Presentation on theme: "Latest Developments in the Treatment of Invasive Aspergillosis William J. Steinbach, MD Assistant Professor of Pediatrics, Molecular Genetics, and Microbiology."— Presentation transcript:
Latest Developments in the Treatment of Invasive Aspergillosis William J. Steinbach, MD Assistant Professor of Pediatrics, Molecular Genetics, and Microbiology Pediatric Infectious Diseases Duke University Medical Center Durham, NC USA
Possible Areas for Improving Outcome in IA Understanding IA epidemiology Host factors: Underlying & concomitant diseases Immunosuppression / Corticosteroids Antifungal prophylaxis Early diagnosis Early therapy Antifungal resistance Antifungal therapies Immune reconstitution, Immunotherapy
Invasive Aspergillosis Incidence at FHCRC Marr KA, et al. Clin Infect Dis. 2002;34: Incidence (%) Year Allograft recipients Autograft recipients
Invasive Aspergillosis Epidemiology data from 533 total cases of IA Autologous HSCT <1 % 5.3% Allogeneic HSCT 4% 12% Non-fumigatus Aspergillus18.3%33.7% Average median survival of 29 days after diagnosis Marr KA, et al. Clin Infect Dis 2002;34: Wald A, et al. J Infect Dis 1997;175:
Probability of Developing Proven or Probable IA among patients alive at day 40 Overall P = Marr KA, et al. Blood 2002;100:
Corticosteroids as a Risk Factor Pharmacologic doses of hydrocortisone (10 -6 M), equivalent to 20 mg IV In vitro mean specific growth rate of A. fumigatus at 37° C increased by 40% (p=0.0001) A. fumigatus doubling time increased to 48 minutes Ng TTC, et al. Microbiology 1994;140:
Host Susceptibility Variations: Different Inbred Mouse Strains Sensitive: CAST/Ei, C3H/HEJ, A/J, DBA/2J Intermediate: MRL/MPJ, NZW/LAC Resistant: BalbC/ByJ, AKR/J, Balb/C, 129/SVJ, C57BL/6 Zaas AK, et al. 7 th European Conference on Fungal Genetics, 2004
Antifungal Therapy for Invasive Aspergillosis
A. terreus Infection Murine model – Amphotericin B resistance confirmed Graybill JR, et al. Antimicrob Agents Chemother 2004;48: Review of 28 in vitro analyses, 9 animal models, and 60 previously reported clinical cases – AmB resistance shown in vitro and in vivo Steinbach WJ, et al. Antimicrob Agents Chemother 2004;48: Multicenter retrospective analysis of 83 cases ( ) – Mortality at 12 weeks decreased in those who received voriconazole (HR 0.29; 95% CI, ) vs. AmB Steinbach WJ, et al. Clin Infect Dis 2004;39:192-8.
Aspergillosis Survival with Amphotericin B by Site of Infection Lin et al. Clin Infect Dis. 2001;32: Cumulative Survival Rate Pulmonary (n=83) Days Aspergilloma (n=10) Multi-site (n=11) Sinusitis (n=17) CNS or Disseminated (n=35)
Outcomes Research: Treatment Practices Patterson TF, et al. Medicine 2000;79: IA cases after 1990, most from (595 total cases of IA) Asked for recent case records, non-sequential Lipid formulations of AmB investigational, so few received Outcome data from 34 patients with L-AmB excluded because patients were in other clinical trials Few Combinations Used: AmB + 5-FC (2%) AmB + Rifampin (2%) AmB + Itraconazole(3%) Outcomes: AmBItraconazole AmB Itraconazole Pts treated 31%10%16% All pts CR 25%40%39% All pts PR 7%17%15%
Outcomes Research: Treatment Practices Denning DW, et al. J Infect 1998;37: (123 total cases of IA) Monotherapy in 29 pts, Combination therapy in 91 pts AmBLipid AmBItraconazole5-FC 75%36%40%12% Six month outcomes for IPA: Alive w/o IAAlive w/ IAExpired AmB14%41%46% Lipid AmB23%31%46% AmB + Itra28%56%15% Itra33%17%50% 61% mortality within 28 days after diagnosis
