Objective stated in the publication

“To compare the efficacy of pritelivir with valacyclovir for suppression of genital HSV-2 infection.” (opens the source at this quote in a new tab)
“In the present study, pritelivir was compared with valacyclovir for reduction of genital HSV shedding and lesions in persons with recurrent genital herpes.” (opens the source at this quote in a new tab)

Research question stated in the publication

“Is pritelivir more effective than valacyclovir for suppression of genital herpes simplex virus 2 (HSV-2) shedding in patients with frequent recurrences?” (opens the source at this quote in a new tab)

Purpose of comparing pritelivir with valacyclovir early in development

“The comparison between pritelivir to valacyclovir early in the drug development process aimed to understand the balance between efficacy and safety.” (opens the source at this quote in a new tab)

Aim stated in the registry record

“The aim of the study is to evaluate the safety and efficacy of "AIC316 (pritelivir)" 100 mg once daily compared to valacyclovir 500 mg once daily for the prevention of HSV-2 genital shedding.” (opens the source at this quote in a new tab)

Sites and conduct period in the publication

“The study was conducted at 4 clinical research centers located in Seattle, Washington; Portland, Oregon; Indianapolis, Indiana; and Houston, Texas, between October 2012 and July 2013.” (opens the source at this quote in a new tab)

Dates of the FDA clinical hold and of study termination

“On May 9, 2013, the US Food and Drug Administration (FDA) imposed a clinical hold (an order to the sponsor to suspend ongoing investigation), based on hematologic and dermatologic findings such as dry skin, crusty skin lesions, and alopecia in a chronic toxicity study involving monkeys. Because the duration of the clinical hold was uncertain, the sponsor terminated the study on June 24, 2013.” (opens the source at this quote in a new tab)

Study dates and status in the registry record

Field	Registry entry
Recruitment status	“Terminated”
Study start	“2012-10”
Primary completion (actual)	“2013-05”
Study completion (actual)	“2013-07”
Results first posted	“2023-04-21”

Study locations in the registry record

“This study has 4 locations” (opens the source at this quote in a new tab)

Location	Facility
“Indianapolis, Indiana, United States, 46202”	“Indiana University School of Medicine, IU Infectious Diseases Research”
“Portland, Oregon, United States, 97210”	“Westover Heights Clinic”
“Houston, Texas, United States, 77030”	“University of Texas Health Science Centre, Center for Clincial Studies”
“Seattle, Washington, United States, 98104”	“University of Washington, Virology Research Clinic”

Phase 2, randomized, double-blind, crossover design

“A phase 2, randomized, double-blind, crossover clinical trial at clinical research centers in 4 US cities (October 2012-July 2013) compared daily oral doses of 100 mg of pritelivir with 500 mg of valacyclovir.” (opens the source at this quote in a new tab)
“Participants took the first drug for 28 days followed by 28 days of washout before taking the second drug for 28 days.” (opens the source at this quote in a new tab)

Randomization method and strata

“Randomization was conducted centrally with random-number generators using a dynamic scheme to ensure treatment balance overall and within strata, allocating each subsequent participant to the least populated group, or in the case of ties, using a pregenerated random-number list to determine assignment; the strata used were sex and study site.” (opens the source at this quote in a new tab)

Masking with matching placebo and encapsulated valacyclovir

“Valacyclovir was encapsulated and placebo tablets or capsules were manufactured to be indistinguishable from active agents to permit blinding of participants and investigators.” (opens the source at this quote in a new tab)

Swab collection four times daily, symptom diary, and lesion-free start of each period

“Participants were required to be free of genital lesions on the first day of each treatment period. Throughout the two 28-day treatment periods, participants obtained swabs from their genital area 4 times during each 24-hour period, approximately 6 to 8 hours apart.” (opens the source at this quote in a new tab)
“If a lesion consistent with genital herpes developed, an additional swab was obtained from the lesion at home and participants came to clinic for evaluation. Participants maintained a diary of genital lesions and symptoms, and recorded adherence to the swabbing procedure and the study drugs.” (opens the source at this quote in a new tab)

HSV DNA assay, positivity threshold, and resistance monitoring

“Samples of genital secretions were tested for HSV DNA with a real-time, quantitative polymerase chain reaction TaqMan assay at the University of Washington Virology Laboratory.” (opens the source at this quote in a new tab)
“Swabs were considered positive for HSV when at least 150 (2.2 log10) HSV DNA copies per mL were detected.” (opens the source at this quote in a new tab)
“To monitor potential signals of drug-resistance, HSV detected during administration of pritelivir at more than 5000 copies of DNA per mL were sequenced in the resistance-associated regions within UL5 and UL52 of HSV-2.” (opens the source at this quote in a new tab)

Safety assessments and adverse event grading

“Safety of the study drugs was evaluated with a weekly history and physical examination; laboratory assays for hematology, metabolic panel, and liver function tests; and an electrocardiogram during each treatment period. All adverse events were graded using the division of acquired immunodeficiency syndrome (DAIDS) table of adverse events.” (opens the source at this quote in a new tab)

Rationale for the crossover design, its drawbacks, and the washout period

“A crossover design of the trial allowed participants to be their own controls. This design is more efficient relative to a parallel group study of the same size because in patients with established genital HSV-2 infection, shedding and recurrence rates have been shown to be stable over months and shedding rates are highly variable between persons; thus, studying within-person changes allows for a more precise estimate of treatment efficacy.” (opens the source at this quote in a new tab)
“A potential drawback to this design occurs if either there are temporal trends that affect shedding rates over time, if the effect of the first drug remains after the second drug is initiated, or if there are high dropout rates, which would make within-participant comparisons unfeasible.” (opens the source at this quote in a new tab)
“The placebo-controlled trial of pritelivir suggested that a month-long washout period is sufficient because shedding rates returned to baseline within 2 weeks of drug cessation.” (opens the source at this quote in a new tab)

