SHP465 MAS Found to Be Safe, Effective in Adult ADHD

NEW ORLEANS—At Psych Congress 2017, researchers presented data on the safety and efficacy of SHP465 mixed amphetamine salts (MAS) in adults with attention-deficit/hyperactivity disorder (ADHD).

SHP465 MAS is a once-daily, extended-release oral agent for the treatment of ADHD that contains equal parts of 4 salts: dextroamphetamine sulfate, amphetamine sulfate, dextroamphetamine saccharate, and amphetamine aspartate monohydrate. In addition, each capsules contains two types of delayed-release beads and an immediate-release bead. 

The safety and efficacy of SHP465 MAS were examined in adults aged 18–55 years in three Phase 3 studies ranging from 4 to 7 weeks (Study 301 [n=274], Study 303 [n=412], and Study 306 [n=275]). The primary efficacy endpoint was ADHD Rating Scale (ADHD-RS) total score change from baseline at end-of-study/early termination (EOS/ET) in Studies 301 and 303, or at Week 4 for Study 306. Treatment-emergent adverse effects (TEAEs) were documented from the time of informed consent; vital signs (eg, blood pressure, pulse) were also assessed. 

The results showed a decrease in mean ADHD-RS total scores across all treatment groups in each study. Treatment differences for ADHD-RS total score change “significantly favored SHP465 MAS in all short-term efficacy studies,” noted lead author, Brigitte Robertson, MD, from Shire, Lexington, MA. The least squares mean treatment difference as –8.10 (95% CI: –10.79, –5.41; P<0.0001) in Study 301; –9.9 (95% CI: –13.0, –6.7; P<0.0001 for 25mg), –10.6, (95% CI: –13.8, –7.5; P<0.0001 for 50mg), and –11.2 (95% C: –14.4, –8.0; P<0.0001 for 75mg) in Study 303; and –8.1 (95% CI: –11.7, –4.4; P<0.001 for 12.5mg) and –13.4 (95% CI: –17.1, –9.7; P<0.001 for 37.5mg) in Study 306.

The TEAEs seen in at least 5% of participants with SHP465 MAS and at least twice the placebo rate were decreased appetite, insomnia, dry mouth, and anxiety. Most occurrences were deemed mild or moderate intensity with resolution seen during treatment. 

Patient global functioning, a secondary endpoint, was evaluated using the Clinical Global Impressions-Improvement (CGI-I) score at EOS/ET. Vital sign changes from baseline were used to assess tolerability and safety. The data showed a significantly higher percentage of patients had improvement on the CGI-I with SHP465 MAS treatment vs. placebo: Study 301 (51.5% vs. 21.2%; P<0.0001); Study 303 (61.2% [25mg], 66.3% [50mg], 68.4% [75mg] vs. 20.4%; P<0.0001); and Study 306 (55.1% [12.5mg], 75.0% [37.5mg] vs. 30.2%; P<0.001).

Treatment with SHP465 MAS resulted in small changes from baseline in the following vital signs across the studies: pulse (0.9 to 7.1 beats/min); systolic blood pressure (–0.3 to 1.7mmHg); diastolic blood pressure (–0.3 to 2.8mmHg). 

Overall, Dr. Robertson and colleagues concluded that these findings show SHP465 MAS is effective in improving ADHD symptoms, improving global functioning in adults with ADHD, and carries a safety profile consistent with other long-acting amphetamine medications. 

References:

Robertson, Brigitte MD. Efficacy and Safety of SHP465 Mixed Amphetamine Salts Extended-Release in Adults With Attention-Deficit/Hyperactivity Disorder. Poster presented at Psych Congress 2017; September 16–19, 2017; New Orleans, LA. http://www.psychcongress.com