Shark variable new antigen receptor biologics – a novel technology platform for therapeutic drug development

Figures & data

Figure 1. Illustration of VNAR isotypes showing the similarities and differences between different isotypes of VNAR domain.

Figure 2. Relative size of Ig and Ig-like biologics is shown. Molecular models depicting the relative size of four different antibody-based scaffolds currently under clinical development are shown. VNAR and VHH are illustrated in two potential therapeutic formats. In general, the VNAR protein is ∼ 20% smaller than the VHH equivalent. The authors wish to thank Springer Science and Business Media, LLC and Landes Bioscience for their kind permission for inclusion of this modified figure from Barelle et al., 2009 [41].

Table 1. Published VNAR domains isolated by selection against specific targets.

Target	Application	Source	Ref.
VHSV	Anti-viral	Semi-synthetic, Banded houndshark	[63]
HEL	Proof of concept	Semi-synthetic, Banded houndshark	[64]
TNF-α	Endotoxic shock	Immunised, Horn shark	[56]
HSA	Half-life extension	Immunised, Spiny dogfish	[51]
HBeAg of HBV	Anti-viral	Semi-synthetic, Wobbegong	[62]
Ebola virus	Immunodiagnostic	Immunised, Nurse	[50]
Cholera toxin	Biosensor	Naïve, Spiny dogfish	[45]
Staphylococcal enterotoxin B	Sensor	Semi-synthetic, Spiny dogfish	[55]
Ricin	Sensor	Semi-synthetic, Spiny dogfish	[55]
Botulinum toxin	Sensor	Semi-synthetic, Spiny dogfish	[55]
Leptin	Proof of concept	Semi-synthetic, Nurse	[59]
AMA1	Malaria diagnosis	Semi-synthetic, Wobbegong	[48]
Tom70	Diagnosis & therapy	Semi-synthetic, Wobbegong	[47]
HEL	Proof of concept	Immunised, Nurse	[49]
Gingipain K protease	Proof of concept	Naïve/semi-synthetic, Wobbegong	[46,61]

HBV: Hepatitis B virus; HEL: Hen egg lysozyme; HSA: Human serum albumin; VNAR: Variable new antigen receptor; VHSV: Viral haemorrhagic septicaemia virus.

Figure 3. Schematic representation of VNAR formats showing different re-formatting options for VNAR domains.

Figure 4. Allometric scaling of the anti-albumin VNAR domain, E06 is shown. Comparison of the published half-life of albumin in mouse, rat and cynomolgus monkey (⧫) and that of 2V-E06 (▪) from the data published in Müller et al., 2012 [51] is depicted.

Table 2. Next-generation scaffolds currently in the clinic.

Drug	Scaffold	Target/indication	Structure/origin	Commercial developer	Clinical trial phase	Year last verified
Kalbitor (Escallantide)	Kunitz domain	Hereditary angiooedema	Human protease inhibitor LACI-D1	Dyax	FDA approved drug	–
DX-890 (Depelestat, EPI-hNE4)	Kunitz domain	Acute respiratory distress syndrome	Human protease inhibitor ITI-D2	Debiopharm S.A./Dyax	Phase II	2008
ABY-025	Affibody	Imaging Her2 expression in breast cancer	Bacterial protein A	Affibody	Phase II	2013
ALX-0081 (Caplacizumab)	Nanobody	von Willebrand’s factor/cardiovascular	Camelid domain	Ablynx	Phase II	2014
ATN-103 (Ozoralizumab)	Nanobody	TNF-α and HSA/RA	Camelid domain	Ablynx	Phase II	2013
CT-322 (Angiocept)	Adnectin	VEGFR2/NHL/glioblastoma/CRC	FN3 domain of fibronectin	Adnexus/Bristol-Myers Squibb	Phase I/II	2009/10
ALX-0061	Nanobody	IL6R/autoimmune	Camelid domain	Ablynx/Abbvie	Phase I/II	2012
MP0112	DARPin	VEGF-A/ophthalmology	Ankyrin repeats domain	Molecular Partners	Phase I/IIa	2011
Angiocal (PRS-050)	Anticalin	VEGF/cancer	Lipocalins	Pieris	Phase I	2011
ALX-0761	Nanobody	Anti-inflammatory	Camelid domain	Ablynx/Merck Serono	Phase I	2014
ALX-0141	Nanobody	RANKL/musculoskeletal	Camelid domain	Ablynx	Phase I	2011
ALX-0171	Nanobody	RSVF-protein/respiratory disease	Camelid domain	Ablynx	Phase I	2012
GSK1995057	dAb	TNFR1/lung Injury	Human single-domain antibody	GSK	Phase I	2014
GSK2374697	dAb	Anti-HSA dAb-GLP1/diabetes	Human single-domain antibody	GSK	Phase I	2013
BI 1034020	Nanobody	Not disclosed/Alzheimer’s disease	Camelid domain	Boehringer Ingelheim	Phase I	2014

Ig and non-Ig based scaffolds in the clinic at the date this manuscript was submitted. Information was collated from references [105-107].

CRC: Colorectal cancer; GSK: GlaxoSmithKline; HSA: Human serum albumin; NHL: Non-Hodgkin lymphoma; RANKL: Receptor activator of nuclear factor kappa-B ligand; RSVF-protein: Respiratory syncytial virus fusion-protein.

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