Within-person comparison as described by the investigators' institution

“Because the viral shedding rate is highly variable from person to person but relatively stable within the same person, the trial was designed to compare the two drugs within rather than between people.” (opens the source at this quote in a new tab)

Design fields in the registry record

Field	Registry entry
Official title	“A Double-blind, Double Dummy, Randomized Crossover Trial to Compare the Effect of "AIC316 (Pritelivir)" 100 mg Once Daily Versus Valacyclovir 500 mg Once Daily on Genital HSV Shedding in HSV-2 Seropositive Adults.”
Other study identifier	“AIC316-01-II-02”
Phase	“Phase 2”
Allocation	“Randomized”
Interventional model	“Crossover Assignment”
Masking	“Triple”
Primary purpose	“Prevention”
Sponsor	“AiCuris Anti-infective Cures AG”
Collaborator	“Medpace, Inc.”

Detailed description in the registry record

“Enrolled patients with Mucocutaneous genital HSV, will be randomized to receive either AIC326 or Valacyclovir first and then will be crossed over to receive the opposite Intervention. The study will consist of two treatment periods of 28 days separated by a washout period of 28 days.” (opens the source at this quote in a new tab)

Funding and role of the sponsor

“This study was supported by AiCuris GmbH & Co KG.” (opens the source at this quote in a new tab)
“The study was designed collaboratively by investigators at University of Washington and AiCuris. AiCuris had a role in the conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript. The sponsor did not have the right to prevent submission or publication of the data. The statistical analyses reported herein were conducted independently at the University of Washington.” (opens the source at this quote in a new tab)

Inclusion criteria in the publication

“Eligible participants included healthy adults who were aged 18 years or older, HSV-2 seropositive, HIV seronegative, hepatitis B and C negative, and had a history of 4 to 9 genital herpes recurrences in the last year or in the year prior to starting suppressive antiviral therapy.” (opens the source at this quote in a new tab)
“Participants had to agree to use effective contraception, refrain from using any anti-HSV therapy for 7 days prior to and during the treatment period, and be willing to complete all trial procedures.” (opens the source at this quote in a new tab)

Exclusion criteria and dietary restrictions in the publication

“Exclusion criteria were pregnancy, nursing, malignancy or immunosuppression, steroid administration, other immunosuppressive medications, or medications that induced drug-metabolizing enzymes or transporters. In addition, participants had to avoid grapefruit and products containing quinine or quinidine during the study.” (opens the source at this quote in a new tab)

Inclusion criteria in the registry record

“Adult, immunocompetent men and women in good health of any ethnic group” (opens the source at this quote in a new tab)
“Seropositive for Herpes Simplex Virus Type 2 (HSV-2)” (opens the source at this quote in a new tab)
“History of recurrent episodes (>=4 to <=9) of genital herpes for at least 12 months and willingness to obtain 4 swabs per day.” (opens the source at this quote in a new tab)

Exclusion criteria in the registry record

“Present episode of genital herpes at time of randomization” (opens the source at this quote in a new tab)
“Clinically relevant acute or chronic infections (excluding HSV-2)” (opens the source at this quote in a new tab)
“Known intolerance to valacyclovir, acyclovir, or any component of the formulation” (opens the source at this quote in a new tab)
“Documented HSV resistance to acyclovir, valacyclovir, famciclovir or penciclovir” (opens the source at this quote in a new tab)

Age, sex, and healthy volunteer fields in the registry record

Field	Registry entry
Ages eligible for study	“18 Years and older (Adult, Older Adult )”
Sexes eligible for study	“All”
Accepts healthy volunteers	“No”

Pritelivir 100 mg daily after a 400 mg loading dose, and valacyclovir 500 mg daily

“In this randomized, double-blind, double-dummy crossover trial, participants received 100 mg of oral pritelivir (after a loading dose of 400 mg on day 1) plus placebo or 500 mg of valacyclovir plus placebo daily for 28 days, followed by a 28-day washout period, and then 28 days of the other drug with matching placebo and 28 days of follow-up.” (opens the source at this quote in a new tab)

Rationale for the pritelivir dose

“The dose of 100 mg of pritelivir daily was chosen based on phase 1 and 2 studies suggesting safety and tolerability of this regimen and also on the high efficacy of 75 mg of pritelivir in suppressing viral shedding in the prior trial.” (opens the source at this quote in a new tab)

Treatment sequences in the registry record

“Participants first received AIC316 100 mg once daily for 28 days. After a washout period of 28 days, they then received Valacyclovir 500 mg once daily for 28 days.” (opens the source at this quote in a new tab)
“Participants first received Valacyclovir 500 mg once daily for 28 days. After a washout period of 28 days, they then received AIC316 100 mg once daily for 28 days.” (opens the source at this quote in a new tab)

Measurement of adherence, and adherence to swabs and study drug

“Adherence was calculated as the proportion of the expected amount of the drug taken and calculated by pill counts of returned blister pack. Adherence to swabs was defined as the proportion of swabs returned of expected.” (opens the source at this quote in a new tab)
“In both groups, more that 96% of participants collected at least 80% of the expected genital swabs. Adherence to the study drug was very high, as measured by returned study medication, with 93% of persons reporting having taken at least 95% of prescribed doses.” (opens the source at this quote in a new tab)

Half-lives of acyclovir and pritelivir as stated by the investigators

“The drugs also have a difference in their half-lives, with acyclovir having a half-life of 3 hours and pritelivir of 50 to 80 hours.” (opens the source at this quote in a new tab)

Primary endpoint defined in the publication

“The primary end point was the intent-to-treat comparison of within-participant HSV shedding, defined as the number of swabs that tested positive for HSV per study participant relative to the total number of swabs collected per participant, during pritelivir vs valacyclovir therapy.” (opens the source at this quote in a new tab)

