PDF file - 2015K, Injection site reaction in patient M21

Objective To investigate the efficacy and safety of hu3S193, a humanized anti-Lewis-Y monoclonal antibody, as a consolidation strategy in patients with platinum-sensitive recurrent epithelial ovarian cancer who achieved a second complete response after salvage platinum-doublet chemotherapy. Methods This single-arm phase II study accrued patients with recurrent epithelial ovarian cancer with Lewis-Y expression by immunohistochemistry who had achieved a second complete response after five to eight cycles of platinum-based chemotherapy. Patients received intravenous infusions of hu3S193, 30 mg/m 2 every 2 weeks starting no more than 8 weeks after the last dose of chemotherapy and continuing for 12 doses, until disease progression, or unacceptable toxicity. The primary endpoint was progression-free survival of the second remission. Secondary objectives were safety and pharmacokinetics. Results Twenty-nine patients were enrolled. Most had a papillary/serous histology tumor (94%), stage III disease at diagnosis (75%), and five (17%) underwent secondary cytoreduction before salvage chemotherapy. Two patients were not eligible for efficacy but were considered for toxicity analysis. Eighteen patients (62%) completed the full consolidation treatment while nine patients progressed on treatment. At the time of analysis, 23 patients (85%) of the eligible population had progressed and seven of these patients (26%) had died. Median progression-free survival of the second remission was 12.1 months (95% CI: 10.6–13.9), with a 1-year progression-free survival of the second remission rate of 50.1%. The trial was terminated early since it was unlikely that the primary objective would be achieved. The most commonly reported treatment-related adverse events were nausea (55%) and vomiting (51%). Conclusions Hu3S193 did not show sufficient clinical activity as consolidation therapy in patients with recurrent epithelial ovarian cancer who achieved a second complete response after platinum-based chemotherapy. Trial registration NCT01137071 .

e17039 Background: Lewis-Y (LeY) antigen is a blood group related antigen expressed in 75% of OC. hu3S193 is a humanized anti-LeY IgG1 mAb with strong complement and antibody dependent cytotoxicity with clinical benefit shown in a phase II study in pts with platinum-resistant OC and small tumor burden. Improving progression free survival (PFS) in pts who achieve a 2CR is an unmet need. Methods: This phase II study accrued pts with relapsed OC, LeY expression by IHC, and a KPS ≥ 70% who had achieved a 2CR after 5-8 cycles of platinum doublet chemotherapy (chemoRx). Patients received intravenous infusions of hu3S193, 30mg/m2every 2 weeks starting ≤ 8 weeks after the last dose of chemoRx and continuing for 12 doses (24 weeks) or until disease progression or unacceptable toxicity. Primary endpoint was PFS with a sample size calculated to detect a 50% increase in PFS, compared to a historical value of 10.8 months. Secondary objectives were safety and pharmacokinetics (PK). Results: 29 pts were enrolled. Median age: 55 yrs (range 29-67); Median KPS: 90% (range 80-100); LeY expression by IHC (N): strong (20), weak (9); stage at initial diagnosis: I/II (2), III/IV (27); median CA-125 prior to 2CR chemoRx: 104 (range 9-514); chemoRx agents to achieve 2CR: paclitaxel/platin (21), liposomal doxo/carboplatin (8); median cycles of prior chemoRx to achieve a 2CR:6; median doses of hu3S193 delivered: 10 (range 10-12). Evaluable pts: 28 (1 pt did not have 2CR); median PFS: 11.8 months (95% CI: 10.6-13.9) while 3 pts achieved PFS of 25+ months. Grade 4 toxicities observed: none. Most frequent toxicities (any grade/grade 3): Nausea (16/2), Vomiting (15/3), Hypersensitivity (9/0). PK data will be presented. Conclusions: Despite the good tolerance and the longer PFS compared to historical control, this trial did not show a significant improvement with hu3S193 as a consolidative strategy in patients with 2CR in platinum-sensitive OC. Tumor molecular analysis of patients with long PFS may provide insight for future studies. Clinical trial information: NCT01137071.

