Early Lyme Disease as 
Manifested by Erythema 
Migrans: Developing 
Drugs for Treatment 
Guidance for Industry 
 
 
 
DRAFT GUIDANCE
 
 
This guidance document is being distributed for comment purposes only. 
 
 
Comments and suggestions regarding this draft document should be submitted within 60 days of 
publication in the Federal Register of the notice announcing the availability of the draft 
guidance.  Submit electronic comments to https://www.regulations.gov.  Submit written 
comments to the Dockets Management Staff (HFA-305), Food and Drug Administration, 5630 
Fishers Lane, Rm. 1061, Rockville, MD  20852.  All comments should be identified with the 
docket number listed in the notice of availability that publishes in the Federal Register. 
 
For questions regarding this draft document, contact (CDER) Shabnam Naseer at 
Shabnam.Naseer@fda.hhs.gov. 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
February 2023 
Clinical/Antimicrobial
50891222dft.docx 
1/30/2023   
Early Lyme Disease as 
Manifested by Erythema 
Migrans: Developing 
Drugs for Treatment 
Guidance for Industry 
 
Additional copies are available from: 
 
Office of Communications, Division of Drug Information 
Center for Drug Evaluation and Research 
Food and Drug Administration 
10001 New Hampshire Ave., Hillandale Bldg., 4th Floor 
Silver Spring, MD  20993-0002 
Phone: 855-543-3784 or 301-796-3400; Fax: 301-431-6353; Email: druginfo@fda.hhs.gov 
https://www.fda.gov/drugs/guidance-compliance-regulatory-information/guidances-drugs 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
February 2023 
Clinical/Antimicrobial
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
TABLE OF CONTENTS 
 
I.  INTRODUCTION............................................................................................................. 1 
II.  BACKGROUND ............................................................................................................... 2 
III.  DEVELOPMENT CONSIDERATIONS ........................................................................ 2 
A.  Trial Population ............................................................................................................................. 2 
B.  Trial Design .................................................................................................................................... 2 
C.  Efficacy Considerations ................................................................................................................. 3 
1. Choice of Comparators, Prior and Concomitant Antibacterial Drugs ............................................ 3 
2. Efficacy Endpoints ........................................................................................................................... 3 
a.  Primary efficacy endpoint ......................................................................................................... 3 
b.  Secondary endpoints ................................................................................................................. 4 
3. Statistical Considerations ................................................................................................................ 4 
a.  Analysis populations ................................................................................................................. 4 
b.  NI margins ................................................................................................................................ 5 
c.  Subject follow-up/missing data ................................................................................................. 5 
D.  Safety Considerations .................................................................................................................... 5 
E.  Other Considerations ..................................................................................................................... 5 
1. Clinical Microbiology Considerations ............................................................................................ 5 
a.  Serology .................................................................................................................................... 5 
b.  Antimicrobial susceptibility testing .......................................................................................... 6 
c.  Animal models of infection ....................................................................................................... 6 
2. Inclusion of Pediatric and Pregnant Subjects in Drug Development .............................................. 6 
3. Labeling Considerations .................................................................................................................. 7 
REFERENCES .............................................................................................................................. 8 
APPENDIX:  JUSTIFICATION FOR NONINFERIORITY MARGIN FOR EARLY 
LYME DISEASE .......................................................................................................................... 9 
 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
1  Early Lyme Disease as Manifested by Erythema Migrans: 
2  Developing Drugs for Treatment 
3  Guidance for Industry1 
4   
5   
6   
7  This draft guidance, when finalized, will represent the current thinking of the Food and Drug 
8  Administration (FDA or Agency) on this topic. It does not establish any rights for any person and is not 
9  binding on FDA or the public. You can use an alternative approach if it satisfies the requirements of the 
10  applicable statutes and regulations. To discuss an alternative approach, contact the FDA staff responsible 
11  for this guidance as listed on the title page. 
12   
13   
14   
15  I.  INTRODUCTION 
16   
17  The purpose of this guidance is to provide the Food and Drug Administrations (FDAs) current 
18  recommendations regarding the development of drugs2 to support an indication for the treatment 
19  of early Lyme disease as manifested by erythema migrans (EM).3  
20   
21  This guidance does not contain discussion of the general issues of statistical analysis or clinical 
22  trial design. Those topics are addressed in the International Council for Harmonisation guidances 
23  for industry E9 Statistical Principles for Clinical Trials (September 1998), E9(R1) Statistical 
24  Principles for Clinical Trials: Addendum: Estimands and Sensitivity Analysis in Clinical Trials 
25  (May 2021) and E10 Choice of Control Group and Related Issues in Clinical Trials (May 
26  2001).4 This guidance also does not discuss general considerations (e.g.,  pharmacology/ 
27  toxicology or clinical pharmacology) of drug development because these considerations are 
28  similar to those for other indications for anti-infective drugs.  
29   
30  In general, FDAs guidance documents do not establish legally enforceable responsibilities.  
31  Instead, guidances describe the Agencys current thinking on a topic and should be viewed only 
32  as recommendations, unless specific regulatory or statutory requirements are cited.  The use of 
33  the word should in Agency guidances means that something is suggested or recommended, but 
34  not required.  
35   
 
1 This guidance has been prepared by the Division of Anti-Infectives in the Center for Drug Evaluation and 
Research (CDER) at the Food and Drug Administration. 
 
