Development of Novel Antibiotic Classes

Product Class Main Segment Status ABT 492 Quinolone Community Ph II DK507k Quinolone Community Ph I Daptomycin Lipopeptide Hospital Reg. Oritavancin Glycopeptide Hospital Ph III Dalbavancin Glycopeptide Hospital Ph III Tigecycline Glycylcycline Hospital Ph III AR 100 Trimethoprime Hospital Ph II BAL 9141 Cephalosporin Hospital Ph II BB-83698 PDF-inhibitor Community Ph I CS-023 Carbapenem Hospital Ph II

Until 2008 very few antibiotics will reach the market !

Harald Labischinski

60 years ago… 1942

Gardner and Chain discover a substance with antibacterial activity, produced by a strain of Proactinomyces (later Streptomyces gardneri), which they name proactinomycin A. Macrolide structure

• Macrolides are lipophilic molecules with a characteristic central lactone ring bearing 12 to 17 atoms, few if any double bonds and no nitrogen athoms (until the advent of the azalides).

• Several amino and/or neutral sugars can bind to the lactone ring. MACROLIDE ANTIBIOTICS

12-membered-ring 14-membered-ring 15-membered-ring 16-membered-ring 17-membered-ring

Methymycin Natural Semi-synthetic Azithromycin Natural Semi-synthetic Lankacidin Neomethymycin compounds derivatives compounds derivatives complex YC-17 Litorin

Erythromycin A to F Roxithromycin Josamycin Rokitamycin Oleandomycin Dirithromycin Kitasamycin Miokamycin Sporeamicin Flurithromycin Spiramycin Clarithromycin Midecamycin • The macrolides narrow the entrance of the tunnel through which the nascent polypeptide chain is extruded from the ribosome. • In all cases, the crystal structures confirm the broad mechanisms of action previously known from indirect evidence. • The structural detail show exactly which chemical groups in the antibiotics interact with which RNA nucleotides. A Ery14, Cbm16, Tyl16, A C A U Nucleotides C Tel14 mG U C C at which G G mG C G C macrolides C C C G Cbm16, A G interact: G G G A C G 16 U A A A Tyl C C A D Domain V U C A A A 16 A Domain II UG G Tyl Cbm16 C C A Cbm16, C Mutations G 16 U conferring Tyl C G G ψ macrolide C G G G Domain V resistance C A U ψ C G G C C A A A A U G C C A G U 14 14 U U G Ery , Tel G C U A A A GG C U G ψ A A U G A C ψ GG A U U A G C G G G C G A U G U A A U C G C C C T mG Cbm16, C G C ψ A A Tyl16 Tel14 Ery14, Cbm16, Tyl16, Domain II Tel14 Macrolides are inactive against:

• Gram-negative rods (e.g. Enterobacteriaceae) because, being hydrophobic and having high molecular weight, they poorly cross the outer membrane The Azalides

• In 1982, ring expansion and the introduction of the secondary amino group resulted in slightly decreased in vitro activity against erythromycin-sensitive S.aureus strains.

• However, these compounds (named Azalides) showed improved MICs against Gram-negative organisms.

• The degree of anti-Gram-negative activity generally correlates positively with the hydrophilicity of the compound. MICs (μg/ml) of macrolide and azalide derivatives

R N S.aureus H.influenzae E.coli

-CH3 0.39 0.78 6.25

-CH2-CH CH2 0.20 0.78 6.25 -CH-C CH 0.20 1.56 25 -CH-C N 0.78 1.56 25

-NH2 0.70 0.78 12.5 erythromycin A 0.10 3.12 100

Guidelines for antimicrobial therapy of pharyngitis (Sanford Guide, 1998)

PRIMARY •Penicillin V po x 10 days REGIMEN: or if compliance unlikely •Benzathine penicillin IM as a single dose

ALTERNATIVE •Oral 2nd gen. cephalosporins x 10 days REGIMENS: or •Erythromycin x 10 days or •Azithromycin / Clarithromcin Guidelines for antimicrobial therapy of streptococcal tonsillopharyngitis, scarlet fever and peritonsillar cellulitis (J. D. Nelson, 1996-97)

•Penicillin V 25-50 mg/kg/day PO div q6-8h x 10 days or •Benzathine penicillin 25,000 u/kg IM as a single dose (max 1.2 milion u)

alternatives:

•Oral cephalosporins •Erythromycin or clindamycin for penicillin-allergic patients (Caution: ~5% of Group A strep resistant) 60 %

1996 1979

1990 2.3 %

Erythromycin-resistant S.pyogenes 1989 in Asia and Oceania 18 % S.pyogenes

In Finland, the frequency of resistance to erythromycin in group A streptococci from blood cultures increased from 4% in 1988 to 24% in 1990.

