Juliet Escalon

Vaccination with NY-ESO-1 protein and CpG in Montanide induces integrated antibody/Th1 responses and CD8 T cells through cross-priming

The use of recombinant tumor antigen proteins is a realistic approach for the development of generic cancer vaccines, but the potential of this type of vaccines to induce specific CD8+ T cell responses, through in vivo cross-priming, has remained unclear. In this article, we report that repeated vaccination of cancer patients with recombinant NY-ESO-1 protein, Montanide ISA-51, and CpG ODN 7909, a potent stimulator of B cells and T helper type 1 (Th1)-type immunity, resulted in the early induction of specific integrated CD4+ Th cells and antibody responses in most vaccinated patients, followed by the development of later CD8+ T cell responses in a fraction of them. The correlation between antibody and T cell responses, together with the ability of vaccine-induced antibodies to promote in vitro cross-presentation of NY-ESO-1 by dendritic cells to vaccine-induced CD8+ T cells, indicated that elicitation of NY-ESO-1-specific CD8+ T cell responses by cross-priming in vivo was associated with the induction of adequate levels of specific antibodies. Together, our data provide clear evidence of in vivo cross-priming of specific cytotoxic T lymphocytes by a recombinant tumor antigen vaccine, underline the importance of specific antibody induction for the cross-priming to occur, and support the use of this type of formulation for the further development of efficient cancer vaccines.

Resiquimod as an Immunologic Adjuvant for NY-ESO-1 Protein Vaccination in Patients with High-Risk Melanoma

Sabado, Pavlick, and colleagues show that NY-ESO-1 protein in Montanide with or without topical resiquimod is safe, well-tolerated, and induces antibody and CD4 T-cell responses in most patients, but the addition of topical resiquimod is not sufficient to induce consistent NY-ESO-1–specific CD8 T-cell responses. The Toll-like receptor (TLR) 7/8 agonist resiquimod has been used as an immune adjuvant in cancer vaccines. We evaluated the safety and immunogenicity of the cancer testis antigen NY-ESO-1 given in combination with Montanide (Seppic) with or without resiquimod in patients with high-risk melanoma. In part I of the study, patients received 100 μg of full-length NY-ESO-1 protein emulsified in 1.25 mL of Montanide (day 1) followed by topical application of 1,000 mg of 0.2% resiquimod gel on days 1 and 3 (cohort 1) versus days 1, 3, and 5 (cohort 2) of a 21-day cycle. In part II, patients were randomized to receive 100-μg NY-ESO-1 protein plus Montanide (day 1) followed by topical application of placebo gel [(arm A; n = 8) or 1,000 mg of 0.2% resiquimod gel (arm B; n = 12)] using the dosing regimen established in part I. The vaccine regimens were generally well tolerated. NY-ESO-1–specific humoral responses were induced or boosted in all patients, many of whom had high titer antibodies. In part II, 16 of 20 patients in both arms had NY-ESO-1–specific CD4+ T-cell responses. CD8+ T-cell responses were only seen in 3 of 12 patients in arm B. Patients with TLR7 SNP rs179008 had a greater likelihood of developing NY-ESO-1–specific CD8+ responses. In conclusion, NY-ESO-1 protein in combination with Montanide with or without topical resiquimod is safe and induces both antibody and CD4+ T-cell responses in the majority of patients; the small proportion of CD8+ T-cell responses suggests that the addition of topical resiquimod to Montanide is not sufficient to induce consistent NY-ESO-1–specific CD8+ T-cell responses. Cancer Immunol Res; 3(3); 278–87. ©2015 AACR.

Tolerance and activity of oxaliplatin with protracted topotecan infusion in patients with previously treated ovarian cancer. A phase I study

BACKGROUND Topotecan 14-day infusion combined with cisplatin was highly active in ovarian cancer, but too myelosuppressive. We therefore sought to evaluate the feasibility of substituting oxaliplatin for cisplatin to improve safety. METHODS Ovarian and primary peritoneal cancer patients, pretreated with at least one prior platinum-containing regimen, performance status (PS) 0-1, without prior pelvic radiation were eligible. Topotecan was continuously infused days 1-15; oxaliplatin was given days 1 and 15; cycles were repeated every 28 days. Five dose levels were explored: topotecan (mg/m2/day)/oxaliplatin (mg/m2) doses: (1) 0.2/65; (2) 0.2/75; (3) 0.2/85; (4) 0.3/85; (5) 0.4/85. RESULTS Twenty-three patients (20 ovarian, 1 tubal, and 2 peritoneal) were entered: median age 56 years (range, 37-77); PS: 0=12 and 1=11; histology: papillary serous 7, serous 4, adenocarcinoma 8, poorly differentiated 2. Median of 4 cycles were delivered. Grade 3 neutropenia occurred in 3 of 7 patients at level 5 (with fever at levels 4 and 5), without grade 4 neutropenia or thrombocytopenia. Other toxicities were mild and reversible (mainly gastrointestinal), except one grade 3 neuropathy and one oxaliplatin-related grade 3 hypersensitivity reaction. Six objective responses (five of them complete) were documented among 22 patients spanning several dose levels. CONCLUSION Topotecan continuous infusion, combined with oxaliplatin, was associated with no grade 4 hematologic toxicity and evidence of activity. The recommended phase II dose is topotecan 0.4 mg/m2/day continuous infusion d1-15 with oxaliplatin 85 mg/m2 on days 1 and 15. A phase II evaluation as second-line treatment for both platinum-sensitive and -resistant ovarian cancer recurrences is ongoing.

Phase I/II study of resiquimod as an immunologic adjuvant for NY-ESO-1 protein vaccination in patients with melanoma.

Meeting abstracts The TLR 7/8 agonist, Resiquimod has been shown to induce local activation of immune cells, production of cytokines, and antigen-presentation by dendritic cells, features desirable for cancer vaccine adjuvants. In this study, we evaluated the safety and immunogenicity of