Beutler, Andreas S.

AbstractIntroductionIntrathecal interleukin (IL)‐10 delivered by plasmid or viral gene vectors has been proposed for clinical testing because it is effective for chronic pain in rodents, is a potential therapeutic for various human diseases, and was found to be nontoxic in dogs, when the human IL‐10 ortholog was tested. However, recent studies in swine testing porcine IL‐10 demonstrated fatal neurotoxicity. The present study aimed to deliver vector‐encoded human IL‐10 in swine, measure expression of the transgene in cerebrospinal fluid and monitor animals for signs of neurotoxicity.ResultsHuman IL‐10 levels peaked 2 weeks after vector administration followed by a rapid decline that occurred concomitant with the emergence of anti‐human IL‐10 antibodies in the cerebrospinal fluid and serum. Animals remained neurologically healthy throughout the study period.ConclusionsThe findings of the present study suggest that swine are not idiosyncratically sensitive to intrathecal IL‐10 because, recapitulating previous reports in dogs, they suffered no clinical neurotoxicity from the human ortholog. These results strongly infer that toxicity of intrathecal IL‐10 in large animal models was previously overlooked because of a species mismatch between transgene and host. The present study further suggests that swine were protected from interleukin‐10 by a humoral immune response against the xenogeneic cytokine. Future safety studies of IL‐10 or related therapeutics may require syngeneic large animal models.

AbstractPaclitaxel‐induced peripheral neuropathy (PIPN) cannot be predicted from clinical parameters and might have a pharmacogenomic basis. Previous studies identified single nucleotide variants (SNV) associated with PIPN. However, only a subset of findings has been confirmed to date in more than one study, suggesting a need for further re‐testing and validation in additional clinical cohorts. Candidate PIPN‐associated SNVs were identified from the literature. SNVs were retested in 119 patients selected by extreme phenotyping from 269 in NCCTG N08C1 (Alliance) as previously reported. SNV genotyping was performed by a combination of short‐read sequencing analysis and Taqman PCR. These 22 candidate PIPN SNVs were genotyped. Two of these, rs7349683 in the EPHA5 and rs3213619 in ABCB1 were found to be significantly associated with PIPN with an Odds ratios OR = 2.07 (P = 0.02) and OR = 0.12 (P = 0.03), respectively. In addition, three SNVs showed a trend toward a risk‐ or protective effect that was consistent with previous reports. The rs10509681 and rs11572080 in the gene CYP2C8*3 showed risk effect with an OR = 1.49 and rs1056836 in CYP1B1 showed a protective effect with an OR = 0.66. None of the other results supported the previously reported associations, including some SNVs displaying an opposite direction of effect from previous reports, including rs1058930 in CYP2C8, rs17222723 and rs8187710 in ABCC2, rs10771973 in FGD4, rs16916932 in CACNB2 and rs16948748 in PITPNA. Alliance N08C1 validated or supported a minority of previously reported SNV‐PIPN associations. Associations previously reported by multiple studies appeared to have a higher likelihood to be validated by Alliance N08C1.

Purpose Given that the clinical course of oxaliplatin-induced neuropathy is not well defined, the current study was performed to better understand clinical parameters associated with its presentation. Methods Acute and chronic neuropathy was evaluated in patients receiving adjuvant FOLFOX (fluorouracil, leucovorin, and oxaliplatin) on study N08CB (North Central Cancer Treatment Group, Alliance). Acute neuropathy was assessed by having patients complete daily questionnaires for 6 days with each cycle of FOLFOX. Before each dose of FOLFOX and as long as 18 months after chemotherapy cessation, chronic neurotoxicity was assessed with use of the 20-item, European Organisation for Research and Treatment of Cancer quality-of-life questionnaire for patients with chemotherapy-induced peripheral neuropathy. Results Three hundred eight (89%) of the 346 patients had at least one symptom of acute neuropathy with the first cycle of FOLFOX; these symptoms included sensitivity to touching cold items (71%), sensitivity to swallowing cold items (71%), throat discomfort (63%), or muscle cramps (42%). Acute symptoms peaked at day 3 and improved, although they did not always resolve completely between treatments. These symptoms were about twice as severe in cycles 2 through 12 as they were in cycle 1. For chronic neurotoxicity, tingling was the most severe symptom, followed by numbness and then pain. During chemotherapy, symptoms in the hands were more prominent than they were in the feet; by 18 months, symptoms were more severe in the feet than they were in the hands. Patients with more severe acute neuropathy during the first cycle of therapy experienced more chronic sensory neurotoxicity (P < .0001). Conclusion Acute oxaliplatin-induced neuropathy symptoms do not always completely resolve between treatment cycles and are only half as severe on the first cycle as compared with subsequent cycles. There is a correlation between the severities of acute and chronic neuropathies.

