Policies for reirradiation of recurrent high-grade gliomas: a survey among Italian radiation oncologists.

PURPOSE: To assess the contribution of Italian radiation oncologists in the current management of recurrent high-grade gliomas (HGG), focusing on a reirradiation (reRT) approach. METHODS: In 2015, the Reirradiation and the Central Nervous System Study Groups on behalf of the Italian Association of Radiation Oncology (AIRO) proposed a survey. All Italian radiation oncologists were individually invited to complete an online questionnaire regarding their clinical management of recurrent HGG, focusing on a reRT approach. RESULTS: A total of 37 of 210 questionnaires were returned (18% of all centers): 16 (43%) from nonacademic hospitals, 14 (38%) from academic hospitals, 5 (13%) from private institutions, and 2 (6%) from hadron therapy centers. The majority of responding centers (59%) treated ≤5 cases per year. Performance status at the time of recurrence, along with a target diameter <5 cm and an interval from primary radiation ≥6 months, were the prevalent predictive factors considered for reRT. Sixty percent of reirradiated patients had already received a salvage therapy, either chemotherapy (40%) or reoperation (20%). The most common approach for reRT was fractionated stereotactic radiotherapy to a mean (photon) dose of 41.6 Gy. CONCLUSIONS: Although there were wide variations in the clinical practice of reRT across the 37 centers, the core activities were reasonably consistent. These findings provide a basis for encouraging a national collaborative study to develop, implement, and monitor the use of reRT in this challenging clinical setting.

Prostatic fiducial markers implantation by transrectal ultrasound for adaptive image guided radiotherapy in localized cancer: 7-years experience.

OBJECTIVE: we present our 7-years' experience with fiducial gold markers inserted before Image-Guided Radiotherapy (IGRT) focusing on our echo-guided technique reporting early and late complications. MATERIAL AND METHODS: 78 prostate cancer (PCA) patients who underwent fiducial markers placement for adaptive IGRT (period 2007-2014) were selected. Mean patient age was 75 years (range 60-81), mean PSA 7.8 ng/ml (range 3.1-10), clinical stage < T3, mean Gleason Score 6.4 (range 6-7). We recorded early and late complications. Maximum distance between the Clinical Target Volume (CTV) and Planning Target Volume (PTV) was assessed for each direction and the mean PTV reduction was estimated. RESULTS: we describe in details our echo-guided technique of intraprostatic gold fiducial markers insertion prior to adaptative IGRT. We report rare early toxicity (5-7% grade 1-2), a mean PTV reduction of 37% and a very low late toxicity (only 3.4% bladder G3 and 8% rectal G2 side effects). CONCLUSION: Our technique of fiducial gold markers implantation for adaptative IGRT is safe and well-tolerated and it resulted helpful to reduce CTV-PTV margin in all cases; the effects on clinical practice seem significant in terms of late toxicity but further investigations are needed with longer follow-up.

Safety and comparative immunogenicity of an HIV-1 DNA vaccine in combination with plasmid interleukin 12 and impact of intramuscular electroporation for delivery.

BACKGROUND: DNA vaccines have been very poorly immunogenic in humans but have been an effective priming modality in prime-boost regimens. Methods to increase the immunogenicity of DNA vaccines are needed. METHODS: HIV Vaccine Trials Network (HVTN) studies 070 and 080 were multicenter, randomized, clinical trials. The human immunodeficiency virus type 1 (HIV-1) PENNVAX®-B DNA vaccine (PV) is a mixture of 3 expression plasmids encoding HIV-1 Clade B Env, Gag, and Pol. The interleukin 12 (IL-12) DNA plasmid expresses human IL-12 proteins p35 and p40. Study subjects were healthy HIV-1-uninfected adults 18-50 years old. Four intramuscular vaccinations were given in HVTN 070, and 3 intramuscular vaccinations were followed by electroporation in HVTN 080. Cellular immune responses were measured by intracellular cytokine staining after stimulation with HIV-1 peptide pools. RESULTS: Vaccination was safe and well tolerated. Administration of PV plus IL-12 with electroporation had a significant dose-sparing effect and provided immunogenicity superior to that observed in the trial without electroporation, despite fewer vaccinations. A total of 71.4% of individuals vaccinated with PV plus IL-12 plasmid with electroporation developed either a CD4(+) or CD8(+) T-cell response after the second vaccination, and 88.9% developed a CD4(+) or CD8(+) T-cell response after the third vaccination. CONCLUSIONS: Use of electroporation after PV administration provided superior immunogenicity than delivery without electroporation. This study illustrates the power of combined DNA approaches to generate impressive immune responses in humans.

