Conditions: Hamstring Injury
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 8
Healthy volunteers: no

Brief summary:
The goal of this study is to determine safety and tolerability of Losartan when used for treatment of an acute grade II or III hamstring strain and determining the effect of losartan on recovery of hamstring muscle function. Subjects will be adults age 18 and older with grade 2 or 3 hamstring injury who participate in greater than 100 hours per year in Level 1 or Level 2 athletics or have a similar activities or physical work load (e.g. military personnel). Subjects will undergo examination, MRI, and functional assessment before, during, and after 4 weeks of losartan (50mg QD) or placebo.

Detailed description:

Arms:
arm 1: Subjects will taken 50mg of losartan per day for 4 weeks arm 2: Subjects will be given placebo to replicate appearance of losartan pills. Placebo pill will be taken once per day.

Interventions: intervention 1: Losartan intervention 2: Placebo
Intervention descriptions: intervention 1: Cozaar intervention 2: None

Protocol document:
Prot_SAP_000.pdf: 
 
 
1 
 
 
Phase 1/2 Prospective Double-blind, Placebo-controlled Randomized Clinical Trial 
Using Losartan to Treat Grade II and III Hamstring Strains 
 
 
NCT Number: NCT02263729 
 
 
March 28, 2014 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


 
 
2 
 
 
 
 
IND APPLICATION: 
 
CLINICAL STUDY PROTOCOL FOR 
 
The Use of Losartan to Treat Grade II and III 
Hamstring Strains 
 
 
 
 
 
 
 
 
Principal Investigator: 
 
Johnny Huard, PhD 
Department of Orthopedic Surgery 
University of Pittsburgh 
3500 Fifth Avenue, Suite 303 
Pittsburgh, PA 15213 
 
Version 2.0 
March 28, 2014 
 
 
 
 
 
 


 
 
3 
C. CLINICAL PROTOCOL: Summary Information 
 
Clinical Protocol Title:  
 
The Use of Losartan to Treat Grade II and III Hamstring Strains 
 
Protocol number:   
 
Version number and date: 
 
Version 1.0 
January 31, 2014 
 
Phase of clinical investigation: 
 
Phase I 
 
IND number:   
 
Pending 
 
Investigational drug(s): 
 
Losartan Potassium 
 
Sponsor: 
 
Johnny Huard, PhD 
Department of Orthopedic Surgery 
 
University of Pittsburgh 
 
3500 Fifth Avenue, Suite 303 
 
Pittsburgh, PA 15213 
 
 
Study Monitor:   
 
Education and Compliance Office for Human Subject Research 
 
Research Conduct and Compliance Office 
 
University of Pittsburgh 
 
3500 Fifth Avenue, Suite 303 
 
Pittsburgh, PA 15213 
 
Medical Director:   
 


 
 
4 
Vonda Wright, MD 
UPMC Center for Sports Medicine 
3200 South Water Street 
Pittsburgh, PA 15203 
 
Investigator(s):  
 
James J. Irrgang PT PhD ATC FAPTA 
Department of Orthopaedic Surgery 
University of Pittsburgh 
Suite 911, Kaufman Building 
3471 Fifth Avenue 
Pittsburgh, PA 15213 
 
Jeanie Doperak MD 
UPMC Center for Sports Medicine 
3200 South Water Street 
Pittsburgh, PA 15203 
 
Camilo Borrero MD 
Department of Radiology 
University of Pittsburgh Physicians  
Montefiore University Hospital 
Pittsburgh, PA 15206 
 
Shay Soker 
Wake Forest University 
A1 PTRP 
391 Technology Way 
Winston-Salem, NC 27101 
 
Johnny G. Owens, MPT 
Director of Limb Salvage Rehabilitation 
Center for the Intrepid 
Department of Orthopedics and Rehabilitation-Physical Medicine Fort Sam 
Houston, TX 78234  
Ph. 210.916.1920  
johnny.g.owens.civ@mail.mil 
 
Thomas J. Walters, Ph.D. 
Research Physiologist 
Extremity Trauma and Regenerative Medicine United States Army Institute of 
Surgical Research 
3400 Rawley E. Chambers Ave. 
Fort Sam Houston, TX  78234-6315 
Ph. 210.539.2726 


 
 
5 
Fx. 210.539.3877 
thomas.j.walters22.civ@mail.mil 
 
MAJ Travis C. Burns, MD 
Assistant Program Director - Research 
Department of Orthopedics and Rehabilitation San Antonio Military Medical 
Center 
3851 Roger Brooke Dr Suite 3600 
Fort Sam Houston, TX 78234 
travis.c.burns.mil@mail.mil 
 
Clinical Laboratory(ies), Technical Department(s), and 
Institution(s) Providing Clinical Study Services:  
 
UPMC Center for Sports Medicine 
3200 South Water Street 
Pittsburgh, PA 15203 
 
UPMC Magnetic Resonance Research Center 
Presbyterian University Hospital 
200 Lothrop Street, B-800 
Pittsburgh, PA 15213 
 
UPMC Presbyterian Hospital 
Investigational Drug Service 
326B Scaife Hall 
200 Lothrop Street 
Pittsburgh, PA  15213 
 
Brooke Army Medical Center 
Department of Orthopedics 
Fort Sam Houston, Houston TX 78234 
 
Brooke Army Medical Center 
Center for the Intrepid 
Fort Sam Houston, Houston TX 78234 
 
 


 
 
6 
C.  Clinical Protocol 
 
1. Introduction: 
 
1.1 Background: 
 
Muscle injuries stem from a variety of events, including direct trauma (i.e., 
muscle lacerations, contusions, or strains) and indirect causes (i.e., ischemia 
or neurological dysfunction)1-15. They account for a large number of all injuries 
sustained by participants in professional and recreational sports. In fact, 
muscle injuries constitute between 10% and 55% of all injuries sustained by 
athletes, depending on the type of sport1-16. The hamstring muscle complex is 
the most commonly involved11, 17, 18 and mainly occurs in the sports requiring 
bursts of speed or rapid acceleration19. Although muscles can undergo 
regeneration after injury, the healing process is slow and often culminates in 
incomplete functional recovery1, 2 and fibrosis. The formation of dense scar 
tissue can impair muscle function and lead to muscle contracture and chronic 
pain and diminish the individual’s ability to achieve full recovery and return to 
prior levels of performance. Despite the considerable medical need, there has 
been relatively little progress in the development of therapeutic approaches to 
enhance healing following muscle injury.  
A growing understanding of the cellular and molecular events that commonly 
occur during fibrosis in various tissues, including skeletal muscle, has provided 
a strong foundation for the development of effective therapies to prevent 
fibrosis and improve tissue healing. Because TGF-β1 plays such a crucial role 
in tissue fibrosis20-32, particularly in skeletal muscle33-38, it warrants attention as 
a key target for anti-fibrotic applications. In an effort to test various methods of 
antagonizing the effect of TGF-β1, we have investigated the abilities of decorin, 
suramin, IFN-γ, relaxin and an angiotensin II receptor blocker, to neutralize 
TGF-β1’s effect and improve muscle healing after injury. Our preliminary 
animal studies have shown that blocking TGF-β1 can decrease fibrosis and 
improve muscle healing33, 39-45. Of the agents to block TGF-β1, Losartan 
(Merck), which is an angiotensin II receptor blocker, is particularly attractive for 
clinical application because it is FDA approved and has minimal side effects.  
Losartan has been in clinical use for over 20 years and has been associated 
with a reduction in fibrosis in several tissues46-48, improved myoblast 
transplantation49 and protection against sarcopenia50. 
 
To evaluate the effects of Losartan on muscle healing and prevention of 
fibrosis we plan to conduct a phase 1 randomized double blind placebo-
controlled trial to compare Losartan to placebo for the treatment of grade II 
and III hamstring injuries in athletes or military personnel, veterans or their 
families that have sustained a sports-related hamstring injury.  We 
hypothesize that subjects who receive Losartan will have decreased 


 
 
7 
formation of fibrosis and a faster return to their prior level of activity and 
muscle function.  
 
 
1.2 Rationale: 
 
Developed in 1990, losartan potassium is an FDA-approved drug for the 
treatment of hypertension, left ventricular hypertrophy and diabetic nephropathy. 
Losartan and EXP3174 have been referenced in 184 studies according to 
PubMed (United States Library of Medicine). These reports have shown losartan 
is a specific blocker of the type-1 angiotensin II receptor51, 52, which regulates the 
expression of TGF-β153. Our research shows strong expression of TGF-β1 in 
injured skeletal muscle, which clearly implicates TGF-β1 in the fibrotic cascade 
that occurs after the onset of muscle disease or trauma54, 55. Indeed, the use of 
anti-fibrotic agents that inactivate TGF-β1 reduce muscle fibrosis, improves 
muscle healing and leads to enhanced recovery of injured muscle56-62.  Losartan 
potassium (MerckTM) is an FDA approved drug whose use has been associated 
with a reduction in fibrosis in several tissues46-48. Furthermore, it has been used 
to improve myoblast transplantation49 and protect against sarcopenia50.  
 
Based on our promising experimental data in a murine muscle injury model, the 
goal of this phase 1 randomized double blind placebo-controlled clinical trial is to 
test the effects of Losartan on muscle healing after sports, military training or 
combat injuries. Muscle injury caused by vigorous physical activity occurs in the 
US Active Duty Army at rates 3 to 4 fold higher than the civilian population63.  
Subject recruitment will include athletes or military personnel, veterans or their 
families that have sustained an acute sports-related hamstring injury.  This is 
relevant to the injured military population, since advances in combat field 
medicine translates into high rates of survival and increased numbers of 
wounded warriors64, with the majority of injuries occurring in the upper and lower 
extremities65. 
  
Recently, we performed a preliminary phase 1 case study involving two adult 
males with acute/recurrent hamstring muscle injury66. In both patients, we 
initiated treatment with Losartan after the acute period of necrosis/degeneration 
and inflammation. Both patients demonstrated normal hamstring flexibility and 
strength recovery by 6-9 weeks after injury. To date (> 2 years after treatment) 
neither individual has suffered any re-injury to their hamstring muscles, which 
may represent the most important feature of the study.  Furthermore, both 
individuals tolerated the Losartan with no reported side effects and remained 
normotensive throughout the 30 day course of treatment.  Despite the limitations 
of making treatment decisions based on two case reports, we are encouraged by 
the results of these interventions.  
 
Based on our basic science results and preliminary clinical experience, we 
hypothesize that subjects who receive Losartan for a short duration along with 
the current standard of care treatment after sustaining an acute grade II or III 


 
 
8 
hamstring muscle injury will have less formation of fibrosis and a faster return to 
their prior level of activity and muscle function when compared to a placebo 
control group who only receives the current standard of care treatment. To test 
this hypothesis we propose a phase 1 randomized double blind placebo-
controlled clinical trial to compare the use of Losartan (50mg/day) to placebo in 
20 individuals with an acute grade II or III hamstring injury between the ages of 
18-35.  The main goal of this study is to determine safety and tolerability and to 
provide pilot data to determine the magnitude of the effect and variability in the 
outcome of Losartan in comparison to placebo, which will allow a more accurate 
prediction of sample size for a future definitive clinical trial.  Subjects enrolled in 
this study that are randomized to the active drug arm of the study will be given 50 
mg of Losartan to be taken daily by mouth. This dose was chosen as it is the 
prescribed starting dose for the FDA-approved uses of losartan. It is also the 
dose prescribed for a case study of 2 patients with a severe hamstring strain that  
demonstrated improved muscle structure and function66.  
 
In conducting this phase 1 study, we will utilize the multidisciplinary collaboration 
of an experienced group of scientists, surgeons and physical therapists in a 
unique environment at the University of Pittsburgh and the USAISR (United 
States Army Institute of Surgical Research) at Brooke Army Medical Center 
(BAMC) San Antonio, Texas. The main outcome measures will be to (a) quantify 
the length and volume of fibrosis in the injured hamstring muscle, based on a 
baseline 3 Tesla MRI and a subsequent follow-up MRI examination 6 months 
post-injury and (b) prospectively follow the subjects to evaluate the amount of 
scarring and time to return to prior activity66.  Safety and tolerability will be 
assessed by monitoring adverse events,  symptoms (dizziness, new fatigue, 
peripheral edema or urinary symptoms), hypotension, and laboratory measures 
of liver and renal function, hemoglobin and hematocrit counts and serum 
potassium and uric acid levels.   
 
A 1999 study in the United Kingdom67 examined the safety of losartan potassium 
post-marketing in over 14,000 patients. The results of this study indicate losartan 
potassium, like other angiotensin II receptor antagonists (ARAs), does not 
present any significant adverse events. The most commonly cited specific 
adverse events include dizziness, headache, malaise, nausea, lassitude, cough, 
diarrhea, dyspnea and impotence. A literature review conducted by Sica et al.68 
found other adverse events being decreases in hemoglobin and hematocrit 
counts, dysgeusia and ageusia, migraines and acute psychosis, hepatic 
abnormalities, angioedema, increase in serum potassium, decrease in serum uric 
acid, and changes in renal function. As is the case with all drugs directly affecting 
the renin-angiotensin system, Losartan should not be taken by anyone who is 
pregnant or thinks they may be pregnant. The use of these drugs can cause 
neonatal injury, hypotension, neonatal skull hypoplasia, anuruia, renal failure and 
death. To our knowledge losartan potassium has not been withdrawn from 
research or marketing in the United States or any other country. 
 


 
 
9 
 
2. Clinical Study Objectives: 
 
2.1 Primary objective: 
 
Our long term objective is to improve muscle healing by decreasing pathologic 
fibrosis that occurs after skeletal muscle injury limiting effective muscle 
regeneration. Our overall hypothesis is that Losartan, which is an angiotensin II 
receptor blocker, will improve muscle healing and function after acute hamstring 
injuries in athletes and military personnel.  
In this phase 1 prospective double-blind placebo-controlled randomized 
clinical our objective will be to evaluate safety and tolerability and to provide 
pilot data to determine the magnitude of the effect and variability in the outcome 
of Losartan in comparison to placebo, which will allow a more accurate prediction 
of sample sized needed for a future definitive trial.  The specific aims of the study 
are to: 
Specific Aim #1: To determine safety and tolerability of Losartan when 
used for treatment of an acute grade II or III hamstring strain. 
Hypothesis 1a: Use of Losartan will have an acceptable adverse event profile 
that is comparable to placebo.  To test this hypothesis we will monitor adverse 
and serious adverse events throughout the duration of the study.   
Hypothesis 1b: The side effect profile of Losartan will be comparable to placebo.  
To test this hypothesis we will monitor subject complaints, symptoms, 
hypotension, and laboratory values.   
Specific Aim #2: To determine the effect of Losartan on recovery of 
hamstring muscle function and structure following an acute grade II or III 
hamstring strain. 
Hypothesis 1.1: Subjects who receive Losartan will have a quicker return of 
normal hamstring muscle function, as evidenced by better flexibility and strength 
of the hamstring muscle when compared to the control group who receives the 
current standard of care treatment without Losartan.  
Hypothesis 1.2: Subjects who receive Losartan will have less formation of fibrosis 
compared to the control group who receives the current standard of care 
treatment without Losartan.  
Specific Aim #3: To determine the effect of Losartan on time to return to 
prior level of function following an acute grade II or III hamstring strain.  
Hypothesis 3: Subjects who receive Losartan for a short duration along with the 
current standard of care treatment after sustaining an acute grade II or III 


 
 
10 
hamstring muscle injury will have a faster return to their prior level of sports 
activity when compared to the control group who receives the current standard of 
care treatment without Losartan.  
Specific Aim #4: To determine the effect of losartan on recurrence of injury 
following an acute grade II or III hamstring strain.  
Hypothesis 4: Subjects who receive Losartan will have a lower incidence of 
recurrent injury after return to their prior level of sports and military activity 
compared to the control group who receives the current standard of care 
treatment without Losartan.  
3.  Study Design: 
 
We will conduct a  phase 1 prospective double-blind placebo-controlled 
randomized clinical trial to evaluate the safety and tolerability and to provide 
preliminary data related to the the magnitude and variability of the effect of 
Losartan, an angiotensin II receptor blocker, for the treatment of acute grade II 
and III hamstring strains in athletes and military personnel.  Safety will be 
evaluated in terms of the adverse event profile and tolerability (Specific Aim 1).   
The effect of Losartan will be evaluated in terms of function and structure of the 
muscle (Specific Aim 2), time to return to sports (Specific Aim 3), and recurrence 
of injury (Specific Aim 4).  Subjects will be followed over the course of 12 months 
after injury.   
 