2 For the purposes of this guidance, all references to drugs include both human drugs and therapeutic biological 
products regulated by CDER unless otherwise specified. 
 
3 Sponsors that intend to develop drugs for patients with cardiac or neurologic manifestations of early Lyme disease, 
or for late Lyme disease, should discuss this with FDA before trial initiation. 
 
4 We update guidances periodically. To make sure you have the most recent version of a guidance, check the FDA 
guidance web page at https://www.fda.gov/regulatory-information/search-fda-guidance-documents. 
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36   
37  II.  BACKGROUND 
38   
39  Lyme disease is a tick-borne infection, transmitted by the bite of infected Ixodid ticks. In North 
40  America, Lyme disease is primarily caused by the spirochete Borrelia burgdorferi and rarely by 
41  B. mayonii, which is an emerging pathogen for Lyme disease in the Upper Midwest of the United 
42  States.5 In Europe and Asia, Lyme disease is caused by B. afzelli and B. garinii; B. burgdorferi is 
43  also reported in Europe. There are some differences in clinical manifestations of Lyme disease in 
44  the United States and in Europe and Asia with patients in the United States having higher rates of 
45  systemic symptoms as well as multiple and more rapidly expanding EM lesions (Strle et al. 
46  1999; Jones et al. 2008). 
47   
48  Clinically, Lyme disease can be divided into early localized, early disseminated, and late disease. 
49  Early localized disease occurs within 1 month following the tick bite and is characterized by EM, 
50  a rash at the site of the tick bite that may be accompanied by nonspecific symptoms (e.g., fatigue, 
51  myalgias).6 Diagnosis of early localized disease rests primarily on clinical findings because 
52  serology is often negative early in the infection. Early disseminated disease occurs days to 
53  months after the tick bite and is characterized by multiple EM lesions often distant from the bite 
54  site, and/or neurologic and/or cardiac findings. Late disease occurs months after the onset of 
55  infection, and arthritis in a large joint is the most common feature. The goal of antibacterial 
56  treatment is to resolve symptoms and prevent later complications. 
57   
58   
59  III.  DEVELOPMENT CONSIDERATIONS 
60   
61  A.  Trial Population 
62   
63  The trial(s) should enroll subjects with early localized (i.e., a single EM lesion) or early 
64  disseminated (i.e., multiple EM lesions) disease, who reside in or traveled to a Lyme-endemic 
65  area. In general, sponsors should not enroll subjects with musculoskeletal, neurologic, or cardiac 
66  manifestations of Lyme disease (e.g., active arthritis, myocarditis, meningitis, cranial 
67  neuropathy). Also, sponsors should not enroll subjects with ongoing symptoms attributed to a 
68  history of Lyme disease or a concurrent tick-borne infection (e.g., babesiosis, ehrlichiosis, 
69  anaplasmosis).  
70   
71  B.  Trial Design 
72   
73  Trials are expected to be randomized, double-blinded, and controlled. Subjects should not be left 
74  untreated; thus, placebo-controlled trials, unless of an add-on design, would not be appropriate. 
75  Superiority trials with a direct comparison to an approved drug or as an add-on design are 
 
5 See the Centers for Disease Control and Prevention (CDC) Lyme Disease web page at 
https://www.cdc.gov/lyme/index.html.  
 
