ETX0282, a Novel Oral Agent Against Multidrug-Resistant Enterobacteriaceae Thomas Durand-Réville 02 June 2017 - ASM Microbe 2017 (Session #113)
Disclosures Thomas Durand-Réville: Full-time Employee; Self; Entasis Therapeutics. 2
The cefpodoxime proxetil/etx0282 combination addresses a significant unmet medical need Unmet need: Lack of effective, oral agents for treatment of MDR UTIs There is an unmet need for new treatments due to increasing incidence of UTI due to MDR Gram-negative bacteria not covered by available oral therapies (fluoroquinolones, TMP-SMX) Uncomplicated UTI patients (typically treated in the community) require hospitalization for I.V. treatment when infected with MDR strains 95% of community UTIs are caused by Enterobacteriaceae, ~75% by E. coli Our vision: An oral BL/BLI combination to treat MDR Enterobacteriaceae Oral and BID administration providing well tolerated and convenient dosing Outpatient setting: First-line treatment for UTI and avoid Prodrug Active Agent hospitalization Hospital setting: Oral step-down resulting in a reduced length of hospitalization β-lactamase inhibitor (BLI) β-lactam (BL) ETX0282 Cefpodoxime proxetil (CPDP) ETX1317 Cefpodoxime (CPD) * Foxman, B. Urinary Tract Infection Syndromes: Occurrence, Recurrence, Bacteriology, Risk Factors, and Disease Burden. Infect. Dis. Clin. N. Am. 2014, (28): 1-13 3
MDR Gram-negative uropathogens are rapidly emerging and spreading globally 1.8% 2.0% 7.5% 3.0% 13.3% 72.4% E. E. coli Klebsiella spp. Proteus spp. P. P. aeruginosa Enterobacter spp. Other % Resistance (HAIs, 2011-2014, USA) CDDEP Resistance Map, CDC Antibiotic Resistance Atlas ESBL CRE FQ-R MDR E. coli 13.4 0.7 33.0 7.5 Klebsiella spp. 20.0 8.7 ND 14.2 Enterobacter spp. 28.5 4.1 ND 7.9 N = 216,645 global UTI isolates (2009-2014) A new orally-bioavailable, broad spectrum BLI is needed * Zowawi, H.M., et al. The emerging threat of multidrug-resistant Gram-negative bacteria in urology. Nat. Rev. Urol. 2015, 12(12): 570-584. 4
Diazabicyclooctenones: the next generation β-lactamase inhibitors Optimize β-lactamase inhibition and MIC by exploring substitutions around core and activating groups Optimize ADME properties and oral bioavailability ETX2514 (IV) Class A, C and D BLI Restores β-lactam activity in A. baumannii, P. aeruginosa, Enterobacteriaceae ETX1317 Class A, C and D BLI Restores β-lactam activity in Gram-negative bacteria In vivo activation (liver) ETX0282 (PO) Oral prodrug 5
ETX1317 displays broad spectrum inhibition of serine β-lactamases and E. coli PBP2 E. coli W3110 (ΔampC) β-lactamase inhibition (IC 50, µm) total cell membrane extract (competition with Bocillin FL) ETX1317 AZT MEC PEN Compound Class A Class C Class D CTX-M-15 SHV-5 KPC-2 TEM-1 AmpC P. aeruginosa P99 OXA-24/40 OXA-48 1a 1b 0 10µM 100µM 100µM 100µM avibactam 0.009 0.23 0.18 6.9 0.52 0.12 32 0.88 ETX2514 0.001 0.004 0.002 0.001 0.006 0.001 0.28 0.005 2 3 ETX1317 0.002 0.036 0.043 0.003 0.16 0.024 0.54 0.077 4 ETX1317 is a broad spectrum serine β-lactamase inhibitor ETX1317 inhibits E. coli PBP2 which results in intrinsic antibacterial activity AZT: aztreonam, MEC: mecillinam, PEN: penicillin G 6
ETX1317 restores activity of multiple β-lactams against K. pneumoniae strain MIC (mg/l) for single agents and combinations K. pneumoniae SHV-18, OXA-2, OKP-6 (ATCC 700603) ETX1317 Cefpodoxime Cefuroxime Tigemonam Faropenem Cefixime Loracarbef 32 16 0.25 32 4 32 0.5 8 0.5 8 0.06 32 0.125 *ETX1317 tested at a fixed concentration of 4 mg/l in combinations + ETX1317* + ETX1317* + ETX1317* + ETX1317* + ETX1317* + ETX1317* A series of β-lactams from different chemical subclasses were tested in combination with ETX1317 Cefpodoxime selected as partner based on microbiological data, PK profile and dosage 7