Gene therapy with adeno-associated virus (AAV) has advanced in the last few years from promising results in animal models to >100 clinical trials (reported or under way). While vector availability was a substantial hurdle a decade ago, innovative new production methods now routinely match the scale of AAV doses required for clinical testing. These advances may become relevant to translational research in the chronic pain field. AAV for pain targeting the peripheral nervous system was proven to be efficacious in rodent models several years ago, but has not yet been tested in humans. The present review addresses the steps needed for translation of AAV for pain from the bench to the bedside focusing on pre-clinical toxicology. We break the potential toxicities into three conceptual categories of risk: First, risks related to the delivery procedure used to administer the vector. Second, risks related to AAV biology, i.e., effects of the vector itself that may occur independently of the transgene. Third, risks related to the effects of the therapeutic transgene. To identify potential toxicities, we consulted the existing evidence from AAV gene therapy for other nervous system disorders (animal toxicology and human studies) and from the clinical pharmacology of conventional analgesic drugs. Thereby, we identified required preclinical studies and charted a hypothetical path towards a future phase I/II clinical trial in the oncology-palliative care setting.

ObjectiveMutations in Charcot–Marie–Tooth disease (CMT) genes are the cause of rare familial forms of polyneuropathy. Whether allelic variability in CMT genes is also associated with common forms of polyneuropathy—considered “acquired” in medical parlance—is unknown. Chemotherapy‐induced peripheral neuropathy (CIPN) occurs commonly in cancer patients and is individually unpredictable. We used CIPN as a clinical model to investigate the association of non‐CMT polyneuropathy with CMT genes.MethodsA total of 269 neurologically asymptomatic cancer patients were enrolled in the clinical trial Alliance N08C1 to receive the neurotoxic drug paclitaxel, while undergoing prospective assessments for polyneuropathy. Forty‐nine CMT genes were analyzed by targeted massively parallel sequencing of genomic DNA from patient blood.ResultsA total of 119 (of 269) patients were identified from the 2 ends of the polyneuropathy phenotype distribution: patients that were most and least susceptible to paclitaxel polyneuropathy. The CMT gene PRX was found to be deleteriously mutated in patients who were susceptible to CIPN but not in controls (p = 8 × 10−3). Genetic variation in another CMT gene, ARHGEF10, was highly significantly associated with CIPN (p = 5 × 10−4). Three nonsynonymous recurrent single nucleotide variants contributed to the ARHGEF10 signal: rs9657362, rs2294039, and rs17683288. Of these, rs9657362 had the strongest effect (odds ratio = 4.8, p = 4 × 10−4).InterpretationThe results reveal an association of CMT gene allelic variability with susceptibility to CIPN. The findings raise the possibility that other acquired polyneuropathies may also be codetermined by genetic etiological factors, of which some may be related to genes already known to cause the phenotypically related Mendelian disorders of CMT. Ann Neurol 2014;76:727–737