6 Sponsors can refer to the CDCs clinical case definition on the web page Lyme Disease (Borrelia burgdorferi) 
2017 Case Definition at https://ndc.services.cdc.gov/case-definitions/lyme-disease-2017/. 
2  Contains Nonbinding Recommendations 
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76  acceptable to support an indication of treatment for early Lyme disease. Noninferiority (NI) trials 
77  are also acceptable (see the Appendix regarding the justification of an NI margin).  
78   
79  Sponsors can consider stratification of randomization according to clinical manifestations (e.g., a 
80  single EM lesion versus multiple EM lesions) to ensure similar proportions of subjects with 
81  disseminated disease in each group. Sponsors can also consider additional stratification by age 
82  group (pediatric, adult) when enrollment is not limited to adult subjects. 
83   
84  C.  Efficacy Considerations 
85   
86  Generally, two adequate and well controlled trials are necessary to provide evidence for drug 
87  effectiveness.7 In some cases, such as development of a drug previously approved to treat a 
88  serious infection, a robust finding from a single, adequate, and well-controlled trial supported by 
89  other independent clinical and/or nonclinical data such as in vitro or animal models, may provide 
90  evidence of effectiveness (see section III., E., Other Considerations). If a single, adequate, and 
91  well-controlled trial is proposed, the sponsor should discuss with FDA the other independent 
92  evidence that could be used to support the findings from this single trial.  
93   
94  1.  Choice of Comparators, Prior and Concomitant Antibacterial Drugs 
95   
96  For an NI trial, FDA recommends an active control with known activity in early Lyme disease. 
97  Sponsors can use oral doxycycline or other comparators if adequate evidence is available to 
98  justify an NI margin. We recommend that the sponsor discuss with FDA the choice of 
99  comparator before study initiation. 
100   
101  No antibacterial drug known to be active against B. burgdorferi or B. mayonii should be 
102  administered to subjects within 48 hours before enrollment or during the trial. If concomitant 
103  antibacterial drugs are administered, the sponsors should report the reason, dosing, and dates of 
104  administration.  
105   
106  2.  Efficacy Endpoints 
107   
108  a.  Primary efficacy endpoint 
109   
110  The primary efficacy endpoint should be a responder outcome at 6 months after randomization.  
111   
 
7 See the draft guidance for industry Demonstrating Substantial Evidence of Effectiveness for Human Drug and 
Biological Products (December 2019). When final, this guidance will represent the FDAs current thinking on this 
topic. For the most recent version of a guidance, check the FDA guidance web page at 
https://www.fda.gov/regulatory-information/search-fda-guidance-documents. 
 
3  Contains Nonbinding Recommendations 
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112  Clinical success should be defined as resolution of EM and continued absence of objective 
113  manifestations of Lyme disease without need for additional antibacterial treatment for Lyme 
114  disease.8  
115   
116  Clinical failure should be defined as the presence of unresolving or recurrent EM, objective 
117  manifestations of Lyme disease, or the need for additional antibacterial treatment for Lyme 
118  disease.9  
119   
120  b.  Secondary endpoints 
121   
122  Secondary endpoints should include the following: 
123   
124    Clinical success or clinical failure (as defined above) through 30 days after randomization 
125   
126    Clinical success or clinical failure (as defined above) through 12 months after 
127  randomization 
128   
129  3.  Statistical Considerations 
130   
131  In general, sponsors should provide a detailed statistical analysis plan stating the trial hypotheses 
132  and the analysis methods before trial initiation. The primary efficacy analysis is usually based on 
133  the difference in the proportions of subjects achieving clinical success.  
134   
135  To improve the precision of treatment effect estimation and inference, sponsors should consider 
136  adjusting for prespecified baseline factors that are anticipated to be prognostic of the outcome. If 
137  randomization is stratified by baseline covariates, the analysis should account for the stratified 
138  randomization.10 
139   
140  a.  Analysis populations 
141   
142  The following are definitions of various analysis populations. The primary analysis population 
143  for efficacy should be the intent-to-treat population. 
144   
145  Intent-to-treat (ITT) population: All randomized subjects 
 
8 Objective manifestations could include signs of advanced Lyme disease involving the musculoskeletal, cardiac, or 
nervous system as defined by CDCs clinical case definition on the web page Lyme Disease (Borrelia burgdorferi) 
2017 Case Definition at https://ndc.services.cdc.gov/case-definitions/lyme-disease-2017/. 
 
9 Sponsors that intend to use a different endpoint for the assessment of the primary endpoint in early Lyme disease 
should discuss this with FDA. Sponsors should document the reasons for clinical failure and should plan for 
supplementary analyses to compare treatment groups with respect to proportions of subjects with objective 
manifestations of Lyme disease and need for additional antibacterial treatment for Lyme disease. Sponsors should 
also plan for supplementary analyses to compare treatment groups with respect to the proportions of subjects who 
received antibacterial drugs with activity against B. burgdorferi for infections other than Lyme disease during the 
trial period. 
 
