledge of these findings is critical for optimal care, maintaining dose intensity, and health-related quality of life in cancer patients receiving PD-1 inhibitors.

Activation of NF-kappa B may be necessary but is not sufficient for induction of H-2 antigens by TNF in J558L murine myeloma cells.

We have investigated the role of the transcription factor NF-kappa B in the induction of H-2 antigens by tumor necrosis factor (TNF) in murine J558L myeloma cells. An earlier report suggested that J558L cells may have a defect in NF-kappa B activation in response to some stimuli. Treatment of J558L cells with either TNF or lipopolysaccharide (LPS) resulted in nuclear translocation of NF-kappa B, as demonstrated by electrophoretic mobility shift assay. Both TNF and LPS activated the same NF-kappa B nuclear complexes, composed of the p50 and p65 subunits. LPS mediated a stronger and more sustained activation of NF-kappa B than TNF. In contrast, TNF induced higher levels of H-2 antigen surface expression than did LPS, suggesting that activation of NF-kappa B is not sufficient for optimal enhancement of H-2 expression. An inhibitor of NF-kappa B activation, pyrrolidinedithiocarbamate (PDTC), dramatically reduced the induction of H-2 antigen by TNF, supporting the view that NF-kappa B is required for TNF-induced H-2 antigen expression. Constitutive levels of H-2 antigen expression on the cell surface and of nuclear NF-kappa B also decreased after PDTC treatment. However, PDTC had a smaller inhibitory effect on LPS-induced NF-kappa B activation and H-2 antigen expression, suggesting that TNF and LPS activate NF-kappa B by somewhat different pathways.

Alternative roles for interferon-gamma in the immune response to DNA vaccines encoding related melanosomal antigens.

Tyrosinase-related proteins-1 and -2 (gp75/TRP-1 and TRP-2) are melanosomal membrane glycoproteins recognized by antibodies and T-cells from patients with melanoma. Xenogeneic DNA immunization against gp75/TRP-1 generates antibody-dependent tumor immunity and autoimmune depigmentation. In contrast xenogeneic TRP-2 DNA immunization induces immunity mediated by CD8+ T-cells. The role of IFN-gamma in the generation of tumor immunity and autoimmune depigmentation in these two models was investigated. No tumor protection and minimal depigmentation was observed after immunization with human TRP-2 DNA in mice deficient in IFN-gamma ligand. Repletion with recombinant murine IFN-gamma restored tumor immunity. Experiments using IL4 deficient mice demonstrated that tumor immunity was unaffected but that autoimmune depigmentation was potentially accelerated, consistent with down-modulation of autoimmunity against TRP-2 by IL4. In contrast, IFN-gamma was not required for the generation of immunity to gp75/TRP-1. In fact, exogenous IFN-gamma ablated autoantibody responses against gp75/TRP-1 after xenogeneic DNA immunization, consistent with a down-regulatory effect of IFN-gamma. These results show that immunity to TRP-2 following DNA immunization uses an IFN-gamma-dependent Th1 pathway, but immunity to gp75/TRP-1 is down-regulated by IFN-gamma.

Immunization with DNA coding for gp100 results in CD4 T-cell independent antitumor immunity.

BACKGROUND: Xenogeneic DNA immunization can exploit small differences in expressed protein sequence resulting in immune recognition of self-molecules. We hypothesized that immunizing mice with xenogeneic DNA coding for the human melanosomal membrane glycoprotein gp100 would overcome immune ignorance or tolerance and result in tumor immunity. We also investigated the immunologic mechanisms of the antitumor immunity. METHODS: C57BL/6 mice were immunized with DNA coding for human gp100, mouse gp100, or control vector by gene gun. After immunization, mice were challenged with a syngeneic melanoma expressing gp100, and tumor growth was analyzed. Mice deficient in major histocompatibility complex class I or class II molecules were similarly studied to assess the immunologic mechanism of the tumor protection. RESULTS: There was significant tumor protection after vaccination with xenogeneic human gp100 DNA. Class I, but not class II, major histocompatibility complex molecules were required for tumor immunity. In addition, mice immunized with human gp100 demonstrated autoimmunity manifested as coat color depigmentation. CONCLUSIONS: Immunization with xenogeneic DNA coding for the melanosomal glycoprotein gp100 results in tumor protection and autoimmune depigmentation. These results show that xenogeneic DNA vaccines can lead to cancer immunity without CD4(+) T-cell help with potential implications for rational vaccine design.

Localized squamous cell carcinoma of the bladder causing hypercalcemia and inhibition of PTH secretion.

We report a case of symptomatic hypercalcemia in a patient with muscle-invasive, resectable squamous cell carcinoma of the bladder. Serum parathyroid hormone was consistent with secretion of parathyroid hormone-related protein. After radical cystoprostatectomy, calcium levels returned to normal. Patients with squamous cell carcinoma and an abnormal serum calcium level may have localized disease and should not be denied definitive local therapy.

Vaccines and other adjuvant therapies for melanoma.

Patients with thick primary melanomas or regional lymph node involvement are at high risk of relapse. Investigations of adjuvant therapy over the past 30 years show only one significantly positive trial employing high dose interferon-alpha-2b. This is a potentially toxic regimen, therefore, other better-tolerated forms of adjuvant immunotherapy are being studied. Recent advances in basic science have led to a better understanding of the T-cell response to human cancer. This article discusses the background and current clinical trials of active specific immunotherapies for melanoma, including peptide and ganglioside vaccines.

Clinical results using biochemotherapy as a standard of care in advanced melanoma.

Phase II studies of biochemotherapy in metastatic melanoma patients have reported response rates of 47-63%. Even though these were highly selected patients, we were intrigued by these promising response rates and began using this regimen as standard care in advanced melanoma patients. We report the results of the first 65 patients with AJCC stage IV melanoma (n = 57) or unresectable stage III (n = 8) melanoma treated with concurrent biochemotherapy at Memorial Hospital. Treatment was repeated every 3 weeks and patients were assessed for antitumour effects after every other cycle. The overall response rate among the 63 patients evaluable for response was 29% (three complete responses, 15 partial responses). The median duration of responses was 3.7 months. The response rate among previously treated and previously untreated patients was 6% and 38%, respectively. The estimated median survival for all patients was 8.5 months; the median survival for previously untreated patients was 9.2 months. Tumour response did not correlate with survival. Our experience, which is a retrospective evaluation, does not provide support for the routine use of biochemotherapy as standard treatment. The low response rate among previously treated patients indicates that biochemotherapy is not useful as second-line therapy.