From January to December 1990, the frequency of resistance in isolates from throat swabs increased from 7% to 20%, and resistance in isolates from pus increased from 11% to 31%.

(Seppälä et al., NEJM 326:292-297, 1992) Nationwide reductions in the use of macrolide antibiotics for outpatient therapy were followed by a steady decrease in the frequency of erythromycin- resistance, from 16.5% in 1992 to 8.6% in 1996.

(Seppälä et al., NEJM 337:441-446, 1997) Erythromycin-resistant S.pyogenes in Monza 55%

37,1%

4,6% 5,1% 1993 1994 1995 1996 no data available

< 5%

5 - 15%

16-25%

> 25%

Incidence of macrolide resistance in S. pyogenes (G. Cornaglia and P. Huovinen, 12th ECCMID, Berlin, 1999) GUIDELINE ON THE PHARMACODYNAMIC SECTION OF THE SPC FOR ANTI-BACTERIAL MEDICINAL PRODUCTS

Susceptibility should be categorized as follows:

* Group A : Resistance not yet described or still uncommon (< 10%) * Group B : Resistance occurs in 10%-50% * Group C : Inherent or frequently occurring resistance (> 50%)

The ‘B’ category implies an intrinsic risk of therapeutic failure when empiric therapy is chosen and no microbiological information is available. The potential benefits must be weighted against the risk of failure. no data available

< 5%

5 - 15%

16-25%

> 25%

Incidence of macrolide resistance in S. pyogenes G. Cornaglia and A. Bryskier, in E. L. Kaplan and J.-C. Péchére (eds.), 2003 no data < 5% 5 - 15% 16-25% > 25% available Incidence of macrolide resistance in S.pyogenes 1999 - 2002 Antimicrobial Resistance (%) among S.pyogenes in Russia (N=470, 2000-2001)

Аntibiotic Central N.-W.* South Ural Siberia Russia Erythromycin 9 10 0 3 25 10

Аzithromycin 9 10 0 3 25 10 Clarithromycin 9 10 0 3 25 10 Clindamycin 0 0 0 6 0 0.4 Levofloxacin 0 0 0 0 0 0 Telithromycin 0 0 0 0 0 0

Kozlov et al., AAC 2002 Outpatient antibiotic sales in 1997 in the E.U.

4 Macrolides - lincos.

2 DDD / 1,000 inhabitants DDD / day inhabitants / 1,000

0 France Portugal Luxembourg Greece Ireland Austria Sweden Netherlands (Cars et al., 2001) S.pyogenes resistance to erythromycin and consumption of macrolides

30 4

3,5 ( man et al., JAC 2001) 25 Čiž

20 2,5 Resistance (SLO) Resistance (ESP) 15 2 Consumption (SLO) Consumption (ESP) 1,5 10

DDD/1000 inhabitants/day DDD/1000 1

5 0,5 (Granizo et al., JAC 2000)

0 0 '94 '95 '96 '97 '98 units x 100 20000 18000 16000 14000 12000 10000 Azithromycin 8000 Clarithromycin 6000 Roxithromycin 4000 16-membered 2000 Erythromycin 0 90 91 92 93 94 95 96

Macrolide market in Italy 1990-1996 Relationship between erythromycin resistance in S.pneumoniae and S.pyogenes

resistance (%) resistance 40

0 S.pneumoniae 0 20 40 60 80 S.pyogenes resistance (%)

(Gómez-Lus et al., AAC 1999) Antibiotic resistance in Streptococcus pneumoniae

0 Isolates non susc. to erythromycin (%) to erythromycin susc. non Isolates 0 20 40 60 80 Isolates non susceptible to penicillin (%) In many European countries, macrolide resistance in pneumococci has overcome the level of beta-lactam resistance, and rates are still increasing. Mean proportion of S.pneumoniae penicillin non-susceptible (PNSP) in Europe

EARSS Annual Report Mean proportion of erythromycin non-susceptible S.pneumoniae in Europe

EARSS Annual Report Mean proportions of erythromycin non- susceptible and penicillin non-susceptible S.pneumoniae in Europe

EARSS Annual Report 2003 Resistance to penicillin and erythromycin in S. pneumoniae Different phenotypes of macrolide-resistant streptococci

c-MLSB i-MLSB M

R R R C14 - C15

RC RI S CLINDA

R S/R S C16

> 64 µg/ml ~ 16 µg/ml ~ 16 µg/ml MIC (ERY)

1979 MLSB

1989 M

1992 M

1996 MLSB

1995 M / MLSB

Prevalent phenotypes of resistance to macrolide antibiotics Incidence of macrolide resistance mechanisms among macrolide- resistant Streptococcus pyogenes (Nagai et al., AAC 2002)

i-ermA c-ermA i-ermB c-ermB mefA

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% ALL Incidence of macrolide resistance mechanisms among macrolide- resistant Streptococcus pyogenes (various sources, 2002-2003)

i-ermA c-ermA i-ermB c-ermB mefA

100%

80%

60%

40%

20%

0% Do the different phenotypes imply different clinical outcomes ?