10 See the draft guidance for industry Adjusting for Covariates in Randomized Clinical Trials for Drugs and 
Biological Products (May 2021). When final, this guidance will represent the FDAs current thinking on this topic. 
4  Contains Nonbinding Recommendations 
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146   
147  Safety population:  All subjects who received at least one dose of the investigational drug 
148  during the trial. 
149   
150  Per-protocol population:  Subjects who are not lost to follow-up and adhere to trial procedures 
151  as specified in the protocol. 
152   
153  b.  NI margins 
154   
155  There are some historical data available to help support the appropriateness of NI trials for the 
156  treatment of Lyme disease (see the Appendix for an example). Note that the NI justification used 
157  for any particular trial will depend on the active control used, trial population, and trial 
158  endpoints.   
159   
160  c.  Subject follow-up/missing data 
161   
162  The protocol should include plans to minimize the amount of missing data. All subjects should 
163  be followed throughout the trial unless a subject withdraws consent, is lost to follow-up, or dies. 
164  The protocol should clearly outline how the sponsor will handle the outcomes of subjects with 
165  missing data in the primary analysis.   
166   
167  D.  Safety Considerations 
168   
169  The size of the safety database may depend on several factors, such as the adverse event profile 
170  expected with the drug or drug class, and the duration of use. Sponsors should discuss the 
171  appropriate size of the premarketing safety database with FDA during development. A minimum 
172  size of 300 subjects treated at the proposed dose and duration is expected for drugs with no prior 
173  clinical experience. The required safety database may be larger depending on the safety signals 
174  identified during the development program.  
175   
176  E.  Other Considerations 
177   
178  1.  Clinical Microbiology Considerations 
179   
180  a.  Serology 
181   
182  In general, confirmatory serological testing is not required in the presence of single or multiple 
183  lesions consistent with EM. Sponsors could use detection of antibodies to B. burgdorferi to 
184  confirm the infection in atypical EM presentations (antibody testing performed on an acute-phase 
185  serum sample followed by a convalescent-phase serum sample if the initial result is negative). 
186  FDA-cleared tests are recommended. If tests are not FDA-cleared, sponsors should submit 
187  performance characteristics (e.g., sensitivity and specificity) for FDA review.  
188   
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189  b.  Antimicrobial susceptibility testing 
190   
191  The in vitro activity of antibacterial drugs against some Borrelia species has been described in 
192  the literature; however, there are no standardized methods for antibacterial susceptibility testing 
193  (AST) of Borrelia species. The clinical relevance of Borrelia species susceptibility testing is 
194  unknown because of variability in testing methodology and the presence of different 
195  morphological forms of B. burgdorferi (Lantos et al. 2014). However, AST results (e.g., 
196  minimum inhibitory concentration (MIC)) and antibacterial activity determination may be useful 
197  for proof-of-concept studies when used with appropriate controls. To distinguish between 
198  isolates with the same MICs, genotypic testing may be useful. 
199   
200  c.  Animal models of infection 
201   
202  Nonclinical studies to examine the effect of antibacterial drugs in animals infected with B. 
203  burgdorferi have included various methods, including the use of healthy animals infected by tick 
204  bite.11 Successful infections in animal models have been confirmed by serologic analysis, and 
205  the treatment outcomes have been evaluated using several laboratory criteria including bacterial 
206  outgrowth assays, xenodiagnostic tests (detection of B. burgdorferi in ticks), transplantation of 
207  tissues from infected animals, immunohistochemistry, and polymerase chain reaction test for B. 
208  burgdorferi DNA. Activity in animal models of infection can be used as supportive evidence for 
209  the use of antibacterial drugs for the treatment of active B. burgdorferi infections in clinical 
210  trials; however, evidence of pathogen or B. burgdorferi antigen persistence and ongoing 
211  inflammatory responses following treatment have been observed in some animal models of B. 
212  burgdorferi infection (Brockenstedt et al. 2002; Brockenstedt et al. 2012; Hodzic et al. 2008; 
213  Straubinger et al 1998; Straubinger et al. 2000; Sapi et al. 2011). We recommend that sponsors 
214  discuss with FDA animal models of infection and the doses to be evaluated before study 
215  initiation. 
216   
217  2.  Inclusion of Pediatric and Pregnant Subjects in Drug Development 
218   
219  It is important to conduct clinical studies in the pediatric population to inform dosing and assess 
220  the safety and effectiveness of anti-infective drugs. Sponsors should consider whether efficacy 
221  results from adequate and well-controlled clinical trials of an investigational drug in adult 
222  subjects could be extrapolated to a pediatric population.12 In addition, inclusion of adolescent 
223  subjects in adult trials may be appropriate for some investigational drugs. FDA encourages 
224  sponsors to begin discussions about their pediatric clinical development plans as early as is 
225  feasible but no later than 60 days after an end-of-phase 2 meeting.13  
 
11 We support the principles of the 3Rs (reduce/refine/replace) for animal use in testing when feasible. We 
encourage sponsors to consult with review divisions when considering a nonanimal testing method believed to be 
suitable, adequate, validated, and feasible. We will consider if such an alternative method could be assessed for 
equivalency to an animal test method.   
 
12 See the guidance for industry Development of Anti-Infective Drug Products for the Pediatric Population 
(December 2021).  
 