Outcomes Research: Open Label Compassionate use itraconazole (125 patients) – Complete response 27%; Improved 36% Stevens DA and Lee JY. Arch Intern Med 1997;157: Multicenter open label itraconazole (76 patients) – Complete or partial response 39% Denning DW, et al. Am J Med 1994;97: Open label ABLC (130 patients) – Complete or partial response 42% Walsh TJ, et al. Clin Infect Dis 1998;26:
Antifungal Pre-Exposure Serial passages of 10 clinical isolates to fluconazole (x4) – 4-fold increase in MFC (but not MIC) of Itraconazole and Voriconazole – Fluconazole pre-exposure attenuates Itraconazole/ Voriconazole fungicidal activity, but no effect in AmB – XTT growth rates pre-exposed/no fluconazole were same Liu W, et al. Antimicrob Agents Chemother 2003;47: In vitro pre-exposure of A. fumigatus to Itraconazole or Caspofungin resulted in enhanced activity for either, in contrast to antagonistic effect of sequential itraconazole then AmB – Suggests a preferential role for azole-Caspofungin sequential combinations over azole-AmB regimens Kontoyiannis DP, et al. Diag Microbiol Infect Dis 2003;47:415-9.
Aspergillus Antifungal Resistance ? Itraconazole resistance described in 1997 Denning DW, et al. Antimicrob Agents Chemother 1997;41: Estimated 2.1% of > 900 A. fumigatus strains resistant to itraconazole Moore CB, et al. J Infect 2000;41: sequential A. fumigatus isolates from 26 immunocompromised patients MICs similar pre- and post-treatment with AmB (n=100) or itraconazole (n=91) Emergence of resistance while on antifungal therapy is likely low Genotypic diversity and sequential colonization with multiple strains could explain low resistance Dannaoui, et al. J Med Microbiol 2004;53:
Voriconazole Fungicidal Activity on Hyphae Previous in vitro studies examined killing of conidia and germinated conidia (sporelings) But patients have hyphae growing Voriconazole killed hyphae in both time- and concentration-dependent fashions – Kill curve and MTT cell wall viability testing Voriconazole had better fungicidal activity against A. fumigatus hyphae than AmB at 48 hours – VCZ 1 ug/ml >95% killed on agar (AmB 1 ug/ml 70% killed) – VCZ 1 ug/ml 99% killed in broth (AmB 1 ug/ml 82% killed) Krishnan S, et al. J Antimicrob Chemother ePub April 20005
Only Three Randomized Clinical Trials ever completed for the Treatment of Invasive Aspergillosis
Global Comparative Aspergillosis Study (307/602) DRC-Assessed Success at Week 12 (MITT) Voriconazole arm success = 52.8%; Amphotericin arm = 31.6% Difference (raw) = 21.2%, 95 % CI (9.9, 32.6) Difference (adjusted) = 21.8%, 95% CI (10.5, 33.0) 76/144 42/133 Same outcome in each separate protocol Herbrecht R, et al. N Engl J Med 2002; 347:
% Difference in Success Rates (95% CI) Overall Pulmonary Extra Pulmonary Allogeneic BMT Autologous BMT / other hematological (e.g. leukemia) Other immunosuppressed state (e.g. SOT, HIV/AIDS) Neutropenic (ANC < 500) Non-Neutropenic (ANC 500) Probable IA Global Comparative Aspergillosis Study (307/602) DRC-Assessed Success at Week 12 (MITT) Herbrecht R, et al. N Engl J Med 2002; 347: Proven IA
Global Comparative Aspergillosis Study (307/602) Time to Death (MITT) Number of days of Therapy Probability of Survival Amphotericin B +/- OLAT Voriconazole +/- OLAT Day 84 survival: Voriconazole arm 71%; Amphotericin B arm 58% Hazard ratio = % CI (0.40, 0.89) Herbrecht R, et al. N Engl J Med 2002; 347:
ABCD (6 mg/kg/d) vs. AmB-D (1.0–1.5 mg/kg/d) Prospective, double-blind, randomized, controlled clinical trial, risk stratified before randomization; ABCD AmB-D Evaluable Patients(n=50)(n=53) Therapeutic response52%50.9% p=0.96 (complete, partial, or stable) Overall Mortality36%45% p=0.4 Fungal Mortality32%26% p=0.7 Renal Toxicity25%49% p=0.002 Median time to renal toxicity301 d22 d p<0.001 Intent to Treat(n=88)(n=86) Complete Response5.7%3.5% Partial Response6.8%11.6% ABCD equivalent efficacy and superior renal safety Study terminated early due to low accrual Bowden R, et al. Clin Infect Dis 2002;35:
Liposomal AmB 1 mg/kg/d versus 4 mg/kg/d 1 mg/kg/d 4 mg/kd/dp value (n=41) (n=46) Clinical CR + PR (inc. stable) 64% 48%0.144 Radiologic CR + PR 58% 54% month survival 43% 37% Overall deaths 59% 67% Overall response rate of 55% Overall 6-month mortality of 63% Ellis M, et al. Clin Infect Dis 1998;27:
Switching to Other Licensed Therapies Received OLT in Voriconazole vs. AmB – Initial VCZ 36% (52/144) – Initial AmB80% (107/133) 159 total patients received OLT – 38% Lipid AmB formulation – 33% Itraconazole – 21% AmB deoxycholate (inc. reduced dose) – 8% Other antifungals Switches due to Intolerance/Insufficient response – VCZ 24% (35/144) after median 12 days (1-83 days) – AmB 70% (93/133) after median 9 days (1-74 days) (p< ) Boucher HW, et al. ICAAC 2003, Abstract M-964
Use the Best Therapy First Patient Success – 33% (31/93) AmB receiving OLT – 30% (14/47) AmB followed by lipid AmB (median 13 days) – 53%All randomized to VCZ (p<0.01) Strategy of Voriconazole followed by OLT for intolerance or insufficient response was more successful than AmB with OLT (including lipid AmB) Stresses the importance of initial therapy of voriconazole for IA Boucher HW, et al. ICAAC 2003, Abstract M-964
Early Treatment is Critical Mortality when treatment started after diagnosis: < 10 days 40% > 11 days 90% Von Eiff, et al. Respiration 1995;62:241-7.
Echinocandin Activity on Aspergillus Hyphal Tip Caspofungin (0.3 ug/ml)-treated, DiBAC-stained A. fumigatus 6 hours incubation 2,000X magnification Bowman JC, et al. Antimicrob Agents Chemother 2002;46:
Caspofungin Salvage Therapy Open, non-comparative, multi-center trial 90 patients with IA enrolled (median 51 yrs; 15-73) Efficacy evaluation of 83 patients – 71 patients (86%) refractory to therapy – 12 patients (14%) intolerant to therapy 45% (37/83) with favorable outcome – 50% (32/64) with pulmonary IA – 23% (3/13) with disseminated IA Maertens J, et al. Clin Infect Dis 2004; 39: Neutropenic patients with IA Favorable response (35%) – 42% as primary therapy – 32% as salvage therapy Kartsonis N, et al. 14 th ECCMID, Abstract 0422
Concentration-Dependent Caspofungin Activity Murine model of pulmonary IA – Substantial differences in fungal burden as determined by qPCR – Largest reduction in burden by those dosing regimens achieving the highest peak concentrations – Histological apical hyphal damage most at highest dose Trend toward improving survival with maximal dosing Paradoxical Eagle Effect at highest dose, with an increase in tissue burden (but no decrease in survival) – Same effect seen in other cell-wall active antibacterials Wiederhold NP, et al. J Infect Dis 2004;190:
Micafungin Monotherapy Open-Label Trial in Japan 70 patients at 29 sites; 56 pts eval. for efficacy (IA = 42) DiseaseResponse Invasive pulmonary (n=10)60% (8 pts with leukemia or lymphoma; 2 neutropenic) Max dose 50 mg/d50% (1/2) 75 mg/d33% (1/3) 150 mg/d80% (4/5) Disseminated(n=1)0% Chronic necrotizing pulmonary(n=9)67% Pulmonary aspergilloma(n=22)55% AE related to micafungin reported in 30% of patients Kohno S, et al. Scand J Infect Dis 2004;36:372-9.
