OBJECTIVES

To evaluate the economic impact and relapse rates of switching patients with schizophrenia from oral atypical antipsychotics (OAAs) to once-monthly (PP1M) and once-every-three-months paliperidone palmitate (PP3M).

METHODS

A 36-month Markov model was developed from a Medicaid payer’s perspective, targeting two schizophrenia sub-populations who were nonadherent to OAAs: 1) recently relapsed adults, and 2) young adults (aged 18-35 years) with or without prior relapse. Patients were assumed nonadherent to OAAs until treatment switch and may switch multiple times. Patients switching to PP1M may transition to PP3M per label. At similar adherence, relapse rates were assumed consistent across treatments. All model inputs were literature-based.

RESULTS

Among a hypothetical health plan of 1M members, 10,053 were nonadherent adults with schizophrenia, 7,454/10,053 were recently relapsed and 4,002/10,053 were young adults. Compared to continuing on OAAs, switching 5% of nonadherent recently relapsed patients to PP1M (n=373) yielded cost savings of $6,554, $6,351, and $5,243 per-patient-switched (PPS), and $0.20, $0.20, and $0.16 per-member-per-month in years 1, 2, 3. At the plan-level, cost savings were $2.4M, $2.4M, and $2.0M, with 231, 197, and 162 relapses avoided in years 1, 2, 3. By doubling the number of patients switched, the cumulative 3-year plan-level savings and relapses avoided doubled from $6.8M to $13.5M and 590 to 1,180, respectively. When the proportion of eligible patients transitioning from PP1M to PP3M was increased from 14% to 20%, cost savings were $6,648, $6,616, and $5,471 PPS for years 1, 2, 3. Trends were similar among young adults: switching 5% of patients saved $1,002, $1,885, and $1,759 PPS for years 1, 2, 3; at the plan-level, $0.9M was saved and 205 relapses were avoided after 3 years.

CONCLUSIONS

Switching from OAAs to PP1M and PP3M is associated with substantial cost savings and reduced relapse rates in both nonadherent recently relapsed and young adult patients with schizophrenia.