Therapeutic vaccination with human papillomavirus type 16 synthetic long peptides (HPV16-SLPs) results in T cell-mediated regression of HPV16-induced premalignant lesions but fails to install clinically effective immunity in patients with HPV16-positive cervical cancer. We explored whether HPV16-SLP vaccination can be combined with standard carboplatin and paclitaxel chemotherapy to improve immunity and which time point would be optimal for vaccination. This was studied in the HPV16 E6/E7-positive TC-1 mouse tumor model and in patients with advanced cervical cancer. In mice and patients, the presence of a progressing tumor was associated with abnormal frequencies of circulating myeloid cells. Treatment of TC-1-bearing mice with chemotherapy and therapeutic vaccination resulted in superior survival and was directly related to a chemotherapy-mediated altered composition of the myeloid cell population in the blood and tumor. Chemotherapy had no effect on tumor-specific T cell responses. In advanced cervical cancer patients, carboplatin-paclitaxel also normalized the abnormal numbers of circulating myeloid cells, and this was associated with increased T cell reactivity to recall antigens. The effect was most pronounced starting 2 weeks after the second cycle of chemotherapy, providing an optimal immunological window for vaccination. This was validated with a single dose of HPV16-SLP vaccine given in this time window. The resulting proliferative HPV16-specific T cell responses were unusually strong and were retained after all cycles of chemotherapy. In conclusion, carboplatin-paclitaxel therapy fosters vigorous vaccine-induced T cell responses when vaccination is given after chemotherapy and has reset the tumor-induced abnormal myeloid cell composition to normal values.

New treatments based on combinations of standard therapeutic modalities and immunotherapy are of potential use, but require a profound understanding of immune modulatory properties of standard therapies. Here, the impact of standard (chemo)radiotherapy on the immune system of cervical cancer patients was evaluated. Thirty patients with cervical cancer were treated with external beam radiation therapy (EBRT), using conventional three-dimensional or intensity modulated radiation therapy without constraints for bone marrow sparing. Serial blood sampling for immunomonitoring was performed before, midway and at 3, 6 and 9 weeks after EBRT to analyze the composition of lymphocyte and myeloid-cell populations, the expression of co-stimulatory molecules, T-cell reactivity and antigen presenting cell (APC) function. Therapy significantly decreased the absolute numbers of circulating leukocytes and lymphocytes. Furthermore, the capacity of the remaining T cells to respond to antigenic or mitogenic stimulation was impaired. During treatment the frequency of both CD4+ and CD8+ T cells dropped and CD4+ T cells displayed an increased expression of programmed cell death-1 (PD-1). In vitro blocking of PD-1 successfully increased T-cell reactivity in all five samples isolated before radiotherapy but was less successful in restoring reactivity in samples isolated at later time points. Moreover, (chemo)radiotherapy was associated with an increase in both circulating monocytes and myeloid-derived suppressor cells (MDSCs) and an impaired capacity of APCs to stimulate allogeneic T cells. T-cell reactivity was slowly restored at 6–9 weeks after cessation of therapy. We conclude that conventional (chemo)radiotherapy profoundly suppresses the immune system in cervical cancer patients, and may restrict its combination with immunotherapy.

No abstract

The prognosis of patients with metastatic cervical cancer is poor with a median survival of 8-13 months. Despite the potency of chemotherapeutic drugs, this treatment is rarely curative and should be considered palliative only. The last decades, targeted therapies such as immunotherapy have emerged as an attractive option for the treatment of these patients. Immunotherapy can consist of different modalities such as monoclonal antibodies, adoptive lymphocyte transfer and vaccines, which all are intended to augment the antitumor immune responses in cancer patients. The available evidence indicates that both active and adoptive immunotherapeutical strategies are quite effective against small tumor burdens, but are usually insufficient to eradicate the disease in patients with advanced stages of different kinds of cancer, despite strong induction of tumor-specific immune responses. Although chemotherapy and immunotherapy have not shown to be curative as single modalities, accumulating evidence suggests that combinations of these treatments hold potential for improved clinical outcomes in advanced stages of cancer. Therefore, the combination of chemotherapy and immunotherapy is no longer considered incompatible, because of the emerging insight that certain chemotherapy-based cancer treatments may activate the immune system against the tumor through several molecular and cellular mechanisms. Chemotherapeutic agents and immunotherapy may thus be synergistic and enhance the clinical response. In this review, we show the rationale for combined chemo-immunotherapeutic strategies, and summarize recent data from clinical trials performed in patients with different types of cancer. Challenges such as the selection of the optimal dose and treatment schedule, will be discussed as well as the identification of immune-specific biomarkers. Furthermore, we evaluated the long-term clinical outcomes of patients with advanced cervical cancer treated with HPV16 E6/E7 SLP vaccination with or without chemotherapy. Finally, the future of vaccination therapy in combination with chemotherapy for the treatment of cervical cancer is discussed.