3.1 Study design schematic 
 
After signed informed consent is provided, subjects will undergo screening that 
will include collection of baseline demographics, medical history, activity level, 
baseline vital signs (blood pressure and heart rate), blood tests including a 
chemistry panel with electrolytes and complete blood cell count (CBC), 
pregnancy test for women, physical examination, measurements of pain and 
hamstring flexibility and strength and a 3.0 Tesla MRI.  After screening to confirm 
eligibility, subjects will be randomized to receive Losartan or placebo for four 
weeks.  All subjects will undergo standard of care rehabilitation.  During the 
period of active intervention, subjects will be followed weekly.  Blood work will be 
repeated 2, 4, and 6 weeks after randomization.  Pregnancy tests for females will 
also be repeated 2, 4, and 6 weeks after randomization.  Throughout the 
remainder of the year-long study period, subjects will undergo follow-up testing at 
6 and 12 weeks, 4, 6, 9 and 12 months. The study procedures over time are 
summarized in the table (Table 1) below. 
 
  


 
 
11 
 
Table 1 – Summary of Study Procedures 
 
Pre-
treat 
Day 
0 
1w 
2w 3w 
4w 
6w 12w 4m 
6m 9m 12m 
Informed Consent 
X 
 
 
 
 
 
 
 
 
 
 
 
Demographic 
Questionnaire 
X 
 
 
 
 
 
 
 
 
 
 
 
Activity Level 
X 
 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Medical History 
X 
 
 
 
 
 
 
 
 
 
 
 
Vital Signs ( standard 
and orthostatic blood 
pressure and heart rate) 
X 
 
X 
X 
X 
X 
X 
 
 
X 
 
 
Physical Examination 
X 
 
 
 
 
 
 
 
 
 
 
 
Blood Work 
X 
 
 
X 
 
X 
X 
 
 
 
 
 
Numerical Pain Rating 
Scale  
X 
 
X 
X 
X 
X 
X 
X 
 
X 
 
 
Hamstring flexibility 
X 
 
X 
X 
X 
X 
X 
 
 
X 
 
 
Isometric 
hamstring 
strength testing 
X 
 
X 
X 
X 
X 
X 
 
 
X 
 
 
Isokinetic 
hamstring 
strength testing 
 
 
 
 
 
 
X 
 
 
X 
 
 
3.0 Tesla MRI 
X 
 
 
 
 
 
 
 
 
X 
 
 
Randomization 
 
X 
 
 
 
 
 
 
 
 
 
 
Day of 1st Dose 
 
X 
 
 
 
 
 
 
 
 
 
 
Medication Log Review 
 
 
X 
X 
X 
X 
 
 
 
 
 
 
Telephone follow-up 
 
 
 
 
 
 
 
X 
X 
 
X 
X 
 
Legend: pre-treat = pre-treatment; w = week; m = months 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


 
 
12 
Figure 1 – Flow Chart for Study Design 
 
 
 
 


 
 
13 
3.2 Allocation to treatment   
 
 
Subjects will be randomized in a 1:1 ratio to either treatment with Losartan or 
placebo.  Both groups will otherwise undergo the same standard of care 
rehabilitation for treatment of an acute hamstring injury.  The randomization list 
will be generated using a random number generator.  An equal number of 
subjects will be allocated to each group in random block sizes of two and four. 
Group assignments will be placed in sequentially numbered opaque envelopes, 
which will be opened by the Project Coordinator at each site once the participant 
has agreed to participate in the study and baseline testing has been completed to 
confirm subject eligibility. Thus the treatment allocation will be concealed from 
the Project Coordinator and others responsible for recruitment. To minimize bias 
throughout the study, both the subject and individuals responsible outcome 
measure collection/analysis will remain blinded to the group assignment. 
 
 
3.3 Breaking the blind  
 
Unblinding of subjects will be limited to reduce the potential for bias.  Unblinding 
of a subject will only be considered in cases in which there is a significant safety 
or health concern to the subject and only after consultation with the treating 
physician, the study Medical Director (Dr. Vonda Wright MD) and Principal 
Investigator (Dr. Johnny Huard).  Only those individuals who need to know the 
subject’s group assignment to ensure the health and safety of the subject will be 
unblinded.  To the extent possible, all of the other study staff will remain blinded 
to the subject’s group assignment.   
A statement will be placed in the electronic medical record of the subject stating 
the subject is enrolled in a double-blinded placebo controlled trial using losartan 
potassium as an investigational drug.  In the event of a medical emergency, a 
health care provider can contact the study Medical Director or other designated 
study investigator to obtain information about the assigned study drug during the 
dosing period. 
If unblinding becomes necessary, the following information will be recorded: 
• Randomization identification number of the unblinded subject; 
• Reason for unblinding; 
• Study staff member that is responsible for unblinding the subject and 
• A list of person(s) who are not blinded. 
 
 
 
 
4. Subject Selection: 


 
 
14 
 
Subjects will be drawn from the population of patients with an acute grade II 
or grade III hamstring injury that present to the UPMC Center for Sports 
Medicine or Athletic Training Rooms at the University of Pittsburgh or to the 
Brooke Army Medical Center.   A total of 20 subjects will be enrolled in the 
study.  A subject will consider to be enrolled in the study if he/she has 
provided informed consent for study participation. 
 
 
4.1 Subject inclusion criteria 
Subjects will be eligible for participation in this study if they are between 18 
and 35 years of age and if they have had a grade II or III hamstring injury in 
the previous 7 days of enrolling in the study. Only those individuals who are 
regular participants (greater than 100 hours per year) in Level I (football, 
basketball or soccer) or Level II (racquet sports, skiing, manual labour 
occupations/heavy physical work) activities will be eligible for participation in 
this study. Individuals from BAMC that suffer a grade II or III hamstring injury  
in the previous 7 days of enrolling in the study that are involved in military 
training that at least is equivalent to heavy physical work in the civilian 
subjects will be eligible to participate in the study.  To be eligible to participate 
in the study, subjects will need to agree to take the study medications as 
prescribed.    
 
4.2 Subject exclusion criteria 
 
Subjects will be excluded if they: 1) have had a previous hamstring injury on 
the same side or chronic symptoms; 2) have an injury that requires surgical 
intervention (e.g. avulsion with associated bony involvement, grade III 
complete tears); 3) have concurrent lower back symptoms; 4) are pregnant or 
breast feeding;  5) are a smoker; 6) have contraindications to Losartan 
therapy (e.g. known hypersensitivity to losartan, hepatic impairment);  7) 
currently use angiotensin I converting enzyme inhibitor (ACEI) / angiotensin II 
receptor blocker (ARB); 8) have hypertension (blood pressure greater than or 
equal to 140 mm Hg systolic pressure or greater than or equal to 90 mm Hg 
diastolic pressure); 9) have hypotension (blood pressure less than or equal to 
90 mm Hg systolic pressure or less than or equal to 60 mm disastolic 
pressure); 10) have orthostatic hypotension defined as a drop in systolic 
pressure greater than or equal to 20 mm Hg or a drop in diastolic blood 
pressure greater than or equal to 10 mm Hg or reports of lightheadedness or 
dizziness would be considered abnormal upon standing or 11) have diabetes 
mellitus, cardio-vascular, renal or hepatic co-morbidities. 
Additionally, because participation in this study requires undergoing MRI, 
subjects will be excluded if they: 1) had prior surgery for an aneurysm; 2) 
have a cardiac pacemaker; 3) have metal fragments in the eyes, brain or 


 
 
15 
spinal cord from shrapnel, metal work or welding; 4) have surgical implants, 
such as an ear implant or neurostimulator; 5) have a history of claustrophobia 
or 6) have a history of not tolerating previous MRI scans without medication.   
For the military personnel, individuals recruited to participate in this study 
should not have a scheduled deployment within 6 months following initial 
injury to ensure adequate follow up. 
 
 
5. Study Drug(s): 
 
As described in section 1.2, losartan potassium is an FDA-approved drug for 
the treatment of hypertension, left ventricular hypertrophy and diabetic 
nephropathy.  It is prescribed for oral intake at doses from 25-100 mg per day 
with a usual starting dose of 50 mg per day which is what will be used for this 
study. Losartan potassium was developed by Merck under the proprietary 
name Cozaar® and is now generically available. 
Prior to starting the study medication, a study physician will review the effects 
of losartan, its side-effects and how the medication should be taken with all 
subjects. At this time, the physician will answer any questions the subject has 
regarding the study medication. Subjects will be evaluated weekly while they 
are taking the medication. Blood work will be repeated 2, 4 and 6 weeks after 
randomization to identify any clinically relevant abnormalities.   
Following randomization, subjects will begin a closed label course of 50mg of 
Losartan daily for 4 weeks or placebo for the same duration of time.  Losartan 
will be initiated within 7 days of injury after initial tests are performed and any 
abnormalities are ruled out. No initial dosage adjustment is necessary. The 
drug will be self-administered by the subject with or without food and will be 
ingested once a day.  With the dose that will be used in this study, no tapering 
is necessary at the end of the intervention phase or if the subject needs to be 
withdrawn from the study.   
 
5.1 Study drug compliance/adherence 
 
During the weekly patient encounters, a member of the research team will 
answer any questions the subject might have about the medication, will 
assess and promote medication adherence and monitor any side effects that 
the patient might be experiencing. The subject will be instructed to bring the 
medication so that pill counting can be performed as a measure to assess 
adherence. Also, at the time of randomization and at each weekly encounter, 
the subject will be given a medication log to complete.  The medication log 
will allow the patient to record the day and time of day the study medication 
and any concomitant medications were taken during that time period.   
 


 
 
16 
The medication log will become part of the research records, but will not be 
placed in the medical record. A statement will be placed in the electronic 
medical record of the subject stating the subject is enrolled in a  double-
blinded placebo controlled trial using losartan potassium as aninvestigational 
drug.  In the event of a medical emergency, a health care provider can 
contact the study Medical Director or designated study investigator to obtain 
information about the assigned study drug during the dosing period. 
 
5.1.1 Withdrawal of subjects due to non-compliance/ 
adherence 
 
Because we are interested in evaluating efficacy, we will use a per-
protocol approach, as opposed to an intention-to-treat approach for the 
conduct of this study.  As such, subjects that are non-compliant with the 
medication regimen (defined as taking less than 80% of the medication 
doses) will be withdrawn from the study and additional subjects will be 
recruited to replace subjects that have been withdrawn due to non-
compliance.  Subjects that are withdrawn for non-compliance will be 
instructed to terminate administration of the study medication without 
tapering down the dose and to return unused medication to the 
investigators.  
 
 
5.2  Study drug supplies 
 
5.2.1 Formulation and packaging 
 
Losartan will be ordered through HC central pharmacy and billed to the 
study. The UPMC Investigational Drug Service will provide the Losartan or 
placebo. The placebo will be formulated to have the same appearance as 
the Losartan. Study medications will be provided to the subjects free of 
charge. 
 
5.2.2 Preparing and dispensing 
 
IDS will blind the IP and matching placebo.  The IDS will dispense per 
physician order. 
 
 
5.2.3 Drug administration 
 
The drug is self-administered orally with or without food and will be 
ingested once a day as per protocol 
 


 
 
17 
 
5.4 
Study drug storage and accountability 
 
The IDS will store IP under controlled room temperature which is monitored daily 
and will maintain accountability records.  Upon completion of the study or 
expiration of the medication, destruction will occur per IDS policy #103. 
 
 
5.5 Concomitant Medications 
 
 
At the time of randomization and at each weekly encounter with the study 
staff, the subject will be given a medication log to complete.  The 
medication log will allow the patient to record the times/days the study 
medication and any concomitant medications taken during that time 
period. During the review of the log, the study staff will ask and document 
questions about concomitant medications and the reasons for taking them.  
Adverse events related to concomitant medications will be recorded. 
 
5.5.2 Rescue Medication 
 
 
6. Research Study Procedures: 
 
6.1 
Recruitment Procedures 
This prospective randomized phase 1 trial is a joint effort of the UPMC Center 
for Sports Medicine/University of Pittsburgh and the Department of 
Orthopaedics and Rehabilitation at BAMC. 
Subjects recruited through the UPMC Center for Sports Medicine will be 
informed of and referred to the study by their athletic trainer and/or physician. 
With permission of the subject, a research assistant will then contact them 
and initiate the study process. Alternatively, potential subjects will sign a 
Health Insurance Portability and Accountability Act (HIPAA) authorization for 
sharing of contact information, which will be forwarded to the study 
coordinator, who will in turn contact the subject to provide additional 
information concerning the study. 
Subjects recruited through the Department of Orthopaedics and Rehabilitation 
at Brooke Army Medical Center (BAMC) in San Antonio, Texas that meet the 
inclusion criteria (grade II/III hamstring strains due to sports or duty related 
injury) will be referred to the Research Coordinator in the BAMC Department 
of Orthopaedics and Rehabilitation for possible recruitment.  All testing and 
evaluation of recruited subjects will be conducted at the Center for the 
Intrepid in the Department of Orthopaedics and Rehabilitation at BAMC, 


 
 
18 
MRI's will be performed at the BAMC Department of Orthopaedics and 
Rehabilitation MRI Clinic. 
6.2 
Informed Consent Process 
The Research Coordinator will explain the details of the study, including the 
purpose of the study, procedures that will be utilized and the associated risks 
and benefits. Potential subjects will be assured that the decision of whether or 
not to participate in this study will not have any effect on their care. All 
questions that the subject may have prior to signing the informed consent 
form will be answered to the subject’s satisfaction by one of the investigators. 
If the subject is willing to participate in the study, the subject will sign an 
informed consent form that has been approved by the University of Pittsburgh 
Institutional Review Board (for subjects recruited at the UPMC Center for 
Sports Medicine) or by the BAMC-IRB (for subjects recruited at Brooke Army 
Medical Center) prior to participating in any research-related activities. 
 