CPD/ETX1317 has excellent microbiological profile against Enterobacteriaceae Session 198 - AAID11, New Antimicrobial Agents: New Beta-lactams and New Betalactamase Inhibitors SATURDAY Poster 279, S. McLeod, et al. Activity vs. ~900 global, diverse, ESBL-enriched Enterobacteriaceae isolates (from UTI in 2013-2015) Compound MIC 50 (mg/l) MIC 90 (mg/l) CLSI Breakpoint (mg/l) CPD >32 >32 2 ETX1317 2 32 ND CPD/ETX1317 * 0.015 0.03 ND LVX 16 32 2 TZP* 16 >32 16 *BLIs tested at a fixed concentration of 4 mg/l in combinations LVX: levofloxacin; TZP: piperacillin/tazobactam 8
Consistent CPD/ETX1317 activity across the different Enterobacteriaceae pathogens and different serine β-lactamases Session 198 - AAID11, New Antimicrobial Agents: New Beta-lactams and New Betalactamase Inhibitors SATURDAY Poster 279, S. McLeod, et al. Activity vs. ~900 global, diverse, ESBL-enriched Enterobacteriaceae isolates (from UTI in 2013-2015) Bacterial species All E. coli K. pneumoniae K. oxytoca Citrobacter spp. E. aerogenes E. cloaceae Proteus spp. N 911 301 253 53 120 40 51 93 MIC 50 (mg/l) 0.015 0.015 0.015 0.015 0.06 0.015 0.015 0.015 MIC 90 (mg/l) 0.03 0.015 0.03 0.125 0.06 0.06 0.25 0.12 β-lactamase class All Not classified None or OSBL ESBL KPC OXA-48-like wildtype AmpC De-repressed AmpC Plasmid AmpC MBL N 911 7 15 621 18 30 98 69 25 28 MIC 50 (mg/l) 0.015 0.015 0.015 0.015 0.015 0.015 0.015 0.015 0.015 0.015 MIC 90 (mg/l) 0.03 0.03 0.03 0.03 0.03 0.06 0.03 0.06 0.06 >32 9
Concentration, µm Liver S9 incubations demonstrate consistent conversion of ETX0282 to ETX1317 in vitro Session 198 - AAID11, New Antimicrobial Agents: New Beta-lactams and New Betalactamase Inhibitors SATURDAY Poster 278, J. O'Donnell, et al. in vitro S9 stability (T 1/2 in minutes, 37 o C) Buffer ph 7.4 Rat Intestinal (RI) S9 Rat Liver (SL) S9 Dog Intestinal (DI) S9 Dog Liver (DL) S9 Human Intestinal (HI) S9 Human Liver (HL) S9 ETX0282 186 240 32 186 30 163 39 ETX1317 formation HL DL RL HI DI RI Buffer ETX0282 is predominantly stable in the presence of buffer and intestinal S9 More rapid conversion of ETX0282 into ETX1317 by rat, dog and human liver S9 enzymes Time, min 10
Concentration, ng/ml ETX0282 delivers high bioavailability in preclinical species Session 198 - AAID11, New Antimicrobial Agents: New Beta-lactams and New Betalactamase Inhibitors SATURDAY Poster 278, J. O'Donnell, et al. Species (n=3) ETX0282 PO Pharmacokinetics (ETX1317 concentrations) Dose Eq. (mg/kg) C max (µg/ml) AUC (µg.h/ml) T 1/2 (hr) Oral Bioavailability F% Rat 10 5.8 ± 0.2 7.0 ± 0.6 1.1 ± 0.3 98 Dog 1 1.27 ± 0.02 2.7 ± 0.2 1.3 ± 0.6 97 100000 10000 1000 100 10 Rat 100000 10000 1000 100 10 Dog Excellent bioavailability achieved in both rats and dogs PK profile similar to cefpodoxime proxetil 1 0 5 10 Time, hr 1 0 5 10 15 Time, hr 11
Log(CFU/g) CPDP/ETX0282 combination is orally efficacious against MDR E. coli in murine studies Session 198 - AAID11, New Antimicrobial Agents: New Beta-lactams and New Betalactamase Inhibitors SATURDAY Poster 278, J. O'Donnell, et al. Neutropenic mouse thigh model (PO) 6.63 10.86 10.24 9.56 5.77 5.59 5.52 5.17 Stasis MDR E. coli (AmpC, CTX-M-14): Levofloxacin resistant (MIC > 4 mg/l) Cefpodoxime resistant (MIC > 64 mg/l) Meropenem (MIC = 0.03 mg/l) ETX1317 (MIC = 0.5 mg/l) Cefpodoxime/ETX1317 (MIC 0.03 mg/l) ETX0282 + CPDP 50 mg/kg In vivo oral efficacy also observed for CPDP/ETX0282 combination against 4 other MDR Enterobacteriaceae isolates (including K. pneumoniae CRE strain where ETX1317 MIC > 32 mg/l) 12
CPDP/ETX0282 represents the first, new oral BL/BLI combination for the treatment of MDR Gram-negative uropathogens in decades ETX1317 potently restores the activity of CPD against ESBL-producing, carbapenemresistant, fluoroquinolone-resistant and colistin-resistant Enterobacteriaceae The prodrug ETX0282 demonstrates high bioavailability of ETX1317 following oral administration in preclinical species with similar ADME attributes as CPDP The promising activity of CPDP/ETX0282 in vitro and in vivo warrants further preclinical evaluation of the combination 13
Acknowledgements Pharmaron IHMA, Inc. NeoSome Life Sciences, LLC 14