CCTG 595: Text Messaging Intervention to Improve Adherence to PrEP in High-risk MSM

A total of 400 HIV-uninfected men who have sex with men (MSM)and male to female (M to F)
transgender individuals with recent high-risk transmission behavior will be enrolled into
the study. Each subject will be followed for up to 48 weeks after enrollment of the last
subject. The primary endpoint will be measured at 48 weeks.

All subjects will start PrEP with TDF + FTC fixed dose combination given once daily.
Subjects will be randomized (1:1) to either the iTAB text messaging adherence reminder
intervention with SoC or the SoC alone arm. Subjects placed into the iTAB intervention arm
will receive a personalized, automated texting system to maintain adherence and retention.
Both groups will receive access to PrEP in accordance with standardized comprehensive
methods of prescribing, risk reduction counseling, adherence counseling, and clinical
assessments that include safety monitoring, as well as HIV and STD screening.

TDF 300 mg + FTC 200 mg fixed dose combination will be given orally once daily starting at
the baseline visit (month 0) and continued throughout the study.

Inclusion Criteria:

- Man or transgender M to F who has sex with men.

- Age 18 years or older.

- Subjects must have substantial ongoing risk of acquisition of HIV as evident by one
or more of the following:

- Has at least one HIV infected sexual partner for ≥4 weeks.

- No condom use during anal intercourse with ≥3 male sex partners who are
HIV-positive or of unknown HIV status during the last 3 months.

- No condom use during anal sex with ≥1 male partner and STI diagnosis during the
last 3 months.

- Negative for HIV infection by rapid HIV test and confirmed negative by NAT or other
sensitive method such as antibody- antigen test.

- Acceptable laboratory values in the past 30 days:

- Calculated creatinine clearance of at least 60 mL/min by the Cockcroft-Gault
formula (eCcr (male) in mL/min = [(140 - age in years) x (lean body weight in
kg)] / (72 x serum creatinine in mg/dL)

- Alanine aminotransferase (ALT) and/ or aspartate aminotransferase (AST) < 3 x
upper limit of normal (ULN)

- Hemoglobin > 9 g/dL

- Absolute neutrophil count > 750/ mm3

- Platelets > 75,000/ mm3

Exclusion Criteria:

- Unable to give informed consent.

- Active hepatitis B (positive hepatitis B surface antigen (HBSAg) or HBSAg negative/
HB core antibody positive/ HBV PCR positive).

- Has substantial medical condition, that in the opinion of the investigator would
preclude participation, as defined by

- cardiovascular condition that may lead to an increased risk of complication if
placed on study drugs.

- gastrointestinal condition that would impair absorption of study drugs.

- neurological or psychiatric condition that would significantly impair the
ability to adhere to PrEP.

- calculated GFR < 60 mL/min.

- alcohol or drug abuse or dependence that would significantly impair the ability
to adhere to PrEP (only for those with severe impairment).

- other medical condition that would unacceptably increase the risk of harm from
study drug or significantly impair the ability to adhere to PrEP.

- Suspected sensitivity or allergy to the study drug or any of its components.

- Currently using an essential product or medication that interacts with the study drug
such as the following:

- ART (including nucleoside analogs, non-nucleoside reverse transcriptase
inhibitors, protease inhibitors or investigational antiretroviral agents)

- Agents with known nephrotoxic potential:

- aminoglycoside antibiotics (including gentamicin)

- IV amphotericin B

- cidofovir

- cisplatin

- foscarnet

- IV pentamidine

- IV vancomycin

- oral or IV gancyclovir

- other agents with significant nephrotoxic potential

- Drugs that slow renal excretion

- Probenecid

- Immune system modulators

- Systemic chemotherapeutic agents (i.e. cancer treatment medications)

- Ongoing systemic corticosteroids (with the exception of short courses of
tapering steroid doses for asthma or other self- limited condition).

- Interleukin-2 (IL-2)

- Interferon (alpha, beta, or gamma)

- Other agent known to have a significant interaction with TDF or FTC

- Proteinuria 2+ or greater by urine dipstick

- Signs or symptoms suggestive of acute HIV infection

- Any other reason or condition that in the opinion of the investigator would
interfere with participation, complicate interpretation of study outcome data,
or otherwise interfere with achieving the study objectives.