6.3 Screening procedures 
 
6.3.1 Baseline Demographics and Activity Level 
Demographic information that will be recorded include age, sex, weight, height, 
body mass index (BMI), education level, sports and work activity level, smoking 
history and marital status. 
Sports Activity - We will use the sports activity rating scale developed by Marx 
et al.69 to measure the subject’s level of sports activity in the year prior to injury. 
This scale consists of 4 questions (running, cutting, decelerating and pivoting) 
that are rated in terms of the frequency with which the subject performed the 
activity (less than once per month, once per month, once per week, 2 or 3 times 
per week or 4 or more times per week) in the prior year. Test retest reliability for 
this scale over a two-week period was high (ICC=0.97) and it had moderately 
strong correlations with the Cincinnati and Lyhsolm scores69.  
Work Activity - Work activity will be measured with the Occupational Rating 
Scale of the Cincinnati Knee Rating System70. This is a patient-reported measure 
of work activity in which individuals will report the duration or frequency of sitting, 
standing and walking, walking on uneven ground, squatting, climbing, lifting and 
carrying as well as the amount of weight that they carry while at work. Each item 
is scored on a scale that ranges either from 0 to 5 or 0 to 10 such that higher 
scores indicate less sedentary activity and more physically demanding work 
activity. The item scores are summed and multiplied by 2 to create a score that 
ranges from 0 to 100. Cincinnati Occupational Rating Scale has demonstrated 
high test-retest reliability in both patients (ICC=.97) and uninjured subjects 
(ICC=.87)70. 
6.3.2 Baseline Assessment of Injury 


 
 
19 
At the time of study enrollment, the subject will be interviewed about the 
mechanism of injury (movement that was made during injury), presence or 
absence previous symptoms at the injury site, presence or absence of 
ecchymosis and the ability to walk and run. An examination will include 
inspection to confirm the presence or absence of ecchymosis. Palpation of the 
posterior thigh will be performed with the subject in prone and the knee 
extended71. The point of greatest pain will be marked and the distance to the 
ischial tuberosity will be measured71 and the presence or absence of a palpable 
defect will be recorded. Pain during resisted knee flexion will be graded on an 11 
point (0 to 10) numerical pain rating scale.   
Subjects will be eligible for participation in the study if the physical examination 
reveals: 1) localized tenderness with or without a palpable defect; 2) pain and 
weakness with resisted knee flexion with the individual in the prone position and 
3) pain and a limitation (in comparison to the contralateral leg) in the popliteal 
angle with the hip at 90 degrees of flexion.  Presence of a grade II/III hamstring 
strain will be confirmed on the baseline MRI that is performed prior to 
randomization.  MRI evidence of a grade II/III hamstring strain includes edema 
with architectural disruption indicating a partial tear (grade II) or edema with 
complete rupture of the muscle or tendon (grade III).  Excellent intra- and inter-
rater reliability has been reported for this MRI grading system of acute hamstring 
injuries72. 
6.3.3 Baseline Vital Signs, Medical History and Physical Examination 
Blood pressure will measured according to the American Heart Association 
Guidelines73. The subject will be comfortably seated, with his legs uncrossed. 
The cuff will be placed on the upper arm that will be at the level of the midpoint of 
the sternum and all measurements will be performed with an aneroid 
sphygmomanometer. For the initial visit, measurements will be performed in both 
upper extremities. The midline of the bladder of the cuff will be placed over the 
brachial artery. The stethoscope will be placed over the brachial artery but in the 
antecubital fossa. The cuff will then be inflated until the brachial artery is 
occluded (usually until 30 mm Hg above the point at which the radial pulse 
disappears). The cuff is then deflated and the first and last sounds should are the 
systolic and diastolic pressures. 
We will also measure orthostatic blood pressure using procedures described by 
the Centers for Disease Control.  After lying in the supine position for 5 minutes, 
heart rate and blood pressure will be measured using the procedure described in 
the paragraph above.  Following this, the subject will stand and blood pressure 
and heart rate will be measured again after 1 and 3 minutes.  A drop in systolic 
pressure greater than or equal to 20 mm Hg or a drop in diastolic blood pressure 
greater than or equal to 10 mm Hg or reports of lightheadedness or dizziness 
would be considered abnormal.  Individuals with orthostatic hypotension will be 
excluded from further participation in the study. 


 
 
20 
A medical history, review of systems and physical examination will be performed 
for all subjects during screening.  The medical history will include a review of the 
chief complaint, history of present injury, past medical history, allergies, 
medications, and social and family history.  
6.3.4 Blood Draw Procedures 
For the blood draws, the subject will be comfortably seated and identification of 
the subject will be confirmed. Blood will be drawn from the median cubital vein. 
Initially a tourniquet will be placed on the arm, proximal to the location where the 
blood will be drawn. The skin around this area will be wiped with an alcohol swab 
(or iodine prep). A needle will be inserted, bevel facing upwards, into the median 
cubital vein. Once the needle is in the vein, a vacutainer is pushed onto the 
needle holder and this will be repeated until all blood samples required are 
completed. Once the needle is removed, clean cotton wool will be pressed onto 
the wound. The tubes will be labeled immediately. Sufficient blood will be drawn 
to permit a chemistry panel with electrolytes and CBC.  Hemoglobin and 
hematocrit counts, serum potassium and uric acid, liver function (alanine 
aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline 
phosphatase), renal function (blood urea nitrogen [BUN] and serum creatinine), 
creatine phosphokinase (CPK) to assess muscle injury, and pregnancy in women 
(human chorionic gonadotropin (hCG)) will be assessed. 
 
 
6.3  Study drug procedures 
 
Following randomization, subjects will begin a closed label course of 50mg of 
losartan daily for 4 weeks or placebo for the same duration of time.  Losartan will 
be initiated within 7 days of injury after initial testing has been performed and any 
abnormalities are ruled out. No initial dosage adjustment is necessary. The drug 
is self-administered with or without food and will be ingested once a day.  
Prior to starting the study medication, a study physician will review the effects of 
Losartan, its side-effects and how the medication should be taken with all 
subjects. At this time, the physician will answer any questions the subject has 
regarding the study medication.  
The UPMC Investigational Drug Service will provide the Losartan or placebo. The 
placebo will be formulated to have the same appearance as the Losartan. Study 
medications will be provided to the subjects free of charge. Subjects will be 
evaluated weekly while they are taking the medication. Blood work will be 
repeated 2, 4, and 6 weeks after randomization.   
During the weekly patient encounters, a member of the research team will 
answer any questions the subject might have about the medication, will assess 
and promote medication adherence and monitor any side effects that the patient 


 
 
21 
might be experiencing. Also, the subject will be instructed to bring the medication 
to each visit so that pill counting can be performed as a measure to assess 
adherence. At each weekly encounter with the study staff, the subject will be 
given a medication log to complete.  The medication log will allow the patient to 
record the times/days the study medication and any concomitant medications 
taken during that time period. 
 
6.4  Follow-up procedures  (Incorporate only if follow-up procedures 
will be performed) 
 
6.4.1 Standard of Care Rehabilitation 
All subjects will undergo a standardized post-injury rehabilitation program, 
supervised by a physical therapist or athletic trainer. The rehabilitation protocol 
will be similar to that described by Sherry74. The rehabilitation will be divided into 
2 phases. The initial phase will focus on static stretching, isometric hamstring 
exercises and active range of motion. This will include 10 minutes of low-intensity 
cycling on a stationary ergometer with no resistance, static supine and long-sit 
hamstring stretching exercises (30 second hold, 4 repetitions each), submaximal 
isometric hamstring contractions at 20° and 90° of knee flexion (10 second hold, 
10 repetitions at each angle) and prone knee flexion without resistance (30 
repetitions). Ice will be applied at the end of the exercise session for 20 minutes. 
The phase 1 exercise program will be performed daily.  
Subjects will progress to phase 2 when they can walk with the same stride length 
and stance time on the injured and un-injured legs and can do a high knee march 
in place without pain. In phase 2, the focus will be on dynamic stretching and 
concentric and eccentric hamstring strengthening. Subjects will ride a stationary 
ergometer for 15 minutes with a moderate level of resistance, during which the 
subject shoulder perceive a moderate level of exertion (12-13 on Borg scale of 
perceived exertion). This will be followed with standing, supine and long-sit 
dynamic hamstring stretching exercises. Prone leg curls will be performed to 
strengthen the hamstring muscles using a daily adjustable progressive resistance 
exercise (DAPRE) method as describe by Knight75. In this method, subjects will 
perform 4 sets of resisted hamstring exercises against variable levels of 
resistance and repetitions as described in the table below (Table 2). The number 
of repetitions completed in the 3rd set will be utilized to determine the amount of 
weight used for the 4th set and the number of repetitions performed in the 4th set 
will determine the working weight for the next exercise session (Table 3). The 
“foot catch exercise”76 will be performed in the standing position. In this exercise, 
subjects will simulate the swing phase of walking or running as they quickly 
contract the quadriceps and catch or stop the lower leg before reaching terminal 
knee extension using an eccentric hamstring contraction. During phase 2, 
subjects will be permitted to run and jog without high-speed maneuvers as 
tolerated by pain. Ice will be applied at the end of the exercise session for 20 


 
 
22 
minutes. Except for the prone leg curls, which will be performed every other day, 
the phase 2 exercise program will be performed daily. 
Table 2 – Sets, Weight and Number of Repetitions for DAPRE Program 
Set 
Portion of Working Weight 
Used 
Number of Repetitions 
1 
50% 
10 
2 
75% 
6 
3 
100% 
As many as possible 
4 
Adjusted based on number of 
repetitions in 3rd set 
As many as possible 
 
Subjects will be permitted to begin high-speed running and agility drills when: 1) 
they have no palpable tenderness in the posterior thigh, 2) hamstring flexibility is 
within 3° of the un-injured leg and 3) resisted hamstring strength is 85% of the 
un-injured leg. Subjects will be permitted to return to full practice or military 
activity when they can tolerate high-speed running and agility drills for 3 
consecutive days with no exacerbation of symptoms and when they can perform 
a 40-yard sprint with no posterior thigh tightness or twinges. Upon return to 
sports, subjects will be encouraged to continue with the rehabilitation program 3 
days a week for at least 2 months after returning to sports. 
To ensure consistency in the rehabilitation program for all subject, we will create 
educational training materials (video and written instructions) demonstrating the 
correct performance and progression of the rehabilitation program. This 
information will be distributed to all physical therapists and athletic trainers 
responsible for rehabilitation of the subjects participating in this study. 
Compliance with the rehabilitation program will be assessed by reviewing the 
physical therapy or athletic training rehabilitation records. Additionally, subjects 
will independently track exercise compliance by recording the rehabilitation tasks 
that are performed on a daily basis in an exercise log. This log will be reviewed at 
each follow-up visit to ensure compliance with the rehabilitation program. To 
control for co-interventions, applications of heat and ultrasound and use of 
neuromuscular electrical will be avoided.  
Table 3 – Change in Working Weight for Fourth Set and Next Session 
Based Upon Number of Repetitions Performed 
Number of 
Repetitions 
Performed During 
Third Set 
Fourth Set 
Next Session 
0-2 
Decrease 5-10 lbs. 
No change 
3-4 
Decrease 0-5 lbs. 
Increase 5 lbs. 
5-7 
No change 
Increase 5-10 lbs. 
8-12 
Increase 5-10 lbs. 
Increase 10-15 lbs. 
> 13 
Increase 10-15 lbs. 
Increase 15-20 lbs. 


 
 
23 
6.4.2 Outcome Measures 
The outcomes measures will be collected at the time of study enrolment and at 
the 1, 2, 3, 4 and 6 weeks and 3, 4, 6, 9 and 12 month follow-up as described in 
Table 1 above, using procedures described in a Manual of Operations and 
Procedures. We will use a trained Clinical Research Assistant at each site, who 
has a background as a physical therapist or athletic trainer, to collect the 
measures of hamstring flexibility and strength and to conduct all follow-up 
telephone calls. Prior to data collection, co-I Irrgang (who has greater than 30 
years of experience with collection of clinical outcomes data) will train the Clinical 
Research Assistants.  
A musculoskeletal radiologist will read and interpret the MRI scans to determine 
the presence and extent of fibrosis and muscle atrophy. A bilateral magnetic 
resonance imaging (MRI) of both thighs will be conducted. The amount of fibrosis 
atrophy will be determined from the MRI using MIPAV software (Medical Imaging 
Processing, Analysis and Visualization, NIH, Bethesda, MD).  
All individuals responsible for collecting outcome measures will be blinded to the 
subject’s group assignment throughout the duration of the study.  
6.4.2.1 Return to Previous Level of Sports Activity and Recurrence of 
Injury (Specific Aims 3 and 4) 
The primary outcome for return to sports will be the number of days from injury to 
full, unrestricted return to practice or military training. The secondary outcome for 
level of sports activity will be the Marx Activity Scale Score. At 4 and 6 weeks, 
the Marx Sports Activity Scale will be modified to measure sports activity in the 
last week and at 4, 6 and 12 months the scale will be modified to measure sports 
activity in the past month.  
Recurrence of injury will be monitored over the course of 12 months after study 
enrolment and randomization. A subject will be considered to have a recurrent 
injury if there was a specific mechanism of injury that caused a return of posterior 
thigh pain, tenderness to palpation along the muscle-tendon unit, pain with 
resisted knee flexion and the inability to participate in sports activities. Recurrent 
injuries will be monitored weekly during the course of rehabilitation and at each 
follow-up study visit (1, 2, 3, 4 & 6 weeks, 6 months) and follow-up phone call (3, 
4, 9 and 12 months). After return to sports participation, any subject experiencing 
a recurrent injury will be instructed to contact the Project Coordinator and a 
return visit will be scheduled to confirm the presence and severity of re-injury.  
6.4.2.2 
Function and Structure of Hamstring Muscle (Specific Aim 2) 
Pain – An 11 point (0 to 10) numeric pain rating scale will be used to rate pain at 
rest and walking at the time of study enrolment and at 1, 2, 3, 4 and 6 weeks 
after enrolment. Pain with jogging and sprinting will be rated starting when these 
activities are initiated through the remainder of the in-person and telephone 


 
 