Objectives. The primary objective was to evaluate the clinical efficacy of hu3S193, a humanized monoclonal antibody against the Lewis-Y antigen, in patients with platinum resistant/refractory ovarian, fallopian tube and primary peritoneal carcinoma. Secondary objectives were safety and pharmacokinetics. In addition, we sought to determine the potential interaction of clinical benefit and patient characteristics.Methods. This two-stage, multicenter, single arm, phase II trial enrolled eligible patients to receive hu3S193 weekly at a dose of 20 mg/m(2) intravenously for 8 weeks (1 cycle) to a maximum of 3 cycles. Efficacy was measured as clinical benefit rate (objective response or stable disease for at least 24 weeks).Results. 26 of 31 patients were eligible for efficacy analysis. No complete/partial responses were observed. Six patients had stable disease for 24+ weeks [clinical benefit rate 23% (95% CI = 9.77%-46.71%)]. Median PFS was 8.4 weeks (95% CI = 6.0 to 16.1). Median PFS differed between patients with no ascites and no visceral disease and patients with ascites and/or visceral disease [16.1 vs. 8.1 weeks (p = 0.0058)]. The most commonly reported treatment-related adverse events were fatigue (19.3%) and nausea (16.2%). Allergic reactions occurred in 6 patients (5 with Grade 1/2; 1 with Grade 3).Conclusions. Hu3S193 lacked sufficient activity in the first stage of the study to open enrollment to the second stage. However, based on the longer PFS in patients with no ascites and no visceral disease, consolidation strategies in platinum sensitive disease are currently being tested. (C) 2015 Elsevier Inc. All rights resenied.

Background Arginine deiminase (ADI) is an enzyme that degrades arginine, an amino acid that is important for growth and development of normal and neoplastic cells. Melanoma cells are auxotrophic for arginine, because they lack argininosuccinatesynthetase (ASS), a key enzyme required for the synthesis of arginine. Patients and methods Patients with advanced melanoma were treated with 40, 80 or 160 IU/m2 ADI-PEG 20 i.m. weekly. Primary endpoints were toxicity and tumor response, secondary endpoints included metabolic response by 18FDG-PET, pharmacodynamic (PD) effects upon circulating arginine levels, and argininosuccinate synthetase tumor expression by immunohistochemistry. Results 31 previously treated patients were enrolled. The main toxicities were grade 1 and 2 adverse events including injection site pain, rash, and fatigue. No objective responses were seen. Nine patients achieved stable disease (SD), with 2 of these durable for >6 months. Four of the 9 patients with SD had uveal melanoma. PD analysis showed complete plasma arginine depletion in 30/31 patients by day 8. Mean plasma levels of ADI-PEG 20 correlated inversely with ADI-PEG 20 antibody levels. Immunohistochemical ASS expression analysis in tumor tissue was negative in 24 patients, whereas 5 patients had <5 % cells positive. Conclusions ADI-PEG 20 is well tolerated in advanced melanoma patients and leads to consistent, but transient, arginine depletion. Although no RECIST responses were observed, the encouraging rate of SD in uveal melanoma patients indicates that it may be worthwhile to evaluate ADI-PEG 20 in this melanoma subgroup.

Abstract Purpose: Long peptides are efficiently presented to both CD4+ and CD8+ T cells after intracellular processing by antigen-presenting cells. To investigate the safety and in vivo immunogenicity of synthetic overlapping long peptides (OLP) from a human tumor self-antigen, we conducted a phase I clinical trial with OLP from cancer-testis antigen NY-ESO-1 in various adjuvant combinations. Experimental Design: Twenty-eight patients with advanced ovarian cancer in second or third remission were enrolled sequentially in three cohorts and received at least one vaccination. Patients in Cohort 1 (n = 4) received 1.0 mg OLP, Cohort 2 (n = 13) received OLP in Montanide-ISA-51, and Cohort 3 (n = 11) received OLP + 1.4 mg Poly-ICLC in Montanide-ISA-51 on weeks 1, 4, 7, 10, and 13. Humoral and cellular responses were evaluated by standardized immunomonitoring techniques (ELISA, ELISPOT assay, intracellular cytokine staining, and tetramer staining). Results: The vaccine was generally well tolerated with injection site reactions and fatigue that resolved. NY-ESO-1–specific antibody and CD8+ T cells were undetectable after vaccination with OLP alone, but were found in 6 of 13 (46%) and 8 of 13 (62%) patients, respectively, after vaccination with OLP+Montanide, and in 10 of 11 (91%) and 10 of 11 (91%) patients, respectively, after vaccination with OLP+Montanide+Poly-ICLC. NY-ESO-1–specific CD4+ T cells were detected in all patients with greater frequency and polyclonality when Montanide-ISA-51 was used for vaccination. Inclusion of Poly-ICLC as an adjuvant further accelerated the induction of NY-ESO-1–specific immune responses. Conclusions: The current study shows that NY-ESO-1 OLP vaccine is safe and rapidly induces consistent integrated immune responses (antibody, CD8+ and CD4+) in nearly all vaccinated patients when given with appropriate adjuvants. Clin Cancer Res; 18(23); 6497–508. ©2012 AACR.

