Early Improvement in Somatic or Psychic Anxiety as a Predictor of Response/Remission in Patients With GAD: Post Hoc Analysis of 3 Vilazodone Studies
This poster was presented at the 30th annual Psych Congress, held Sept. 16-19, 2017, in New Orleans, Louisiana.
Background: Vilazodone (VLZ), approved for major depressive disorder in adults, has also shown efficacy in three 8-week double-blind, placebo (PBO)-controlled trials in generalized anxiety disorder (GAD; NCT01629966, NCT01766401, NCT01844115). Pooled data were analyzed post hoc to evaluate whether early improvement with VLZ was predictive of later response or remission.
Methods: VLZ was titrated to 20 mg/d over 2 weeks. VLZ 40 mg/d dosing began at Week 3 (fixed-dose) or Week 3/Week 5 (flexible-dose). Early improvement was defined as ≥30% decrease from baseline to Week 2 in Hamilton Anxiety Rating Scale (HAMA) subscale scores (Psychic Anxiety [HAMA-Psych], Somatic Anxiety [HAMA-Som]). Response was defined as ≥50% decrease from baseline to Week 8 in the HAMA total score; remission as HAMA total score ≤7 at Week 8. Predictor model parameters included sensitivity (% responders/remitters with early improvement) and positive predictive value (PPV; % with early improvement and subsequent response/remission).
Results: At Week 2, more patients had early improvement with VLZ (20 mg/d) versus placebo in HAMA-Psych (VLZ=45.8%; PBO=35.6%) and HAMA-Som (VLZ=45.0%; PBO=41.4%). Sensitivity values for HAMA-Psych: response (VLZ=64.0%; PBO=59.8%), remission (VLZ=72.2%; PBO=65.8%); for HAMA-Som: response (VLZ=62.6%; PBO=63.0%), remission (VLZ=68.8%; PBO=70.0%). PPV values for HAMA-Psych: response (VLZ=62.6%; PBO=61.5%), remission (VLZ=41.0%; PBO=37.1%); for HAMA-Som: response (VLZ=62.3%; PBO=55.6%), remission (VLZ=39.7%; PBO=33.9%). All predictor models were statistically significant (all P<.001).
Conclusions: In adults with GAD, early improvements in psychic and somatic anxiety were significant predictors of later response and remission. Results may be limited by some VLZ-treated patients not reaching optimal therapeutic dose by Week 2.