Protracted low doses of temozolomide for the treatment of patients with recurrent glioblastoma: A phase II study.

O(6)-alkylguanine-DNA alkyltransferase (AGAT), involved in temozolomide-induced DNA damage repair, plays a key role in the efficacy of temozolomide. AGAT activity may be reduced by protracted temozolomide doses. On the basis of the preclinical findings, we treated patients with a histologically-proven diagnosis of glioblastoma (GBM) following adjuvant temozolomide failure with a low protracted dose of temozolomide (130 mg/m(2)/day, days 1-7 and 15-21, every 4 weeks). The primary endpoint of the study was 6-month progression-free survival (PFS-6 m). The secondary endpoints were overall survival (OS) from the start of temozolomide alternative schedule and toxicity. Enrolment was ceased at 27 patients due to the lack of effectiveness of this regimen. Results indicate that our schedule is well-tolerated, but ineffective in patients with GBM and further strategies are required to improve the outcome of these patients.

Safety and immunogenicity of an HIV-1 gag DNA vaccine with or without IL-12 and/or IL-15 plasmid cytokine adjuvant in healthy, HIV-1 uninfected adults.

BACKGROUND: DNA vaccines are a promising approach to vaccination since they circumvent the problem of vector-induced immunity. DNA plasmid cytokine adjuvants have been shown to augment immune responses in small animals and in macaques. METHODOLOGY/PRINCIPAL FINDINGS: We performed two first in human HIV vaccine trials in the US, Brazil and Thailand of an RNA-optimized truncated HIV-1 gag gene (p37) DNA derived from strain HXB2 administered either alone or in combination with dose-escalation of IL-12 or IL-15 plasmid cytokine adjuvants. Vaccinations with both the HIV immunogen and cytokine adjuvant were generally well-tolerated and no significant vaccine-related adverse events were identified. A small number of subjects developed asymptomatic low titer antibodies to IL-12 or IL-15. Cellular immunogenicity following 3 and 4 vaccinations was poor, with response rates to gag of 4.9%/8.7% among vaccinees receiving gag DNA alone, 0%/11.5% among those receiving gag DNA+IL-15, and no responders among those receiving DNA+high dose (1500 ug) IL-12 DNA. However, after three doses, 44.4% (4/9) of vaccinees receiving gag DNA and intermediate dose (500 ug) of IL-12 DNA demonstrated a detectable cellular immune response. CONCLUSIONS/SIGNIFICANCE: This combination of HIV gag DNA with plasmid cytokine adjuvants was well tolerated. There were minimal responses to HIV gag DNA alone, and no apparent augmentation with either IL-12 or IL-15 plasmid cytokine adjuvants. Despite the promise of DNA vaccines, newer formulations or methods of delivery will be required to increase their immunogenicity. TRIAL REGISTRATION: Clinicaltrials.gov NCT00115960 NCT00111605.

Timing of plasmid cytokine (IL-2/Ig) administration affects HIV-1 vaccine immunogenicity in HIV-seronegative subjects.