8547 Background: Immunotherapy has demonstrated notable effects in metastatic melanoma (MM) with durable responses achieved by high-dose IL-2 and IFNα2b, leading to approval of these therapies for treatment of melanoma. However, complete responses occur in only a minority of patients. KW2871 is a chimeric monoclonal antibody (mAb) targeting the GD3 ganglioside with demonstrated antitumor activity and enhancement of antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). IFNα2b has potent immunoregulatory, anti-proliferative, differentiation-inducing, pro-apoptotic, and anti-angiogenic properties against a variety of malignancies including melanoma. Combining high dose IFNα2b (HDI) + KW2871 was hypothesized to have synergistic anti-tumor activity due to (1) the ability of HDI to enhance KW2871 induced ADCC in vitro (Liu, Cancer Immun 2002); (2) improved mAb targeting due to increased GD3 expression and induced inflammatory cytokines (TNF-α, IL-4 and IFN-γ) (Hoon, Cancer Res, 1991); (3) increased tumor-infiltrating immune cells (Kirkwood, Cancer 2002; Moschos, J Clin Oncol 2006). Methods: This is an open label, dose-escalation, phase II study of KW2871 plus HDI in patients with measurable MM. Primary objectives are progression-free survival (PFS) and safety. Secondary objectives include assessment for tumor response by RECIST, ADCC, CDC, pharmacokinetics, human antichimeric antibodies (HACA), tumor-infiltrating immune cells, biomarkers and OS. Patients with measurable disease by RECIST, stable brain metastases, and performance status ECOG 0 or 1 are eligible. Patients with severe comorbidities or autoimmune disease or prior exposure to anti-GD3 antibodies are excluded. Sequential enrollment to cohorts of KW2871 at 5, 10 , 20 mg/m2 IV every 2 week in combination with HDI 20 MU/m2 IV once daily x 5 Days for 4 weeks, then 10 MU/m2 SC three times weekly until disease progression. Results: To date, Cohort 1 (5 mg/m2 KW2871) and Cohort 2 (10 mg/m2 KW2871) have been completed safely. Cohort 3 (20 mg/m2 KW2871) has enrolled of 18 of 27 planned patients. Conclusions: Will be presented at study completion.