Posaconazole Monotherapy Multicenter study for salvage therapy – Included 25 pts with IA – Effective in 53% (8/15) at week 4 – Effective in 85% (6/7) at week 8 – No mention of patients without complete follow-up Hachem RY, et al. ICAAC 2000, Abstract 1109 Multi-center study of patients with IA refractory to or intolerant of AmB formulations and itraconazole – 107 posaconazole, 86 controls – Global response rate at end of treatment Posaconazole 42% Controls26% Walsh TJ, et al. ASH 2003, Abstract 682
Cerebral Aspergillosis 86 patients (9 mo - 81yo) with proven or probable CNS aspergillosis – A. fumigatus (n=34); A. nidulans (n=5); Aspergillus spp. (n=24) Underlying disease – BMT (n=33); Hem malignancy (n=14) – SOT (n=12); Acquired/Cong immunosuppression (n=15) – Other (n=12) Only 13/86 received VCZ primary therapy (others with previous antifungal therapy before VCZ use) Global Clinical Outcome – Complete / Partial Response34% – Stable / Failed response 66% – BMT Recipient Response15% – All Others Response42-50% Troke PF, et al. ICAAC 2003, Abstract M-1755
Bone Aspergillosis 20 patients from Clinical trials and Compassionate use Bone Involvement – Spondylodiscitis (n=9); Sternum/Rib (n=6); Peripheral (n=5) Immunocompromised (n=14) – Largest population: Chronic Granulomatous Disease (n=5) Bone was the only infection site in 10 patients Salvage voriconazole therapy in 18/20 patients Median duration of voriconazole 83.5 days (4-395 days) Global Clinical Outcome Complete / Partial Response 55% (11/20) – Complete (n=4); Partial (n=7), Failure (n=9) Mouas H, et al. Clin Infect Dis 2005;40:
Combination Antifungal Therapy in Invasive Aspergillosis
Combination Therapy Rationale Widened spectrum and potency More rapid antifungal effect Additive or synergistic efficacy effects Lowered dosing or less toxicity Reduce risk of emerging resistance Historic poor outcomes with monotherapy Increased penetration / transport Inhibit different stages of the same biochemical pathway Simultaneous inhibition of different fungal targets Creation of a fungicidal combination
Review of Combination Therapy StudiesSynAddIndiff Antag In vitro (n=28)36%24% 28% 11% In vivo (n=18)14% 20% 51% 14% AmB + Itraconazole generally indifferent interactions in vitro, in vivo, and clinically 249 cases met combination Rx inclusion criteria Most common combinations: – AmB + Flucytosine (49%) – AmB + Itraconazole (16%) – AmB + Rifampin (11%) Overall 63% of clinical cases reported improvement Steinbach WJ, et al. Clin Infect Dis 2003;37 (suppl 3): S
Only Clinical Trial of Combination Antifungal Therapy for Aspergillosis 28 neutropenic adult pts with proven IFI – AmB (0.5 mg/kg/d) (n=14) – AmB + 5-FC (n=14) Survival: – AmB alone: 2/14 (mortality 86%) – AmB + 5-FC: 3/14 (mortality 79%) – 15/18 with invasive aspergillosis died – 3 who survived had immune recovery Study terminated early, problems included: – IA so far advanced at initiation – Low dose AmB used Verweij PE, et al. Infection 1994;22:81-5.