13 See the guidance for industry Pediatric Study Plans: Content of and Process for Submitting Initial Pediatric 
Study Plans and Amended Initial Pediatric Study Plans (July 2020).  
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226   
227  As treatment options are limited for pregnant subjects with early Lyme disease, it may be 
228  appropriate to characterize safety and pharmacokinetics in pregnant subjects with early Lyme 
229  disease who have the potential to benefit from the investigational drug after completion of 
230  reproductive toxicology studies and phase 1 and 2 clinical trials in nonpregnant adult subjects. 
231  Sponsors should follow infants born to pregnant subjects who received the investigational drug 
232  for pregnancy outcome.14  
233   
234  3.  Labeling Considerations 
235   
236  The labeled indication should reflect the patient population and Borrelia species evaluated in the 
237  clinical trials. 
 
14 See the draft guidance for industry Pregnant Women: Scientific and Ethical Considerations for Inclusion in 
Clinical Trials (April 2018). When final, this guidance will represent the FDAs current thinking on this topic.  
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238  REFERENCES 
239   
240  Brockenstedt L, Gonzalez D, Haberman A, and Belperron A, 2012, Spirochete Antigens Persist 
241  Near Cartilage After Murine Lyme Borreliosis Therapy, J Clin Invest, 122(7):26522660.  
242   
243  Brockenstedt L, Mao J, Hodzic E, Barthold S, and Fish D, 2002, Detection of Attenuated, 
244  Noninfectious Spirochetes in Borrelia burgdorferi-Infected Mice After Antibiotic Treatment, J 
245  Infect Dis, 186(10):14301437. 
246   
247  Hodzic E, Feng S, Holden K, Freet K, and Barthold S, 2008, Persistence of Borrelia burgdorferi 
248  following Antibiotic treatment in Mice, Antimicrob Agents and Chemother, 52(5):17281736. 
249   
250  Jones KL, Muellegger RR, Means TK, Lee M, Glickstein LJ, Damle N, Sikand VK, Luster AD, 
251  and AC Steere, 2008, Higher mRNA Levels of Chemokines and Cytokines Associated with 
252  Macrophage Activation in Erythema Migrans Skin Lesions in Patients from the United States 
253  Than in Patients from Austria with Lyme Borreliosis, Clin Infect Dis, 46(1):8592. 
254   
255  Lantos PM, Auwaerter PG, and Wormser GP, 2014, A Systematic Review of Borrelia 
256  burgdorferi Morphologic Variants Does Not Support a Role in Chronic Lyme Disease, Clin 
257  Infect Dis, 58(5):663671. 
258   
259  Sapi E, Kaur N, Anyanwu S, Luecke DF, Datar A, Patel S, Rossi M, and Stricker RB, 2011, 
260  Evaluation of In-Vitro Antibiotic Susceptibility of Different Morphological Forms of Borrelia 
261  burgdorferi, Infect Drug Resist, 4:97113. 
262   
263  Straubinger RK, Straubinger AF, Summers BA, and Jacobson RH, 2000, Status of Borrelia 
264  burgdorferi Infection after Antibiotic Treatment and the Effects of Corticosteroids: An 
265  Experimental Study, J Infect Dis, 181(3):10691081. 
266   
267  Straubinger RK, Straubinger AF, Summers BA, Jacobson RH, and Erb HN, 1998, Clinical 
268  Manifestations, Pathogenesis, and Effect of Antibiotic Treatment on Lyme Borreliosis in Dogs, 
269  Wien Klin Wochenschr, 110(24):874881. 
270   
271  Strle F, Nadelman RB, Cimperman J, Nowakowski J, Picken RN, Schwartz I, Maraspin V, 
272  Aguero-Rosenfeld ME, Varde S, Lotric-Furlan S, and GP Wormser, 1999, Comparison of 
273  Culture-Confirmed Erythema Migrans Caused by Borrelia burgdorferi sensu stricto in New 
274  York State and by Borrelia afzelii in Slovenia, Ann Intern Med, 130(1):3236. 
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275  APPENDIX:  
276  JUSTIFICATION FOR NONINFERIORITY MARGIN FOR EARLY LYME DISEASE 
277   
278  This justification is for the use of doxycycline as an active control in a noninferiority (NI) trial. Because 
279  no randomized placebo-controlled trials of doxycycline in the treatment of early Lyme disease were 
280  identified to date in the literature, the assessment of the treatment effect of doxycycline is based on a 
281  comparison of a meta-analyzed estimate of the effect of doxycycline from U.S. studies with a twice-a-
282  day (BID) regimen for 20 to 21 days to a meta-analyzed estimate of the effect of no treatment from U.S. 
283  natural history studies. The primary efficacy endpoint considered here is the absence of objective 
