Evaluation of recombinant monoclonal antibody SVmab1 binding to NaV1.7 target sequences and block of human NaV1.7 currents

Abstract

Identification of small and large molecule pain therapeutics that target the genetically validated voltage-gated sodium channel Na V1.7 is a challenging endeavor under vigorous pursuit. The monoclonal antibody SVmab1 was recently published to bind the Na V1.7 DII voltage sensor domain and block human Na V1.7 sodium currents in heterologous cells. We produced purified SVmab1 protein based on publically available sequence information, and evaluated its activity in a battery of binding and functional assays. Herein, we report that our recombinant SVmAb1 does not bind peptide immunogen or purified Na V1.7 DII voltage sensor domain via ELISA, and does not bind Na V1.7 in live HEK293, U-2 OS, and CHO-K1 cells via FACS. Whole cell manual patch clamp electrophysiology protocols interrogating diverse Na V1.7 gating states in HEK293 cells, revealed that recombinant SVmab1 does not block Na V1.7 currents to an extent greater than observed with an isotype matched control antibody. Collectively, our results show that recombinant SVmab1 monoclonal antibody does not bind Na V1.7 target sequences or specifically inhibit Na V1.7 current.

Updating the guidelines for data transparency in the British Journal of Pharmacology – data sharing and the use of scatter plots instead of bar charts

“…This has added further fuel to the fire that was first stoked up by the findings from Bayer (Prinz et al ., ) and Amgen (Begley and Ellis, ) and supported by many others (for e.g. see McGrath and Lilley, ; Liu et al, ; Ortuno et al, ; Wang et al, ). All of this activity has led to soul‐searching within the research community, prompting a critical re‐appraisal of the processes of implementation and publication of preclinical research.…”

GpTx‐1 and [Ala5, Phe6, Leu26, Arg28]GpTx‐1, two peptide NaV1.7 inhibitors: analgesic and tolerance properties at the spinal level

“…Recently, a monoclonal antibody SVmab1 from a hybridoma has been shown to selectively inhibit Na V 1.7 and suppress inflammatory and neuropathic pain after spinal and systemic administrations (Lee et al, 2014;Bang et al, 2018). However, the recombinant monoclonal antibodies (arSVmab or rSVmab) that target Na V 1.7 had no or weak binding to Na V 1.7 and did not specifically inhibit Na V 1.7 currents in HEK293 cells (Liu et al, 2016;Bang et al, 2018), implying that the sources of monoclonal antibodies is a critical requirement for their efficacy. In addition, to systemically evaluate this proof-of-concept of analgesics targeting Na V 1.7, the antinociceptive profiles of potent Na V 1.7 inhibitors were also investigated in different pain models.…”

Pharmacologic Characterization of AMG8379, a Potent and Selective Small Molecule Sulfonamide Antagonist of the Voltage-Gated Sodium Channel NaV1.7

“…All cell lines were maintained at 37°C in a humidified 95% O 2 /5% CO 2 atmosphere in the presence of the selection antibiotic geneticin 400 mg/ml (Gibco Life Technologies). U-2 OS cells were maintained and transduced at 200 multiplicity of infection with mouse Na V 1.1 or mouse Na V 1.6 BacMam viruses as previously described (Liu et al, 2016). For routine passaging, cells were lifted with 0.05% trypsin-EDTA (Gibco Life Technologies) and grown in T-75 or T-150 flasks (Corning, Corning, NY) to 50-80% confluency to prevent contact inhibition of channel expression.…”