Primary outcome measures in the registry record

“Subjects were assessed for within-subject genital HSV mucocutaneous shedding rate, as calculated by the number of HSV-positive swabs per subject relative to the total number of swabs collected per subject. The swab test detects the presence of herpes virus DNA. A swab was regarded as positive for HSV-DNA if at least 3 HSV genome copies were detected by quantitative PCR per reaction (equaling 150 copies per mL of swab collection medium). When multiple swabs were available from the same time point (e.g., genital and lesional swab), the swab with the highest copy number was retained for computation of the shedding rate.” (opens the source at this quote in a new tab)
“Subjects were assessed for overall shedding rate as the total number of HSV-positive swabs per treatment group divided by the number of swabs collected per treatment group.” (opens the source at this quote in a new tab)

Advantages of shedding over recurrences as a trial outcome

“Several advantages to using HSV shedding as an outcome rather than recurrences are apparent. First, HSV shedding occurs more commonly than HSV genital lesions. While >65% of our study population had HSV-2 DNA detected in their genital swab samples, only about 40% of participants noted genital lesions.” (opens the source at this quote in a new tab)
“As such, studies that use shedding as an outcome require relatively fewer participants to achieve similar power and therefore provide potential efficiency in terms of recruitment time and staffing costs (although PCR assays for HSV DNA detection incur additional laboratory costs). Second, we showed that HSV shedding rates were consistent within persons over time.” (opens the source at this quote in a new tab)

Proportion of the valacyclovir effect on lesions and recurrences explained by shedding

“Similarly, evaluation of valacyclovir versus placebo showed that 53% and 40% of the drug’s effect on the lesion rate and recurrence rate, respectively, were due to valacyclovir’s effect on HSV shedding (Table 2).” (opens the source at this quote in a new tab)
“In this study, using lesion and recurrence rates as outcomes, we achieved values of 40%–82% for the PTE explained through shedding; these large values further confirm HSV shedding is a precursor in the causal pathway to genital lesions.” (opens the source at this quote in a new tab)

Shedding as an indicator of transmission potential

“Unlike surrogates that serve as biomarkers for disease activity or treatment response, genital HSV shedding is also an important indicator for the potential to transmit the infection to sex partners.” (opens the source at this quote in a new tab)
“While viral shedding is required for HSV-2 transmission to either partner or neonate, the relationship between the viral shedding during a given sexual encounter and the risk of transmission is unlikely to ever be empirically verified and can only be modeled” (opens the source at this quote in a new tab)

Secondary endpoints and definition of a shedding episode

“Secondary end points included a comparison of copy number of the HSV DNA on the days that HSV was detected, HSV shedding on days with and without lesions, frequency of lesions, and frequency of episodes. An episode was defined as an event in which consecutive swabs tested positive for HSV DNA and were preceded and followed by swabs that tested negative. Additional secondary analyses evaluated the duration of pain, shedding episodes, and recurrences.” (opens the source at this quote in a new tab)

Endpoints as described in the company release

“The primary endpoint of the study was within-participant genital HSV shedding, defined as number of HSV positive swabs relative to the total number of swabs per participant, while receiving pritelivir compared with valacyclovir. Secondary endpoints included clinical outcomes such as days with genital lesions and frequency of pain.” (opens the source at this quote in a new tab)

Sample size calculation and planned enrollment

“The sample size estimate for the primary efficacy end point was based on the anticipated occurrence of genital shedding, defined as the number of swabs that tested positive for HSV for study participants relative to the total numbers of swabs collected from each participant. We estimated HSV shedding at 5% during valacyclovir administration and 1% to 2% during pritelivir therapy.” (opens the source at this quote in a new tab)
“Using a crossover design with 80% power, 5% type 1 error, and a discontinuation rate of 6%, we planned to screen 120 volunteers and randomize 90. However, after trial initiation, the decision was made to increase enrollment to 98 because of concern for the possibility that a greater number of participants would drop out given the burden of the study procedures.” (opens the source at this quote in a new tab)
“The planned sample size was 98 adults, allowing for detection of a 50% reduction in viral shedding between the study treatments.” (opens the source at this quote in a new tab)

Participants screened, randomized, and treated

“Of 150 screened participants, 91 were randomized (45 to receive pritelivir first) and took at least 1 dose of the study drug (Figure 1). The most common cause of ineligibility was lack of HSV-2 antibody (n = 11). Seventy-five participants received pritelivir and 76 received valacyclovir.” (opens the source at this quote in a new tab)

Participants in the primary and per-protocol analyses

“The 88 persons included in primary analysis took at least 1 dose and provided at least 1 swab during the first period.” (opens the source at this quote in a new tab)
“Per-protocol analyses conducted on 51 persons who completed study medication without protocol deviations” (opens the source at this quote in a new tab)

Participants contributing to efficacy analyses by first-period assignment

Measure	Pritelivir first, n = 45	Valacyclovir first, n = 46	Total, n = 91
Contributed to efficacy analyses, number (%)	“44 (98)”	“44 (96)”	“88 (97)”
Swabs obtained during study, median (range)	“213 (2-231)”	“214 (13-222)”	“214 (2-231)”

Swabs collected during each treatment

“Overall, 7276 swabs were collected during pritelivir and 7453 swabs were collected during valacyclovir treatment (Table 2).” (opens the source at this quote in a new tab)

Participants enrolled, analyzed, and at risk in the registry results

Measure	AIC316 (pritelivir)	Valacyclovir
Participants analyzed for the primary outcome measures	“76”	“76”
Participants at risk for adverse events	“77”	“78”

Field	Registry entry
Enrollment (actual)	“91”