24 
follow-up visits. The numerical pain rating scale is anchored so that 0 
corresponds with no pain and 10 corresponds with worst imaginable pain. The 
psychometric properties of the numeric pain rating scale compare favorably to 
other pain rating scales and are the preferred method of rating pain by young and 
old individuals in a study of experimentally induced pain77.  
Measurement of Hamstring Flexibility – Hamstring length will be assessed by 
measuring the popiteal angle as described by ten Berge et al78. This will be 
performed by placing the ipsilateral hip at 90° of flexion and passively extending 
the knee to the end range of motion. To eliminate the possibility of initial muscle 
stiffness, the knee will be moved to end range extension 3 times before taking 
the measurement. A standard goniometer will be used to measure the angle of 
knee flexion. The proximal arm of the goniometer will be aligned with the lateral 
midline of the thigh on a line between the lateral epicondyle and the center of the 
greater trochanter of the femur and the distal arm will be positioned parallel to the 
lateral midline of the leg on a line between the lateral malleolus and lateral 
epicondyle of the femur.  To account for variability between subjects, hamstring 
flexibility will be expressed as the difference in popliteal angle between the 
hamstring-injured and contra-lateral normal leg. Using this methodology, ten 
Berge et al78 demonstrated adequate levels of intra- and inter-observer reliability 
(ICC=.82 and .72 respectively) in healthy subjects between 20 and 29 years of 
age.   
Isometric Hamstring Strength – A Lafayette hand-held dynamometer 
(Lafayette Instrument Company, Lafayette IN) will be used to measure isometric 
hamstring strength at the time of study enrolment and at 1, 2, 3, 4, and 6 weeks 
after enrolment. For these measurements, the subject will be positioned in the 
prone position. The dynamometer will be placed on the distal leg approximately 2 
cm proximal to the level of the lateral malleolus. The distance from the point of 
application of the hand-held dynamometer to the lateral joint line will be recorded 
in centimeters. The amount of force generated by the subject will be resisted by 
the examiner (i.e. a “make test” will be performed). The test will be performed at 
30° and 90° of knee flexion, first on the un-injured leg than on the injured leg. To 
calculate torque, the force will be multiplied times the distance from the point of 
application of the hand-held dynamometer to the lateral joint line of the knee. 
Isometric strength (Newton-meters) of the involved hamstrings will be expressed 
as an absolute number and as a percentage of strength of the un-injured leg. 
Trudelle-Jackson et al79 demonstrated high levels of intra- (ICC ranging from .97-
.98) and inter-day (ICC ranging from .85-.87) reliability when using a hand-held 
dynamometer to test hamstring strength in healthy subjects. Additionally, 
measurements with the hand-held dynamometer were strongly related to 
concurrent measurements of isometric strength on an isokinetic dynamometer (r 
from 0.83 - 0.85). 
Isokinetic Hamstring Strength – Isokinetic hamstring strength at 60 and 180° 
per second will be measured on the Biodex isokinetic dynamometer (Biodex 
Medical Systems, Shirley NY) 4 and 6 weeks after study enrolment as well as at 


 
 
25 
the 6 month follow-up visit. Prior to performing the test, the subject will ride a 
stationary ergometer for 5 minutes at a moderate intensity level and will perform 
static hamstring stretching exercises (30 second hold, 4 repetitions) for each leg. 
The subject will be seated on the isokinetic dynamometer so that the axis of 
rotation of the dynamometer is aligned with the lateral epicondyle of the femur. 
The length of the input arm will be adjusted so that the pad is positioned just 
above the lateral malleolus. The dynamometer settings will be recorded to 
ensure consistency during subsequent testing sessions. To familiarize the 
subject with the testing protocol prior to performing the maximal effort tests, the 
subject will perform 2 sub-maximal contractions and 1 maximal contraction at 
60°/sec and 6 sub-maximal and 3 maximal contractions at 180°/sec. For the test 
that is recorded, the subject will perform 3 maximal concentric quadriceps and 
hamstring contractions at 60°/sec and 20 maximal concentric quadriceps and 
hamstring contractions at 180°/sec. Verbal encouragement will be provided 
during testing to ensure maximal effort.  
The primary outcome variable of interest will be the involved to un-involved ratio 
of hamstring peak torque at 60°/sec. Secondary isokinetic variables that will be 
evaluated include the involved to un-involved ratio of total hamstring work at 60°, 
the involved hamstring to quadriceps ratio in peak torque at 60°/sec, peak torque 
and total work at 180°/sec and the ratio of work in the last 3 repetitions to work in 
the first 3 repetitions at 180°/sec. Pincivero et al80 demonstrated high levels of 
test re-test reliability (ICCs ranging from ) over a 7 day period in normal healthy 
subjects using the Biodex System 2 Isokinetic Dynamometer and a testing 
protocol similar to that which we will be using. 
6.4.2.3 
Evaluation by 3.0 Tesla MRI (Specific Aim 2) 
Magnetic Resonance Imaging Procedures - Participants in this study will 
undergo 3T MRI at the UPMC Magnetic Resonance Research Center or the 
Magnetic Resonance Facility, BAMC, Wilford Hall, San Antonio before treatment 
is initiated and 6 months after injury. Rigorous procedures to ensure high quality 
MRI that are capable of reliably detecting small changes in muscle structure over 
time will be undertaken. These include standardized procedures to position and 
minimize motion of the subject, establishment of criteria to assess the quality of 
the magnetic resonance images and daily, weekly, monthly and annual quality 
control procedures for maintenance of the magnetic resonance scanner.  
Images of both thighs will be acquired from the ischial tuberosity to just below the 
knee so that the entire length and volume of the hamstrings will be imaged.  A 
torso coil will be used. Total scan time is approximately 30 minutes. Following a 
conventional 3-plane localizer, axial, sagittal and coronal T1-weighted non-fat 
saturated, axial and coronal short inversion recovery time (STIR) and axial and 
sagittal T2 fat saturated (FS) images will be obtained.  The details for each of the 
sequences are specified in the Table 4 below.   


 
 
26 
Table 4 – Summary of MRI Parameters 
Sequence  
Slice/Gap 
Thickness 
(mm) 
Matrix 
Field of View 
Axial T1a 
8/1 
512 x 180 
40 cm/phase 75 
Sagittal T1a 
5/2 
194 x 384 
38 cm/phase 84 
Coronal T1a 
5/2 
192 x 512 
40 cm/phase 75 
Axial STIRb 
8/1 
256 x 256 
40 cm/phase 75 
Axial T2 FSc 
8/1 
203 x 384 
40 cm/phase 75 
Sagittal T2 FSc 
5/2 
194 x 384 
38 cm/phase 84 
Coronal STIRb 
5/2 
256 x 256 
40 cm/phase 75 
a T1 weighted non-fat saturated. 
b Short inversion recovery time. 
c T2 weighted fat saturated. 
 
The primary MRI outcome measures for analysis will be the maximal cranio-
caudal length and volume of the injury/scar tissue. To calculate volume of 
injury/scar tissue, the area of injury/scar tissue will be determined on each slice. 
This area will be multiplied by the slice thickness and summed across all slices in 
which the injury/scar tissue is visible.  Additionally, total volume of the involved 
compared to the non-involved hamstring muscles will be determined as a 
measure of muscle atrophy.  
 
6.5 
Schedule of activities (Study Table) 
 
 
Table 1 – Summary of Study Procedures 
 
Pre-
treat 
Day 
0 
1w 
2w 3w 
4w 
6w 12w 4m 
6m 9m 12m 
Informed Consent 
X 
 
 
 
 
 
 
 
 
 
 
 
Demographic 
Questionnaire 
X 
 
 
 
 
 
 
 
 
 
 
 
Activity Level 
X 
 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Medical History 
X 
 
 
 
 
 
 
 
 
 
 
 
Vital Signs (standard 
and orthostatic blood 
pressure and heart rate) 
X 
 
X 
X 
X 
X 
X 
 
 
X 
 
 
Physical Examination 
X 
 
 
 
 
 
 
 
 
 
 
 


 
 
27 
Blood Work 
X 
 
 
X 
 
X 
X 
 
 
 
 
 
Numerical Pain Rating 
Scale  
X 
 
X 
X 
X 
X 
X 
X 
 
X 
 
 
Hamstring flexibility 
X 
 
X 
X 
X 
X 
X 
 
 
X 
 
 
Isometric 
hamstring 
strength testing 
X 
 
X 
X 
X 
X 
X 
 
 
X 
 
 
Isokinetic 
hamstring 
strength testing 
 
 
 
 
 
 
X 
 
 
X 
 
 
3.0 Tesla MRI 
X 
 
 
 
 
 
 
 
 
X 
 
 
Randomization 
 
X 
 
 
 
 
 
 
 
 
 
 
Day of 1st Dose 
 
X 
 
 
 
 
 
 
 
 
 
 
Medication Log Review 
 
 
X 
X 
X 
X 
 
 
 
 
 
 
Telephone follow-up 
 
 
 
 
 
 
 
X 
X 
 
X 
X 
 
Legend: pre-treat = pre-treatment; w = week; m = months 
 
 
 
  
 
 
7. 
Safety and Effectiveness Assessments: 
 
7.2 Safety assessments 
 
Vital signs (including blood presure and heart rate) will be monitored daily prior to 
each rehabilitation session.  Blood work, including a chemistry panel with 
electrolytes and complete blood cell count (CBC) and pregnancy tests for women 
will be performed prior to randomization and at 2, 4, and 6 weeks after 
randomization.  The blood work will be used to assess hemoglobin and 
hematocrit counts, serum potassium and uric acid, liver function (alanine 
aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline 
phosphatase), renal function (blood urea nitrogen [BUN] and serum creatinine), 
creatine phosphokinase (CPK) to assess muscle injury, and pregnancy in women 
(human chorionic gonadotropin (hCG)).   
 
The profile of adverse and serious adverse events will also be monitored to 
assess safety throughout the duration of the subject’s participation in the study. 
 
 
7.2 Effectiveness assessments 
 


 
 
28 
Our overall hypothesis is that Losartan, which is an angiotensin II receptor 
blocker, will improve muscle healing and function after acute hamstring injuries in 
athletes and military personnel. The effectiveness assessments for each specific 
aims of the study are to: 
Specific Aim #2: Recovery of Hamstring Muscle Function and Structure. 
Recovery of muscle function will be assessed in terms of hamstring flexibility and 
strength.  Hamstring length will be assessed by measuring the popiteal angle as 
described by ten Berge et al78.  To account for variability between subjects, 
hamstring flexibility will be expressed as the difference in popliteal angle between 
the hamstring-injured and contra-lateral normal leg.  To assess hamstring 
strength, isometric testing with the knee flexed to 30˚ and 90˚ will be performed 
before treatment and at 1, 2, 3, 4 and 6 weeks and 6 months after enrolment and 
isokinetic testing at 60˚ and 180˚/sec will be performed 6 weeks and 6 months 
after enrolment.  The detailed procedures for measuring hamstring flexibility and 
strength are described in section 6.4.2.2.  
3 Tesla MRI will be performed at enrolment and at 6 months follow-up to assess 
hamstring structure in terms of the length and volume of the injury and scarring.  
Additionally total volume of the injured and contra-lateral hamstrings will be 
calculated to determine the degree of atrophy.  The detailed procedures for use 
of 3T MRI to assess hamstring structure are described in section 6.4.2.3.  
Specific Aim #3: Time to Return to Prior Level of Function  
The primary outcome for return to sports will be the number of days from injury to 
full, unrestricted return to practice. The secondary outcome for return to sports 
activity will be the Marx Activity Scale Score at 4 and 6 weeks and 3, 4, 6 and 12 
months. At 4 and 6 weeks, the Marx Sports Activity Scale will be modified to 
measure sports activity in the last week and at 4, 6 and 12 months the scale will 
be modified to measure sports activity in the past month. 
Specific Aim #4: Recurrence of Injury 
Recurrence of injury will be monitored over the course of 12 months after study 
enrolment and randomization. A subject will be considered to have a recurrent 
injury if there was a specific mechanism of injury that caused a return of posterior 
thigh pain, tenderness to palpation along the muscle-tendon unit, pain with 
resisted knee flexion and the inability to participate in sports activities. Recurrent 
injuries will be monitored weekly during the course of rehabilitation and at each 
follow-up study visit (1, 2, 3, 4 & 6 weeks, 6 months) and follow-up phone call (3, 
4, 9 and 12 months). 
 
8. 
Adverse Event Reporting: 
 


 
 
29 
 
8.1 Adverse event definitions   
 
 
 
 
Adverse event means any untoward medical occurrence associated with the use 
of the drug in humans, whether or not considered drug related. 
 
Adverse reaction means any adverse event caused by a drug. 
 
Suspected adverse reaction means any adverse event for which there is a 
reasonable possibility that the drug caused the adverse event.  Suspected 
adverse reaction implies a lesser degree of certainty about causality than 
“adverse reaction”. 
 
• Reasonable possibility.  For the purpose of IND safety reporting, “reasonable 
possibility” means there is evidence to suggest a causal relationship between 
the drug and the adverse event. 
 
Life-threatening, suspected adverse reaction.  A suspected adverse reaction is 
considered “life-threatening” if, in the view of either the Investigator (i.e., the 
study site principal investigator) or Sponsor, its occurrence places the patient or 
research subject at immediate risk of death.  It does not include a suspected 
adverse reaction that had it occurred in a more severe form, might have caused 
death. 
 
Serious, suspected adverse reaction. A suspected adverse reaction is 
considered “serious” if, in the view of the Investigator (i.e., the study site principal 
investigator) or Sponsor, it results in any of the following outcomes: death, a life-
threatening adverse reaction, inpatient hospitalization or prolongation of existing 
hospitalization, a persistent or significant incapacity or substantial disruption of 
the ability to conduct normal life functions, or a congenital anomaly/birth defect. 
 
• Important drug-related medical events that may not result in death, be life-
threatening, or require hospitalization may be considered “serious” when, 
based upon appropriate medical judgment, they may jeopardize the research 
subject and may require medical or surgical intervention to prevent one of the 
outcomes listed in this definition.  Examples of such medical events include 
allergic bronchospasm requiring intensive treatment in the emergency room 
or at home, blood dyscrasias or convulsions that do not result in inpatient 
hospitalization, or the development of drug dependency or drug abuse. 
 
Unexpected, suspected adverse reaction.  A suspected adverse reaction is 
considered “unexpected” if it is not listed in the general investigational plan, 
clinical protocol, or elsewhere in the current IND application; or is not listed at 
the specificity or severity that has been previously observed and/or specified.  
 


 
 
30 
8.2 
Recording/Reporting requirements  
 
 
8.2.1 Eliciting adverse event information 
 
Throughout the duration of the study subjects will be monitored for adverse 
events.  At each study visit (weeks 1, 2, 3, 4, 6 and 6 months) and follow-up 
phone call (3, 4, 9 and 12 months), subjects will be asked to provide any 
information about possible adverse events that may have occurred since the 
last visit.  Subjects will be asked to provide information about any reaction to 
the study medication, any new health-related symptoms they may be 
experiencing, and any new events or injury that may impact their compliance 
with the study protocol.  If during the follow-up phone call the subject reports 
a new or ongoing adverse event, a follow-up clinic visit will be scheduled. 
 
 
8.2.2 Recording requirements   
 
 
All observed or volunteered adverse events (serious or non-serious) and 
abnormal test findings, regardless of study group or suspected causal 
relationship to the study drug(s) will be recorded in the subjects’ case 
histories.  For all adverse events, sufficient information will be pursued and/or 
obtained so as to permit 1) an adequate determination of the outcome of the 
event (i.e., whether the event should be classified as a serious adverse event) 
and; 2)  an assessment of the casual relationship between the adverse event 
and the study drug(s).    
 
Adverse events or abnormal test findings felt to be associated with the study 
drug(s) will be followed until the event (or its sequelae) or the abnormal test 
finding resolves or stabilizes at a level acceptable to the Sponsor-Investigator. 
 
8.2.2.1 Abnormal test findings   
 
 
An abnormal test finding will be classified as an adverse event if one or 
more of the following criteria are met: 
 
• The test finding is accompanied by clinical symptoms. 
 