284  manifestations of Lyme disease (specifically, arthritis, carditis, or neurological disease) at a 6-month 
285  follow-up.   
286   
287  A review of the literature found two U.S. natural history studies of Lyme disease and three U.S. 
288  doxycycline treatment studies of early Lyme disease that reported outcomes at 6 months (see Table 1). 
289   
290  Table 1: U.S. Studies in Lyme Disease 
291   
#  Author/  Study Design  Regimen/Dose  Treatment  N  Study  Study  Follow- # of 
Publication  Duration  Endpoints  Population  up  Centers 
1  Steere et al.  Natural history  None  N/A  48  Absence of  EM/NSS  6 and 18  1 
1979a  disease  months 
progression 
(joint, 
neurologic) 
2  Steere et al.  Natural history  None  N/A  55  Absence of  EM/NSS  6, 12,  1 
1980b  with inclusion of  disease  and 18 
Penicillin  7-10 days  42 
nonrandomized  progression  months 
250,000 U QID 
open label  (joint,   
Erythromycin  7-10 days  9 
treatment arms  neurologic, 
250 mg QID 
cardiac) 
Tetracycline 250  7-10 days  7 
mg QID 
3  Dattwyler  Randomized,  Doxycycline  21 days  37  Development  EM/NSS  Day 21  1 
et al. 1990c  controlled,   100 mg BID  of disease  and 6 
open label  Amoxicillin +  21 days  38  progression  months 
probenecid 500 
mg TID 
continued 
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#  Author/  Study Design  Regimen/Dose  Treatment  N  Study  Study  Follow- # of 
Publication  Duration  Endpoints  Population  up  Centers 
4  Massaroti  Randomized,  Doxycycline  10 days  22  Resolution of  EM/NSS  Day 10  7 
et al. 1992d  controlled,    100 mg BID  early  and 6 
open label  Amoxicillin +  10 days  17  symptoms  months 
probenecid 500  and 
mg TID  development 
Azithromycin  5 days  16  of disease 
500 mg x 1 day,  progression 
then 250 mg x 4 
days 
5  Dattwyler  Randomized,  Doxycycline100  21 days  72  Clinical cure  EM/NSS;  3, 6, and  9 
et al. 1997e  controlled,    mg BID  or failure  early  9 months 
open label  Ceftriaxone 2 g  14 days  68  disseminated 
QD  Lyme disease 
(14%) 
292  N/A  not available, EM  erythema migrans, NSS  non-specific symptoms, QID  four times a day, QD  daily, BID  
293  twice a day, TID  three times a day, U  units, mg  milligrams, g  gram. 
294   
295  a Steere AC, Hardin JA, Ruddy S, Mummaw JG, and Malawista SE, 1979, Lyme Arthritis: Correlation of Serum and 
296  Cryoglobulin IgM with Activity, and Serum IgG with Remission, Arthritis Rheum, 22(5):471483. 
297  b Steere AC, Malawista SE, Newman JH, Spieler PN, and Bartenhagen NH, 1980, Antibiotic Therapy in Lyme Disease, Ann 
298  Intern Med, 93(1):18. 
299  c Dattwyler RJ, Volkman DJ, Conaty SM, Platkin SP, and Luft BJ, 1990, Amoxycillin Plus Probenecid Versus Doxycycline 
300  for Treatment of Erythema Migrans Borreliosis, Lancet, 336(8728):14041406. 
301  d Massarotti EM, Luger SW, Rahn DW, Messner RP, Wong JB, Johnson RC, and Steere AC, 1992, Treatment of Early Lyme 
302  Disease, Am J Med, 92(4):396403. 
303  e Dattwyler RJ, Luft BJ, Kunkel MJ, Finkel MF, Wormser GP, Rush TJ, Grunwaldt E, Agger WA, Franklin M, Oswald D, 
304  Cockey L, and Maladorno D, 1997, Ceftriaxone Compared with Doxycycline for the Treatment of Acute Disseminated Lyme 
305  Disease, N Engl J Med, 337(5):289294. 
306   
307  A meta-analytic approach (random effects analysis using the DerSimonian and Laird method1) was used 
308  to estimate the pooled response rates and corresponding confidence intervals for no treatment and 
309  doxycycline, respectively. The following two approaches were used to calculate an estimate of the 
310  treatment effect of doxycycline: 
311   
312  1.  The difference of the lower bound of the doxycycline confidence interval and the upper bound of 
313  the no treatment confidence interval 
314   
315  2.  The difference of the meta-analytic point estimates with a corresponding confidence interval 
316   
317  Given the data come from separate sources, the first approach can be considered to provide a more 
318  conservative estimate of the treatment effect as compared to the second approach. Table 2 summarizes 
319  the response rates of no treatment from the U.S. natural history studies. The response rate reported for 
320  the Steere et al. 19792 study is based only on the cohort with onset in 1977 since a 6-month rate could 
321  not be determined from the data presented in the publication for the cohort with onset in 1976. The 
 