e17558 Background: Small cell lung cancer (SCLC) is a rapidly progressing malignancy. The majority of patients show relapse after initial therapy. Second-line chemotherapy has limited activity, and alternative therapies are desperately needed. ADI-PEG 20 is pegylated recombinant arginine deiminase which degrades arginine, resulting in growth inhibition of SCLC tumor cells deficient in argininosuccinate synthetase (ASS) in xenografts and in vitro, and induction of sensitivity to cell autophagy. Based on ASS deficiency identified in ~50% of human SCLC, a phase II trial in patients with relapsed SCLC was initiated. Methods: This is an open label, multicenter, phase II study of ADI-PEG 20 in subjects with relapsed SCLC. The primary objective is to determine overall response rate according to RECIST. Secondary objectives are to measure safety, overall survival, pharmacodynamics, and immunogenicity. Patients with histologically documented SCLC, measurable disease, and ASS negative (by immunohistochemistry) or weakly positive (< 5%) tumor are eligible. Patients with severe comorbidities, metastatic disease of the central nervous system, prior treatment with 3 or more lines of chemotherapy, and known allergy to pegylated products are excluded. Patients are enrolled in either Cohort 1 (Sensitive disease—response to first-line therapy maintained ≥ 90 days) or Cohort 2 (Refractory disease—no response to first-line therapy or progression within 90 days, or progression after 2 lines of therapy). All patients receive weekly intramuscular injections of ADI-PEG 20 at a dose of 320 IU/m2 (36.8 mg/m2) until disease progression. The two cohorts will be analyzed separately with a two-stage design. For Cohort 1, if 3/15 patients respond, additional 13 patients will be accrued to the second stage. For Cohort 2, if 1/9 patients responds, additional 8 patients will be accrued to the second stage. Results: Cohort 1 has enrolled 2 of planned 15 patients and Cohort 2 has enrolled 7 of 9 planned patients. Conclusions: Will be published when study is complete.

5078 Background: Lewis-Y (LeY) antigen is a blood group related antigen expressed in 75% of OC. hu3S193 is a humanized anti-LeY IgG1 mAb with strong complement dependent cytotoxicity and excellent targeting characteristics with a good safety profile in Phase I studies. METHODS This phase II study accrued pts with PRR, OC, PPC or FTC, with LeY expression by IHC, ≤ 1 prior chemotherapy regimens in the PRR state, and a KPS ≥ 70%. Pts received weekly intravenous infusions (1 cycle = 8 weeks) of hu3S193 at 20mg/m2 for up to 3 cycles, until disease progression or unacceptable toxicity. Primary endpoint was clinical benefit rate [objective response (OR) + stable disease (SD) ≥ 24 weeks]. A two-stage design was utilized with H1 set at 15%, requiring at least 1 OR. Secondary objectives were safety, progression-free survival (PFS) and pharmacokinetics (PK). RESULTS 31 pts were enrolled. Median age: 55 yrs (range 25-78); primary site: OC-29, PPC-1 FTC-1; LeY-positive by IHC (N): 1+ (15), 2+ (5), 3+ (8), 4+ (3). Prior platinum response: refractory 8, primary resistant 8, secondary resistant 14, allergy 1; median KPS: 90% (range 70-100); median CA-125: 257 (range 18-10,041). Number of cycles of hu3S193 delivered: 32 (median 1, range <1-3). Evaluable patients: 26 (5 pts < 4 doses); Responses: OR=0; SD=11 (42%); SD ≥ 24 weeks=6 (23%). No grade 4 toxicities observed. Most frequent toxicities in all pts (N any grade/grade 3): fatigue 4/1, allergy 4/1, tremor 2/1, fever 3/0, nausea 4/0, hypertension 3/0. Median PFS was 10 weeks (95 % CI, 4-15). PK data will be presented. CONCLUSIONS single agent hu3S193 induces disease stabilization in a significant rate in this heavily pretreated population, including long term stabilization. PFS is comparable to historic chemotherapy data with acceptable toxicity. Further studies in combination with chemotherapy are underway.

We conducted a phase I clinical trial of a cancer vaccine using a 20‐mer NY‐ESO‐1f peptide (NY‐ESO‐1 91–110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 μg of NY‐ESO‐1f peptide mixed with 0.2 KE Picibanil OK‐432 and 1.25 ml Montanide ISA‐51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY‐ESO‐1f peptide vaccine was well tolerated. Vaccine‐related adverse events observed were fever (Grade 1), injection‐site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY‐ESO‐1f peptide resulted in an increase or induction of NY‐ESO‐1 antibody responses in nine of ten patients. The sera reacted with recombinant NY‐ESO‐1 whole protein as well as the NY‐ESO‐1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine‐induced CD4 and CD8 T cells responded to NY‐ESO‐1 91–108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20‐mer NY‐ESO‐1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY‐ESO‐1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients.

NY-ESO-1 protein formulated in ISCOMATRIX™ results in CD4+, CD8+ T cell and antibody-mediated immunity. We evaluated persistence of immunity, relapse-free survival and tumour antigen expression upon relapse in patients vaccinated in an earlier trial.