Experimental: Voriconazole + Caspofungin In Vitro – 48 isolates, Synergy (87.5%) of interactions (FICI < 1.0) Perea S, et al. Antimicrob Agents Chemother 2002;46: In Vivo: Neutropenic guinea pig model – Mortality (0/12 animals) and survival time (8 days) SAME in EACH of these arms: VCZ 5mg/kg/d CAS (1 mg/kg/d) + VCZ CAS (2.5 mg/kg/d) + VCZ – Fungal burden (CFU) with combination better than untreated controls only – Number of organs with positive cultures with combination better than monotherapy Kirkpatrick WR, et al. Antimicrob Agents Chemother 2002;46:2564-8
Experimental: Ravuconazole + Micafungin Neutropenic rabbit model – Survival Micafungin monotherapy (0/8) Ravuconazole monotherapy (2/8) Micafungin + Ravuconazole (9/12) – Fungal burden, GM assay, Pulmonary injury, Pulmonary infiltrates all less in the combination Petraitis V, et al. J Infect Dis 2003;187:
Ravuconazole + Micafungin Hyphal Damage The spherical chlamydoconidial structures are evidence of the effect of echinocandins The focal hyphal disintegration and disruption are compatible with the effects of triazoles Original magnification ×630; Insert, ×1000; Scale bar 20 um Petraitis V, et al. J Infect Dis 2003;187: Untreated Control Micafungin Ravuconazole Ravuconazole + Micafungin
Clinical Combination Therapy Reports Caspofungin + L-AmB salvage after previous L-AmB (n=48) – Overall response rate 42%; Response in progressive IA 18% Kontoyiannis DP, et al. Cancer 2003;15:292-9 Micafungin + existing antifungal in 85 BMT pts – 39% (28%) complete/partial response Ratanatharathorn V, et al. ASH 2002, Abstract A-2472 Open-label Micafungin salvage therapy in 283 patients – In salvage patients (IA, >7d prior therapy & >7d micafungin) 11/49 (22%) allogeneic HSCT responded 22/45 (49%) leukemia patients responded Ullman AJ, et al. ECCMID 2003, Abstract 0400 Salvage therapy with posaconazole – Posaconazole 29% – AmB lipid8% (p=0.01) – AmB lipid + Itraconazole 16% (p=0.2) Raad II, et al. IDSA 2004, Abstract 678
Voriconazole + Terbinafine Previously reported in vitro synergistic/additive effect with terbinafine against Aspergillus Immunosuppressed rat model A. fumigatus – AmB 1 mg/kg/d – VCZ 6 or 9 mg/kg/d – Terbinafine 150 mg/kg/d VCZ 9 mg/kg/d (41%) increased survival over AmB (28%) (p< 0.05) All treatment groups except AmB significantly increased survival compared to Terbinafine (13%) Addition of Terbinafine to VCZ did not improve survival Combination reduced fungal counts compared to control and AmB Gavalda J, et al. ICAAC 2004, Abstract M-224
New Data: Combination Therapy for IA 47 patients with proven/probable IA from Patients experienced failure of initial therapy with AmB formulations Received either voriconazole (n=31) or voriconazole + caspofungin (n=16) as salvage therapy Voriconazole + Caspofungin with improved 3-month survival rate compared to voriconazole monotherapy (HR 0.42; 95% CI ; p=0.048) Multivariate model, combination with reduced mortality (HR 0.28; 95% CI ; p=0.11) Marr KA, et al. Clin Infect Dis 2004;39:
Voriconazole vs. Voriconazole + Caspofungin Kaplan-Meier probability of survival after diagnosis P =.048, calculated from the likelihood ratio test using Cox regression Marr KA, et al. Clin Infect Dis 2004;39:
Primary Combination Therapy Retrospective single center cohort review of consecutive patients with IA and an underlying hematologic malignancy (Jan 98 – July 03) Proven (n=17) / Probable (n=17) / Possible (n=11) by EORTC/MSG Data presented below for Proven / Probable cases only ALL ComboMono P value (n=34)(n=10)(n=24) 12 wk Survival53%50%54% 0.82 Median Survival (d) CR/PR41%50%37.5% 0.5 Stable5.9%0%8.3% -- Failure53%50%54% 0.86 No differences in survival between primary therapy with mono vs. combo Munoz LS, et al. ICAAC 2004, Abstract M-1024