1 DerSimonian R and Laird N, 1986, Meta-Analysis in Clinical Trials, Control Clin Trials, 7(3):177188. 
 
2 Steere AC, Hardin JA, Ruddy S, Mummaw JG, and Malawista SE, 1979, Lyme Arthritis: Correlation of Serum and 
Cryoglobulin IgM with Activity, and Serum IgG with Remission, Arthritis Rheum, 22(5):471483. 
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322  Steere et al. 19803 study also reported on subjects with an onset in 1977 (a total of eight subjects). 
323  Because the study site was the same in both Steere publications, it is possible that these subjects are not 
324  unique. However, given the relatively small number reported in Steere et al. 1980 (eight subjects) as 
325  compared to Steere et al. 1979 (35 subjects), it will be assumed that the subjects in each study are 
326  unique. 
327   
328  Table 2: Absence of Objective Manifestations of Lyme Disease at 6-Month Follow-ups  Natural 
329  History (No Treatment) 
330   
Study  Response Ratea  Notes 
[n/N (%)] 
Steere et al.  23/35 (65.7)c  12 subjects developed arthritis ( CNS disease) 
1979b 
Steere et al.  31/55 (56.4)  24 subjects developed arthritis ( CNS disease) 
1980d 
Random  60.2, 95% CI (50.1, 70.3)   
effects meta-
analysis 
331  CNS  central nervous system, CI  confidence interval. 
332   
333  a Positive response was defined as the absence of arthritis or neurologic manifestations of early disseminated or late 
334  Lyme disease. 
335  b Steere AC, Hardin JA, Ruddy S, Mummaw JG, and Malawista SE, 1979, Lyme Arthritis: Correlation of Serum and 
336  Cryoglobulin IgM with Activity, and Serum IgG with Remission, Arthritis Rheum, 22(5):471483. 
337  c Based only on the cohort with onset in 1977. 
338  d Steere AC, Malawista SE, Newman JH, Spieler PN, and Bartenhagen NH, 1980, Antibiotic Therapy in Lyme Disease, 
339  Ann Intern Med, 93(1):18 
340   
341  The response rates of doxycycline from the U.S. studies for 20 to 21 days of treatment with doxycycline 
342  BID are summarized in Table 3. Subjects in the Massaroti et al. 19924 study were to receive 10 days of 
343  treatment with doxycycline. However, if symptoms were still present at day 10, the subject could receive 
344  an additional 10 days of treatment. Therefore, the study is being considered as a 20-day treatment for the 
345  efficacy assessment. The Dattwyler et al. 19975 study enrolled 10 of 72 (14 percent) subjects with signs 
346  of early disseminated Lyme disease (joint swelling, facial palsy, and carditis) and had a high 
347  unevaluable rate as compared to the other two studies. Given this difference in baseline characteristics, a 
348  meta-analyzed estimate for doxycycline was calculated for all three studies as well as by excluding the 
349  Dattwyler et al. 1997 study. 
350   
 
3 Steere AC, Malawista SE, Newman JH, Spieler PN, and Bartenhagen NH, 1980, Antibiotic Therapy in Lyme Disease, Ann 
Intern Med, 93(1):18. 
 
4 Massarotti EM, Luger SW, Rahn DW, Messner RP, Wong JB, Johnson RC, and Steere AC, 1992, Treatment of Early Lyme 
Disease, Am J Med, 92(4):396403. 
 
