. 2020 Jun 4;11:793. doi: 10.3389/fphar.2020.00793

Table 3.

Small molecule inhibitors and biologics used against P2X7.

Molecule	Format	pEC50/pIC50 (method used)	Binding site/other targets	Development stage	Disease settings	References
Nonselective inhibitors
Suramin	Small molecule	> 300 μM (change in current)	Orthosteric site; Binds to multiple other targets including several P2 receptor subtypes, several growth factors, human immunodeficiency virus (HIV) reverse transcriptase, vasoactive intestinal peptide receptors and G protein–coupled receptors.	In the clinic	Used as antiparasitic agent against trypanosomes infection. Tested in the clinic for the treatment of autism and hand foot and mouth disease. Tested as combination with chemotherapy in multiple solid and blood born tumors.	(Middaugh et al., 1992; Surprenant et al., 1996; Jacobson et al., 2002)
NF279 (Suramin analog)	Small molecule	20 µM (Ca²⁺ influx at 3min) 891 nM (Yo-Pro uptake)	Orthosteric site High affinity to P2X₁	Preclinical	N/A	(Donnelly-Roberts et al., 2009a)
MRS2159	Small molecule	1.7 µM (Ca²⁺ influx at 3min) 288 nM (Yo-Pro uptake)	High affinity to P2X₁	Preclinical	N/A	(Donnelly-Roberts et al., 2009a)
2_,3_-dialdehyde ATP (oxidized ATP)	Small molecule closely related to ATP	100–300 μM (change in current)	Orthosteric site	Preclinical	N/A	(Surprenant et al., 1996; Michel et al., 2000; Hibell et al., 2001)
pyridoxalphosphate-6-azophenyl-2’,4’-disulfonic acid (PPADS)	Small molecule	3.2 µM (Ca²⁺ influx at 3min) 1.2 µM (Yo-Pro uptake)	Orthosteric site	Preclinical	N/A	(Donnelly-Roberts et al., 2009a; Huo et al., 2018)
pyridoxal-5′-phosphate-6-(2′-naphthylazo-6′-nitro-4′,8′-disulphonate) (PPNDS)	Small molecule	407 nM (Ca²⁺ influx at 3min) 200 nM (Yo-Pro uptake)	Orthosteric site	Preclinical	N/A	(Donnelly-Roberts et al., 2009a)
KN-62	Small molecule	10 µM (Ca²⁺ influx at 3min) 214 nM (Yo-Pro uptake)	Inter-subunit allosteric pocket and central cavity involving D92, F103, T90, and V312 in human P2X7. High concentrations (≥1 μM) also block Ca2⁺/calmodulin-dependent protein kinase II.	Preclinical	N/A	(Donnelly-Roberts et al., 2009a; Bin Dayel et al., 2019)
Brilliant Blue G (BBG)	Small molecule	< 100 µM (Ca²⁺ influx at 3min) 1.9 µM (Yo-Pro uptake)	Inter-subunit allosteric pocket and central cavity involving D92, F103, and V312 residues. Also blocks voltage-gated sodium channels.	Preclinical	N/A	(Donnelly-Roberts et al., 2009a; Bin Dayel et al., 2019)
Selective inhibitors
A438079	Small molecule	123 nM (Ca²⁺ influx at 3min) 933 nM (Yo-Pro uptake)	Inter-subunit allosteric pocket involving F88, D92, T94, F95, and F103 residues.	Preclinical	N/A	(Nelson et al., 2006; Donnelly-Roberts et al., 2009a; Allsopp et al., 2018)
A740003	Small molecule	44 nM (Ca²⁺ influx at 3min) 93 nM (Yo-Pro uptake)	Inter-subunit allosteric pocket involving F88, D92, T94, F95 and F103, M105 and V312 residues.	Preclinical	N/A	(Honore et al., 2006; Donnelly-Roberts et al., 2009b; Karasawa and Kawate, 2016; Allsopp et al., 2018)
A804598	Small molecule	11 nM (Ca²⁺ influx)	Inter-subunit allosteric pocket involving F88, F95, F103, M105, and F108 residues.	Preclinical	N/A	(Donnelly-Roberts et al., 2009b; Karasawa and Kawate, 2016)
A839977	Small molecule	20–150 nM (Ca²⁺ influx and Yo-Pro uptake)	Not known	Preclinical	N/A	(Honore et al., 2009)
AZ10606120	Small molecule	10 - 200 nM (Ethudium uptake and Ca²⁺ influx)	Inter-subunit allosteric pocket involving residues 73 to 79, T90, T94, F103, and V312 residues.	Preclinical	N/A	(Michel and Fonfria, 2007; Karasawa and Kawate, 2016; Allsopp et al., 2017)
AZ11645373	Small molecule	10–20 nM (change in current and Yo-Pro uptake)	Inter-subunit allosteric pocket involving L83, S86, F88, D92, T94, F95, P96, F108, I310, and V312 residues.	Preclinical	N/A	(Stokes et al., 2006; Caseley et al., 2015; Bin Dayel et al., 2019)
AZD9056	Small molecule	12 nM (IL-1β secretion)	Not known	Evaluated in a Phase 2b against rheumatoid arthritis. Clinical trial number: NCT00520572	Rheumatoid arthritis	(Keystone et al., 2012; McInnes et al., 2014)