Intent-to-treat, per-protocol, and safety populations

“The intent-to-treat analyses included all randomized participants who received at least 1 dose of the study drug and obtained at least 1 genital swab; per-protocol analyses excluded persons with major protocol deviations, including early discontinuation of the study or study medication. The first day of treatment was excluded from efficacy analyses. Safety analyses included all randomized participants who received at least 1 dose of the study drug. Missing data were not imputed.” (opens the source at this quote in a new tab)

Statistical model, period and carryover tests, and significance level

“The analysis was conducted using a nonlinear mixed-effects model with a log link with a random intercept for each participant to account for extra-Poisson variability.” (opens the source at this quote in a new tab)
“Period and carryover effects were examined at a 10% significance level using, respectively, a term for time period and an interaction term between the treatment group and time period. Analyses of duration used Wilcoxon signed rank test.” (opens the source at this quote in a new tab)
“Statistical significance was defined as a 2-sided P value of <.05. Analyses were performed using SAS 9.4 statistical software (SAS Institute Inc).” (opens the source at this quote in a new tab)

Full analysis set and safety reporting in the registry results

“All subjects who received at least one dose of trial medication and provided at least 1 analyzable genital-perianal swab (not including the training swab) during the treatment period were included in the efficacy analysis (Full Analysis Set).” (opens the source at this quote in a new tab)
“All randomized subjects assign to a treatment sequence.” (opens the source at this quote in a new tab)
“AE reporting is based on the safety set versus the full analysis set” (opens the source at this quote in a new tab)

Randomization and completion at study termination

“Ninety-one participants were randomized: 45 to receive pritelivir and 46 to receive valacyclovir first when the US Food and Drug Administration placed the trial on clinical hold based on findings in a concurrent nonclinical toxicity study, and the sponsor terminated the study.” (opens the source at this quote in a new tab)
“At the time of the study termination, 74 participants completed their first treatment period and 56 completed both treatment periods.” (opens the source at this quote in a new tab)

Participant randomized in error

“One participant was randomized in error and discontinued from the study due to a prolonged QT interval that was noted prior to initiating therapy with pritelivir.” (opens the source at this quote in a new tab)

Screening outcomes in the registry results

“150 subjects were screened, 59 were screen failures (did not meet study eligibility requirements: 35, withdrawal of Consent 1, Lost to Follow-up 1, Other 22). 91 subjects were randomized.” (opens the source at this quote in a new tab)

Participant flow by period and treatment sequence in the registry results

Period	Milestone	AIC316 (pritelivir), then valacyclovir	Valacyclovir, then AIC316 (pritelivir)
Period 1: first intervention (28 days)	Started	“45”	“46”
Period 1: first intervention (28 days)	Completed	“38”	“36”
Period 1: first intervention (28 days)	Not completed	“7”	“10”
Washout period (28 days)	Started	“38”	“36”
Washout period (28 days)	Completed	“32”	“32”
Washout period (28 days)	Not completed	“6”	“4”
Period 2: second intervention (28 days)	Started	“32”	“32”
Period 2: second intervention (28 days)	Completed	“29”	“27”
Period 2: second intervention (28 days)	Not completed	“3”	“5”

Reasons for not completing by period and treatment sequence in the registry results

Period	Reason	AIC316 (pritelivir), then valacyclovir	Valacyclovir, then AIC316 (pritelivir)
Period 1	“Withdrawal by Subject”	“1”	“0”
Period 1	“Adverse Event”	“1”	“2”
Period 1	“Termination of the Study by the Investigator or Sponsor”	“5”	“6”
Period 1	“Protocol Violation”	“0”	“1”
Period 1	“Patient was non-compliant with study medication, swabbing and maintaining diary”	“0”	“1”
Washout period	“Withdrawal by Subject”	“1”	“1”
Washout period	“Termination of the Study by the Investigator or Sponsor”	“5”	“3”
Period 2	“Withdrawal by Subject”	“0”	“1”
Period 2	“Termination of the Study by the Investigator or Sponsor”	“3”	“4”

Completion as described by the investigators' institution

“Fifty-six participants had completed both treatment periods when the study was terminated due to the FDA hold.” (opens the source at this quote in a new tab)

Sequence allocation and reduced participant number as printed in the company release

“In the double-blind, randomized crossover study 91 participants with recurrent genital herpes but not with an active outbreak were randomized to receive daily oral doses of 100 mg pritelivir over 28 days followed by a 28-day wash-out period before taking 500 mg valacyclovir for 28 days (n=46) or to start the treatment cycle with valacyclovir first (n=45).” (opens the source at this quote in a new tab)
“The reduced number of patients was due to the termination of the study following the placement of a clinical hold by the US Food and Drug Administration based on findings in a concurrent nonclinical toxicity study. In 2016 the FDA partially lifted the clinical hold for the treatment of specific patient populations.” (opens the source at this quote in a new tab)

Age, sex, race, time since acquisition, and recurrence frequency

“The median age of participants was 48 years; 57 (63%) were women; and 66 (72%) were white (Table 1). The median time from HSV-2 acquisition was 17 years and the median number of recurrences in the year prior was 5 (range, 4-9 years). The demographic and clinical characteristics were similar in participants initially randomized to pritelivir and those initially randomized to valacyclovir.” (opens the source at this quote in a new tab)

Demographic and clinical characteristics by first-period assignment in the publication

Characteristic	Pritelivir first, n = 45	Valacyclovir first, n = 46	Total, n = 91
Age, median (range), years	“46 (21-66)”	“50 (21-61)”	“48 (21-66)”
Women, number (%)	“28 (62)”	“29 (63)”	“57 (63)”
White, number (%)	“37 (82)”	“29 (63)”	“66 (72)”
HSV-2 antibody only, number (%)	“27 (60)”	“27 (59)”	“54 (59)”
HSV-1 and HSV-2 antibody, number (%)	“18 (40)”	“19 (41)”	“37 (41)”
Years since HSV-2 acquisition, median (range)	“15 (1-41)”	“20 (1-42)”	“17 (1-42)”
Recurrences per year before the study, median (range)	“5 (4-9)”	“5 (4-9)”	“5 (4-9)”
Suppressive therapy before study entry, number (%)	“5 (11)”	“7 (15)”	“12 (13)”