BACKGROUND: To investigate the potential immunostimulatory effect of interleukin (IL) 2 as a human immunodeficiency virus type 1 (HIV-1) vaccine adjuvant, we conducted a study of a plasmid coding for a fusion protein of IL-2 and immunoglobulin (IL-2/Ig). METHODS: This phase I trial evaluated an HIV-1 DNA vaccine with the plasmid cytokine adjuvant (IL-2/Ig) in 70 HIV-negative adults. Subjects received placebo (group C), adjuvant alone (group A), vaccine alone (group D), increasing doses of adjuvant concurrent with vaccine (groups T1-T4), or adjuvant given 2 days after vaccine (group T5). RESULTS: No significant differences in adverse events were observed between treatment groups. Cellular immune responses to envelope protein EnvA peptides were detected by interferon (IFN) γ and IL-2 enzyme-linked immunospot (ELISPOT) assays in 50% and 40% of subjects, respectively, in T4, and in 100% and 80% in T5. The median responses for groups T4 and T5, respectively, were 90 and 193 spot-forming cells (SFCs)/106 peripheral blood mononuclear cells (P = .004; T4 vs T5) for the IL-2 ELISPOT assay and 103 and 380 SFCs/106 PBMCs (P = .003; T4 vs T5) for the IFN-γ ELISPOT assay. A trend to more durable cellular immune responses in T5 was observed at 1 year (T5 vs T4/D; P = .07). Higher anti-Env antibody responses were detected with T5 than with T4. CONCLUSIONS: Plasmid IL-2/Ig significantly increased immune responses when administered 2 days after the DNA vaccine, compared with simultaneous administration. These observations have important implications for the development of cytokine augmentation strategies. CLINICAL TRIALS REGISTRATION: NCT00069030.

Phase 1 safety and immunogenicity testing of DNA and recombinant modified vaccinia Ankara vaccines expressing HIV-1 virus-like particles.

BACKGROUND: Recombinant DNA and modified vaccinia virus Ankara (rMVA) vaccines represent a promising approach to an HIV/AIDS vaccine. This Phase 1 clinical trial compared the safety and immunogenicity of a rMVA vaccine administered with and without DNA vaccine priming METHODS: GeoVax pGA2/JS7 DNA (D) and MVA/HIV62 (M) vaccines encode noninfectious virus-like particles. Intramuscular needle injections were used to deliver placebo, 2 doses of DNA followed by 2 doses of rMVA (DDMM), one dose of DNA followed by 2 doses of rMVA (DMM), or 3 doses of rMVA (MMM) to HIV-seronegative participants. RESULTS: Local and systemic symptoms were mild or moderate. Immune response rates for CD4 + and CD8 + T cells were highest in the DDMM group and lowest in the MMM group (77% vs 43% CD4 + and 42% vs 17% CD8 +). In contrast, response rates for Env binding and neutralizing Ab were highest in the MMM group. The DMM group had intermediate response rates. A 1/10th-dose DDMM regimen induced similar T cell but reduced Ab response rates compared with the full-dose DDMM. CONCLUSIONS: MVA62 was well tolerated and elicited different patterns of T cell and Ab responses when administered alone or in combination with the JS7 DNA vaccine.

A phase I trial of preventive HIV vaccination with heterologous poxviral-vectors containing matching HIV-1 inserts in healthy HIV-uninfected subjects.

We evaluated replication-defective poxvirus vectors (modified vaccinia Ankara [MVA] and fowlpox [FPV]) in a homologous and heterologous vector prime-boost vaccination regimen containing matching HIV inserts (MVA-HIV and FPV-HIV) given at months 0, 1, 3, 5 and 7 in 150 healthy HIV-negative vaccinia-naïve participants. FPV-HIV alone was poorly immunogenic, while the high dose (10(9)pfu/2 ml) of MVA-HIV alone elicited maximal responses after two injections: CD4+ and CD8+ T-cell responses in 26/55 (47.3%) and 5/60 (8.3%) of participants, respectively, and IFN-γ ELISpot responses in 28/62 (45.2%). The infrequent CD8+ T-cell responses following MVA-HIV priming were boosted only by the heterologous (FPV-HIV) construct in 14/27 (51.9%) of participants post 4th vaccination. Alternatively, HIV envelope-specific binding antibodies were demonstrated in approximately two-thirds of recipients of the homologous boosting regimen, but in less than 20% of subjects after the heterologous vector boost. Thus, a heterologous poxvirus vector prime-boost regimen can induce HIV-specific CD8+ T-cell and CD4+ T-cell responses, which may be an important feature of an optimal regimen for preventive HIV vaccination.