Purpose: NY-ESO-1 is a highly immunogenic antigen expressed in a variety of malignancies, making it an excellent target for cancer vaccination. We recently developed a vaccine consisting of full-length recombinant NY-ESO-1 protein formulated with ISCOMATRIX adjuvant, which generated strong humoral and T-cell - mediated immune responses and seemed to reduce the risk of disease relapse in patients with fully resected melanoma. This study examines the clinical and immunologic efficacy of the same vaccine in patients with advanced metastatic melanoma.Experimental Design: Delayed-type hypersensitivity responses, circulating NY-ESO-1 - specific CD4(+) and CD8(+) Tcells, and proportions of regulatory Tcells (Treg) were assessed in patients.Results: In contrast to patients with minimal residual disease, advanced melanoma patients showed no clinical responses to vaccination. Although strong antibody responses were mounted, the generation of delayed-type hypersensitivity responses was significantly impaired. The proportion of patients with circulating NY-ESO-1 - specific CD4(+) Tcells was also reduced, and although many patients had CD8(+) Tcells specific to a broad range of NY-ESO-1 epitopes, the majority of these responses were preexisting. Tregs were enumerated in the blood by flow cytometric detection of cells with a CD4(+)CD25(+)FoxP3(+) and CD4(+)CD25(+)CD127(-) phenotype. Patients with advanced melanoma had a significantly higher proportion of circulating Treg compared with those with minimal residual disease.Conclusions: Our results point to a tumor-induced systemic immune suppression, showing a clear association between the stage of melanoma progression, the number of Treg in the blood, and the clinical and immunologic efficacy of the NY-ESO-1 ISCOMATRIX cancer vaccine.

9030 Background: ADI-PEG 20 is an enzyme that degrades arginine, a crucial amino acid central to metabolism and biosynthesis of growth and development of normal and neoplastic cells. Melanoma is auxotrophic for arginine because it lacks argininosuccinate synthetase (ASS), a key enzyme required for synthesis of arginine from citrulline via the urea cycle. This study evaluates the safety and clinical efficacy of ADI-PEG 20 in patients with MM. Methods: Patients with histologically confirmed stage III (unresectable)/ IV cutaneous, uveal or mucosal MM were treated with 40, 80 or 160 IU/m2 ADI-PEG 20 i.m. weekly for 9 weeks in a phase I setting. In a phase II component, 16–25 pts receiving 160 IU/m2 will be evaluated for tumor response (TR) by RECIST. Secondary endpoints for all patients included metabolic response by 18FDG-PET, pharmacodynamics (PD), immunogenicity and ASS tumor expression by immunohistochemistry. Results: As of Nov. 2008, 24 pts were enrolled (40 IU/m2, n=6, 80 IU/m2, n=6, 160 IU/m2, n=12): 14 males, 10 females. Median age: 66 yrs (range 29- 83 yrs). Toxicity consisted primarily of Grade 1/2 adverse events (AE) (injection site pain, myalgia, arthralgia, fatigue, flushing, rash/itch, nausea, diarrhea, hyperuricemia, taste alteration). One dose limiting toxicity (DLT) of G3 arthralgia was observed at 80 IU/m2. Two DLTs (G3 seizure and G3 lymphedema) were reported, at 160 IU/m2. No grade 4 or 5 AEs were observed. Of 22 patients evaluable for TR, 8 had stable disease (SD) with 2 of these durable for ≥ 6 months. Notably, 3 SD were uveal melanoma. 14 patients had progressive disease. PD analysis showed plasma arginine depletion during study weeks 1–6 regardless of dose. Immunohistochemical ASS expression analysis in tumor tissue: negative= 13 pts, < 5% cells positive= 5 pts. Conclusions: ADI-PEG 20 as a single agent is well tolerated in advanced MM leading to consistent arginine depletion. The extent of clinical activity has yet to be shown. Combination therapy of ADI-PEG20 with other treatments such as pro-apoptotic reagents during the first 6 weeks of ADI-PEG 20 treatment while arginine is depleted could lead to synergistic anti-cancer activity. No significant financial relationships to disclose.