Demographics by treatment sequence in the registry results

Characteristic	AIC316 (pritelivir), then valacyclovir, n = 45	Valacyclovir, then AIC316 (pritelivir), n = 46	Total, n = 91
Age, mean (standard deviation), years	“45.2 (13.22)”	“45.5 (11.4)”	“45.4 (12.26)”
Female, count (%)	“28”( “62.2%”)	“29”( “63.0%”)	“57”( “62.6%”)
Male, count (%)	“17”( “37.8%”)	“17”( “37.0%”)	“34”( “37.4%”)
Hispanic or Latino, count (%)	“7”( “15.6%”)	“7”( “15.2%”)	“14”( “15.4%”)
Not Hispanic or Latino, count (%)	“38”( “84.4%”)	“39”( “84.8%”)	“77”( “84.6%”)
American Indian or Alaska Native, count (%)	“0”( “0.0%”)	“0”( “0.0%”)	“0”( “0.0%”)
Asian, count (%)	“0”( “0.0%”)	“2”( “4.3%”)	“2”( “2.2%”)
Native Hawaiian or other Pacific Islander, count (%)	“0”( “0.0%”)	“1”( “2.2%”)	“1”( “1.1%”)
Black or African American, count (%)	“7”( “15.6%”)	“9”( “19.6%”)	“16”( “17.6%”)
White, count (%)	“37”( “82.2%”)	“29”( “63.0%”)	“66”( “72.5%”)
More than one race, count (%)	“1”( “2.2%”)	“5”( “10.9%”)	“6”( “6.6%”)

Primary endpoint: genital HSV shedding during pritelivir and valacyclovir treatment

“Herpes simplex virus was detected in 173 of 7276 swabs (2.4%) obtained during pritelivir treatment and 392 of 7453 swabs (5.3%) obtained during valacyclovir treatment. The frequency of detection of HSV in genital swabs was lower during pritelivir treatment than during valacyclovir treatment (relative risk [RR], 0.42; 95% CI, 0.21-0.82; P = .012; Table 2 and Figure 2A).” (opens the source at this quote in a new tab)

Virologic end points by treatment in the publication

End point	Pritelivir, n = 75	Valacyclovir, n = 76	Relative risk or difference in copy number, pritelivir vs valacyclovir (95% CI)	P value
Genital HSV shedding, overall, number of swabs/total (%)	“173/7276 (2.4)”	“392/7453 (5.3)”	“0.42 (0.21 to 0.82)”	“.01”
Genital HSV shedding, subclinical, number of swabs/total (%)	“127/6989 (1.8)”	“284/6984 (4.1)”	“0.40 (0.20 to 0.81)”	“.01”
Genital HSV shedding, lesional, number of swabs/total (%)	“40/134 (29.9)”	“106/294 (37.1)”	“0.86 (0.22 to 3.30)”	“.76”
Shedding episodes/person-months	“78/60”	“97/61”	“0.80 (0.52 to 1.22)”	“.29”
HSV DNA log10 copies/mL, overall, mean (SD)	“3.2 (1.2)”	“3.7 (1.3)”	“−0.1 (−0.6 to 0.5)”	“.83”
HSV DNA log10 copies/mL on days with no lesions, mean (SD)	“2.8 (0.6)”	“3.3 (1.0)”	“−0.3 (−0.5 to −0.1)”	“<.001”
HSV DNA log10 copies/mL on days with lesions, mean (SD)	“4.4 (1.3)”	“4.8 (1.4)”	“0.7 (0.3 to 1.0)”	“<.001”

Clinical end points by treatment in the publication

End point	Pritelivir, n = 75	Valacyclovir, n = 76	Relative risk, pritelivir vs valacyclovir (95% CI)	P value
Days with lesions, number/total (%)	“35/1855 (1.9)”	“75/1900 (3.9)”	“0.40 (0.17 to 0.96)”	“.04”
Recurrences/person-months	“11/61”	“18/63”	“0.65 (0.35 to 1.22)”	“.18”

Incidence rates per person-month and durations by treatment in the publication

Measure	Pritelivir, n = 75	Valacyclovir, n = 76	P value
Duration of shedding episodes, median (IQR), hours	“6.0 (6.0 to 12.0)”	“6.0 (6.0 to 36.0)”	“.06”
Duration of recurrences, median (IQR), days	“3.0 (1.0 to 4.0)”	“5.0 (3.0 to 6.0)”	“.10”

Measure	Pritelivir, n = 75	Valacyclovir, n = 76
Shedding episodes, incidence rate per person-month	“1.3”	“1.6”
Recurrences, incidence rate per person-month	“0.2”	“0.3”

Quantity of HSV DNA in positive swabs

“The HSV copy number on the days that HSV was detected did not differ by group: for a mean 3.2 log10 copies/mL during pritelivir treatment vs a mean 3.7 log10 copies/mL during valacyclovir treatment (P = .83; Figure 2B).” (opens the source at this quote in a new tab)

Subclinical shedding and shedding on days with lesions

“The frequency of subclinical shedding was significantly lower during pritelivir treatment than during valacyclovir treatment, 1.8% vs 4.1% (RR, 0.40; 95% CI, 0.20-0.81; P = .01; Figure 2C). The rate of shedding when patients reported genital lesions was not significantly different during pritelivir and valacyclovir treatment, 29.9% vs 37.1% (P = .76).” (opens the source at this quote in a new tab)

