FDA Approves Tibotec Therapeutics's PREZISTA(R)/ritonavir Once-Daily Dosing for HIV-1 Treatment-Experienced Adults With No Darunavir Resistance-Associated Mutations

In treatment-experienced adult patients, the following points should be considered when initiating therapy with PREZISTA/ritonavir:

• Treatment history and, when available, genotypic or phenotypic testing, should guide the use of PREZISTA/ritonavir.

• The use of other active agents with PREZISTA/ritonavir is associated with a greater likelihood of treatment response.

Drug Interactions

• Coadministration of PREZISTA/ritonavir is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events (e.g., alfuzosin, dihydroergotamine, ergonovine, ergotamine, methylergonovine, cisapride, pimozide, oral midazolam, triazolam, lovastatin, or simvastatin)

• Coadministration of PREZISTA/ritonavir is also contraindicated with rifampin and products containing St. John's wort (Hypericum perforatum) because this may cause significant decrease in plasma concentration of darunavir, resulting in loss of therapeutic effect and development of resistance

• Coadministration is not recommended with indinavir, lopinavir/ritonavir, saquinavir, and pravastatin

• Caution should be used when prescribing agents such as sildenafil, vardenafil, tadalafil, or other substrates, inhibitors, or inducers of CYP3A in patients receiving PREZISTA/ritonavir.

• This list of potential drug interactions is not complete.

Warnings & Precautions

• PREZISTA must be coadministered with ritonavir and food to achieve the desired antiviral effect. Failure to administer PREZISTA with ritonavir and food may result in a loss of efficacy of darunavir. Please refer to ritonavir prescribing information for additional information on precautionary measures

• Drug-induced hepatitis (e.g., acute hepatitis, cytolytic hepatitis) has been reported with PREZISTA/ritonavir. During the clinical development program (N=3063), hepatitis has been reported in 0.5% of patients receiving combination therapy with PREZISTA/ritonavir. Patients with preexisting liver dysfunction, including chronic active hepatitis B or C, have an increased risk for liver function abnormalities, including severe hepatic adverse events

Post-marketing cases of liver injury, including some fatalities, have been reported. A causal relationship with PREZISTA/ritonavir therapy has not been established

Appropriate laboratory testing should be conducted prior to initiating therapy with PREZISTA/ritonavir and patients should be monitored during treatment. Increased AST/ALT monitoring should be considered in patients with underlying chronic hepatitis, cirrhosis, or in patients who have pretreatment elevations of transaminases, especially during the first several months of PREZISTA/ritonavir treatment. Evidence of new or worsening liver dysfunction (including clinically significant elevation of liver enzymes and/or symptoms such as fatigue, anorexia, nausea, jaundice, dark urine, liver tenderness, hepatomegaly) in patients on PREZISTA/ritonavir should prompt consideration of interruption or discontinuation of treatment

• Severe Skin Reactions: Severe skin reactions (0.4%), accompanied by fever and/or elevations of transaminases in some cases, Stevens-Johnson Syndrome (<0.1%), and toxic epidermal necrolysis (post-marketing experience) have been reported in patients receiving PREZISTA/ritonavir. Discontinue PREZISTA/ritonavir immediately if signs or symptoms of severe skin reactions develop (including, but not limited to, severe rash or rash accompanied with fever, general malaise, fatigue, muscle or join aches, blisters, oral lesions, conjunctivitis, hepatitis and/or eosinophilia)

In clinical trials (N=3063), rash (all grades, generally mild to moderate, regardless of causality) occurred in 10.3% of patients receiving PREZISTA/ritonavir. Discontinuation due to rash was 0.5%

• Sulfa Allergy: PREZISTA should be used with caution in patients with known sulfonamide allergy

• Diabetes Mellitus/Hyperglycemia and Hemophilia: New-onset or exacerbations of preexisting diabetes mellitus, hyperglycemia, and increased bleeding in hemophiliacs have been reported in patients receiving protease inhibitors. Initiation or dose adjustments of insulin or oral hypoglycemic agents may be required. A causal relationship between protease inhibitors and these events has not been established

• Fat Redistribution: Redistribution and/or accumulation of body fat have been observed in patients receiving ARV therapy. The causal relationship, mechanism, and long-term consequences of these events have not been established

• Immune reconstitution syndrome has been reported in patients treated with ARV therapy

• Resistance/Cross Resistance: The potential for HIV-1 cross-resistance among protease inhibitors has not been fully explored in PREZISTA/ritonavir-treated patients

Use in Specific Populations

• Hepatic Impairment: PREZISTA/ritonavir is not recommended for use in patients with severe hepatic impairment. There are no pharmacokinetic or safety data available in patients with severe hepatic impairment

• Pregnancy: PREZISTA should be used during pregnancy only if the potential benefit justifies the potential risk. No adequate and well-controlled studies have been conducted in pregnant women

Adverse Reactions

• In treatment-naïve adult patients, the most common adverse drug reactions (greater than or equal to 5%) reported of at least moderate intensity (greater than or equal to Grade 2) in the PREZISTA/ritonavir arm through 96 weeks were diarrhea (8%), headache (6%), abdominal pain (5%), and rash (5%)

• In treatment-experienced adult patients, the most common adverse drug reactions (greater than or equal to 5%) reported of at least moderate intensity (greater than or equal to Grade 2) in the PREZISTA/ritonavir arm through 96 weeks were diarrhea (14%), nausea (7%), rash (7%), abdominal pain (6%), and vomiting (5%)

Media Contact:

Pamela Van Houten, 609-730-7902 (office)

908-295-7367 (mobile)

Investor Contacts:

Louise Mehrotra, 732-524-6491

Stan Panasewicz, 732-524-2524