fighting coccidioidomycosis prevention: vaccine fighting coccidioidomycosis prevention: vaccine...
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Fighting Coccidioidomycosis Fighting Coccidioidomycosis Prevention: VaccinePrevention: Vaccine
Treatment: Nikkomycin ZTreatment: Nikkomycin Z
Valley Fever Vaccine ProjectValley Fever Vaccine Project
A brief history…
Valley Fever Vaccine Project
• Epidemic of early 90’s spawned renewed interest in a vaccine
• Bakersfield locals created a group to organize project & secure financing
• With funds in hand, “exploratory phase” was initiated and research begun in ‘98
• VFVP formally began in 2000 with 5 yrs of funding for 5 research institutions
The Valley Fever Vaccine Project
Valley Fever Vaccine Project
University of Arizona– John Galgiani– Lisa Shubitz
UT San Antonio– Rebecca Cox– Mitch Magee (ASU)
Med. College of Ohio– Garry Cole– Chiung Yu
UC Davis– Demo Pappagianis– Susan Johnson
UC San Diego– Theo Kirkland
UC San Francisco– George Rutherford– Richard Hector
CSU Bakersfield
Supporting Organizations
Valley Fever Vaccine Project
• California HealthCare Foundation• State of California (Ashburn, Parra)• CDC (Thomas)• Rotary’s Valley Fever Project of the
Americas, Valley Fever Research Foundation, & many local contributors
• Kern County• NIH for sequencing of C. posadasii
Major AccomplishmentsMajor Accomplishments
• • Dozens of antigens identified, cloned Dozens of antigens identified, cloned
• • Attenuated mutant strains createdAttenuated mutant strains created
• • Genome of Genome of C. posadasiiC. posadasii sequenced sequenced
• • Expression systems & manufacturingExpression systems & manufacturing
evaluated for fusion proteinevaluated for fusion protein
• • Primate trial to evaluate fusion protein Primate trial to evaluate fusion protein
• • 10 patents filed; 4 patents issued10 patents filed; 4 patents issued
• • Canine incidence/prevalence trialCanine incidence/prevalence trial
• • Coccidioidin Phase 1 & 2 trialsCoccidioidin Phase 1 & 2 trialsValley Fever Vaccine Project
Possible Value Of A Vaccine
• Prevent ~3,500 disseminated cases/yr• Prevent ~10-30,000 primary illnesses/yr
– Public Health risk• Residents of California, Arizona, Nevada, Utah• Tourists to the Southwest• Relocated employees• Immunocompromised individuals
– Military risk• Desert training bases within Southwest• Biodefense
Valley Fever Vaccine Project
Cost-effectiveness of a vaccine
Valley Fever Vaccine Project
0
50,000
100,000
150,000
200,000
250,000
300,000
20% 30% 40% 50% 60% 70% 80% 90%
Vaccine Efficacy
Co
st-E
ffec
tive
nes
s R
atio
($/
QA
LY) Infants: vaccinate vs. no vaccination
Resident 15 yo: vaccinate vs. no vaccination
Immigrant 15 yo: vaccinate vs. no vaccination
Resident 35 yo: screen/vaccinate vs. no vaccination
Immigrant 35 yo: vaccinate vs. no vaccination
Base case
* Barnato et al. Cost-effectiveness of a potential vaccine for coccidioidomycosis. Emerg Infect Dis 2001; 7:797-806.