Frequency and duration of shedding episodes

“The frequency of shedding episodes was not found to differ by treatment, with 1.3 per person-months while taking pritelivir and 1.6 per person-months while taking valacyclovir (RR, 0.80; 95% CI, 0.52-1.22; P = .29). The proportion of episodes lasting less than 24 hours was higher during receipt of pritelivir vs valacyclovir (87% vs 69%, P = .005; eFigure 1 in Supplement 3).” (opens the source at this quote in a new tab)

Days with genital lesions and recurrences

“The overall frequency of genital lesions was low, with participants reporting lesions on only 2.9% of days. However, genital lesions were reported on 1.9% of days during pritelivir treatment compared with 3.9% of days during valacyclovir administration (RR, 0.40; 95% CI, 0.17-0.96; P = .04; Figure 3).” (opens the source at this quote in a new tab)
“Twenty participants experienced at least 1 recurrence during the study. The median duration of recurrences did not differ by treatment group.” (opens the source at this quote in a new tab)

Period and carryover effects

“No period or carryover effects were found for genital shedding or lesion occurrence.” (opens the source at this quote in a new tab)

Subgroup analyses by sex, age, and duration of genital herpes

“Subgroup analyses by sex, age, and duration of genital herpes showed potentially stronger reductions in shedding and lesions for women and for those younger than 50 years. However, this study was not designed to compare efficacy between groups; and group differences were not tested statistically.” (opens the source at this quote in a new tab)

Per-protocol and sensitivity analyses

“Per-protocol analyses conducted on 51 persons who completed study medication without protocol deviations also showed similar results (eTable 1 in Supplement 3), except HSV quantity was significantly lower during treatment with pritelivir (pritelivir, log10 2.9 vs valacyclovir, log10 3.7, P < .001) and median duration of recurrences was not significantly lower during pritelivir treatment (3.0 days vs 6.0 days, P = .050). A sensitivity analysis that excluded the initial week of each group was also consistent (eTable 2 in Supplement 3).” (opens the source at this quote in a new tab)

Resistance sequencing of swabs collected during pritelivir treatment

“Fifty-five swabs collected during pritelivir administration contained HSV DNA of more than 5000 copies/mL. Fifty-four were sequenced for UL5 and 55 were sequenced for UL52. No change from the reference sequence (HSV-2 strain HG52, accession No. NC_001798.1) was detected in any of the samples.” (opens the source at this quote in a new tab)

Primary outcome measures in the registry results

Measure	AIC316 (pritelivir)	Valacyclovir
Participants analyzed	“76”	“76”
Within-subject shedding rate, mean (standard deviation), percentage of positive swabs per subject	“2.3 (5.2)”	“4.9 (10.8)”
Overall shedding rate, percentage of positive swabs	“2.4”	“5.2”

Statistical analysis of the within-subject shedding rate in the registry results

Field	Registry entry
Comparison type	“SUPERIORITY”
Method	“non-linear mixed effects model”
Estimation parameter	“Risk Ratio (RR)”
Estimated value	“0.43”
95% confidence interval, lower limit	“0.30”
95% confidence interval, upper limit	“0.63”
P value	“<0.0001”

Findings and conclusion stated in the publication

“In this double-blind, randomized crossover study of 91 adults with recurrent genital herpes, the percentage of genital swabs with HSV detected over 28 days was significantly lower during use of pritelivir than use of valacyclovir (2.4% vs 5.3%).” (opens the source at this quote in a new tab)
“Among adults with frequently recurring genital HSV-2, the use of pritelivir compared with valacyclovir resulted in a lower percentage of swabs with HSV detection over 28 days. Further research is needed to assess longer-term efficacy and safety.” (opens the source at this quote in a new tab)

Results as reported in the company release

“Analysis of a total of nearly 15,000 genital swabs showed HSV shedding of 2.4% during pritelivir treatment compared to 5.3% during valacyclovir treatment, meeting the primary endpoint with a p value of 0.012. Pritelivir also showed superior clinical characteristics with genital lesions of 1.9% of days versus 3.9% of days under valacyclovir treatment and pain of 4.0% of days versus 6.7% of days respectively.” (opens the source at this quote in a new tab)

Shedding rate predicted by a mathematical model before comparison with the trial result

“We performed 10 simulations of a 90 participant trial at 100 mg daily and obtained a median shedding rate of 1.7% (range: 0.6% – 2.7%). In a subsequent trial of 91 participants who performed swabs every 6 hours in which pritelivir 100 mg daily was compared to valacyclovir 500 mg daily, the shedding rate on pritelivir was 2.4% (173 of 7276 swabs positive for HSV DNA)” (opens the source at this quote in a new tab)

Days with pain recorded by participants

“The proportion of days with pain was 4.0% while taking pritelivir and 6.7% while taking valacyclovir (RR, 0.53; 95% CI, 0.30-0.93; P = .03).” (opens the source at this quote in a new tab)

End point	Pritelivir, n = 75	Valacyclovir, n = 76	Relative risk, pritelivir vs valacyclovir (95% CI)	P value
Days with pain, number/total (%)	“72/1778 (4.0)”	“123/1878 (6.7)”	“0.53 (0.30 to 0.93)”	“.03”

Duration of pain

Measure	Pritelivir, n = 75	Valacyclovir, n = 76	P value
Duration of pain, median (IQR), days	“4.0 (2.0 to 4.0)”	“4.0 (2.0 to 4.0)”	“.83”

Exposure and treatment-emergent adverse events overall

“Safety was assessed in all 91 randomized persons; the mean number of days of exposure was 26 for both pritelivir and valacyclovir. Overall, 48 participants (62.3%) had a treatment-emergent adverse event while taking pritelivir and 54 (69.2%) while taking valacyclovir” (opens the source at this quote in a new tab)