GSK1482160	Small molecule	Kd=5.09 ± 0.98 nmol/l, Ki=2.63 ± 0.6 nmol/l ([11C]GSK1482160 binding to HEK293-hP2X7 live cells)	noncompetitive, negative allosteric modulators	Phase 1: First Time in Human Study Evaluating the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics and the Effect of Food of Single Assending Doses of GSK1482160. Clinical trial number: NCT00849134	Pain from inflammatory disease such as arthritis	(Di Virgilio et al., 2017; Han et al., 2017)
GW791343	Small molecule (positive modulator)	Negative allosteric modulator of human P2X7 but positive allosteric modulator of rat P2X7 at high concentrations.	Inter-subunit allosteric pocket involving F103 and V312 residues.	Preclinical	N/A	(Michel et al., 2008a; Karasawa and Kawate, 2016)
CE-224535 (Pfizer)	Small molecule	4 nM (Yo-Pro uptake) 1 nM (IL-1β secretion)	noncompetitive, negative allosteric modulators	Phase 2a: Efficacy and safety of CE-224,535, an antagonist of P2X7 receptor, in treatment of patients with rheumatoid arthritis inadequately controlled by methotrexate. Clinical trial number: NCT00628095;	Rheumatoid arthritis	(Duplantier et al., 2011; Di Virgilio et al., 2017)
EVT-401 (Evotec)	Small molecule	Not known	Not known	Phase 1 in healthy volunteers to investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of EVT-401.	Inflammatory conditions such as Rheumatoid Arthritis	M.G. Kelly, J. Kincaid, Bicycloheteroaryl compounds as P2X7 modulators and uses thereof, US 7297700, 2007. Evotec Announces the Successful Completion of the First Phase 1 Study with EVT 401: https://www.evotec.com/en/invest/news–announcements/press-releases/p/evotec-announces-the-successful-completion-of-the-first-phase-i-study-with-evt-401-an-oral-p2x7-receptor-antagonist—very-good-safety-profile-and-confirmed-on-target-activity-4447
JNJ47965567	Small molecule	5 nM (Ca²⁺ influx)	Inter-subunit allosteric pocket involving F88, F103, M105, F108 and V312 residues.	Preclinical	N/A	(Bhattacharya et al., 2013; Karasawa and Kawate, 2016)
JNJ42253432	Small molecule	20nM (Ca²⁺ influx)	Not known	Preclinical	N/A	(Lord et al., 2014)
JNJ54232334	Small molecule	0.3 nM against human P2X7, 32 nM against rat P2X7 (Ca²⁺ influx)	Not known	Preclinical	N/A	(Lord et al., 2015)
JNJ54140515	Small molecule	79 nM against rat P2X7 (Ca²⁺ influx)	Not known	Preclinical	N/A	(Lord et al., 2015)
JNJ54166060	Small molecule	4 nM (Ca²⁺ influx)	Not known Inhibits CYP3A (IC50 = 2 μM)	Preclinical	N/A	(Swanson et al., 2016)
Biologics
L4	mAb	5nM (change in current)	Not known	Preclinical	N/A	(Buell et al., 1998b)
Hano43	Rat mAb	N/A	Not known	N/A	N/A	(Adriouch et al., 2008)
Hano44	Rat mAb	N/A	Paratope includes R151 in finger-like structure cysteine-rich region	N/A	N/A	(Adriouch et al., 2008)
K1G	Rabbit polyclonal Ab.	N/A	Paratope includes R151 in finger-like structure cysteine-rich region	N/A	N/A	(Adriouch et al., 2008)
1F11	Rat mAb	N/A	Not known	N/A	N/A	(Kurashima et al., 2012)
13A7 nanobody	Bivalent nanobody-Fc	0.5 nM (inhibit CD62L shedding in mouse cell line)	Bind finger-like structure cysteine-rich region (same region as Hano44) mouse P2X7. No binding to human P2X7	N/A	N/A	(Danquah et al., 2016)
14D5 nanobody (enhancer)	Bivalent nanobody-Fc	0.1 nM (enhanced CD62L shedding in mouse cell line)	Bind finger-like structure cysteine-rich region (same region as Hano44) mouse P2X7. No binding to human P2X7	N/A	N/A	(Danquah et al., 2016)
Dano1-Fc	Bivalent nanobody-Fc	0.2 nM (Ca²⁺ influx and DAPI uptake)	Not known	Preclinical	N/A	(Danquah et al., 2016)
BIL010t	Polyclonal Anti-nfP2X7 ointment	N/A	E200 peptide in P2X7 extracellular domain	Investigation of the Safety and Tolerability of BSCT (Anti-nf-P2X7) 10% Ointment (Completed, has results) Clinical trial number: NCT02587819	Basal Cell carcinoma (BCC)	(Gilbert et al., 2017)
BIL06v	Vaccine	N/A	E200 peptide in P2X7 extracellular domain	A Phase 1 Study to Evaluate the Safety, Tolerability, Immunogenicity and Antitumor Activity of BIL06v/Alhydrogel in Patients with Advanced Solid Tumors. (Active, not recruiting) Clinical trial number: ACTRN12618000838213	Solid Tumors