• The test finding necessitates additional diagnostic evaluation(s) or 
medical/surgical intervention; including significant additional 
concomitant drug treatment or other therapy.  
 
o Note: simply repeating a test finding, in the absence of any of the 
other listed criteria, does not constitute an adverse event.   


 
 
31 
 
• 
The test finding leads to a change in study drug dosing or 
discontinuation of subject participation in the clinical research study. 
 
• The test finding is considered an adverse event by the Sponsor-
Investigator of the IND application. 
 
 
8.2.2.2 Causality and severity assessment   
 
 
The Sponsor-Investigator of the IND application will promptly review 
documented adverse events and abnormal test findings to determine: 1) if 
the abnormal test finding should be classified as an adverse event; 2) if 
there is a reasonable possibility that the adverse event was caused by the 
study drug(s); and 3) if the adverse event meets the criteria for a serious 
adverse event. 
 
If the Sponsor-Investigator’s final determination of causality is “unknown 
and of questionable relationship to the study drug(s)”, the adverse event 
will be classified as associated with the use of the study drug(s) for 
reporting purposes.  If the Sponsor-Investigator’s final determination of 
causality is “unknown but not related to the study drug(s)”, this 
determination and the rationale for the determination will be documented 
in the respective subject’s case history.  
 
8.3 Reporting of adverse reactions   
 
 
 
8.3.1 Reporting of adverse reactions to the FDA 
 
8.3.1.1 Written IND Safety Reports 
 
The Sponsor-Investigator will submit a written IND Safety Report (i.e., 
completed FDA Form 3500 A) to the responsible new drug review division 
of the FDA for any observed or volunteered adverse event that is 
determined to be a serious and unexpected, suspected adverse reaction.  
Each IND Safety Report will be prominently labeled, “IND Safety Report”, 
and a copy will be provided to all participating investigators (if applicable) 
and sub-investigators.   
 
Written IND Safety Reports will be submitted to the FDA as soon as 
possible and, in no event, later than 15 calendar days following the 


 
 
32 
Sponsor-Investigator’s receipt of the respective adverse event information 
and determination that it meets the respective criteria for reporting. 
 
For each written IND Safety Report, the Sponsor-Investigator will identify 
all previously submitted IND Safety Reports that addressed a similar 
suspected adverse reaction experience and will provide an analysis of the 
significance of newly reported, suspected adverse reaction in light of the 
previous, similar report(s) or any other relevant information. 
 
Relevant follow-up information to an IND Safety Report will be submitted 
to the applicable review division of the FDA as soon as the information is 
available and will be identified as such (i.e., “Follow-up IND Safety 
Report”).   
 
If the results of the Sponsor-Investigator’s follow-up investigation show 
that an adverse event that was initially determined to not require a written 
IND Safety Report does, in fact, meet the requirements for reporting; the 
Sponsor-Investigator will submit a written IND Safety Report as soon as 
possible, but in no event later than 15 calendar days, after the 
determination was made. 
 
8.3.1.2 Telephoned IND Safety Reports – Fatal or life-
threatening suspected adverse reactions 
 
 
In addition to the subsequent submission of a written IND Safety Report 
(i.e., completed FDA Form 3500A), the Sponsor-Investigator will notify the 
responsible review division of the FDA by telephone or facsimile 
transmission of any unexpected, fatal or life-threatening suspected 
adverse reaction.  
 
The telephone or facsimile transmission of applicable IND Safety Reports 
will be made as soon as possible but in no event later than 7 calendar 
days after the Sponsor-Investigator’s receipt of the respective adverse 
event information and determination that it meets the respective criteria for 
reporting. 
 
8.3.2 Reporting adverse events to the responsible IRB 
 
In accordance with applicable policies of the University of Pittsburgh 
Institutional Review Board (IRB), the Sponsor-Investigator will report, to the 
IRB, any observed or volunteered adverse event that is determined to be: 1) 
associated with the investigational drug or study treatment(s); 2) serious; and 
3) unexpected.  Adverse event reports will be submitted to the IRB in 
accordance with the respective IRB procedures.  
 


 
 
33 
Applicable adverse events will be reported to the IRB as soon as possible 
and, in no event, later than 10 calendar days following the sponsor-
investigator’s receipt of the respective information.  Adverse events which 
are: 1) associated with the investigational drug or study treatment(s); 2) fatal 
or life-threatening; and 3) unexpected will be reported to the IRB within 24 
hours of the Sponsor-Investigator’s receipt of the respective information.  
 
Follow-up information to a reported adverse event will be submitted to the IRB 
as soon as the relevant information becomes available.  If the results of the 
Sponsor-Investigator’s follow-up investigation show that an adverse event 
that was initially determined to not require reporting to the IRB does, in fact, 
meet the requirements for reporting; the Sponsor-Investigator will report the 
adverse event to the IRB as soon as possible, but in no event later than 10 
calendar days, after the determination was made. 
 
8.4 
Withdrawal of subjects due to adverse events 
 
Vital signs, including blood pressure and heart rate will be monitored daily prior to 
each rehabilitation session.  Individuals with symptomatic hypotension (defined 
as symptoms consistent with hypotension including dizziness, lightheadedness 
etc. with systolic or diastolic blood pressure less than 90 and 60 mm Hg 
respectively) will be discontinued from the study. Withdrawal of a subject due to 
symptomatic hypotension will be reported as an adverse event.   
 
Blood work, including a chemistry panel with electrolytes and complete blood cell 
count (CBC) will be performed prior to randomization and at 2, 4, and 6 weeks 
after randomization.  The blood work will be used to assess hemoglobin and 
hematocrit counts, serum potassium and uric acid levels, liver function (alanine 
aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline 
phosphatase), renal function (blood urea nitrogen [BUN] and serum creatinine), 
creatine phosphokinase (CPK) to assess muscle injury, and pregnancy in women 
(human chorionic gonadotropin (hCG)).  Additional blood work will be ordered if 
subjects report new fatigue, peripheral edema or urinary symptoms.  Follow-up 
blood work will be performed 4-6 weeks (±3 days) after discontinuing medication 
to ensure that lab values have returned to normal ranges after discontinuation of 
the study medication.  Abnormal lab values resulting in subject withdrawal from 
the study will be reported as an adverse event.    
Human chorionic gonadotropin (hCG) be determined to identify pregnant women 
will be assessed prior to randomization and at 2, 4 and 6 weeks after 
randomization.  Women that are pregnant prior to randomization will be 
discontinued from the study, but will not be reported as an adverse event.  
Human chorionic gonadotropic will also be determined for females enrolled in the 
study who expect that they For females enrolled in the study that have become 
pregnant, the study medication will be stopped immediately and the subject will 
be withdrawn from the study.  Pregnancy necessitating withdrawal from the study 
will be reported as an adverse event. 


 
 
34 
 
Adverse events or abnormal test findings felt to be associated with the study 
drug(s) will be followed until the event (or its sequelae) or the abnormal test 
finding resolves or stabilizes at a level acceptable to the Sponsor-Investigator. 
 
 
The severity of an adverse event will be determined by the study medical director 
based on the criteria stated in section 8.1.  Additionally, the medical director will 
assign the event a grade of mild, moderate, or severe. If it becomes medically 
necessary to withdraw the subject from the study, the study medication will be 
discontinued.  The subject will be followed clinically until the adverse event or 
abnormal test findings felt to be associated with the study drug resolves or 
stabilizes at a level acceptable to the Sponsor-Investigator.  This follow-up will 
include assessment of vital signs, physical examination and assessment of blood 
work.  Follow-up blood work will be performed 4-6 weeks (±3 days) after 
discontinuing medication to ensure that lab values have returned to normal 
ranges after discontinuation of the study medication.    The subject will be treated 
for any medication related problems as clinically appropriate. Information from 
this appointment will be documented in the subject’s case file.  The patient will be 
terminated from the study, and will not complete any further follow-up 
appointments for the study.  Subjects that are terminated from participation in the 
study due to an adverse event will be replaced by recruitment of another subject.   
 
 
9. 
Statistical Methods/Data Analysis: 
 
9.1 
Study endpoints 
 
9.1.1 Primary endpoint(s) 
 
Specific Aim #1: To determine safety and tolerability of Losartan when 
used for treatment of an acute grade II or III hamstring strain. 
 
To assess safety, vital signs will be monitored daily and we will also monitor the 
frequency of abnormal lab values as well as adverse and serious adverse events 
during period of active intervention as well as throughout the subjects’ 
participation in the study.  To assess the side effect profile of Losartan in this 
population, we will monitor the frequency of subject complaints, symptoms 
(dizziness, new fatigue, peripheral edema, urinary symptoms) and laboratory 
measures of liver and renal function, haemoglobin and haematocrit counts and 
serum potassium and uric acid levels.  The frequency of abnormal lab values, 
adverse and serious adverse events and side effects will be monitored 
separately for the Losartan and placebo control groups.     
Specific Aim #2: Recovery of Hamstring Muscle Function and Structure  


 
 
35 
The primary endpoints to assess hamstring muscle function are the injured to 
contra-lateral leg differences in the popliteal angle at 6 weeks and 6 months and 
the injured to contra-lateral ratio of peak isokinetic hamstring torque at 6 weeks 
and 6 months. 
The primary endpoint to assess hamstring structure will be the length and volume 
of fibrosis within the hamstrings at 6 months as evidence on 3 Tesla MRI.   
Specific Aim #3: Time to Return to Prior Level of Function 
The primary outcome for return to sports will be the number of days from injury to 
full, unrestricted return to practice.   
Specific Aim #4: Recurrence of Injury 
The primary outcome for recurrence of injury will be the incidence of recurrent 
injury.  A recurrent injury will be considered to have occurred if there was a 
specific mechanism of injury that caused a return of posterior thigh pain, 
tenderness to palpation along the muscle-tendon unit, pain with resisted knee 
flexion and the inability to participate in sports activities. Recurrent injuries will be 
monitored weekly during the course of rehabilitation and at each follow-up study 
visit (1, 2, 3, 4 & 6 weeks, 6 months) and follow-up phone call (3, 4, 9 and 12 
months). 
 
9.1.2 Secondary endpoints 
 
Specific Aim #2: Recovery of Hamstring Muscle Function and Structure  
Secondary outcomes for recover of hamstring muscle function include isometric 
strength (Newton-meters) of the involved hamstrings expressed as a percentage 
of strength of the un-injured at 1, 2, 3, 4 and 6 weeks and 6 months.  Secondary 
isokinetic variables that will be explored include the injured to contra-lateral leg 
ratio of total hamstring work at 60°/sec, involved hamstring to quadriceps ratio in 
peak torque at 60°/sec, injured to contra-lateral leg ratio of peak torque and total 
work at 180°/sec and the ratio of work in the last 3 repetitions to work in the first 3 
repetitions at 180°/sec at 6 weeks and 6 months. 
 
The secondary outcome for structure of the hamstring will include atrophy of the 
hamstrings as determined by the ratio of the volume of the injured and contra-
lateral leg 6 months after injury. 
 
Specific Aim #3: Time to Return to Prior Level of Function 
The secondary outcome for return to sports activity will be the Marx Activity Scale 
Score at 4 and 6 weeks and 3, 4, 6 and 12 months. At 4 and 6 weeks, the Marx 
Sports Activity Scale will be modified to measure sports activity in the last week 


 
 
36 
and at 4, 6 and 12 months the scale will be modified to measure sports activity in 
the past month. 
 
 
 
9.2 
Sample size determination 
 
With an approved sample size of 20 patients (10 in each group), we will not have 
enough statistical power to detect statistically significant differences in clinical 
measures between the Losartan and placebo groups. Therefore the objective of 
this phase 1 trial is to observe trends by group and estimate effect sizes that can 
be used to inform power calculations in future clinical trials. 
 
 
 
9.3 
Definition(s): Analysis population(s) 
 
All analyses for treatment group comparisons will use the original treatment 
assignment as randomized for each participant (intent-to-treat) regardless of the 
subject’s actual compliance with taking the study medications.  Secondary 
analyses will consider per protocol analysis, in which compliance with the study 
medication regimen will be defined as taking greater than 80% of the doses. 
 
 
 
9.4 
Effectiveness analysis 
 
The distribution of baseline characteristics and important prognostic factors (age, 
sex, body mass index, pre-injury activity level, etc) will be summarized overall, 
and by treatment (versus control) group to assess the effectiveness of the 
randomized allocation. Continuous variables will be summarized with means and 
standard deviations, and medians and inter-quartile ranges. Categorical data will 
be summarized using frequencies and percentages. We will then graphically 
explore the distributions of the primary outcome variables (for normality or 
skewedness and potential outliers) using q-q plots and histograms before 
conducting any tests to compare the two groups. When appropriate, 
transformations will be applied to outcome measures that are not normally 
distributed.  
We anticipate minimal loss to follow-up (<5% of patients) at the 6 month 
assessment and only 10-15% loss to follow-up at 12 months post-injury. The 
primary outcome measures (safety and tolerance, recovery of muscle structure 
and function, return to prior level of function) will be evaluated between 6 weeks 
and 6 months; therefore the only outcome that could appreciably be affected by 
lost to follow-up is recurrence of injury within 12 months. We will compare 
baseline characteristics between participants and drop-outs, obtain reasons for 


 
 
37 
study drop (to investigate the possible missing data mechanism), and will also 
conduct a sensitivity analysis (assigning poor scores and good scores to those 
persons with missing information differentially by treatment assignment) to 
evaluate the impact on our study results.  
For outcome variables that are measured repeatedly, we will use mixed models 
to adjust for correlation among the observations from the same person as well as 
a clustering effect for each site. In these models, subject characteristics such as 
age, sex, and treatment group will be fixed effect predictors, and subject and site 
identification will be included as random effects. Depending on the type of 
outcome variable of interest, we will employ linear mixed models or mixed effect 
logistic regression. Though we do not anticipate statistically significant 
differences between the Losartan and placebo groups due to the small sample 
size, these analyses will guide us in developing future clinical trials. 
 
For time to recurrence, which will be the focus of Specific Aim 4, we expect 50%-
60% of subjects in control group will have recurrence within one year. Although 
the subjects will report whether they had recurrence or not at intermittent time 
points (3, 4, 6, 9 and 12 months after treatment), we will have subjects report the 
actual date of recurrence. We will perform logistic regression (recurred/not 
recurred), and if we obtain reliable information about recurrence date and we 
have enough number of recurrences, we will consider Cox regression model to 
investigate the effect of treatment on time to recurrence, though we do not 
anticipate having enough power to achieve statistically significant results with 
either logistic or Cox modeling. 
 
Any deviations from the previously described statistical plan will be described 
and justified in a protocol amendment and/or in the final report submitted to the 
IND application. 
 
9.5 
Safety analysis 
 
To assess safety, vital signs will be monitored daily and we will also monitor the 
frequency abnormal lab values as well as adverse and serious adverse events 
during period of active intervention as well as throughout the subjects’ 
participation in the study.  To assess the side effect profile of Losartan in this 
population, we will monitor the frequency of subject complaints, symptoms 
(dizziness, new fatigue, peripheral edema, urinary symptoms) and laboratory 
measures of liver and renal function, hemoglobin and hematocrit counts and 
serum potassium and uric acid levels.  The frequency of abnormal lab values, 
adverse and serious adverse events and side effects will be monitored 
separately for the Losartan and placebo control groups.  Differences between 
groups will be assessed using Fisher exact tests.  
 