Grade 3 and grade 4 events, deaths, and serious adverse events

“No participant had a DAIDS grade 4 treatment-emergent adverse event; 3 participants had a DAIDS grade 3 treatment-emergent adverse event during pritelivir administration (elevated lipase, elevated alanine aminotransferase, and migraine); and 3 participants had a DAIDS grade 3 treatment-emergent adverse event during valacyclovir administration (dyspareunia, tooth infection and back pain, and headache and malaise). No deaths or serious adverse events were observed.” (opens the source at this quote in a new tab)

Participants with treatment-emergent adverse events by treatment in the publication, number (%)

Variable	Pritelivir 100 mg daily, n = 77	Valacyclovir 500 mg daily, n = 78	Total, n = 91
Any treatment-emergent adverse event	“48 (62.3)”	“54 (69.2)”	“71 (78)”
Serious	“0”	“0”	“0”
Leading to discontinuation	“1 (1.3)”	“1 (1.3)”	“2 (2.2)”
DAIDS grade 2 events	“11 (14.3)”	“12 (15.4)”	“21 (23.1)”
DAIDS grade 3 events	“3 (3.9)”	“3 (3.8)”	“5 (5.5)”
Headache, total	“10 (13.0)”	“13 (16.7)”	“21 (23.1)”
Headache, DAIDS grade 2	“3 (3.9)”	“3 (3.8)”	“6 (6.6)”
Headache, DAIDS grade 3	“0”	“1 (1.3)”	“1 (1.1)”
Nervous system disorders, total	“14 (18.2)”	“14 (17.9)”	“25 (27.5)”
Nervous system disorders, DAIDS grade 2	“3 (3.9)”	“4 (5.1)”	“7 (7.7)”
Nervous system disorders, DAIDS grade 3	“1 (1.3)”	“1 (1.3)”	“2 (2.2)”
Skin and subcutaneous tissue disorders, total	“8 (10.4)”	“7 (9.0)”	“12 (13.2)”
Skin and subcutaneous tissue disorders, DAIDS grade 2	“1 (1.3)”	“0”	“1 (1.1)”
Skin and subcutaneous tissue disorders, DAIDS grade 3	“0”	“0”	“0”
Respiratory, thoracic and mediastinal disorders, total	“2 (2.6)”	“2 (2.6)”	“4 (4.4)”
Respiratory, thoracic and mediastinal disorders, DAIDS grade 2	“0”	“0”	“0”
Respiratory, thoracic and mediastinal disorders, DAIDS grade 3	“0”	“0”	“0”

Discontinuations because of adverse events

“One participant receiving pritelivir developed urticaria without angioedema and was discontinued on day 10, and one participant receiving valacyclovir discontinued treatment on day 7 because of a constellation of mild symptoms that included headache, insomnia, and anxiety; these treatment-emergent adverse events were considered probably or possibly related to the trial medication.” (opens the source at this quote in a new tab)

Skin and subcutaneous tissue disorders

“The percentage of participants with skin and subcutaneous tissue disorders were similar during pritelivir (10.4%) and valacyclovir (9.0%) treatment.” (opens the source at this quote in a new tab)

Laboratory findings: lymphocyte count and creatinine

“Potential changes in hemoglobin, white blood cell count, and liver function tests were evaluated statistically. In a paired analysis, although white blood cell counts were was unchanged at every visit, there were statistically significant but not clinically relevant changes in the mean lymphocyte count (110-230 100 × 3/μL lower) and creatinine levels (0.03 and 0.05 mg/dL higher [to convert to μmol/L, multiply by 76.25]) during pritelivir administration (eFigure 2 in Supplement 3). At the week-4 visit following cessation of therapy, only the creatinine levels remained 0.02 mg/dL higher in pritelivir than in the valacyclovir group.” (opens the source at this quote in a new tab)
“The changes observed in lymphocyte count and creatinine levels were small, and longer duration of therapy will be needed to assess their clinical significance.” (opens the source at this quote in a new tab)

Nonclinical findings behind the FDA clinical hold, and corresponding events in trial participants

“The trial was placed on clinical hold by the FDA and terminated by the sponsor based on findings in monkeys in a 39-week toxicity study. These findings included skin related findings such as dry skin, crusty skin lesions, and alopecia as well as anemia (decreases in hemoglobin and in most animals an increase in the percentage of reticulocytes). So far the mechanism of dermatologic and hematologic findings is not understood. However, in the present study participants did not experience any similar adverse events (eg, anemia), although one person developed a rash (hives).” (opens the source at this quote in a new tab)

FDA clinical hold and work to lift it partially, as described by the investigators' institution

“Although the clinical trials conducted so far in humans have shown no serious side effects, the U.S. Food and Drug Administration put a hold on the drug’s clinical use in 2013 because of skin and blood abnormalities shown in a concurrent animal trial. The hold came while the study published today was underway, forcing it to end early.” (opens the source at this quote in a new tab)
“The German drug maker AiCuris is working with the FDA to partially lift the hold so that pritelivir can be tested in a new clinical trial on patients who are resistant to drugs in the acyclovir family, which include acyclovir, famciclovir and valacyclovir.” (opens the source at this quote in a new tab)

All-cause mortality, serious adverse events, and other adverse events in the registry results

Category	AIC316 (pritelivir)	Valacyclovir
All-cause mortality	“0/77 (0.00%)”	“0/78 (0.00%)”
Serious adverse events	“0/77 (0.00%)”	“0/78 (0.00%)”
Other (not including serious) adverse events	“48/77 (62.34%)”	“54/78 (69.23%)”

Adverse events by term in the registry results, participants affected of participants at risk

