10.02 Lisdexamfetamine Dimesylate Approved For ADHD In Adults, USA
In the U.S., in 2007, the prescription medication Vyvanse was introduced for the treatment of ADHD in children aged 6 to 12 years old by the US Food and Drug Administration (FDA). The following year the medication was approved to treat ADHD in adults, and approved in 2010 to treat adolescents aged 13 to 17 with ADHD.
Following results from a randomized withdrawal study assessing the effectiveness of Vyvanse for treating ADHD in individuals aged 18 to 55 years old, the FDA has now approved Vyvanse (lisdexamfetamine dimesylate) Capsules, (CII) as a maintenance treatment for adults with the disorder, according to Shire plc.
Each of the 123 adult study participants who met DSM-IV-TR criteria for ADHD received treatment with the medication for a minimum for six months before taking part in the Phase 4, double-blind, multi-center, placebo-controlled, randomized withdrawal design study.
At present, Vyvanse is available in six once-daily dosage strengths - 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, and 70 mg.
Results from the study showed that considerably more individuals treated with Vyvanse maintained ADHD symptom control than those who received placebo as determined by the percentage of individuals who met relapse of symptoms criteria at the end point during the six-week study (75% for individuals treated with placebo vs. 8.9% of individuals treated with Vyvanse).
The new approval from the FDA adds to the indication for Vyvanse as a ADHD treatment in individuals aged 6+.
Vyvanse is intended to be used as part of a total treatment program that may involve counseling or other therapies. The effectiveness of the medication should be regularly assessed for each patient if the physician decides to prescribe Vyvanse for extended periods.
The researchers randomly assigned patients who respond to Vyvanse to receive placebo or continue receiving the treatment. The primary outcome for the study was the proportion of patients experiencing symptom relapse. This study in individuals with ADHD can be used to show long-term effectiveness in lieu of carrying out a long-term placebo-controlled, parallel-group study. The benefit of the way the study is designed is that the duration of placebo exposure, with the possibility for worsening of ADHA symptoms, is fairly short.
Jeffrey Jonas, M.D., Senior Vice President of Research and Development for Shire's Specialty Pharmaceuticals and Regenerative Medicine businesses, explains:
"Data from this study and the resulting approval illustrate that Vyvanse can help adults with ADHA maintain symptom control. Vyvanse is the first medicine both proven to work and approved to maintain efficacy in adults with ADHD.
This underscores Shire's commitment to providing important advances in the treatment of individuals with ADHD by investing innovative research in this area."
Vyvanse is a Schedule II controlled substance. Stimulants, such as methylphenidates and amphetamines, are subject to addition, abuse, misuse, and criminal diversions. Serious cardiovascular side effects and sudden death may be triggered by misuse of amphetamines.
Before patients were enrolled in the study, they were required to record long-term treatment with Vyvanse 30mg, 50mg or 70mg per day, for a minimum of six months and showed treatment response as defined by an ADHD Rating Scale IV (ADHD-RS-IV) with adult prompts total score of <22 ( The ADHD-RS-IV with adult prompts is a clinician assessment of the severity of the core symptoms of ADHD) and Clinical Global Impressions-Severity (CGI-S) rating <3 (The CGI-S is a clinician assessment of symptom severity).
After the researchers screened the patients, those who met enrollment criteria entered a 3-week open-label treatment phase. During this phase participants continued to receive the same Vyvanse dose they were taking before participating in the study.
Participants who maintained treatment response at week of these open-label treatment then entered the 6-week double-blind, randomized withdrawal phase (n=116). The researchers then randomly assigned 56 of these participants to continue with the same dose of Vyvanse, while 60 participants received placebo.
The percentage of patients who met criteria for relapse of ADHD symptoms at end point during the withdrawal phase of the study, was the primary efficacy outcome measure. The researchers defined end point as the last post-randomization treatment week at which valid ADHD-RS with adult prompts total score and CGI-S were observed.
The team defined relapse of ADHD symptoms as a ?50% increase (worsening) in the ADHD-RS-IV with adult prompts total score and a ?2-point increase in the CGI-S score in comparison to scores at entry into the withdrawal phase. The researchers immediately discontinued study participants who met relapse of ADHD symptoms criteria.
On the primary efficacy measure the researchers found that more patients in the placebo group (75%) met criteria for symptom relapse than those receiving Vyvanse (8.9%) at end point of the withdrawal phase.
Around 62% of participants receiving placebo who met relapse of ADHD symptom criteria did so within the first two weeks after entering the randomized withdrawal phase.
7 participants discontinued from the study during the open-label phase, including 1 participant receiving Vyvanse due to treatment emergent adverse event (TEAE) (lack of efficacy). During the withdrawal phase, one serious adverse event (SAE) was reported in a participant receiving placebo (suicidal ideation).
Among participants receiving Vyvanse, no deaths or SAEs were reported. TEAES were reported during the withdrawal phase by 30% (18/60) participants receiving Vyvanse and 48.2% (27/56) patients receiving placebo.
Among participants in the Vyvanse treatment group, the most prevalent (?2%) TEAEs reported included, insomnia, joint sprain, fatigue, headache, and upper respiratory tract infection.
Compared to participants receiving placebo, mean diastolic and systolic blood pressure and pulse rate were slightly higher among participants receiving Vyvanse.
For the Vyvanse and placebo group, the researchers observed small alterations in mean pulse rate and pressure from baseline to week 3 in the open-label phase and end point of the withdrawal phase.
The safety profile observed in this study was uniform with that of previous investigations of Vyvanse. The researchers found no new clinically relevant safety signals linked to sudden discontinuation of Vyvanse.
Matthew Brams, M.D., lead researcher and Clinical Assistant Professor of Psychiatry at Baylor College of Medicine, explained:
"The finding from this study is important because adult patients with ADHD may have a need for extended treatment, and could benefit from a treatment option proven to maintain efficacy. This study showed that in patients with ADHD who were stable of Vyvanse for 6 months, 91% randomized to receive Vyvanse continued to maintain symptom control compared with 25% taking placebo."
Additional information about Vyvanse is available here.
Written by Grace Rattue
View drug information on Vyvanse.
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