Vaccine CandidatesVaccine Candidates
• • Recombinant proteins:Recombinant proteins:Ag2/PRA106+CsaAg2/PRA106+CsaELI1ELI1
• • Live, attenuated mutants:Live, attenuated mutants: ∆∆cts2/∆ard1/ ∆cts3 straincts2/∆ard1/ ∆cts3 strain ∆ ∆chs5 strainchs5 strain
Valley Fever Vaccine Project
ValleyFever
Center forExcellence
Ag2/PRA106-CSA Chimeric Ag
Flag Ag2/PRA1-106 CSA
EcoRIGlu-Phe
BamHIGly-Ser
Patent issued 2006
Days Survived
0 10 20 30 40 50 60
Pro
port
ion
of M
ice
Sur
vivi
ng
0.0
0.2
0.4
0.6
0.8
1.0
Mouse Survival Studies with Fusion Protein*Mouse Survival Studies with Fusion Protein*
Adj. only
CSA
Ag2/PRA1-106
Both
*Intranasal infection with 80 arthroconidiaShubitz et al., Vaccine 24:5904, 2006
C57BL/6 mice251 and 218 spores IN, Silveira
Days Survived
0 10 20 30 40 50 60 70
Pro
port
ion
of M
ice
Sur
vivi
ng
0.0
0.2
0.4
0.6
0.8
1.0
PRA106+CS
106/CS Chimera
PRA106
CS
Adjuvant
Gehans Wilcoxon: Both > Ag2/PRA1-106 > CSA > Adjuvant
HigherInoculum
Mouse Survival Study with Higher InoculumMouse Survival Study with Higher Inoculum
Adding ELI-1 to Ag2/PRA+CSAAdding ELI-1 to Ag2/PRA+CSA
Days Postinfection
10 20 30 40 50 60 70 80 90 100
Per
cen
t Su
rviv
al
20
40
60
80
100 CPG/IFAAg2/CSAELI-Ag1Ag2/CSA + ELI-Ag1
P=0.04
Magee et al, 2006
Fusion Vaccine IssuesFusion Vaccine Issues
• Efficacy: may prevent dissemination, but Efficacy: may prevent dissemination, but clearly does not prevent infectionclearly does not prevent infection– Recombinant vaccines have not worked in Recombinant vaccines have not worked in
diseases like TBdiseases like TB– No data on duration of immunityNo data on duration of immunity
• Adjuvants: few CMI-promoting adjuvantsAdjuvants: few CMI-promoting adjuvants– MPL is not available to usMPL is not available to us– Alternatives are few & have safety issuesAlternatives are few & have safety issues
• Manufacturing issuesManufacturing issues– Expression is poor; aggregation is a problemExpression is poor; aggregation is a problem
Valley Fever Vaccine Project
Flagellin as an Adjuvant SubstituteFlagellin as an Adjuvant Substitute
• Flagellin binds to TLR 5 to stimulate DC activation and antigen presentation.
• Flagellin + antigen fusion proteins have been shown in mouse models to stimulate cell-mediated immunity
• This technology is being commercialized by Vaxinnate, Inc.; clinical trials underway
• Flagellin + Ag2/PRA+Csa experiment in progress in Galgiani lab
C. posadasiiC. posadasii ∆cts2/∆ard1/∆cts3 ∆cts2/∆ard1/∆cts3 Attenuated MutantAttenuated Mutant
Valley Fever Vaccine Project
Parental strain: C735 cts2/ard1/cts3
Cu
ltu
res
in C
onve
rse
med
ium
Infe
cted
mu
rin
e lu
ng
tiss
ue
Morphology of cts2/ard1/cts3 triple mutant in vitro vs in vivo
Sterile spherules
cts2/ard1/cts3 cts2/ard1/cts3
Days post-challenge0 5 10 15 20 25 30 35
% S
urv
ival
0
20
40
60
80
100
Neg Ct
cts2ard1cts3FKS
45 55
BALB/c mice80 spores i.n.
65 75
Evaluation of survival of BALB/c mice vaccinated with the live cts2/ard1/cts3
mutant or the FKS vaccine and i.n.-challenged
Data courtesy Garry Cole, MUO
Valley Fever Vaccine Project
Attenuated Mutant:Attenuated Mutant:Why it’s a “no go” for humansWhy it’s a “no go” for humans
Valley Fever Vaccine Project
• • Safety: possibility of reversionSafety: possibility of reversion
• • Restrictions on use in humansRestrictions on use in humans
• • Immunogenicity vs. ReactogenicityImmunogenicity vs. Reactogenicity
• • Manufacture of spore-formerManufacture of spore-former
Nikkomycin Z: Nikkomycin Z: The perfect drug for The perfect drug for
coccidioidomycosis?coccidioidomycosis?