We previously reported results of a phase II trial in which recombinant MAGE-A3 protein was administered with or without adjuvant AS02B to 18 non-small-cell lung cancer (NSCLC) patients after tumor resection. We found that the presence of adjuvant was essential for the development of humoral and cellular responses against selected MAGE-A3 epitopes. In our current study, 14 patients that still had no evidence of disease up to 3 years after vaccination with MAGE-A3 protein with or without adjuvant received an additional four doses of MAGE-A3 protein with adjuvant AS02B. After just one boost injection, six of seven patients originally vaccinated with MAGE-A3 protein plus adjuvant reached again their peak antibody titers against MAGE-A3 attained during the first vaccination. All seven patients subsequently developed even stronger antibody responses. Furthermore, booster vaccination widened the spectrum of CD4(+) and CD8(+) T cells against various new and known MAGE-A3 epitopes. In contrast, only two of seven patients originally vaccinated with MAGE-A3 protein alone developed high-titer antibodies to MAGE-A3, and all these patients showed very limited CD4(+) and no CD8(+) T cell reactivity, despite now receiving antigen in the presence of adjuvant. Our results underscore the importance of appropriate antigen priming using an adjuvant for generating persistent B and T cell memory and allowing typical booster responses with reimmunization. In contrast, absence of adjuvant at priming compromises further immunization attempts. These data provide an immunological rationale for vaccine design in light of recently reported favorable clinical responses in NSCLC patients after vaccination with MAGE-A3 protein plus adjuvant AS02B.

NY-ESO-1 is a cancer/testis antigen highly immunogenic in cancer patients. Cholesterol-bearing hydrophobized pullulan (CHP) is a nanoparticle-forming antigen-delivery vehicle and CHP complexed with NY-ESO-1 protein (CHP-NY-ESO-1) efficiently activates CD4 and CD8 T cells in vitro.

T cell-mediated immunity to microbes and to cancer can be enhanced by the activation of dendritic cells (DCs) via TLRs. In this study, we evaluated the safety and feasibility of topical imiquimod, a TLR7 agonist, in a series of vaccinations against the cancer/testis Ag NY-ESO-1 in patients with malignant melanoma. Recombinant, full-length NY-ESO-1 protein was administered intradermally into imiquimod preconditioned sites followed by additional topical applications of imiquimod. The regimen was very well tolerated with only mild and transient local reactions and constitutional symptoms. Secondarily, we examined the systemic immune response induced by the imiquimod/NY-ESO-1 combination, and show that it elicited both humoral and cellular responses in a significant fraction of patients. Skin biopsies were assessed for imiquimod’s in situ immunomodulatory effects. Compared with untreated skin, topical imiquimod induced dermal mononuclear cell infiltrates in all patients composed primarily of T cells, monocytes, macrophages, myeloid DCs, NK cells, and, to a lesser extent, plasmacytoid DCs. DC activation was evident. This study demonstrates the feasibility and excellent safety profile of a topically applied TLR7 agonist used as a vaccine adjuvant in cancer patients. Imiquimod’s adjuvant effects require further evaluation and likely need optimization of parameters such as formulation, dose, and timing relative to Ag exposure for maximal immunogenicity.