In randomized, double blind trials of antibiotic therapy for acute otitis media, clinical success rates were 93% for patients with bacteriological success, 62% for those with bacteriological failure, and 80% for those with non- bacterial otitis media. We conclude that if efficacy is measured by symptomatic response, drugs with excellent antibacterial activity will appear less efficacious than they really are and drugs with poor antibacterial activity will appear more efficacious than they really are. We have called this tendency towards false optimism the “Pollyanna phenomenon”, after the blindly optimistic heroine of the novel Pollyanna.

Marchant et al., J. Pediatr 1992; 120:72-7 The “Pollyanna phenomenon”

100 90 80 70 60 50

Efficacy (%) Efficacy 40 30 20 Bacteriological Clinical efficacy Clinical efficacy efficacy (bacterial AOM) (clinical AOM) The main goals for future macrolides

• to increase the activity against generally susceptible species • to develop new molecules showing little or no cross-resistance with existing macrolides • to expand the antibacterial spectrum • to increase the intracellular uptake and bioactivity within the various cellular compartments MACROLIDE ANTIBIOTICS

12-membered-ring 14-membered-ring 15-membered-ring 16-membered-ring 17-membered-ring

Natural Semi-synthetic compounds derivatives

Josamycin Rokitamycin Kitasamycin Miokamycin Spiramycin Midecamycin 16-membered-ring macrolides

• All 16-membered • On the iMLS strains, B compounds were active the activity of the 16- against almost all membered macrolides isolates with the M proved to be dependent phenotype. on the nature of the erm gene. They were active • All 16-membered against isolates with the compounds were erm(A) gene and inactive inactive against almost all isolates with the against those with the cMLS phenotype. erm(B) gene. B Mazzariol et al., ECCMID 2002 S. pyogenes iMLSB MIC distribution by erm genes Spiramycin

20 ermA ermB 10

0 <0,06 0,25 1 4 16 64 256

Mazzariol et al., ECCMID 2002 S. pyogenes iMLSB - MIC distribution by erm genes Rokitamycin

10 ermA ermB 5

0 <0,06 0,25 1 4 16 64 256

Mazzariol et al., ECCMID 2002 16-membered-ring macrolides

•It should be recalled that the susceptibility of iMLS staphylococcal strains to non-inducing B 16-membered macrolides in the clinical setting proved to be illusory because of the ease with which constitutively resistant mutants were selected as a consequence of nucleotide sequence alterations.

Mazzariol et al., ECCMID 2002 The ketolides

• Removal of L-cladinose at position 3 in the erythronolide A ring and oxidation of the resulting 3-hydroxyl to a 3-keto group has given rise to a new class of compounds designed to overcome erythromycin resistance: the ketolides; • Only one compound, namely telithromycin, is currently introduced in clinical practice.

A Ery14, Cbm16, Tyl16, A C Nucleotides A U C Tel14 mG U C C at which G G mG C G C C C C G Cbm16, macrolides A G interact: G G G A C G 16 U A A A Tyl C C A D Domain V U C A A A 16 A Domain II UG G Tyl Cbm16 C C A Cbm16, C Mutations G Tyl16 U conferring G G C ψ G C G G macrolide Domain V resistance C A U ψ C G G C C A A A A U G C C A G U 14 14 U U G Ery , Tel G C U A A A GG C U G ψ A A U G A C ψ GG A U U A G C G G G C G A U G U A A U C G C C C T mG Cbm16, C G C ψ A A Tyl16 Tel14 Ery14, Cbm16, Tyl16, Domain II Tel14 S.pneumoniae Erythromycin Penicillin 1999-2000 Levofloxacin Telithromycin

180 150 120 90 60 30 No. of isolates No. 0

1 2 4 8 0.5 16 32 64 0.25 128 256 0.008 0.016 0.032 0.064 0.125 >256 <0.006 S S S R R S R R Multicenter study 1999-2001

• Telithromycin was highly active against 94.1% of S.pyogenes.