Daily rhythms in physiology may affect the pharmacokinetics of a drug. The aim of this study was to evaluate 24-hour variation in the pharmacokinetics of the CYP3A substrate midazolam. Oral (2 mg) and intravenous (1 mg) midazolam was administered at six timepoints throughout the 24-hour period in 12 healthy volunteers. Oral bioavailability (population mean value [RSE%] of 0.28 (7.1%)) showed 24-hour variation that was best parameterized as a cosine function with an amplitude of 0.04 (17.3%) and a peak at 12:14 in the afternoon. The absorption rate constant was 1.41 (4.7%) times increased after drug administration at 14:00. Clearance (0.38 L/min (4.8%)) showed a minor 24-hour variation with an amplitude of 0.03 (14.8%) L/min and a peak at 18:50. Simulations show that dosing time minimally affects the concentration time profiles after intravenous administration, while concentrations are higher during the day compared to the night after oral dosing, reflecting considerable variation in intestinal processes.

No abstract

We previously developed a synthetic long overlapping HPV16 E6/E7 peptides (HPV16-SLP) vaccine that was clinically active in patients with HPV16+ high-grade vulvar intraepithelial neoplasia. Complete lesion regression was related to a strong vaccine-prompted HPV16-specific effector T-cell response. However, in patients with HPV16-induced metastatic cervical cancer the vaccine-induced T-cell responses were weaker and did not result in clear clinical benefit. A new study on the immune constitution of PBMC of such patients revealed increased numbers of myeloid cells, low T-cell reactivity against common microbial recall antigens and a lower stimulatory capacity of antigen presenting cells, indicating an immunosuppressive status. When these patients were subsequently treated with standard carboplatin-paclitaxel chemotherapy we observed that at a specific time point during chemotherapy this tumor-biased immune profile was normalized to a profile similar to that found in healthy subjects. Experiments in an HPV16+ mouse tumor model showed that the tumor-induced abnormally high myeloid cell level was also normalized by this chemotherapy, not only among PBMC but also locally in the tumor. Residual tumor-present myeloid cells phenotypically mirrored activated non-suppressive antigen presenting cells. Moreover, combined HPV16 SLP vaccination and chemotherapy effectively led to a higher cure rate of mice with established tumors. Together these data indicated that standard chemotherapy has an immune stimulatory effect by deletion of suppressive myeloid cells in the mouse tumor model and in patients with metastatic cervical cancer . Therefore, a clinical trial was started in which such patients were treated with standard chemotherapy in combination with HPV16 SLP (ISA101) vaccination. Comprehensive immune monitoring confirmed the beneficial effect of myeloid cell depletion associated with a robust induction of HPV16-specific T-cell responses that were sustained throughout several cycles of chemotherapy. The data of these studies will be reported. Currently, we have started a multicenter clinical trial (ISA-HPV-01-12) in which vaccination with the HPV16 SLP ISA101 vaccine is combined with carboplatin-paclitaxel and type I interferon to assess clinical and immunological outcome in a group of HPV16+ metastatic cervical cancer patients. Citation Format: Sjoerd H. Van Der Burg, Tetje C. van der Sluis, Helene van Meir, Judith R. Kroep, Gemma G. Kenter, Mariette I.E. van Poelgeest, Koos Burggraaf, Cornelis J.M. Melief, Marij J.P. Welters. Synergistic effects of properly timed HPV16 synthetic long peptide vaccination during standard carboplatin-paclitaxel chemotherapy in animals and in patients with metastatic cervical carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2938. doi:10.1158/1538-7445.AM2014-2938

No abstract