Intratumoral delivery of tavokinogene telseplasmid yields systemic immune responses in metastatic melanoma patients.

BACKGROUND: Interleukin 12 (IL-12) is a pivotal regulator of innate and adaptive immunity. We conducted a prospective open-label, phase II clinical trial of electroporated plasmid IL-12 in advanced melanoma patients (NCT01502293). PATIENTS AND METHODS: Patients with stage III/IV melanoma were treated intratumorally with plasmid encoding IL-12 (tavokinogene telseplasmid; tavo), 0.5 mg/ml followed by electroporation (six pulses, 1500 V/cm) on days 1, 5, and 8 every 90 days in the main study and additional patients were treated in two alternative schedule exploration cohorts. Correlative analyses for programmed death-ligand 1 (PD-L1), flow cytometry to assess changes in immune cell subsets, and analysis of immune-related gene expression were carried out on pre- and post-treatment samples from study patients, as well as from additional patients treated during exploration of additional dosing schedules beyond the pre-specified protocol dosing schedule. Response was measured by study-specific criteria to maximize detection of latent and potentially transient immune responses in patients with multiple skin lesions and toxicities were graded by the Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4.0). RESULTS: The objective overall response rate was 35.7% in the main study (29.8% in all cohorts), with a complete response rate of 17.9% (10.6% in all cohorts). The median progression-free survival in the main study was 3.7 months while the median overall survival was not reached at a median follow up of 29.7 months. A total of 46% of patients in all cohorts with uninjected lesions experienced regression of at least one of these lesions and 25% had a net regression of all untreated lesions. Transcriptomic and immunohistochemistry analysis showed that immune activation and co-stimulatory transcripts were up-regulated but there was also increased adaptive immune resistance. CONCLUSIONS: Intratumoral Tavo was well tolerated and led to systemic immune responses in advanced melanoma patients. While tumor regression and increased immune infiltration were observed in treated as well as untreated/distal lesions, adaptive immune resistance limited the response.

Anti-PD-1 therapy in patients with advanced melanoma and preexisting autoimmune disorders or major toxicity with ipilimumab.

Background: Anti-PD-1 antibodies (anti-PD-1) have clinical activity in a number of malignancies. All clinical trials have excluded patients with significant preexisting autoimmune disorders (ADs) and only one has included patients with immune-related adverse events (irAEs) with ipilimumab. We sought to explore the safety and efficacy of anti-PD-1 in such patients. Patients and methods: Patients with advanced melanoma and preexisting ADs and/or major immune-related adverse events (irAEs) with ipilimumab (requiring systemic immunosuppression) that were treated with anti-PD-1 between 1 July 2012 and 30 September 2015 were retrospectively identified. Results: One hundred and nineteen patients from 13 academic tertiary referral centers were treated with anti-PD-1. In patients with preexisting AD (N = 52), the response rate was 33%. 20 (38%) patients had a flare of AD requiring immunosuppression, including 7/13 with rheumatoid arthritis, 3/3 with polymyalgia rheumatica, 2/2 with Sjogren's syndrome, 2/2 with immune thrombocytopaenic purpura and 3/8 with psoriasis. No patients with gastrointestinal (N = 6) or neurological disorders (N = 5) flared. Only 2 (4%) patients discontinued treatment due to flare, but 15 (29%) developed other irAEs and 4 (8%) discontinued treatment. In patients with prior ipilimumab irAEs requiring immunosuppression (N = 67) the response rate was 40%. Two (3%) patients had a recurrence of the same ipilimumab irAEs, but 23 (34%) developed new irAEs (14, 21% grade 3-4) and 8 (12%) discontinued treatment. There were no treatment-related deaths. Conclusions: In melanoma patients with preexisting ADs or major irAEs with ipilimumab, anti-PD-1 induced relatively frequent immune toxicities, but these were often mild, easily managed and did not necessitate discontinuation of therapy, and a significant proportion of patients achieved clinical responses. The results support that anti-PD-1 can be administered safely and can achieve clinical benefit in patients with preexisting ADs or prior major irAEs with ipilimumab.

Deleterious effects of short-term, high-intensity exercise on immune function: evidence from leucocyte mitochondrial alterations and apoptosis.

BACKGROUND: Although moderate exercise can benefit health, acute and vigorous exercise may have the opposite effect. Strenuous exercise can induce alterations in the physiology and viability of circulating leucocytes, which have a causal relationship with exercise-induced immune distress. OBJECTIVES: To investigate the use of mitochondrial transmembrane potential (MTP), a functional marker of the energy and viability status of leucocytes, for monitoring the immunomodulating effects of short-term, high-intensity exercise. METHODS: 12 healthy volunteers with a mean Vo(2)max of 70.4 ml/kg/min carried out 3 consecutive days of high-intensity exercise (85% of Vo(2)max for 30 min every day). Blood samples were collected at multiple time points immediately before and after each exercise session and at 24 and 72 h after the completion of exercise. Leucocyte MTP, apoptosis and circulatory inflammation markers were measured by flow cytometry and enzyme-linked immunosorbent assays. RESULTS: MTP of peripheral blood leucocytes had declined immediately after the first exercise session and remained subnormal 24 h later. It did not normalise until 72 h after exercise. The sequential changes in MTP were consistent among the three leucocyte subpopulations (polymorphonuclear neutrophils, lymphocytes and monocytes) and were significant (p<0.05). Leucocytes displayed a gradual and incremental change in their propensity for apoptosis during and after exercise. Similarly, plasma concentrations of tumour necrosis factor-alpha and soluble Fas ligand were raised during the exercise sessions and had not normalised by 72 h after the completion of exercise. Correlation between changes in leucocyte MTP and plasma concentrations of tumour necrosis factor-alpha and soluble Fas ligand was variable, but significant for polymorphonuclear neutrophils and lymphocytes (p<0.05). CONCLUSIONS: Short-term, high-intensity exercise can lead to a significant and prolonged dysfunction of the mitochondrial energy status of peripheral blood leucocytes, which is accompanied by an increased propensity for apoptosis and raised pro-inflammatory mediators. These results support the immunosuppressive effects of excessive exercise and suggest that MTP is a useful marker of these effects.