• All telithromycin-resistant strains (27 isolates) carried an erm(B) gene; 22 isolates had a cMLS phenotype and 5 isolates B an iMLS phenotype. B

Mazzariol et al., ECCMID 2002 MICs of iMLSB S.pyogenes classified by erm gene

Range MIC50 MIC90 erm(A) ERY 256 - >256 >256 >256 TEL 0.006 - 0.125 0.016 0.125 erm(B) ERY 256 - >256 >256 >256 TEL 0.006 - >32 0.125 8

Mazzariol et al., ECCMID 2002 Genotype distribution (%) of ery-R S. pyogenes and S. pneumoniae in Italy

100% 3,8 16,1 80% 28,3 ? mef(A) 11,3 60% erm(A) i 23,9 erm(B) c 40% 79,6 erm(B) i

20% 32,7 4,3 0% Cornaglia and Bryskier S. pyogenes (495) S. pneumoniae (427) (2003) Incidence of macrolide resistance mechanisms among macrolide- resistant Streptococcus pneumoniae (Nagai et al., AAC 2002)

ermB mefE L4 ermA

100%

80%

60%

40%

20%

0% ALL

Telithromycin MIC values (mg/ml) for erythromycin-susceptible and M-type erythromycin-resistant isolates of S. pyogenes isolated in Italy and Spain.

150 125 mefA (-) 100 mefA (+) 75 isolates 50 °

N 25

0.004 0.008 0.016 0.03 0.06 0.12 0.25 0.05 1 2

Mazzariol, Zuliani, Cantón, Morosini, Galán, Baquero, Cornaglia. 12th ECCMID, 2002 Uptake and incorporation of radiolabeled telithromycin in the presence (n) or absence (u) of inhibitor. Phenotype: erythromycin-susceptible

20000 18000 16000 14000 12000 10000

CPM 8000 6000 4000 2000 0 0 5 10 15 20 Time (min)

18000 16000 14000 12000 10000 8000 CPM 6000 4000 2000 0 0 5 10 15 20 Time (min)

Mazzariol, Zuliani, Cantón, Morosini, Galán, Baquero, Cornaglia. 12th ECCMID, 2002 “Since, whether inducible or constitutive, resistance is crossed against macrolides, lincosamides, and streptogramin B-type antibiotics, testing of erythromycin appears sufficient for streptococci.”

(LECLERCQ AND COURVALIN, AAC 1991)

“With the emergence of new resistance mechanisms, it seems advisable to test in vitro the activity of one member each of the 14-, 15-, and 16-membered macrolide, ketolide, lincosamide, and streptogramin class of drugs.”

(DEPARDIEU AND COURVALIN, AAC 2001) Molecules to be tested:

•C14 - C15 •Clindamycin (?) •Lincomycin (?) •Streptogramin B (?) •Telithromycin

•C16 (?) Streptococci to be tested:

•Streptococcus pneumoniae •Streptococcus pyogenes •Group C streptococci •Group G streptococci Distribution of streptococcal groups in pharyngeal cultures

Group A Group B Group C Group D Group F Group G Nongroupable High incidences of macrolide resistance have been described in several countries for Group C and Group G streptococci:

GCS GGS Wu, 1997 41.7 23.5 Philippon, 1997 22.8 24.3 Cornaglia, 2000 41.6 10.5 Strumbelj, 2000 - 53.0 Cornaglia, 2003 45.2 18.7 Macrolide resistance phenotypes of viridans group streptococci from the oropharynx of healthy children

29% 2% 61% 39%

Susceptible M IR CR (Ioannidou et al., 2001) The streptococcal scare S. pyogenes is responsible for a number of different diseases including:

1. Streptococcal pharyngitis (Streptococcal sore throat) S. pyogenes is responsible for a number of different diseases including:

2. Scarlet fever S. pyogenes is responsible for a number of different diseases including:

3. Skin infections such as: • streptococcal pyoderma, a localised purulent skin infection; • erysipelas, spreading infection of the skin; • cellulitis, spreading infection of the skin and underlying tissue. S. pyogenes is responsible for a number of different diseases including:

4. Streptococcal toxic shock syndrome (STSS) S. pyogenes is responsible for a number of different diseases including:

5. Necrotising fasciitis or 'Streptococcal gangrene', the 'flesh-eating disease' The streptococcal scare

•Look for multiresistant pneumococci

•Beware of the non-group A streptococci

•Beware of the invasive streptococci • …………. March 5, 1999

Nosocomial Group A Streptococcal Infections Associated with Asymptomatic Health-Care Workers

•GAS carriers can shed the organism into the immediate environment despite proper gowning and gloving.

•The mode of transmission is presumed to be airborne.

•Surgical and obstetric patients are particularly vulnerable.

•Most nosocomial transmission is traced to carriers involved in direct patient care.