History of Nikkomycin ZHistory of Nikkomycin Z
• 1970s: Evaluated by Bayer as agricultural fungicide
• 1980s: Cured mice with cocci (Hector/Pappagianis)
• 1990s: Clinical Development started by Shaman Pharmaceuticals: Phase Ia conducted
• 2001: Purchased at auction by CSUBF
• 2005: Rights transferred to University of Arizona
• 2006: Nik Z designated as orphan drug
• Oct 2007: Patients enrolled in Phase Ib/II @ UA
Nikkomycins Inhibit Chitin SynthaseNikkomycins Inhibit Chitin Synthase
• UDP-N-acetylglucosamine is a precursor to chitin
• Nikkomycin Z is a competitive inhibitor of chitin synthase
O
OHOH
HH
HH
O
N
NH
O
O
P
O
O-
OP
O
O
O-
O
HN
O
CH3
HO
OH
OHUDP-UDP-NN-Ac-glc-Ac-glc
O
OHOH
HN
N
NH
O
OOO-
O
NH2
CH3
OHN
HO
Nik ZNik Z
ValleyFever
Center forExcellence
Mature Mature C. immitisC. immitis stained with calcofluor white stained with calcofluor white
ValleyFever
Center forExcellence
A. fumigatusA. fumigatus stained with calcofluor white stained with calcofluor white
SUSCEPTIBILITY OF DIVERSE SUSCEPTIBILITY OF DIVERSE FUNGI TO NIKKOMYCIN ZFUNGI TO NIKKOMYCIN Z
OrganismOrganism
Coccidioides immitisCoccidioides immitisBlastomyces dermatitidisBlastomyces dermatitidisHistoplasma capsulatumHistoplasma capsulatum
Sporothrix schenkiiSporothrix schenkiiCandida albicansCandida albicans
Candida parapsilosisCandida parapsilosisCandida rugosaCandida rugosa
Candida tropicalisCandida tropicalisCandida kruseiCandida krusei
Candida lusitaniaeCandida lusitaniaeCryptococcus neoformansCryptococcus neoformans
Torulopsis glabrataTorulopsis glabrataAspergillus flavusAspergillus flavus
Aspergillus fumigatusAspergillus fumigatus
No.No.StrainsStrains
11101099
10105959101011775511
303021212222
Geometric MeanGeometric MeanMICMIC
100100 ( (g/ml)g/ml)
0.06250.06250.250.252.472.47
0.4070.4075.565.564.294.297.87.8
>500>500445445
>500>500144144
>500>500500500500500
Control vs. NZ-treatedControl vs. NZ-treated
SURVIVAL EXPERIMENT WITH SURVIVAL EXPERIMENT WITH COCCIDIOIDOMYCOSISCOCCIDIOIDOMYCOSIS
00
1100
2200
3300
4400
5500
6600
7700
8800
9900
110000
00 22 44 66 88 1100 1122 1144 1166 1188 2200 2222 2244 2266 2288
% S
UR
VIV
AL
--------THERAPY-----------------THERAPY---------
DAYS POST-INFECTIONDAYS POST-INFECTION
Nik Z Nik Z 50 mg/kg50 mg/kg
Nik ZNik Z20 mg/kg20 mg/kg
ControlControl
Nik Z Nik Z 5 mg/kg5 mg/kg
ANIMALS ANIMALS INFECTED withINFECTED with 9 x 109 x 1033 CFU I.N. CFU I.N.
ANIMALS ANIMALS INFECTED withINFECTED with 9 x 109 x 1033 CFU I.N. CFU I.N.
Hector et al. AAC, 1990
SHORT-TERM ORGAN LOADS (Lung) WITH COCCIDIOIDES IMMITIS
GROUPGROUP DOSEDOSE MEAN LOGMEAN LOG(mg/kg)(mg/kg) CFU ± S. E. M.CFU ± S. E. M.
CONTROLCONTROL
FLUCONAZOLEFLUCONAZOLE
““
NIK ZNIK Z
--
2.52.5
2525
5050
6.35 ± .066.35 ± .06
3.77 ± 1.123.77 ± 1.12
2.62 ± .822.62 ± .82
0.37 ± .37 0.37 ± .37
• Enrollment: 60 seropositive subjects with Enrollment: 60 seropositive subjects with uncomplicated cocci pneumoniauncomplicated cocci pneumonia
• Rising multiple doses: 100-2250 mg x 14 days Rising multiple doses: 100-2250 mg x 14 days vs. placebovs. placebo
• End of treatment response based on signs & End of treatment response based on signs & symptoms vs. pre-dosesymptoms vs. pre-dose
– Subjective questionnaire for 12 symptomsSubjective questionnaire for 12 symptoms
– Lab: ESR, C-reactive protein, procalcitonin, lung Lab: ESR, C-reactive protein, procalcitonin, lung lesion volume (CT)lesion volume (CT)
UA: Phase Ib/II DesignUA: Phase Ib/II Design
Valley Fever Vaccine ProjectValley Fever Vaccine Project