 
 
38 
Any deviations from the previously described statistical plan will be described 
and justified in a protocol amendment and/or in the final report submitted to the 
IND application. 
 
9.6 
Interim analysis   
 
No interim analysis is planned. 
 
 
 
9.7 
Data and Safety Monitoring Committee  
 
9.7.1  Type of Monitoring Body 
The data and safety monitoring activities for this phase 1 clinical trial will be 
under the oversight of a Data and Safety Monitoring Committee (DSMC) 
consisting of the principal investigators from each site, the study statistician, and 
other appointed investigators.  The goals of this DSMC are to ensure the safety 
of the study participants, integrity of the data and the validity of the study results.  
The data and safety monitoring activities will focus on safety of the study 
participants; performance of the investigative team with respect to participant 
recruitment, retention and follow-up, adherence to the protocol, and quality of the 
data; and to evaluate if the study should continue. 
 
9.7.2  Membership of the Data and Safety Monitoring Committee 
The DSMC will be comprised of the principal investigators from each site, study 
statistician, and other appointed investigators.  A DSMC member will be 
obligated to bring an issue of any potential conflict of interest to the attention of 
the full DSMC for open discussion and resolution.  
Dr. Irrgang will act as the committee chairperson.  He will be responsible for 
overseeing the meetings and working with the project coordinator at the 
coordinating site to develop the agenda and summarize the meeting.  
Dr. Doperak will serve as the Safety Officer for this study. She will be the contact 
person for serious adverse event reporting and study safety issues.  Dr. Doperak 
will review of events that might impact the safety of participants and/or the safety 
of the data for this study. 
 
9.7.3 Responsibilities of the Data and Safety Monitoring Committee 
The DSMC will be responsible for assuring that subjects are not exposed to 
unnecessary or unreasonable risks and that the investigator conducts the clinical 
trial according to the highest scientific and ethical standards.  
Initially, in the planning and development phase of this study, the DSMC will 
review and make recommendations regarding the research protocol, informed 


 
 
39 
consent documents, quality control plans, and plans for data and safety 
monitoring prior to the study initiation.  
Once the study is implemented, ongoing responsibilities of the DSMC will be to:  
• 
Evaluate the progress of trial, including periodic assessments of data quality 
and timeliness; participant recruitment, accrual and retention; participant risk 
versus benefit ratio; performance of the trial site; and other factors that can 
affect study outcome;  
• 
Consider the impact of factors external to the study when new information, 
such as scientific or surgical developments become available and may affect 
the safety of participants, their willingness to participate in the study, or the 
conduct of the trial;  
• 
Review study performance, make recommendations and assist in the 
resolution of problems reported by the investigators; 
• 
Protect the safety and privacy of study participants; 
• 
Report on the safety and scientific progress of the trial;  
• 
Make recommendations concerning continuation, termination, or other 
modifications of the trial based on the observed adverse effects of the 
treatment under study;  
• 
Ensure data integrity;  
• 
Ensure confidentiality of the trial data and the results of monitoring;  
• 
Assist by commenting on any problems with study conduct, enrollment, 
sample size, statistics, and/or data collection; and 
• 
Review and evaluate requests for protocol modifications after the trial begins 
to evaluate whether the study should continue as approved or undergo a 
protocol modification.  
 
9.7.4  Data and Safety Monitoring Committee Processes and Procedures 
9.7.4.1  Meetings of the Data and Safety Monitoring Committee 
The DSMC will meet at designated intervals to review accumulated data on 
safety.  Meetings will be convened as conference calls or in person, although it is 
recommended that the initial meeting and meetings to discuss interim analyses 
be face-to-face.  An emergency meeting of the DSMC will be called at any time 
by the investigators should questions of patient safety arise. Notes and minutes 
of each meeting of the DSMC will be recorded and stored in the study regulatory 
files.  
Each meeting will include a recommendation to continue or to terminate the 
study made by DSMC majority or unanimous vote. Should the DSMC decide to 
issue a termination recommendation, the full vote of the DSMC will be required. 
In the event of a split vote, the majority vote will rule and a minority report should 


 
 
40 
be appended.  In the event of a 50-50 split vote, the DSMC Chairperson will 
provide the tie breaker. 
9.7.4.2  Interim Analyses  
No interim analyses are planned.  However, any data reviewed by the DSMC will 
be limited to as small a group as possible. Data files to be used for review will 
have undergone established editing procedures to the extent possible.  
9.7.4.3  Termination of Study 
A recommendation to terminate the study may be made by the DSMC at any 
time.   
9.7.4.4  Confidentiality 
All materials, discussions, and proceedings of the DSMC will be completely 
confidential. Members and other participants in DSMC meetings will be expected 
to maintain confidentiality at all times. 
 
 
 
 10. Quality Control and Quality Assurance:   
 
Independent monitoring of the clinical study for protocol and GCP compliance will 
be conducted periodically (i.e., at a minimum of annually) by qualified staff of the 
Education and Compliance Office – Human Subject Research, Research 
Conduct and Compliance Office, University of Pittsburgh. 
 
The Sponsor-Investigator and the University of Pittsburgh and UPMC will permit 
direct access of the study monitors and appropriate regulatory authorities to the 
study data and to the corresponding source data and documents to verify the 
accuracy of this data. 
 
Data integrity and credibility of the study are dependent on strict adherence to 
the protocol, obtaining complete follow-up information on all participants and 
establishing and adhering to quality control measures to maintain high standards 
for data quality.  The quality control procedures that have been developed and 
implemented for this study include following established procedures for the 
conduct of research and patient care at the University of Pittsburgh and 
University of Pittsburgh Medical Center (UPMC) in Pittsburgh, PA and at the 
Brooke Army Medical Center in San Antonio, Tx.  Additionally, we will closely 
monitor data collection and form completion at both research sites.   
All study staff will receive initial and ongoing training related to study procedures 
to maximize adherence to the protocol and to achieve high quality data.  
Additionally, all study investigators and staff and the University of Pittsburgh will 
complete training as required, provided by the Collaborative Institutional Training 


 
 
41 
Institute (CITI) (www.citi.pitt.edu).  The following training modules will be 
completed: 
• Research Integrity 
• Human Subjects Research 
• HIPAA and 
• Good Clinical Practice 
All study investigators and staff at Brooke Army Medical Center will complete 
training as required, provided by the Collaborative Institutional Training Institute 
(CITI) (https://www.citiprogram.org/default.asp).  The following training modules 
will be completed: 
• Avoiding Group Harms: U.S. Research Perspectives  
• Unanticipated Problems and Reporting Requirements in Biomedical 
Research 
• Students in Research  
• History and Ethical Principles  
• Basic Institutional Review Board (IRB) Regulations and Review Process 
• Informed Consent Social and Behavioral Research for 
BiomedicalResearchers 
• Records-Based Research  
• Genetic Research in Human Populations  
• Research With Protected Populations – Vulnerable Subjects: An Overview 
• Vulnerable Subjects - Research Involving Prisoners  
• Vulnerable Subjects - Research Involving Children  
• Vulnerable Subjects - Research Involving Pregnant 
• Women, Human Fetuses, and Neonates 
• International Studies  
• FDA-Regulated Research  
• Human Subjects Research at the VA  
• Research and HIPAA Privacy Protections  
 
This research project is conducted by faculty and staff at the University of 
Pittsburgh and staff at the UPMC in facilities operated by the UPMC and 
University of Pittsburgh as well as by faculty and staff at Brooke Army Hospital.  
Investigators and study staff at the University of Pittsburgh and UPMC must 
adhere to the policies and procedures of the University of Pittsburgh, which can 
be found at http://www.bc.pitt.edu/policies/, and the UPMC, which can be found 
at http://policymanuals.infonet.upmc.com/.  Additionally we strictly adhere to all 
University of Pittsburgh IRB policies and procedures, which can be found at  
http://www.irb.pitt.edu/pandp/default.aspx.  Faculty and staff at Brooke army 
Hospital must adhere to the policies and procedures of the Brooke Army Medical 
Center, which can be found at http://fhpr.dhhq.health.mil/dmrn.aspx.      
 


 
 
42 
 
 
11. Data Handling and Record-Keeping:   
 
11.1 Data recording/Case Report Forms   
 
A Case Report Form (CRF, see Appendix 1) will be completed for each subject 
enrolled into the clinical study.  The Sponsor-Investigator will review, approve 
and sign/date each completed CRF; the Sponsor-Investigator’s signature serving 
as attestation of the Sponsor-Investigator’s responsibility for ensuring that all 
clinical and laboratory data entered on the CRF are complete, accurate and 
authentic.   
 
Source Data are the clinical findings and observations, laboratory and test data, 
and other information contained in Source Documents.  Source Documents are 
the original records (and certified copies of original records); including, but not 
limited to, hospital medical records,  physician or office charts, physician or 
nursing notes, subject diaries or evaluation checklists, pharmacy dispensing 
records, recorded data from automated instruments, x-rays, etc.  When 
applicable, information recorded on the CRF shall match the Source Data 
recorded on the Source Documents.   
 
 
This study will utilize paper CRFs for study visits.  These forms will include 
patient reported outcomes (demographics, Marx Activity Scale, and Cincinnati 
Occupational Rating Scale); vital signs, including blood pressure and heart rate; 
numerical pain rating scale; strength measurements and hamstring flexibility; 
medication logs; telephone follow-up logs, and any narrative notes written by the 
study staff. Study data will be recorded directly on these CRFs.  The CRFs will 
be signed and dated by investigators and will serve as source documentation for 
this study. 
 
The paper-based CRF will be created using word processing software but saved 
as .pdf files to prevent changes.  The finalized forms will be marked as such by 
the generation of a unique form/screen identification number.  Revisions to 
finalized forms and screens will not be encouraged once the study is underway.  
Reasons for revisions will be recorded and stored with the finalized versions of 
the forms and screens and all subsequent revisions.  Dates of revisions will be 
recorded on the data collection forms as they occur.  Forms with variable names 
and codes for the responses for each variable will be used to define all variables 
included in the study data set.   
 
The following guidelines will be used to complete the study CRF:  
• Forms will be completed legibly using black or blue ink; 


 
 
43 
• No participant identifiers will be recorded on patient questionnaires, with the 
exception of the Identification and Contact Information Form; 
• Header information, including the participant identification number and date 
will be completed on all forms; 
• If historical dates are required, the month/day/year should be provided.  If the 
individual cannot recall the specific date of the month, the date should be set 
to the 15th of the month in which the event occurred; 
• Abbreviations will not be used unless defined on the form; 
• Responses should only be written in the spaces provided.  Extraneous writing 
on the form should be avoided; 
• To correct an error, a single line will be drawn through the error and the 
change will be dated and initialed by the individual that made the correction; 
• When answering patient-reported forms, the Clinical Research Assistant will 
not help the subject answer the questions.  Rather subjects will be instructed 
to answer all questions to the best of their ability.  If the participant states they 
do not perform an activity and there is no opt out answer, the subject will be 
instructed to answer the question as if they were to do the activity; 
• All questions should be answered.  No questions should be left blank;  
• If answers are illegible, every effort will be made to read the form.  If possible, 
the participant will be contacted to answer the question or clarify the 
response; 
• If data are not available to complete the form, the item for which the data is 
not available should be circled and the reason for the unavailability of data 
should be documented on the form near the appropriate field using the 
following conventions: 
o If the evaluation was not done, write “Not Done” or “ND” and 
provide a reason; 
o If the evaluation was done but the data is not available at the time 
the forms are being completed, indicate “Not Available” or “NAV” 
and document the reason, initial and date; 
o If an evaluation does not apply to the situation, indicate “Not 
Applicable” or “NA” and document the reason and initial and date; 
• If an entire page is not complete, draw a diagonal line through the form & 
indicate “Not Done”, “Not Available”, or “Not Applicable” as appropriate along 
with the reason. 
 
To ensure patient confidentiality, patient identifiers will not be written on the CRF 
at any time.  Any list linking patient names to study identification numbers will be 
stored in locked file cabinets and /or on secure servers behind firewalls.  All 


 
 
44 
paper based study documents will be stored in secure locked file cabinets.  Any 
computerized records will be stored on secure servers behind firewalls. 
 
 
 
 
 
 
11.2 Record maintenance and retention   
 
The Sponsor-Investigator will maintain records in accordance with Good Clinical 
Practice guidelines; to include: 
 
• FDA correspondence related to the IND and clinical protocol, including copies 
of submitted Safety Reports and Annual Reports  
• IRB correspondence (including approval notifications) related to the clinical 
protocol; including copies of adverse event reports and annual or interim 
reports 
• Current and past versions of the IRB-approved clinical protocol and 
corresponding IRB-approved consent form(s) and, if applicable, subject 
recruitment advertisements 
• Signed FDA Form 1572 Statements of Investigator (i.e., for the Sponsor-
Investigator)  
• Financial disclosure information (i.e., for the Sponsor-Investigator and for sub-
investigators who will be involved in the administration of the study drugs 
and/or the evaluation of research subjects [i.e., who will contribute 
significantly to the research study data]) 
• Curriculum vitae (i.e., for the Sponsor-Investigator)  
• Certificates of required training; e.g., human subject protections, Good 
Clinical Practice, etc. (i.e., for the Sponsor-Investigator and for all sub-
investigators who will be involved in the administration of the study drugs 
and/or the evaluation of research subjects [i.e., who will contribute 
significantly to the study data]) 
• Listing of printed names/signatures. (i.e., for the Sponsor-Investigator and for 
all sub-investigators who will be involved in the administration of the study 
drugs and/or the evaluation of research subjects [i.e., who will contribute 
significantly to the study data])  
• Normal value(s)/range(s) for medical/laboratory/technical procedures or tests 
included in the clinical protocol  
• Laboratory certification information  
• Instructions for on-site preparation and handling of the investigational drug(s), 
study treatment(s), and other study-related materials (i.e., if not addressed in 
the clinical protocol) 
• Responsibility delegation log 
• Signed informed consent forms  


 
 
45 
• Completed Case Report Forms; signed and dated by Sponsor-Investigator  
• Source Documents or certified copies of Source Documents  
• Monitoring visit reports  
• Copies of Sponsor-Investigator correspondence (including notifications of 
safety information) to sub-investigators 
• Subject screening and enrollment logs 
• Subject identification code list 
• Investigational drug accountability records, including documentation of drug 
disposal. 
• Final clinical study report 
 
• Decoding procedures for blinded trials 
• Master randomization list 
 
• Signed FDA Form 1572 Statements of Investigator (i.e. for Investigators 
responsible for the conduct of the clinical research study at external study 
sites). 
• Financial disclosure information (i.e., for Investigators responsible for the 
conduct of the clinical research study at external study sites; also for all study 
site sub-investigators who will be involved in the administration of the study 
drugs and/or the evaluation of research subjects [i.e., who will contribute 
significantly to the study data]) 
• Curriculum vitae (i.e., for Investigators responsible for the conduct of the 
clinical research study at external study sites) 
• Certificates of required training; e.g., human subject protections, Good 
Clinical Practice, etc. (i.e., for Investigators responsible for the conduct of the 
clinical research study at external study sites; also for all study site sub-
investigators who will be involved in the administration of the study drugs 
and/or the evaluation of research subjects [i.e., who will contribute 
significantly to the study data]) 
• Listing of printed names/signatures (i.e., for Investigators responsible for the 
conduct of the clinical research study at external study sites; also for all study 
site sub-investigators who will be involved in the administration of the study 
drugs and/or the evaluation of research subjects [i.e., who will contribute 
significantly to the study data])  
• Copies of initial and continuing IRB approval notifications (i.e., for each of the 
external study sites) 
• Normal value(s)/range(s) for medical/laboratory/technical procedures or tests 
included in the clinical protocol (i.e., for each of the external study sites) 
• Laboratory certification information (i.e., for each of the external study sites) 
• Monitoring visit reports (i.e., for all external study sites) 
• Copies of Sponsor-Investigator correspondence (including notifications of 
safety information) to Investigators responsible for the conduct of the clinical 
research study at external study sites 
 


 
 
46 
The Sponsor-Investigator will retain the specified records and reports for up to 2 
years after the marketing application is approved for the investigational drug; or, 
if a marketing application is not submitted or approved for the investigational 
drug, until 2 years after investigations under the IND have been discontinued and 
the FDA so notified. 
 