5 Dattwyler RJ, Luft BJ, Kunkel MJ, Finkel MF, Wormser GP, Rush TJ, Grunwaldt E, Agger WA, Franklin M, Oswald D, 
Cockey L, and Maladorno D, 1997, Ceftriaxone Compared with Doxycycline for the Treatment of Acute Disseminated Lyme 
Disease, N Engl J Med, 337(5):289294. 
11  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
351  Table 3: Absence of Objective Manifestations of Lyme Disease at 6-Month Follow-ups: 
352  Doxycycline Twice-a-Day Regimen Studies for 20 to 21 Days 
353   
Study  Response Rate  Notes 
[n/N (%)] 
Dattwyler et al. 1990a  35/37 (94.6)  No true failure, 2 unevaluable 
Massaroti et al. 1992b  20/22 (90.9)  1 true failure (facial palsy), 1 
unevaluable 
Dattwyler et al. 1997c  54/72 (75.0)  1 true failure (arthritis), 17 unevaluable 
Random effects meta-    
analysis   
All 3  87.0, 95% CI (74.7, 99.4) 
Excluding Dattwyler et  93.6, 95% CI (87.4, 99.8) 
al. 1997 
354  CI  confidence interval. 
355   
356  a Dattwyler RJ, Volkman DJ, Conaty SM, Platkin SP, and Luft BJ, 1990, Amoxycillin Plus Probenecid Versus Doxycycline 
357  for Treatment of Erythema Migrans Borreliosis, Lancet, 336(8728):14041406. 
358  b Massarotti EM, Luger SW, Rahn DW, Messner RP, Wong JB, Johnson RC, and Steere AC, 1992, Treatment of Early Lyme 
359  Disease, Am J Med, 92(4):396403. 
360  c Dattwyler RJ, Luft BJ, Kunkel MJ, Finkel MF, Wormser GP, Rush TJ, Grunwaldt E, Agger WA, Franklin M, Oswald D, 
361  Cockey L, and Maladorno D, 1997, Ceftriaxone Compared with Doxycycline for the Treatment of Acute Disseminated Lyme 
362  Disease, N Engl J Med, 337(5):289294. 
363   
364  From the natural history studies, the meta-analyzed estimate of the absence of objective manifestations 
365  of Lyme disease at 6-month follow-ups for no treatment is 60.2 percent with an upper bound of the 95 
366  percent confidence interval of 70.3 percent. From all three therapeutic studies, the meta-analyzed 
367  estimate of the absence of objective manifestations of Lyme disease at 6-month follow-ups for treatment 
368  with doxycycline is 87.0 percent with a lower bound of the 95 percent confidence interval of 74.7 
369  percent. Thus, the treatment effect of doxycycline over no treatment can be estimated to be at least 4.4 
370  percent. If the Dattwyler et al. 1997 study is excluded from the meta-analyzed estimate for doxycycline 
371  treatment, the estimate is 93.6 percent with a lower bound of the 95 percent confidence interval of 87.4 
372  percent. A conservative estimate of the treatment effect would then be 17.1 percent.  
373   
374  When considering the (doxycycline  no treatment) difference in estimated response rates, the estimated 
375  difference between doxycycline (all three studies) and no treatment is 26.8 percent with a 95 percent 
376  confidence interval of (10.9, 42.7) and the difference between doxycycline (excluding the Dattwyler et 
377  al. 1997 study) and no treatment is 33.4 percent with a 95 percent confidence interval of (21.6, 45.2). 
378  Regardless of the approach taken to estimate the treatment effect, there appears to be a positive effect of 
379  treatment with doxycycline on the absence of objective manifestations of Lyme disease at 6-month 
380  follow-ups as compared to no treatment. These results are summarized in Table 4. 
381   
12  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
382  Table 4: Estimate of Treatment Effect of Doxycycline 100 Milligrams Twice a Day for 20 to 21 
383  Days 
384   
Approach  Estimate 
Difference of lower bound of doxycycline 95% CI (3 studies) and  74.7  70.3 = 4.4% 
upper bound of no treatment 95% CI 
Difference of lower bound of doxycycline 95% CI (excluding  87.4  70.3 = 17.1% 
Dattwyler et al. 1997a) and upper bound of no treatment 95% CI 
Difference in estimated response rates with 95% CI   
     Between doxycycline (3 studies) and no treatment  87.0  60.2 = 26.8% 
  95% CI (10.9, 42.7) 
   
     Between doxycycline (excluding Dattwyler et al. 1997) and no  93.6  60.2 = 33.4% 
treatment  95% CI (21.6, 45.2) 
385  CI  confidence interval. 
386   
387  a Dattwyler RJ, Luft BJ, Kunkel MJ, Finkel MF, Wormser GP, Rush TJ, Grunwaldt E, Agger WA, Franklin M, Oswald D, 
388  Cockey L, and Maladorno D, 1997, Ceftriaxone Compared with Doxycycline for the Treatment of Acute Disseminated Lyme 
389  Disease, N Engl J Med, 337(5):289294. 
390   
391  Estimates of the treatment effect of doxycycline (M ) can range from 4.4 to 22 percent, see Table 4. As 
1
392  noted in Table 3, there were very few true treatment failures in the doxycycline studies because most of 
393  those classified as nonresponders had unevaluable outcomes. Conversely, the nonresponders in the 
394  natural history studies were true treatment failures because of development of arthritis (plus or minus 
395  central nervous system disease). Given the high rate of unevaluable subjects in the Dattwyler et al. 1997 
396  study, an M  estimate of 17.1 to 21.6 appears most reasonable. However, if the rate of early 
1
397  disseminated Lyme disease (acute neurological, cardiac, or joint involvement) is expected to be higher 
398  than 14 percent in an NI trial, the estimate of M  might need to be reconsidered. An appropriate NI 
1
399  margin for a trial in early Lyme disease with doxycycline as the active control is 10 percent, which 
400  would preserve 40 to 50 percent of this effect.   
13