Broadening inclusion of vulnerable populations in HIV vaccine trials.

The urgent need for a preventive HIV vaccine, as well as the complexities of its development, calls for timely and reinforced efforts to ensure vaccine licensure for use in a broad range of at-risk populations from the outset. Such an integrated strategy to HIV vaccine development should include infants of HIV-infected women, adolescents and injection drug users. A safe and effective HIV vaccine licensed for use in these populations, in addition to sexually active adults, would probably have the most timely and profound impact on the HIV/AIDS pandemic. Advanced clinical development of HIV vaccines in these vulnerable populations imposes particular scientific, operational and ethical challenges. Recent developments, including the early termination of a Phase IIb trial, present additional previously unanticipated challenges.

Mucinous rectal adenocarcinoma can be associated to tumor downstaging after preoperative chemoradiotherapy.

PURPOSE: The aim of this study was to evaluate downstaging as primary end point, and progression-free survival and overall survival as secondary end points, in rectal adenocarcinoma patients treated with preoperative chemoradiation. METHODS: One hundred and thirty-six extraperitoneal adenocarcinoma patients (33 low rectum T2, 74 T3, 29 T4 [without sacral invasion], 25 with mucinous subtype) were treated with posterior pelvis preoperative radiotherapy (5040 cGy total dose, 180 cGy/fr, 5 fr/w, 10-15 MV linac X-rays) and concomitant 5-fluorouracil-based chemotherapy. After 6 to 8 weeks patients underwent surgery and prechemoradiation clinical stage was compared with pathologic stage to evaluate downstaging in each patient. Seventy-four patients received adjuvant chemotherapy. Median follow-up was 39 months (4-84). RESULTS: Forty-four patients had macroscopic complete response, 52 patients had partial response, 37 patients showed no change and 3 patients had progression. At multivariate analysis only histotype showed correlation with downstaging (hazard ratio = 0.350 and 0.138 - 0.885 95 percent confidence interval) because of the evidence for poor downstaging in mucinous subtype. There were no significant differences in overall survival and progression-free survival between adenocarcinoma and mucinous subtype. CONCLUSIONS: The main finding is that mucinous histology is associated with poor downstaging after preoperative chemoradiation but this poor response was not associated with worse outcome in this small study. The good outcome for mucinous histology is at odds with other reports in the literature and requires further study.

Endpoints and regulatory issues in HIV vaccine clinical trials: lessons from a workshop.

A successful HIV vaccine would have a substantial impact on acquisition of infection, progression of disease among the infected, or infectiousness of the infected. Current vaccine candidates are anticipated to have their major effect on viremia, however, with the expectation that this would induce or be concordant with a reduced rate of AIDS, death, or infectiousness. Although direct assessment of disease progression or infectiousness may be impractical, available potential surrogates for these endpoints may be misleading. This article summarizes the proceedings of a National Institute of Allergy and Infectious Disease-sponsored workshop to explore the use of surrogate endpoints for licensure of an HIV vaccine. Early, medium, and late endpoints were discussed, along with challenges such as surrogate validity, the confounding effect of antiretroviral therapy initiation, and potential selection bias in the vaccine and placebo recipients who become infected. Results from 5 hypothetic HIV vaccine clinical trials with ambiguously successful results were presented to an expert panel for interpretation and discussion of next steps. Key recommendations included assessing magnitude and durability of surrogate effects, generalization across populations, and directed improvement of vaccines. Use of acquisition and a postinfection surrogate as coprimary endpoints was supported, along with use of composite endpoints and exploration of heterogeneity in vaccine efficacy by characteristics of the host and virus.