The CHP‐HER2 vaccine, comprising truncated 146HER2 protein complexed with nanogels of cholesteryl pullulan (CHP), is a novel protein antigen vaccine that elicits 146HER2‐specific CD8 + and CD4 + T‐cell immune responses in patients with HER2‐expressing tumors. We analyzed the humoral responses in patients vaccinated with CHP‐HER2 and those with CHP‐HER2 plus granulocyte‐macrophage colony‐stimulating factor (GM‐CSF). The vaccine was injected subcutaneously at a dose of 300 µg protein. Nine patients received the vaccine alone over the first four injections, followed by CHP‐HER2 with GM‐CSF or OK‐432, whereas six received CHP‐HER2 plus GM‐CSF from the first cycle. 146HER2‐specific IgG antibodies were induced in 14 patients, who were negative at baseline. The antibodies became detectable after the second or third vaccination and reached plateau levels after the third or fourth cycle in patients vaccinated with CHP‐HER2 plus GM‐CSF. In contrast, the antibodies appeared only after the third to sixth vaccination and the plateau appeared after the fourth to eighth cycle in patients vaccinated with the CHP‐HER2 vaccine alone over the first four cycles. The antibodies induced by the vaccine were not reactive with HER2 antigen expressed on the cell surface in any of the patients. Epitope analysis using overlapping peptides revealed a single region in the 146HER2 protein, amino acids 127–146, in eight patients who were initially vaccinated with CHP‐HER2 alone. Similarly, the same HER2 region was recognized dominantly in patients vaccinated with GM‐CSF. Our results indicate that CHP‐HER2 induced HER2‐specific humoral responses in patients with HER2‐expressing tumors and that GM‐CSF seems to accelerate the responses. ( Cancer Sci 2008; 99: 601–607)

NY-ESO-1 specific humoral responses are frequently observed in patients with various types of NY-ESO-1 antigen expressing tumors. In a large proportion of NY-ESO-1 antibody-positive patients of NY-ESO-1-specific CD8 T-cells can also be detected suggesting that monitoring of the NY-ESO-1 specific humoral immune response may be a relevant and more practical surrogate for estimating the overall immune response against NY-ESO-1 in clinical vaccine studies. We have immunized 9 cancer patients with full length NY-ESO-1 protein formulated with cholesterol-bearing hydrophobized pullulan (CHP-NY-ESO-1) and investigated the humoral immune responses against NY-ESO-1. Seven patients were NY-ESO-1 antibody-negative and 2 patients were positive prior to vaccination. Vaccination with CHP-NY-ESO-1 resulted in the induction or increase of NY-ESO-1 antibody responses in all 9 patients immunized. Epitope analysis revealed 5 regions in the NY-ESO-1 protein molecule that were recognized by antibodies induced after vaccination. The 5 regions were also recognized by antibodies present in nonvaccinated, NY-ESO-1 antibody-positive cancer patients. A peptide spanning amino acids 91-108 was recognized in 6 out of 9 vaccinated patients and in 8 out of 9 nonvaccinated, sero-positive patients, being the most dominant antigenic epitope in NY-ESO-1 for antibody recognition in cancer patients. In conclusion, we showed that CHP-NY-ESO-1 protein vaccination had a potent activity for inducing humoral immune responses against NY-ESO-1 antigen in cancer patients. The antigenic epitopes recognized by antibodies in the vaccinated patients were similar to those recognized in cancer patients with spontaneous humoral immunity against NY-ESO-1.

The chimeric monoclonal antibody cG250 recognises the G250/CAIX/MN antigen found on 95% of clear cell renal cell carcinomas (RCCs). We performed a phase I clinical trial to evaluate the safety, blood pharmacokinetics (PK), and biodistribution of repeated doses of cG250. The primary endpoint was toxicity. Secondary endpoints were cG250 biodistribution and PK; measurement of human anti-chimeric-antibodies (HACA); and tumour response rates. Eligible patients had unresectable or metastatic clear cell RCC. Doses of 5, 10, 25, or 50 mg/m(2) were given weekly by intravenous infusion for six weeks. Three patients were treated at each dose level. Trace (131)I-labelled cG250 was administered on weeks 1 and 5. Thirteen patients participated and were evaluable. One patient developed brain metastases and was replaced. No grade 3 or 4 toxicities and no dose-limiting toxicity occurred. One patient died due to progressive disease within 30 days of receiving the study drug. One patient developed HACA during the second six-week cycle. PK analysis showed mean whole body and blood alpha and beta half-lives of cG250 of 18.99 +/- 6.84 and 180.19 +/- 86.68 hours, respectively. All patients had cG250 tumour localization by gamma camera imaging in week 1 and 5. One patient had a complete response, nine patients had stable disease, and three had progressive disease. One patient received 11 six-week cycles of treatment with no toxicity or HACA. In conclusion, repeated intravenous doses of up to 50 mg/m(2) of cG250 are safe. Furthermore cG250 has a long half-life and targets clear cell RCC effectively.