System organ class	Term	Pritelivir (AIC316) 100 mg daily	Valacyclovir 500 mg daily
Gastrointestinal disorders	Nausea	“3/77 (3.90%)”	“4/78 (5.13%)”
Gastrointestinal disorders	Diarrhea	“4/77 (5.19%)”	“2/78 (2.56%)”
Gastrointestinal disorders	Hemorrhoids	“1/77 (1.30%)”	“3/78 (3.85%)”
Gastrointestinal disorders	Abdominal Pain Upper	“0/77 (0.00%)”	“3/78 (3.85%)”
Gastrointestinal disorders	Dry Mouth	“0/77 (0.00%)”	“2/78 (2.56%)”
Gastrointestinal disorders	Gastrointestinal sounds abnormal	“2/77 (2.60%)”	“1/78 (1.28%)”
Gastrointestinal disorders	Vomiting	“0/77 (0.00%)”	“2/78 (2.56%)”
General disorders	Fatigue	“3/77 (3.90%)”	“5/78 (6.41%)”
General disorders	Chills	“0/77 (0.00%)”	“2/78 (2.56%)”
Infections and infestations	Upper respiratory tract infection	“11/77 (14.29%)”	“8/78 (10.26%)”
Infections and infestations	Vulvovaginal mycotic infection	“3/77 (3.90%)”	“3/78 (3.85%)”
Infections and infestations	Tooth infection	“2/77 (2.60%)”	“1/78 (1.28%)”
Infections and infestations	Vaginitis bacteria	“1/77 (1.30%)”	“3/78 (3.85%)”
Infections and infestations	Gastroenteritis viral	“0/77 (0.00%)”	“2/78 (2.56%)”
Infections and infestations	Sinusitis	“2/77 (2.60%)”	“0/78 (0.00%)”
Injury, poisoning and procedural complications	Contusion	“2/77 (2.60%)”	“1/78 (1.28%)”
Injury, poisoning and procedural complications	Laceration	“0/77 (0.00%)”	“2/78 (2.56%)”
Musculoskeletal and connective tissue disorders	Back Pain	“1/77 (1.30%)”	“2/78 (2.56%)”
Musculoskeletal and connective tissue disorders	Arthralgia	“0/77 (0.00%)”	“2/78 (2.56%)”
Nervous system disorders	Headache	“12/77 (15.58%)”	“14/78 (17.95%)”
Nervous system disorders	Dizziness	“3/77 (3.90%)”	“3/78 (3.85%)”
Nervous system disorders	Dysgeusia	“0/77 (0.00%)”	“4/78 (5.13%)”
Psychiatric disorders	Anxiety	“2/77 (2.60%)”	“3/78 (3.85%)”
Psychiatric disorders	Insomnia	“1/77 (1.30%)”	“2/78 (2.56%)”
Reproductive system and breast disorders	Vulvovaginal pruritus	“2/77 (2.60%)”	“1/78 (1.28%)”
Respiratory, thoracic and mediastinal disorders	Cough	“2/77 (2.60%)”	“4/78 (5.13%)”
Respiratory, thoracic and mediastinal disorders	Oropharyngeal pain	“1/77 (1.30%)”	“2/78 (2.56%)”
Skin and subcutaneous tissue disorders	Dry Skin	“2/77 (2.60%)”	“2/78 (2.56%)”
Skin and subcutaneous tissue disorders	Erythema	“1/77 (1.30%)”	“3/78 (3.85%)”
Skin and subcutaneous tissue disorders	Pruritus	“2/77 (2.60%)”	“0/78 (0.00%)”
Vascular disorders	Flushing	“0/77 (0.00%)”	“2/78 (2.56%)”

Reporting threshold, time frame, and coding dictionary in the registry results

Field	Registry entry
Frequency threshold for reporting other adverse events	“2%”
Time frame	“28 days for each intervention”
Source vocabulary	“MedDRA (15.1)”

Adverse events as reported in the company release

“No differences in treatment-emergent adverse events were observed between the two treatments.” (opens the source at this quote in a new tab)

Summary

AIC316-01-II-02 enrolled healthy, immunocompetent adults with 4 to 9 genital HSV-2 recurrences per year, a population outside the labeled indication of immunocompromised adults with refractory mucocutaneous HSV infection. The pritelivir regimen (400 mg on day 1, then 100 mg daily) matched the approved dose and was given for 28 days to suppress shedding. The sponsor terminated the trial after the FDA clinical hold of May 2013; 91 participants were randomized against 98 planned, and 56 completed both treatment periods. For the primary endpoint, the publication reports a relative risk of 0.42 (95% CI, 0.21 to 0.82) and the registry reports a risk ratio of 0.43 (95% CI, 0.30 to 0.63). The publication was corrected in January 2017.

Limitations stated by the investigators

“This study was limited by early termination and therefore, fewer participants than planned were treated. However, because of greater viral suppression during pritelivir therapy than assumed in power calculations and because few participants were lost to follow-up, a statistically significant difference in viral shedding and genital lesions was seen during the treatment with the 2 regimens. The persons enrolled had agreed to obtain very frequent genital samples and thus may differ from the general population. However, these differences should not affect the biological activity of the drugs.” (opens the source at this quote in a new tab)

Need for longer-term efficacy and safety data

“Pritelivir may be more effective for suppression of genital HSV-2 infection than valacyclovir, but further research is needed to assess longer-term efficacy and safety.” (opens the source at this quote in a new tab)

Unresolved nonclinical safety findings as described by the lead investigator

“Pritelivir probably is better than valacyclovir, but we need more work on it to understand the safety concerns that have emerged in the animals.” (opens the source at this quote in a new tab)

Correction to the published article

“This article was corrected online January 26, 2017, to fix 2 errors in the abstract and several rows in Table 2.” (opens the source at this quote in a new tab)

Agreement on publication recorded in the registry

“There IS an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed” (opens the source at this quote in a new tab)