Uncoupling of epidermal growth factor-dependent proliferation and invasion in a model of squamous carcinoma progression.

Cell lines pairs were established from a primary squamous carcinoma of tongue and a lymph node metastasis and their biological behavior characterized. HN12 cells, derived from metastatic SCC, formed tumors upon subcutaneous transplantation to athymic mice, whereas HN4, derived from a primary lesion in the same individual, were non-tumorigenic in this assay. EGF stimulated proliferation of HN4 cells; in comparison, not only were metastatic HN12 cells refractory to the stimulatory effects of this growth factor but showed inhibition at higher growth factor concentrations. However, in contrast to the effects on proliferation, EGF (10 ng/ml) readily induced HN12 cells to invade in Boyden chamber assays whereas HN4 were non-invasive under these conditions. The invasive properties of HN12 cells were apparently independent of MMP-2 activity, as levels of active MMP-2 were higher in the non-invasive cells. However, EGF stimulated MMP-9 activity in invasive cells. Additionally, HN12 cells expressed constitutively high levels of active MMP-7 and MMP-3/10. The pharmacological agents LY294002, PD098059, SP600125, or SB202190 inhibited invasion of HN12 cells, suggesting requirement for phosphoinositide 3-OH kinase- and mitogen activated protein kinase-dependent pathways in the process. The data indicate that distinct biochemical differences distinguish metastatic squamous carcinoma cells from those derived from corresponding primary tumors, resulting in their contrasting biological properties.

Down-staging after two different preoperative chemoradiation schedules in rectal cancer.

AIMS: To compare preoperative down-staging, toxicity and sphincter-saving procedures obtained with preoperative radiotherapy and two different concomitant chemotherapy schedules. METHODS: From February 1997 to August 2001, 68 consecutive patients were treated with external radiotherapy (5040 cGy in 28 fractions) and concomitant chemotherapy: group a) 36 patients (10 T2, 19 T3, 7 T4, 25 adenocarcinoma and 11 mucinous histology) were treated with cis-diamminedichloroplatinum bolus + 5-fluorouracil continuous infusion; group b) 32 patients (14 T2, 18 T3, 27 adenocarcinoma and 5 mucinous histology) were treated with 5-fluorouracil bolus +/- mitomycin C. The interval between the end of radiotherapy and surgery ranged from 4 to 9 weeks. RESULTS: Group a) Overall down-staging was 63.9%. Longitudinal shrinkage of the neoplasm allowed conservative surgery in 6 of 11 patients with a pre-chemoradiation tumor location < or = 3 cm from the external anal ring. When patients with adenocarcinoma (25/36) were studied separately from patients with mucinous histology, 7/25 patients (28%) were found to have no microscopic evidence of residual tumor (pT0); 8/25 (32%) were found to have only rare isolated cancer cells (pTmic); only 7/25 patients (28%) were found to have no change. Overall, 72% patients had down-staging. In contrast, only 5/11 (45.5%) of mucinous tumors had partial down-staging and 6/11 (54.5%) no down-staging at all. Group b) Overall down-staging was 46.9%. When patients with adenocarcinoma (27/32) were studied separately, 7/27 (26%) were found to have pT0, 3/27 (11.1%) pTmic, and 13/27 (48.1%) no change. Only 1/5 (20%) of mucinous tumors had down-staging and 4/5 (80%) had no down-staging at all. Overall toxicity was comparable among groups a and b, except for lower hematologic and gastrointestinal G3-4 toxicity observed in group a. CONCLUSIONS: The overall response allowed conservative surgery in 56 (82.3%) of the 68 patients. Continuous infusion of 5-fluorouracil and diamminedichloroplatinum as a radiosensitizer determined better results in group a than group b (63.9% down-staging vs 46.9% even with a higher incidence of mucinous histology). Mucinous histology, for a definitely lower response rate, could benefit from an even more aggressive approach.