1. Geert Jan Groeneveld, MD, PhD
The Reef Biotech Ltd case – What really happened and take home messages
Geert Jan Groeneveld, MD, PhD
June 7, 2017
Castle Oud Poelgeest, Oegstgeest
The Netherlands

2. Reef Biotech Ltd. was Xenome Ltd.
RB3285 was actually Xen-2174

3. The rise and fall of a biotech company
Both CEO & head drug development
leave Xenome
Two board members (investors)
leave Xenome
EU patent
US patent
Japan patent
End of Xenome Ltd
$ 1.25 m
investment
$ 1.25 m
investment
$ 10 m
equity finance
$ 6.25 m
new funding
$ 3.75 m new share issue
$ 2.5 m
new funding
$ 6 m
new funding
$ 5 m
new funding
Xenome Ltd
is founded
Xenome is founded
Ziconotide lincensed by FDA for US market
Ziconotide lincensed by EMA/EC for EU market
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2010
2011
2012
2013
2009
Pre-clinical studies
on Xen2174
(in vitro, rat and dog)
Additional
dog studies
(required by FDA)
Phase I trial
HV, IT admin.
pain tests & EEG
Phase I/II trial
oncology patients
IT admin.
1st Phase II trial
bunion surgery
IT admin.
2nd Phase II trial
bunion surgery
IT admin. (n.d.)
Phase I trial HV
IV admin.
The rise and fall of a biotech company
Phase I HV
IT admin. / EEG
FDA/CDER
IND approval
for Xen2174
FDA puts 1st Phase II
on hold

4. hypothetical concentration in CSF in case of immediate and homogeneous distribution of intrathecally injected dose
Cmax (mg/L)
AUC (ng*h/ml)
CNS effects
in CSF
in plasma
In vitro
rat
dog
human
(0,26 mg/L)
EC50h 183nM
0,6 μg/kg i.t.
EC50 human NET in vitro
(0,30 mg/L)
EC50r 214nM
0.08 μg i.t.
EC50 rat NET in vitro
(2.4 mg/L)
0.64 μg i.t.
ED50 for anti-nociception in Brennan model for post-operative pain
(3.1 mg/L)
0.84 μg i.t.
ED50 for anti-allodynia effect in CCI model for tactile allodynia
(3,2 mg/L)
IC50r 2,57μM
0.86 μg i.t.
IC50 rat NET in vitro
(3,6 mg/L)
IC50h 2,26μM
7,7 μg/kg i.t.
IC50 human NET in vitro
(4.7 mg/L)
0.068 mg/L
93.6
10 μg/kg i.t.
PK-study
26 mg/L
0.097 mg/L
1 mg/animal i.t.
(23.3 mg/L)
0.345 mg/L
516.2
50 μg/kg i.t.
(33.7 mg/L)
9.1 μg i.t.
anti-allodynia effect plateaued at this level in Chung model for peripheral neuropathic pain
(37.0 mg/L)
10 μg i.t.
plateau of post-operative nociception in Brennan model
(46.7 mg/L)
0.597 mg/L
855.8
100 μg/kg i.t.
(76.9 mg/L)
mg/kg i.t.
no adverse effects observed (NOAEL for single i.t. administration)
(84.4 mg/L)
22.8 μg i.t.
ED50 for combined anti-nociception and anti-allodynia in CCI model
(93.4 mg/L)
1.58 mg/L
2152
200 μg/kg i.t.
(133 mg/L)
20 mg/subject
safe and well-tolerated in at least 3 subjects
(156.3 mg/L)
42.2 μg i.t.
anti-allodynia observed for up to 48 hours in CCI model
(154 mg/L)
2 mg/animal i.t.
seizures in 1 dog (in cohort of n=10)
257 mg/L
0.13 mg/L
(200 mg/L)
30 mg/subject
safe and well-tolerated in at least 4 subjects
(308 mg/L)
4 mg/animal i.t.
seizures in 2 dogs (in cohort of n=10)
514 mg/L
0.243 mg/L
(333 mg/L)
0.3 mg/kg i.t.
(267 mg/L)
40 mg/subject
aseptic drug-induced meningitis (1 subject in 6 subjects dosed)
seizure (1 subject in 6 subjects dosed)
(370 mg/L)
100 μg/day i.t.
no effects on rotarod performance
(385 mg/L)
5 mg/animal/day i.t. for 14 days
seizure in 1 dog (in cohort of n=3)
(615 mg/L)
dose up to 8 mg/animal i.t.
no seizures and no effects on EEG in Beagle dogs
1445 mg/L
0.797 mg/L
8 mg/animal i.t.
(741 mg/L)
0.2 mg/animal/day
"significant mortality"
(769 mg/L)
10 mg/animal/day i.t. for 14 days
(1154 mg/L)
15 mg/animal/day i.t.
no effects on Functional Observational Battery
(1481 mg/L)
400 μg/day i.t.
seizures
(2230 mg/L)
29 mg/animal i.t.
upper motor neuronal deficits and seizures
(3076 mg/L)
40 mg/animal i.t.
death

5. Study design
Randomized, double-blind, placebo-controlled, serial-cohort, single ascending dose of Xen2174 or placebo PK/PD study, administered intrathecally in HV
Pharmacokinetics:
CSF PK up to 32 hours (via intrathecal catheter)
Plasma PK
Pharmacodynamics:
Pain threshold and tolerance levels for each of a battery of nociceptive tests
Safety
24h EEG
Cohort
Xen2174 dose
Placebo 1
0.50 mg (n=8)
n=3 2
1.00 mg (n=8) 3
2.50 mg (n=8)
n=2

6. PainCart; multidimensional pain test battery
Electrical Stimulation
Olofsen and Dahan, 2005 Arendt-Nielsen et al., 2007
Pneumatic Pressure
Polianskis, 2001
Cold Pressor
Eckhardt et al and Jones et al. 1988
Conditioned Pain Modulation
DNIC Electrical pre/post cold pressor
Thermal stimulation
Medoc TSA-II 30Thermode CHEPS
UVB model
Capsaicin
(chemical allodynia model)

7. PD results: electrical stair PTT

8. PD results: cold pressor PTT

9. PD results: pressure PTT

10. PD results: Electrical burst PTT

11. PK results
CSF concentration–time profiles of Xen 2174

12. Safety issues
human equivalent doses of Xen-2174

13. CSF concentrations humans vs dogs

14. Out-of-pocket costs Xenome Ltd. 1998-2013
Study phase
Costs
preclinical
$ 2,
Discovery and pharmacology
GLP preclinical
$ 4,
Toxicology and PK
clinical
$ 10, $
Phase I study in HV: plasma PK and safety
Phase I/II study in cancer patients with pain
Phase II study in 200 bunionectomy patients
Phase I study in HV with EEG recording
(no CSF PK!)
Phase I PK/PD study in HV; CSF PK and pain tests
Total
$ 16,

15. Take home messages Fail early to fail cheap
QBCD: which question needs to be answered first?
More (quality) information early on leads to better informed decisions
MTD is not (that) relevant for non-cytotoxic drugs
Allometric scaling leads to estimates that still have to be confirmed