Phase I/II study protocol to assess safety and efficacy of adoptive cell therapy with anti-PD-1 plus low-dose pegylated-interferon-alpha in patients with metastatic melanoma refractory to standard of care treatments: the ACTME trial.

INTRODUCTION: Treatment with anti-PD-1 immunotherapy does not lead to long-lasting clinical responses in approximately 60% of patients with metastatic melanoma. These refractory patients, however, can still respond to treatment with tumour infiltrating lymphocytes (TIL) and interferon-alpha (IFNa). A combination of TIL, pegylated-interferon-alpha (PEG-IFNa) and anti-PD-1 is expected to provide a safe, feasible and effective therapy for patients with metastatic melanoma, who are refractory to standard of care treatment options. METHODS AND ANALYSIS: Patients are treated in two phases. In phase I, the safety of the combination TIL and anti-PD-1 is assessed (cohort 1) according to CTCAE 4.03 criteria. Subsequently, the safety of cotreatment with PEG-IFNa is tested in cohort 2. The efficacy will be evaluated in the second phase of the trial. Efficacy is evaluated according to RECIST 1.1 and immune-related response criteria. Clinical and immunological parameters will be evaluated for their relation with clinical responsiveness. ETHICS AND DISSEMINATION: Ethical approval of the trial was obtained from the Central Committee on Research Involving Human Subjects in the Netherlands. The trial results will be shared with the scientific community at (inter)national conferences and by publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03638375; Pre-results.

Viral vector-based prime-boost immunization regimens: a possible involvement of T-cell competition.

Vaccination with recombinant viral vectors may be impeded by preexisting vector-specific immunity or by vector-specific immunity induced during the priming immunization. It is assumed that virus-neutralizing antibodies represent the principal effector mechanism of vector-specific immunity, while killing of infected cells by vector-specific cytotoxic T lymphocytes (CTLs) has also been suggested. Using recombinant Semliki Forest virus (rSFV) expressing E6E7 antigen from human papillomavirus, we demonstrate that secondary immune responses against E6E7 are neither affected by vector-specific antibodies nor by CTL-mediated killing of infected cells. Instead, the presence of the antigen during the prime immunization appeared to be the main determinant for the boosting efficacy. After priming with rSFVeE6,7, a homologous booster stimulated the primed E6E7-specific CTL response and induced long-lasting memory. Passively transferred SFV-neutralizing antibodies did not inhibit E6E7-specific CTL responses, although transgene expression was strongly reduced under these conditions. Conversely, in mice primed with irrelevant rSFV, induction of E6E7-specific CTLs was inhibited presumably due to vector-specific responses induced by the priming immunization. When during the priming with irrelevant rSFV, E7-protein was co-administered, the inhibitory effect of vector-specific immunity was abolished. These results suggest that, apart from vector-specific antibodies or killing of infected cells, T-cell competition may be involved in determining the efficacy of viral vector-based prime-boost immunization regimens.

Improvement of experimental allergic encephalomyelitis (EAE) by thymoquinone; an oxidative stress inhibitor.

UNLABELLED: Experimental Allergic Encephalomyelitis (EAE) is an autoimmune demyelinating disease of the central nervous system that is widely accepted as an animal model for the human multiple sclerosis. Oxidative stress appears to play a role in the onset and progression of EAE. We reasoned that decreasing oxidative stress might ameliorate symptoms and signs of EAE. Thymoquinone is reported to inhibit oxidative stress. One way of decreasing oxidative stress is to induce glutathione (GSH). We tested the impact of Thymoquinone (1 mg/kg, injected at tail vein) in our EAE model. We induced (EAE) in female Lewis rats using myelin basic protein emulsified with complete Freund's adjuvant. 24 animals were placed into three groups: A) Rats with EAE B) EAE rats with concomitant five day injection of Thymoquinone days 1-5, C) EAE rats with five doses of Thymoquinone injected at day 12-17. Twenty-eight days later, animals were sacrificed; spinal cord tissues collected for glutathione (GSH). RESULTS: 63% of animals in group "A" developed hind limb weakness and/or paralysis while 37% developed mild tail weakness, perivascular inflammation and low spinal cord GSH level. 25% of animals in group "B" exhibited mild tail and hind limb weakness and 75% animals had no symptoms, no perivascular inflammation and high spinal cord GSH level. 63% of animals of group "C" showed improving symptoms following Thymoquinone injections, no perivascular inflammation and higher GSH level while 37% of animals showed no symptoms prior and post Thymoquinone injections. Clinical symptoms correlated well with perivascular inflammation and GSH level. Animals received Thymoquinone at day 12-17 had higher GSH level, no perivascular inflammation and no symptoms compared with other groups. CONCLUSION: Thymoquinone inhibited oxidative stress which leads into improvement in our EAE animals. Thymoquinone may have a role in treatment of Multiple Sclerosis.