12. Ethics: 
 
12.1 
Institutional Review Board (IRB) approval 
   
The Sponsor-Investigator will obtain, from the University of Pittsburgh 
Institutional Review Board (IRB), prospective approval of the clinical  protocol 
and corresponding informed consent form(s); modifications to the clinical protocol 
and corresponding informed consent forms, and advertisements (i.e., directed at 
potential research subjects) for study recruitment.    
 
The only circumstance in which a deviation from the current IRB-approved 
clinical protocol/consent form(s) may be initiated in the absence of prospective 
IRB approval is to eliminate an apparent immediate hazard to the research 
subject(s).  In such circumstances, the Sponsor-Investigator will promptly notify 
the University of Pittsburgh IRB of the deviation.  
 
The University of Pittsburgh IRB operates in compliance with FDA regulations at 
21 CFR Parts 50 and 21 CFR 56, and in conformance with applicable 
International Conference on Harmonization (ICH) Guidelines on Good Clinical 
Practice (CGP).  
 
In the event that the University of Pittsburgh IRB requires, as a condition of 
approval, substantial changes to a clinical protocol submitted under an FDA-
accepted IND application, or in the event of the Sponsor-Investigator’s decision 
to modify the previously accepted clinical protocol: 
 
• 
For a Phase 1 clinical study: The Sponsor-Investigator 
will submit (i.e., in advance of implementing the change) a Protocol 
Amendment to the IND describing any change to the Phase 1 clinical 
protocol  that significantly affects the safety of the subjects.  For changes 
that do not affect critical safety assessments, the revisions to the clinical 
protocol will be addressed in the Annual Report to the IND.  
 
• For Phase 2 and 3 clinical studies:  The Sponsor-Investigator will submit (i.e., 
in advance of implementing the change) a Protocol Amendment to the IND 
describing any change to a Phase 2 or Phase 3 protocol that significantly 
affects the safety of subjects, the scope of the investigation, or the scientific 
quality of the study.  Examples of Phase 2 and 3 clinical protocol changes 
requiring the submission of a Protocol Amendment include: 


 
 
47 
 
o Any increase in drug dosage or duration of exposure of individual subjects 
to the investigational drug beyond that described in the current protocol, or 
any significant increase in the number of subjects under study. 
 
o Any significant change in the design of the protocol (such as the addition 
or deletion of a control group). 
 
o The addition of a new test or procedure that is intended to improve 
monitoring for, or reduce the risk of, a side effect or adverse event; or the 
dropping of a test intended to monitor the safety of the investigational 
drug. 
 
 
12.2 Ethical and scientific conduct of the clinical research 
study  
 
The clinical research study will be conducted in accordance with the 
current IRB-approved clinical protocol; ICH GCP Guidelines adopted by 
the FDA; and relevant policies, requirements, and regulations of the 
University of Pittsburgh IRB, University of Pittsburgh and UPMC, 
Commonwealth of Pennsylvania, and applicable federal agencies. 
 
12.3 Subject informed consent   
 
The Sponsor-Investigator will make certain that an appropriate informed 
consent process is in place to ensure that potential research subjects, or 
their authorized representatives, are fully informed about the nature and 
objectives of the clinical study, the potential risks and benefits of study 
participation, and their rights as research subjects.  The Sponsor-
Investigator, or a sub-investigator(s) designated by the Sponsor-
Investigator, will obtain the written, signed informed consent of each 
subject, or the subject’s authorized representative, prior to performing any 
study-specific procedures on the subject. The date and time that the 
subject, or the subject’s authorized representative, signs the informed 
consent form and a narrative of the issues discussed during the informed 
consent process will be documented in the subject’s case history.  The 
Sponsor-Investigator will retain the original copy of the signed informed 
consent form, and a copy will be provided to the subject, or to the 
subject’s authorized representative. 
 
The Sponsor-Investigator will make certain that appropriate processes and 
procedures are in place to ensure that ongoing questions and concerns of 
enrolled subjects are adequately addressed and that the subjects are 
informed of any new information that may affect their decision to continue 
participation in the clinical study.  In the event of substantial changes to 
the clinical study or the risk-to-benefit ratio of study participation, the 


 
 
48 
Sponsor-Investigator will obtain the informed consent of enrolled subjects 
for continued participation in the clinical study 
 
13. Study Discontinuation Criteria: 
 
13.1 Discontinuation of individual research subjects (refer 
also to sections 5.1.1 and 8.4) 
 
Because we are interested in evaluating efficacy, we will use a per-protocol 
approach, as opposed to an intention-to-treat approach for the conduct of this 
study.  As such, subjects that are non-compliant with the medication regimen 
(defined as taking less than 80% of the medication doses) will be withdrawn 
from the study and additional subjects will be recruited to replace subjects 
that have been withdrawn due to non-compliance.  Subjects that are 
withdrawn for non-compliance will be instructed to terminate administration of 
the study medication without tapering down the dose and to return unused 
medication to the investigators. 
 
As specified in section 8.4 subjects with symptomatic hypotension or 
abnormal lab values will be withdrawn from study participation.  Additionally, 
females that become pregnant while taking the study medication will 
immediately stop the medication and will be withdrawn from the study.    
These withdrawn subjects will be followed clinically based on standards of 
care until the adverse event or abnormal test findings felt to be associated 
with the study drug resolve or stabilize at a level satisfactory to the Sponsor-
Investigator, however no further research data will be collected once the 
subject has been withdrawn.     
 
Subjects that are withdrawn due to non-compliance with the study medication, 
symptomatic hypotension, abnormal lab values or pregnancy will be reported 
as an adverse event.  Withdrawn subjects will be replaced by recruiting 
another subject to take the place of the withdrawn subject. 
 
  
 
 
13.2 Sponsor-Investigator discontinuation of the clinical 
research study 
 
Adverse events will be continuously monitored by the Data and Safety 
Monitoring Committee.  If the number or severity adverse events are greater 
than the expected adverse events associated with Losartan, the DSMC will 
make the recommendation for termination or modification of study.   
 


 
 
49 
Any modifications in the study protocol will be submitted for review and 
approval by the IRB before the modification is implemented.  Modifications in 
the study protocol will be communicated to all study sites in writing.  Subjects 
will be notified of modifications in the study protocol and if appropriate will be 
re-consented for their continued participation in the modified study.   
 
If the DSMC recommends termination of the study due to safety concerns, the 
IRB and all study sites will be notified immediately by the study principal 
investigator, followed by notification in writing.  Enrolled subjects will be 
notified of the study termination by the site principal investigator by phone, 
and also in writing. If subjects are taking study medication at the time of study 
termination, they will be instructed to discontinue the study medication as 
clinically appropriate.    
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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ICF_001.pdf: 
 
Phase 1/2 Prospective Double-blind, Placebo-controlled Randomized Clinical Trial Using 
Losartan to Treat Grade II and III Hamstring Strains 
 
 
NCT Number: NCT02263729 
 
 
December 6, 2022 
 


University of Pittsburgh STUDY19100320    Effective: 12/6/2022    Expires: 12/5/2023
     Page 1 of 11  
Department of Orthopaedic Surgery
UPMC Rooney Sports Complex
UPMC Lemieux Sports Complex
CONSENT TO ACT AS A SUBJECT IN A RESEARCH STUDY
PRINCIPAL INVESTIGATOR:
James Irrgang, PT, PhD
Professor and Chair
Department of Physical Therapy
Vice Chair of Clinical Outcomes Research
Department of Orthopaedic Surgery
100 Technology Drive
Pittsburgh, PA 15219
Phone: 412-383-9865
CO-INVESTIGATORS:
Kelley Anderson, DO
Jeanne Doperak, DO
Bryson Lesniak, MD
Albert Lin, MD
Aaron Mares, MD
Volker Musahl, MD
Dharmesh Vyas, MD
Bryan Galvin, MS, ATC
Department of Orthopaedic Surgery
UPMC Rooney Sports Complex
UPMC Lemieux Sports Complex
Camillo Borrero, MD
Department of Radiology
200 Lothrop Street
Pittsburgh, PA 15213
Bryan Galvin, MS  
Phone: 412-432-3619
Research Coordinator 
M. Beatriz Catelani, PT, MS
Phone:412-383-6760
Research Coordinator
3200 South Water Street
Pittsburgh PA, 15203
Source of Support: Department of Defense 


University of Pittsburgh STUDY19100320    Effective: 12/6/2022    Expires: 12/5/2023
     Page 2 of 11  
Why is this research being done?
Investigators in the University of Pittsburgh Department of Orthopaedic Surgery are 
conducting a research study to evaluate the use of Losartan as a medication for grade II 
or III hamstring (muscle in the back of the thigh) sprains.  Losartan is a prescription 
medication used to as a medical treatment for high blood pressure. The use of losartan 
in this research study is considered to be experimental.
Subjects will be randomized to receive either Losartan medication at the 50 mg dose or 
a placebo pill (inactive substance).  Randomization is a process that assigns you by 
chance, rather than by choice. Randomization is like the flip of a coin and gives you 
equal possibility of being in either group.  We will use a computer program to randomly 
assign you to one of the two groups and neither you nor your health care providers 
(doctor, physical therapist/ athletic trainer) will know which group you are in. In the case 
of emergency, however the study team will be able to determine which you have 
received.  You will be given the supply of study pills to take once daily for 4 weeks.
The goals of this study are:

To determine if Losartan is safe and tolerable, compared to a placebo;

To determine if Losartan is effective in the recovery of hamstring muscle function
after a grade II or III hamstring sprain;

To determine the effect of Losartan how long it takes to return to prior level of
function after a grade II or III hamstring sprain;

To determine the effect of Losartan on another injury after a grade II or III hamstring
sprain.
Who is being asked to take part in this research study?
You are being asked to participate in this study because you are 18 years of age or 
older, participate regularly in very strenuous (football, basketball, or soccer) or 
strenuous (racquet sports, skiing, manual labor occupations) activities including 
activities that requiring running and sprinting, have had a grade II or III hamstring injury 
in the past 7 days, and agreed to be randomized to one or two treatment groups.  
Approximately 10 patients will participate in this study. While you are enrolled in this 
study, you will attend physical therapy visits.
What procedures will be performed for research purposes?
The following activities will be completed throughout your participation in this study.   
Not all activities listed here will be completed at every visit.  You will participate in 8 
visits in-person and 4 – follow-up phone calls over a period of 12 months.
Demographic Information
Demographic Information that will be recorded include age, sex, weight, height, body 
mass index (BMI), education level, sports activity level, work activity, marital status, and 
smoking history. This form will be completed at the pre-treatment visit. (5 minutes to 
complete)
Activity Level Questionnaires- The following questionnaires will be completed at the pre-


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treatment and follow-up visits. The Occupational Rating Scale of the Cincinnati Knee 
Rating System measures work activity by rating the duration or frequency of sitting, 
standing, walking, squatting, climbing, lifting, and carrying performed while working at a 
job.  The Marx Sports Activity Scale consists of four activities (running, cutting, 
decelerating, and pivoting) rated by the frequency you perform the activity.  (10 minutes 
to complete)
Medical History and Physical Examination
A medical history and physical examination will be performed for all subjects in this 
study at the pre-treatment visit.  The medical history will include a review of the chief 
complaint, history of present injury, past medical history, allergies, medications, and 
social and family history. (15 minutes to complete)
An examination of the injury will be performed at the pre-treatment visit. You will be 
examined for any symptoms related to your hamstring injury including pain, bruising, 
swelling, and your ability to walk and run. (15 minutes to complete)
Vital Signs
Your vital signs will be measured by a qualified examiner.  The examiner will take your 
pulse (heart rate) and blood pressure.  Blood pressure will be measured in both arms 
and will be taken while you are seated, after you have been lying quietly on your back 
for 5 minutes, and while you are standing.  Vital signs will be taken at the pre-treatment, 
1 week, 2 week, 3 week, 4 week, 6 week, 12 week, and 6 month follow-up visits.  (10 
minutes to complete)
Pain Scale
You will be asked to rate your hamstring pain on a scale from 0 to 10.  Your pain will be 
assessed at the pre-treatment, 1 week, 2 week, 3 week, 4 week, 6 week, 12 week, and 
6 month follow-up visit. (2 minutes to complete)
Blood Draw
You will have of blood taken 4 times during the study.  You will be sent to a UPMC 
Outpatient Lab for this blood draw.  The blood will be taken from your arm. The amount 
of blood drawn will be enough to assess a chemistry panel with electrolytes (about 2 
teaspoons). The blood will be taken prior to treatment and 2, 4, and 6 weeks after study 
medication is given to you.  (15 minutes to complete)
MRI
An MRI (magnetic resonance imaging) will be used to determine the extent of your leg 
injury.  MRI uses a large circular magnet to construct images of the internal structures of 
your leg and knee.  You will undergo a MRI at the pre-treatment visit and 6 months 
follow-up.  (1 hour to complete)
Losartan or Placebo
This study compares an active drug to a placebo.  A placebo is an inactive substance 
made to look/taste like an active medicine.  You will either be assigned to receive 
Losartan or a placebo.  Research use a placebo to see if the study drug works better or 