In Vitro Treatment PRIOR to Combination Antifungal Therapy Subinhibitory concentration of AmB against Caspo + Vori or Caspo + Ravuconazole Percentage of further reduction in growth following AmB addition AmB 0.1 ug/mlAmB 0.2 ug/ml Caspo + VCZ33% (14-57%)34% (13-59%) Caspo + RVZ11% (0-30%)28% (16-48%) Significant for all species except A. terreus for Cas/VCZ and A. fumigatus Cas/RVZ at AmB 0.1 ug/ml FICI ( ) for each triple combination improved by adding subinhibitory concentration of AmB – additive to indifferent effect OShaughnessy EM, et al. ICAAC 2004, Abstract M-249
Pediatric Antifungal Data
Pediatric Voriconazole Elimination by Linear pharmacokinetics in children following doses of 3 and 4 mg/kg/q12h Single dose, Open, two center study in UK – 11 Children ages 2-11 yrs (mean 5.9 yrs) Multiple dose, Open, 8 center, two-cohort (ages 2-6, 6-12) – 28 children, mean age 6.4 yrs Higher elimination capacity on a weight basis than do adult healthy volunteers Walsh TJ, et al. Antimicrob Agents Chemother 2004;48:
Pediatric Voriconazole Extrapolated plasma pharmacokinetics of pediatric doses (5-12 mg/kg/q12h) vs. adult (4 mg/kg/q12h) – Pediatric dose of approx. 11 mg/kg/q12h is equivalent to adult dose of 4 mg/kg/q12h by AUC and plasma concentration – This is only valid if linear pharmacokinetics maintained throughout full dosage range Walsh TJ, et al. Antimicrob Agents Chemother 2004;48: Correct pediatric dosing not fully established, but clearly higher than adult dosing – prompted a second PK study
2 nd Pediatric Voriconazole Pharmacokinetic Study Study completed, data analyses ongoing PK study (2-12 yo) to evaluate > 4 mg/kg BID dosing – Enrolled 48 (39 completed all three PK periods) – Doses of 4, 6, 8 mg/kg/q12h – Each child received at least two different doses in escalating order, then switched to PO Oral Suspension (40 mg/ml) – FDA approved 12/24/03, orange flavor
Voriconazole for Pediatric Aspergillosis Compassionate Use; 58 IFI including 42 IA Mean age 8.2 yrs (9 mo – 15 yrs) Therapeutic response – Complete or partial response 43% Pulmonary IA (n=12) 33% CNS (n=6)50% Disseminated (n=7) 86% Sinusitis (n=7) 29% Bone / Liver / Skin (n=10) 30% – Stable 7% – Intolerance 10% – Failure 40% Walsh TJ, et al. Pediatr Infect Dis J 2002;21:240-8.
Pediatric Caspofungin Adult dosing: Load 70mg once, then 50mg once daily Initial pediatric (ages 2-17) PK study completed – 39 patients enrolled – Data obtained using a weight-based (1 mg/kg/d) and BSA approach (70 mg/m 2 /d or 50 mg/m 2 /d) Weight-based (1 mg/kg/d) resulted in suboptimal plasma concentrations in all children relative to adults 50 mg/m 2 /d similar C 24hr and increased AUC to adult patients (50 mg/d) Walsh TJ, et al. ICAAC 2002, Abstract M-896; Under review.
Pediatric Caspofungin Caspofungin well-tolerated, no discontinuation due to toxicity Beta-phase half-life reduced 32-43% in children, so plasma levels were lower Subsequent studies in children 2-17 years old evaluating: – Load with 70 mg/m 2 (max 70 mg/d) on Day 1 – Then, 50 mg/m 2 (max 70 mg/d) Walsh TJ, et al. ICAAC 2002, Abstract M-896; Under review.
Summary Aspergillus epidemiology changing GM assay interpretations different in specific populations Aspergillus qPCR still debated for diagnosis Echinocandins unlikely to be best monotherapy (fungistatic against Aspergillus) Voriconazole is clearly the best monotherapy Voriconzole primary therapy better than salvage therapy Voriconazole has linear pharmacokinetics in children Combination therapy – unproven – Reports are often contradictory – Potentially would be best if used as primary therapy