A shared neoantigen vaccine combined with immune checkpoint blockade for advanced metastatic solid tumors: phase 1 trial interim results.

Therapeutic vaccines that elicit cytotoxic T cell responses targeting tumor-specific neoantigens hold promise for providing long-term clinical benefit to patients with cancer. Here we evaluated safety and tolerability of a therapeutic vaccine encoding 20 shared neoantigens derived from selected common oncogenic driver mutations as primary endpoints in an ongoing phase 1/2 study in patients with advanced/metastatic solid tumors. Secondary endpoints included immunogenicity, overall response rate, progression-free survival and overall survival. Eligible patients were selected if their tumors expressed one of the human leukocyte antigen-matched tumor mutations included in the vaccine, with the majority of patients (18/19) harboring a mutation in KRAS. The vaccine regimen, consisting of a chimp adenovirus (ChAd68) and self-amplifying mRNA (samRNA) in combination with the immune checkpoint inhibitors ipilimumab and nivolumab, was shown to be well tolerated, with observed treatment-related adverse events consistent with acute inflammation expected with viral vector-based vaccines and immune checkpoint blockade, the majority grade 1/2. Two patients experienced grade 3/4 serious treatment-related adverse events that were also dose-limiting toxicities. The overall response rate was 0%, and median progression-free survival and overall survival were 1.9 months and 7.9 months, respectively. T cell responses were biased toward human leukocyte antigen-matched TP53 neoantigens encoded in the vaccine relative to KRAS neoantigens expressed by the patients' tumors, indicating a previously unknown hierarchy of neoantigen immunodominance that may impact the therapeutic efficacy of multiepitope shared neoantigen vaccines. These data led to the development of an optimized vaccine exclusively targeting KRAS-derived neoantigens that is being evaluated in a subset of patients in phase 2 of the clinical study. ClinicalTrials.gov registration: NCT03953235 .

Individualized, heterologous chimpanzee adenovirus and self-amplifying mRNA neoantigen vaccine for advanced metastatic solid tumors: phase 1 trial interim results.

Checkpoint inhibitor (CPI) therapies provide limited benefit to patients with tumors of low immune reactivity. T cell-inducing vaccines hold promise to exert long-lasting disease control in combination with CPI therapy. Safety, tolerability and recommended phase 2 dose (RP2D) of an individualized, heterologous chimpanzee adenovirus (ChAd68) and self-amplifying mRNA (samRNA)-based neoantigen vaccine in combination with nivolumab and ipilimumab were assessed as primary endpoints in an ongoing phase 1/2 study in patients with advanced metastatic solid tumors (NCT03639714). The individualized vaccine regimen was safe and well tolerated, with no dose-limiting toxicities. Treatment-related adverse events (TRAEs) >10% included pyrexia, fatigue, musculoskeletal and injection site pain and diarrhea. Serious TRAEs included one count each of pyrexia, duodenitis, increased transaminases and hyperthyroidism. The RP2D was 1012 viral particles (VP) ChAd68 and 30 µg samRNA. Secondary endpoints included immunogenicity, feasibility of manufacturing and overall survival (OS). Vaccine manufacturing was feasible, with vaccination inducing long-lasting neoantigen-specific CD8 T cell responses. Several patients with microsatellite-stable colorectal cancer (MSS-CRC) had improved OS. Exploratory biomarker analyses showed decreased circulating tumor DNA (ctDNA) in patients with prolonged OS. Although small study size limits statistical and translational analyses, the increased OS observed in MSS-CRC warrants further exploration in larger randomized studies.

Amplification of overlapping DNA amplicons in a single-tube multiplex PCR for targeted next-generation sequencing of BRCA1 and BRCA2.

Current PCR-based target enrichment methods for next generation sequencing (NGS) of overlapping amplicons often requires separate PCR reactions and subsequent pooling of amplicons from the different reactions. The study presents a novel method, deemed stem-loop inhibition mediated amplification (SLIMamp), for amplifying overlapping or tiled amplicons in a single multiplex PCR reaction. During a SLIMamp PCR reaction, a stem loop structure formed by the overlapping amplicon suppresses additional amplification of itself by preventing the annealing of the primers. Using the SLIMamp strategy, we designed a next-generation sequencing (NGS) assay to enrich the exon regions of BRCA1 and BRCA2 for sequencing on an Illumina MiSeq system. We used 35 cell line DNAs and 6 patient blood DNAs in the study to evaluate the assay performance. For each sample, all targeted regions were successfully amplified and sequenced with excellent coverage uniformity and specificity. >99% of the total sequencing reads were mapped to the human reference genome (hg19) and >99% of the mapped reads were on the targeted exons. >98% of bases were covered at >0.20x of the mean coverage and >99% are covered at >0.15x of the mean depth. Among 34 independently sequenced samples, all variants were reliably detected with no false positives or false negatives. SLIMamp provides a robust method for single-tube multiplex PCR amplification of numerous, overlapping amplicons that tile for targeted next-generation sequencing.

Nanomedicine strategies for treatment of secondary spinal cord injury.

Neurological injury, such as spinal cord injury, has a secondary injury associated with it. The secondary injury results from the biological cascade after the primary injury and affects previous uninjured, healthy tissue. Therefore, the mitigation of such a cascade would benefit patients suffering a primary injury and allow the body to recover more quickly. Unfortunately, the delivery of effective therapeutics is quite limited. Due to the inefficient delivery of therapeutic drugs, nanoparticles have become a major field of exploration for medical applications. Based on their material properties, they can help treat disease by delivering drugs to specific tissues, enhancing detection methods, or a mixture of both. Incorporating nanomedicine into the treatment of neuronal injury and disease would likely push nanomedicine into a new light. This review highlights the various pathological issues involved in secondary spinal cord injury, current treatment options, and the improvements that could be made using a nanomedical approach.

Kinetics and Mechanistic Studies on the Reaction between Cytochrome c and Tea Catechins.

Green tea is characterized by the presence of an abundance of polyphenolic compounds, also known as catechins, including epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (EGC) and epigallocatechin gallate (EGCG). In addition to being a popular beverage, tea consumption has been suggested as a mean of chemoprevention. However, its mode of action is unclear. It was discovered that tea catechins can react with cytochrome c. When oxidized cytochrome c was mixed with catechins commonly found in green tea under non-steady-state conditions, a reduction of cytochrome c was observed. The reaction rate of the catechins was dependent on the pH and the nature of the catechin. The pseudo-first order rate constant obtained increased in the order of EC < ECG < EGC < EGCG, which is consistent with previously reported superoxide reduction activities and Cu(2+) reduction activities of tea catechins.