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is safer than not taking anything.  You will take the study medication daily for 4 weeks.  
You will bring the study medication with you to each in-person research visit.  Pills will 
be counted by the study staff to check for medication compliance. Because Losartan is 
dangerous in pregnancy, female subjects will have a pregnancy test before starting the 
study pills and at each visit.
Medication Log
You will be asked to complete a medication log while you are taking the study 
medication.  You will record when you took the study medication, as well as any other 
medications you make take during the same time period.  This log will be reviewed with 
a member of the study staff when you return to the office for the 1 week, 2 week, 3 
week, and 4 week follow-up visits.  (15 minutes to complete)
Review of Exercise Log
Your physician will give you plan of stretching and strengthening exercises for physical 
therapy and rehabilitation.  This plan will be supervised by the physical therapist or 
athletic trainer.  The exercises are to be completed by you daily.  For the research 
study, you will complete a log to indicate which exercise you have completed each day.  
This log will be reviewed at the 1, 2, 3, 4, 6, and 12 week visits with the research study 
team.
Hamstring Flexibility
To complete this test, you will lay on your back on an examination table.  An examiner 
will move your leg by straightening your knee as far as it will go.  The angle of your knee 
will be measured and recorded with a goniometer (protractor).  This test will be repeated 
on both sides. This test will be completed at the pre-treatment, 1 week, 2 week, 3 wee, 
4 week, 6 week, and 6 month follow-up visits.  (10 minutes to complete)
Isometric Hamstring Strength
To complete this test, you will lay face down on an examination table.  A dynamometer 
(device to measure force) will be placed on the lower leg, just above the ankle.  The 
amount of force you create by pushing on the dynamometer will be measured.  Your leg 
will be free to move back toward the table.  You will push your leg as hard as you can, 
three times with a one-minute rest in between each.  This test will be repeated on both 
legs. This test will be completed at the pre-treatment visit, 1 week, 2 week, 3 week, 4 
week, week, and 6 month follow-up visits. (15 minutes to complete)
Isokinetic Hamstring Strength
For the isometric dynamometry, you will be seated in a device called the Biodex System 
III (Biodex Medical Systems, Shirley, NY) that measures the amount of force you exert 
while pushing on a force-sensing bar.  You will be seated on the device and the force-
sensing arm will be secured to your ankle.  Testing will begin on with the non-involved 
leg followed by testing of the involved leg.  The test consists of 3 practice trials, followed 
by 3 maximum effort trials (pushing as hard as you can) for contractions of the 
hamstring muscles (back muscles of your thigh).  Each trial will consist of a 5-second 
contraction of the quadriceps muscles followed by a 60 second rest period. There will 
be a 1-minute rest period between the practice trials and the maximum effort trials.  This 


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test will be completed at the 6 week and 6 month follow-up visits.  (15 minutes to 
complete)
Telephone Call Follow-up
A member of the study team will call you to ask questions about your activity level and 
any symptoms you may have, including pain.  You will receive 4 phone calls after your 6 
week visit.  Each call will last approximately 5-10 minutes.
Study Chart
This study chart shows all the study activities you will complete.  Study procedures 
described in this consent form are listed along the left side of the chart.  The study visit 
time points are listed across the top.
Pre-
treat
Day 
0
1
w
2w
3w
4w
6w
12w
4m
6m
9m
12m
Time to 
Complete
Informed Consent
X
Demographic 
Questionnaire
X
5 minutes
Activity Level 
Questionnaries
X
X
X
X
X
X
X
X
X
X
X
10 minutes
Medical History
X
15 minutes
Vital Signs (heart rate 
and blood pressure)
X
X
X
X
X
X
X
10 minutes
Physical Examination
X
15 minutes
Blood Work
X
X
X
X
15 minutes
Urine pregnancy test
X
X
X
X
10 minutes
Numerical Pain 
Rating Scale 
X
X
X
X
X
X
X
X
2 minutes
Hamstring flexibility
X
X
X
X
X
X
X
10 minutes
Isometric hamstring 
strength testing
X
X
X
X
X
X
X
15 minutes
Isokinetic hamstring 
strength testing
X
X
15 minutes
MRI
X
X
1 hour
Randomization
X
Day of 1st Medication 
Dose
X
Medication Log 
Review
X
X
X
X
15 minutes
Exercise Log Review
X
X
X
X
X
X
Telephone follow-up
X
X
X
X
5-10 minutes
Legend: pre-treat = pre-treatment; w = week; m = months
What are the possible risks, side effects, and discomforts of this research study?


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Risks of Losartan
There is a risk that you may experience side effects of taking the medication Losartan 
during the treatment phase of this study.  Side effects include diarrhea, dizziness, 
tiredness, upper respiratory tract infections, cough, sinus disorder, nasal congestion, 
indigestion, heartburn, pain, high blood potassium, low blood pressure, allergic reaction, 
and injury or death to an unborn fetus.  You will be monitored by a study physician for 
these side effects throughout the course of the study.  
Reproductive Risks
Losartan is contraindicated in pregnancy, as it is known to cause harm to an unborn 
baby. Pregnant females will be excluded from this study. Taking this medication while 
pregnant may cause injury or death to an unborn fetus. You will be counseled by the 
investigator of this risk and will be counseled to use appropriate birth control methods. 
You will be screened for pregnancy by blood test prior to being administered the study 
medication.  You will also be screened for pregnancy with a urine pregnancy test at the 
1 week, 2 week, 3 week, and 4 week follow-up visits.  
To avoid risk to the fetus, it is important that female participants not become pregnant 
while you are participating in this research study. Avoiding sexual activity is the only 
certain method to prevent pregnancy. However, if you choose to be sexually active, you 
should use an appropriate “double barrier” method of birth control (such as female use 
of a diaphragm, intrauterine device (IUD), or contraceptive sponge, in addition to male 
use of a condom) or the female should be using prescribed “birth control” pills, 
injections, or implants. If you choose to be sexually active during this study, you 
understand that even with the use of these birth control measures pregnancy could still 
result. The risks of receiving the study drugs while pregnant include potential loss of 
pregnancy or possible birth defects. If you become pregnant while participating in this 
study, you must tell the study doctor immediately.  
Breach of Confidentiality
Subject confidentiality will be maintained at all times, as with any other patient who 
receives treatment at the Center for Sports Medicine.  All records will be assigned a 
case number. Information collected in this study will be stored in a locked file cabinet 
and will be accessible only to the research staff.  The list linking the code number with 
your identity will be stored in a separate secure location.  You will not be identified in 
any publications or presentation of the research results.
Risk of Blood Draw
The risks of taking blood include pain and bruising at the point the blood is taken.
Risk of MRI
There is the risk that the strong magnetic field of the MRI scanner may attract metallic 
objects toward the magnet.  This may cause metallic objects within the body to move 
which may result in injury to the surrounding tissues.  Additionally, some individuals may 
experience claustrophobia due to being a in confined space when in the MRI scanner.
Risks of Isometric and Isokinetic Strength Tests


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The risks associated with the strength tests include mile muscle soreness and 
discomfort following the tests.  In rare instances, individuals may experience a strained 
thigh muscle, which could result in muscle pain and swelling for several days.  These 
risks will be minimized by allowing adequate time for warm-up, stretching, and 
familiarization with the test. 
What are the possible benefits from taking part in this study?
You may not receive any direct benefit from this study.  However, information learned in 
this study may lead to additional methods to treat future patients with hamstring injuries.
If I agree to take part in this research study, will I be told of any new risks that 
may be found during the course of the study?
You will be promptly notified if, during the conduct of this research study, any new 
information about using Losartan to treat hamstring injuries is found. 
Will my insurance provider or I be charged for the costs of any procedures 
performed as part of this research study?
Neither you, nor your insurance provider, will be charged for the costs of any of the 
procedures performed exclusively for the purpose of this research study. You will be 
charged, in the standard manner, for any procedures performed for your routine medical 
care.
Who will pay if I am injured as a result of taking part in this study?
The investigators and their associates who provide services at UPMC recognize the 
importance of your voluntary participation in their research studies.  These individuals 
and their staff will make reasonable efforts to minimize, control, and treat any injuries 
that may arise as a result of this research.  If you believe you were injured as a result of 
the research procedures being performed, please contact immediately the Principal 
Investigator or one of the co-investigators listed on the first page of this form.
Emergency medical treatment for injuries solely and directly related to your participation 
in this research study will be provided to you by the hospitals of UPMC.  It is possible 
that UPMC may bill your insurance provider for the costs of this emergency treatment, 
but none of these costs will be charged directly to you.  If your research-related injury 
requires medical care beyond this emergency treatment, you will be responsible for the 
costs of this follow-up care unless otherwise specifically stated below.  There is no plan 
for monetary compensation. You do not, however, waiver any legal rights by signing this 
form.
Will I be paid if I take part in this research study?
You will receive up to $410 for completion of all research activities.  Payments are 
distributed as follows:

Baseline activities (including consent, physical examination and vital signs, 
strength testing, questionnaires and assessments, MRI and bloodwork): $100

Weeks 1, 2, 3 and 4 activities (including strength assessments, questionnaires 
and vital signs): $25 per timepoint


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
6 Week activities (including strength assessments, questionnaires, vital signs 
and bloodwork): $50 

6 Month activities (including strength assessments, questionnaires, vital signs 
and MRI): $100

12 week, 4, 9 and 12 month telephone questionnaires: $15 per timepoint. 
No partial payments per timepoint will be given.  To receive the full amount at each 
timepoint, all designated activities must be completed.  
Payment to participants is considered taxable income regardless of the amount. If a participant 
receives $600 or more in a calendar year from one organization, that organization is required by 
law to file a “Form 1099 – Miscellaneous” with the IRS and provide a copy to the taxpayer. We 
are required to give your name and social security number to the Accounting Office. Participants 
who do not provide a social security number may still participate in the research, but the IRS 
requires that 26% of the payment be sent by the institution to the IRS for ‘backup withholding;’ 
thus you would only receive 74% of the expected payment.
Who will know about my participation in this research study?
Any information about you obtained from this research will be kept as confidential 
(private) as possible.  All records related to your involvement in this research study will 
be stored in a locked file cabinet at the Center for Sports Medicine.  Your identity on 
these records will be indicated by a case number rather than by your name, and the 
information linking these case numbers with your identity will be kept separate from the 
research records.  Data may be stored on a computer on a password protected network 
drive that will only be accessible to study personnel.  You will not be identified by name 
in any publication of the research results unless you sign a separate consent form 
giving your permission (release).
A description of this clinical trial will be available on http://www.ClinicalTrials.gov as 
required by U.S. Law. This Web site will not include information that can identify you. At 
most, the Web site will include a summary of the results. You can search this Web site 
at any time.
Will this research study involve the use or disclosure of my identifiable medical 
information?
This research study will involve the recording of current and/or future identifiable 
medical information from your hospital and/or other (e.g., physician office) records.  The 
information that will be recorded will be limited to information concerning the purpose of 
the treatment you underwent for your hamstring injury including; your medical care; non-
operative treatment; surgical treatment; physical therapy information; any follow-up care 
related to your hamstring; and information from radiographs and MRI of your lower 
extremities.  Information about your hamstring strength may be placed into your medical 
records.
A statement will be placed into your medical record related to your participation in the 
study stating you are enrolled in a research trial using losartan as a study medication.  
This statement will provide contact information for investigators in the event of an 


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emergency while you are on the study medication.
Who will have access to identifiable information related to my participation in this 
research study?
In addition to the investigators listed on the first page of this authorization (consent) 
form and their research staff, the following individuals will or may have access to 
identifiable information (which may include your identifiable medical information) related 
to your participation in this research study: 
Authorized representatives of the US Army Medical Research and Material Command 
may review your identifiable research information (which may include your identifiable 
medical information) for the purpose conducting and monitoring of this research study.
Authorized representatives of UPMC may review your identifiable medical information 
for the purpose of quality assurance monitoring.
Authorized representatives of the University of Pittsburgh Office of Research 
Protections may review your identifiable research information (which may include your 
identifiable medical information) for the purpose of monitoring the appropriate conduct 
of this research study. 
In unusual cases, the investigators may be required to release identifiable information 
(which may include your identifiable medical information) related to your participation in 
this research study in response to an order from a court of law.  If the investigators learn 
that you or someone with whom you are involved is in serious danger or potential harm, 
they will need to inform, as required by Pennsylvania law, the appropriate agencies.
For how long will the investigators be permitted to use and disclose identifiable 
information related to my participation in this research study?
The investigators may continue to use and disclose, for the purposes described above, 
identifiable information (which may include your identifiable medical information) related 
to your participation in this research study for a minimum of 7 years and for as long 
(indefinite) as it may take to complete this research study.
May I have access to my medical information that results from my participation in 
this research study?
A copy of the results of these tests will be placed into either your physical therapy chart 
or medical chart, depending on who recommended you participate in this study.  
Is my participation in this research study voluntary?
Your participation in this research study, to include the use and disclosure of your 
identifiable information for the purposes described above, is completely voluntary.  
(Note, however, that if you do not provide your consent for the use and disclosure of 
your identifiable information for the purposes described above, you will not be allowed, 
in general, to participate in the research study.)  
Whether or not you provide your consent for participation in this research study will 


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have no effect on your current or future relationship with the University of Pittsburgh.  
Whether or not you provide your consent for participation in this research study will 
have no effect on your current or future medical care at a UPMC hospital or affiliated 
health care provider.
Your doctor is involved as an investigator in this research study.  As both your doctor 
and a research investigator, s/he is interested both in your medical care and the 
conduct of this research study.  Before agreeing to participate in this research study, or 
at any time during your study participation, you may discuss your care with another 
doctor who is not associated with this research study.  You are not under any obligation 
to participate in any research study offered by your doctor.
May I withdraw, at a future date, my consent for participation in this research 
study?
You may withdraw, at any time, your consent for participation in this research study 
(However, if you withdraw your consent for the use and disclosure of your identifiable 
medical record information for the purposes described above, you will also be 
withdrawn, in general, from further participation in this research study.)  
Any identifiable research or medical information recorded for, or resulting from, your 
participation in this research study prior to the date that you formally withdrew your 
consent may continue to be used and disclosed by the investigators for the purposes 
described above.
To formally withdraw your consent for participation in this research study you should 
provide a written and dated notice of this decision to the principal investigator of this 
research study at the address listed on the first page of this form.
Your decision to withdraw your consent for participation in this research study will have 
no effect on your current or future relationship with the University of Pittsburgh.  Your 
decision to withdraw your consent for participation in this research study will have no 
effect on your current or future medical care at a UPMC hospital or affiliated health care 
provider.
If I agree to take part in this research study, can I be removed from the study 
without my consent?
It is possible that you may be removed from the research study by the researchers.  
You may be removed from the study, for example, you do not meet all the eligibility 
criteria prior to randomization or you become non-compliant with the medication 
schedule.


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VOLUNTARY CONSENT 
The above information has been explained to me and all of my current questions have 
been answered. I understand that I am encouraged to ask questions, voice concerns or 
complaints about any aspect of this research study during the course of this study, and 
that such future questions, concerns or complaints will be answered by a qualified 
individual or by the investigator(s) listed on the first page of this consent document at 
the telephone number(s) given. I understand that I may always request that my 
questions, concerns or complaints be addressed by a listed investigator. I understand 
that I may contact the Human Subjects Protection Advocate of the IRB Office, University 
of Pittsburgh (1-866-212-2668) to discuss problems, concerns, and questions; obtain 
information; offer input; or discuss situations in the event that the research team is 
unavailable. By signing this form I consent to participate in this research study and 
provide my authorization to share my medical records with the research team.
_________________________________
Participant’s Name
________________________________ 
__________________
Participant’s Signature
Date
CERTIFICATION of INFORMED CONSENT
I certify that I have explained the nature and purpose of this research study to the 
above-named individual(s), and I have discussed the potential benefits and possible 
risks of study participation. Any questions the individual(s) have about this study have 
been answered, and we will always be available to address future questions, concerns 
or complaints as they arise. I further certify that no research component of this protocol 
was begun until after this consent form was signed.
___________________________________
________________________ 
Printed Name of Person Obtaining Consent
Role in Research Study 
_________________________________
___________________ 
Signature of Person Obtaining Consent
Date