Abstract Introduction: Symptom control is an important objective in the care of patients with cancer and a critical goal for long-term survivors of antineoplastic treatments. Commonly used chemotherapies, including paclitaxel, are associated with a toxic effect on the peripheral nervous system in a substantial fraction of patients, termed chemotherapy induced peripheral neuropathy (CIPN), that is often debilitating. CIPN cannot be predicted from clinical parameters in neurologically normal subjects, suggesting a genetic basis as the root cause. Patients with hereditary neuropathy (HN) due to one of ~50 recognized genes are prone to developing severe CIPN even if the hereditary predisposition is clinically silent. Assessment of CIPN has usually been an afterthought of cancer treatment studies using crude symptom measurement instruments. N08C1 and N08CA are recent clinical trials_the latter analyzed only in early 2013_focusing on extensive phenotyping by patient reported outcomes (PRO) to support genetic investigations of paclitaxel-related CIPN. Massively parallel (“nextgen”) DNA sequencing is the genetic technology of choice and represents an as-yet unrealized potential to study cancer symptom control. Methods: Exome sequencing_analysis of 20,794 genes at nucleotide resolution_was performed on blood of CIPN cases (n=73) and controls (n=46) from N08C1. The primary endpoint was the association of HN genes with CIPN. Bioinformatic analysis determined SNV and other genetic variations across 6.2x107 nucleotides. The association of genes with CIPN was statistically examined by the over-dispersion test C-alpha. The role of singleton SNV was assessed by a burden test. N08CA served as validation. Results: 386,644 SNV were detected with an estimated sensitivity of 90% and specificity of 99.9%; the orthogonal validation rate (PCR of &gt;1000 genotypes) was 99.7%. The association of the minor allele (C&gt;T) at rs7349683 in the gene EPHA5, previously reported by Baldwin et al. (2012) for CALGB40101, was confirmed in N08C1. Two hereditary neuropathy genes were identified as new CIPN candidate genes: Firstly, ARHGEF10 was highly significant with p=5x10-4 based on single gene testing and p&lt;0.02 after Bonferroni correction for multiple testing of 41 hereditary neuropathy genes with non-synonymous SNV. Three SNV were predictive, rs17683288, rs2294039 and rs9657362, the latter with an odds ratio (OR)=3.62. Validation in an independent patient group (n=75) from another paclitaxel CIPN trial, N08CA, confirmed the impact of ARHGEF10 on CIPN (p&lt;0.025; rs9657362 OR=2.51). Secondly, peraxin (PRX) was disrupted by non-synonymous singleton SNV in n=8 cases and n=0 controls (OR=6.4; unadjusted p=0.04). 7 of the 8 mutations were also scored as deleterious by both Polyphen 2 and SIFT. Because PRX SNV were non-recurrent validation was performed in N08C1 by Sanger sequencing. Several neuro-genes across the exome were noted as additional CIPN gene candidates. Conclusions: ARHGEF10 and PRX associations with CIPN suggest that CIPN and HN might share genetic roots in a subset of patients. Construct validity of N08C1 is supported by confirmation of a published result from CALGB40101 relating EPHA5 to CIPN. Germline exome sequencing in cancer patients is highly informative for understanding complex pharmacogenomic traits including outcomes in symptom control research. Citation Format: Andreas S. Beutler, Amit Kulkarni, Rahul Kanwar, Rui Qin, Julie M. Cunningham, Terry M. Therneau, Charles L. Loprinzi. Sequencing symptom control: Results from the Alliance N08C1 and N08CA genetics of chemotherapy neuropathy trials. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-196. doi:10.1158/1538-7445.AM2013-LB-196

Dorsal root ganglia (DRG) are critical anatomical structures involved in nociception. Intraganglionic (IG) drug delivery is therefore an important route of administration for novel analgesic therapies. Although IG injection in large animal models is highly desirable for preclinical biodistribution and toxicology studies of new drugs, no method to deliver pharmaceutical agents into the DRG has been reported in any large species. The present study describes a minimally invasive technique of IG agent delivery in domestic swine, one of the most common large animal models. The technique utilizes CT guidance for DRG targeting and a custom-made injection assembly for convectionenhanced delivery (CED) of therapeutic agents directly into DRG parenchyma. The DRG were initially visualized by CT myelography to determine the optimal access route to the DRG. The subsequent IG injection consisted of 3 steps. First, a commercially available guide needle was advanced to a position dorsolateral to the DRG, and the dural root sleeve was punctured, leaving the guide needle contiguous with, but not penetrating, the DRG. Second, the custom-made stepped stylet was inserted through the guide needle into the DRG parenchyma. Third, the stepped stylet was replaced by the custom-made stepped needle, which was used for the IG CED. Initial dye injections performed in pig cadavers confirmed the accuracy of DRG targeting under CT guidance. Intraganglionic administration of adeno-associated virus in vivo resulted in a unilateral transduction of the injected DRG, with 33.5% DRG neurons transduced. Transgene expression was also found in the dorsal root entry zones at the corresponding spinal levels. The results thereby confirm the efficacy of CED by the stepped needle and a selectivity of DRG targeting. Imaging-based modeling of the procedure in humans suggests that IG CED may be translatable to the clinical setting.