Phase Ib Clinical Trial of IGV-001 for Patients with Newly Diagnosed Glioblastoma.

PURPOSE: Despite standard of care (SOC) established by Stupp, glioblastoma remains a uniformly poor prognosis. We evaluated IGV-001, which combines autologous glioblastoma tumor cells and an antisense oligonucleotide against IGF type 1 receptor (IMV-001), in newly diagnosed glioblastoma. PATIENTS AND METHODS: This open-label protocol was approved by the Institutional Review Board at Thomas Jefferson University. Tumor cells collected during resection were treated ex vivo with IMV-001, encapsulated in biodiffusion chambers with additional IMV-001, irradiated, then implanted in abdominal acceptor sites. Patients were randomized to four exposure levels, and SOC was initiated 4-6 weeks later. On the basis of clinical improvements, randomization was halted after patient 23, and subsequent patients received only the highest exposure. Safety and tumor progression were primary and secondary objectives, respectively. Time-to-event outcomes were compared with the SOC arms of published studies. RESULTS: Thirty-three patients were enrolled, and median follow-up was 3.1 years. Six patients had adverse events (grade ≤3) possibly related to IGV-001. Median progression-free survival (PFS) was 9.8 months in the intent-to-treat population (vs. SOC, 6.5 months; P = 0.0003). In IGV-001-treated patients who met Stupp-eligible criteria, PFS was 11.6 months overall (n = 22; P = 0.001) and 17.1 months at the highest exposure (n = 10; P = 0.0025). The greatest overall survival was observed in Stupp-eligible patients receiving the highest exposure (median, 38.2 months; P = 0.044). Stupp-eligible patients with methylated O6-methylguanine-DNA methyltransferase promoter (n = 10) demonstrated median PFS of 38.4 months (P = 0.0008). Evidence of immune activation was noted. CONCLUSIONS: IGV-001 was well tolerated, PFS compared favorably with SOC, and evidence suggested an immune-mediated mechanism (ClinicalTrials.gov: NCT02507583).

Differential expression of growth factors at the cellular level in virus-infected brain.

The contribution of host factors to rabies virus (RV) transcription/replication and axonal/transsynaptic spread is largely unknown. We previously identified several host genes that are up-regulated in the mouse brain during RV infection, including neuroleukin, which is involved in neuronal growth and survival, cell motility, and differentiation, and fibroblast growth factor homologous factor 4 (FHF4), which has been implicated in limb and nervous system development. In this study, we used real-time quantitative RT-PCR to assess the expression of mRNAs specific for neuroleukin, the two isoforms of FHF4 (FHF4-1a and -1b) encoded by the FHF4 gene, and N protein of RV in neurons and astrocytes isolated by laser capture microdissection from mouse brains infected with the laboratory-adapted RV strain CVS-N2c or with a street RV of silver-haired bat origin. Differences in the gene expression patterns suggest that the capacity of RV strains to infect nonneuronal cells and differentially modulate host gene expression may be important in virus replication and spread in the CNS.

Development of a cocktail of recombinant-expressed human rabies virus-neutralizing monoclonal antibodies for postexposure prophylaxis of rabies.

To provide a cost-effective and safe replacement for human rabies immunoglobulin (HRIG), we used DNA recombinant technology to express 3 human rabies virus-neutralizing human monoclonal antibodies (huMAbs) in a rhabdovirus vector (RhV). Infection of either baby hamster kidney cells or CHO cells, with the resulting RhV-huMAb recombinant viruses, yielded high-level production (< or =40 micro g/mL/48 h) of RhV recombinant-expressed huMAbs (rhuMAbs) that differ in both isotype and epitope-recognition specificity. A cocktail of these rhuMAbs neutralizes several fixed and street wild-type rabies viruses (RVs). Mice and hamsters treated only once with this rhuMAb cocktail after infection with a lethal dose of RV were protected. In the mouse models, the postexposure prophylaxis (PEP) efficacy obtained with the rhuMAb cocktail was comparable to that obtained with HRIG, a finding strongly suggesting that rhuMAbs should be given serious consideration for use in future PEP of humans.

Identification of viral genomic elements responsible for rabies virus neuroinvasiveness.

Attenuated tissue culture-adapted and natural street rabies virus (RV) strains differ greatly in their neuroinvasiveness. To identify the elements responsible for the ability of an RV to enter the CNS from a peripheral site and to cause lethal neurological disease, we constructed a full-length cDNA clone of silver-haired bat-associated RV (SHBRV) strain 18 and exchanged the genes encoding RV proteins and genomic sequences of this highly neuroinvasive RV strain with those of a highly attenuated nonneuroinvasive RV vaccine strain (SN0). Analysis of the recombinant RV (SB0), which was recovered from SHBRV-18 cDNA, indicated that this RV is phenotypically indistinguishable from WT SHBRV-18. Characterization of the chimeric viruses revealed that in addition to the RV glycoprotein, which plays a predominant role in the ability of an RV to invade the CNS from a peripheral site, viral elements such as the trailer sequence, the RV polymerase, and the pseudogene contribute to RV neuroinvasiveness. Analyses also revealed that neuroinvasiveness of an RV correlates inversely with the time necessary for internalization of RV virions and with the capacity of the virus to grow in neuroblastoma cells.