A Review of New Atypical Antipsychotic Launches in the United States

| December 27, 2010 | 0 Comments

by Jeff Ventimiglia, BSE; Amir H. Kalali, MD; and Leslie Citrome, MD, MPH

Mr. Ventimiglia is a Senior Analyst in Clinical Development Services, Quintiles, Inc., Durham, North Carolina; Dr. Kalali is Vice President, Global Therapeutic Group Leader CNS, Quintiles, Inc., and Professor of Psychiatry, University of California, San Diego in San Diego, California; Dr. Citrome is Professor of Psychiatry, New York University School of Medicine, New York

Psychiatry (Edgemont) 2010;7(12):13–15

Funding: There was no funding for the development and writing of this article.

Financial disclosures: Mr. Ventimiglia and reports no conflicts of interest revelant to the content of this article; Dr. Kalali reports that he has served as an advisor to Merck, Novartis, Pfizer, and Vanda Pharmaceuticals; and Dr. Citrome is a consultant for, has received honoraria from, or has conducted clinical research supported by the following: Abbott Laboratories, AstraZeneca Pharmaceuticals, Avanir Pharmaceuticals, Azur Pharma Inc., Barr Laboratories, Bristol-Myers Squibb, Eli Lilly and Company, Forest Research Institute, GlaxoSmithKline, Janssen Pharmaceuticals, Jazz Pharmaceuticals, Merck, Novartis, Pfizer Inc., Sunovion, and Vanda Pharmaceuticals.

Key words: Atypical, antipsychotic, Fanapt, iloperidone, Saphris, asenapine, product launches, schizophrenia, bipolar disorder

Abstract: In this article we investigate the post-launch retail prescription trends of asenapine (Saphris®,  Merck and Co.) and iloperidone (Fanapt®, Vanda Pharmaceuticals Inc./Novartis), two new atypical antipsychotics to launch in the United States market in October 2009 and January 2010, respectively. In the first 12 months following the asenapine launch, and in the nine months since the iloperidone launch, asenapine and iloperidone have secured 0.22 and 0.10 percent of the total prescription market; however, both products nearly double those respective shares when total prescriptions are isolated to new patient prescriptions (0.44% for asenapine and 0.17% for iloperidone). Since launch, asenapine has shown stronger signs of growth, largely attributed to its approval in multiple indications as compared to iloperidone’s single indication.

Introduction

In October 2009, asenapine (Saphris®,  Merck and Co.) was launched in the United States for the treatment of acute schizophrenia and for acute bipolar mania or mixed episodes. Iloperidone (Fanapt®, Vanda Pharmaceuticals Inc./Novartis) was launched in January 2010 for the acute treatment of schizophrenia. In this article, we examine the use and overall growth of asenapine and iloperidone in the context of the highly fragmented and competitive atypical antipsychotic market.

Methods

We obtained national-level, projected retail prescription data from SDI. The SDI data warehouse receives 1.6 billion prescription claims per year and includes prescription samples from nearly 37,000 pharmacies in the United States. To compare the launches of asenapine and iloperidone, we normalized the time since the United States launch of each product.

Results

A review of United States retail prescription data (Table 1) shows that both asenapine and iloperidone have gained only minor shares of the atypical antipsychotic market, 0.22 and 0.10 percent, respectively. However, there are some signs implying future growth including the following:

•    Each product’s share of new patient prescriptions is nearly double their total market share: 0.44 percent for asenapine and 0.17 percent for iloperidone. Albeit low today, continued growth in new patient prescription share can predict future market share growth.
•    Both products have 77 percent of total prescriptions generated from psychiatrists. Comparatively, 56 percent of total prescriptions in the atypical antipsychotic class come from psychiatrists. The higher skew toward psychiatry in the new product prescribing suggests that psychiatrists are the early adopters of the new brands in this market.

Additionally, we wanted to compare the growth of each product since its launch. When reviewing monthly retail prescriptions since introduction to the market (Figure 1), we see that asenapine is growing in monthly retail prescriptions at a rate 54 percent greater than that of iloperidone. Given asenapine’s approval for multiple indications, we can attribute this trend in part to a larger potential patient population.

Expert Commentary
by Leslie Citrome, MD, MPH

Asenapine[1] and iloperidone[2–4] represent two new alternatives for the treatment of schizophrenia, a chronic and complex disease that is difficult to manage. Asenapine is also approved for the acute treatment of bipolar mania/mixed episodes. Although both asenapine and iloperidone bind to the dopamine D2 and serotonin 5HT2A receptor, as expected for atypical antipsychotics, their secondary binding characteristics differ from other agents, as do their tolerability profiles. This heterogeneity among the different antipsychotics available make it possible for clinicians to empirically try one medication after another to find one that is optimal for the individual patient.5 One of the key determinants of therapeutic success is adherence, and a major challenge is finding the right medication at the right dose that the patient finds efficacious enough, tolerable enough, and that he or she is willing to take.

Asenapine brings to the table a unique formulation that is absorbed in the oral cavity. It is the only antipsychotic that, in order to “cheek it,” you have to actually swallow it—a task made quite difficult because of its physical characteristic of rapidly breaking apart in the presence of moisture.[1] Dosing is a relatively simple matter, with patients with schizophrenia receiving 5mg twice daily (BID) as of Day 1, and patients with bipolar mania receiving 10mg BID. Asenapine appears to be metabolically “friendly;” however, it can be sedating at higher doses.

Iloperidone is also administered BID, but must be titrated to 12mg/d over a four-day period.[2–4] This is necessary in order to minimize problems associated with alpha 1 adrenergic antagonism, such as postural hypotension. Iloperidone also appears to be relatively metabolically friendly and is essentially free of extrapyramidal side effects, including akathisia. Iloperidone carries a similar warning reading electrocardiogram (ECG) QT prolongation as for ziprasidone.

The marketing materials for both asenapine and iloperidone are strictly consistent with product labeling, including BID dosing. This may impede some clinicians from considering these agents. The newness of these agents and the lack of information about comparative effectiveness with other agents are additional obstacles. The availability of generic formulations of risperidone, and soon, generic formulations of other atypical antipsychotics make it even more challenging for new antipsychotics to be adopted. It will be interesting to see what the impact of the launch of lurasidone (Latuda®, Sunovion Pharmaceuricals),[6] another new atypical antipsychotic, will have on the uptake of asenapine and iloperidone in 2011.

References
1.     Citrome L. Asenapine for schizophrenia and bipolar disorder: a review of the efficacy and safety profile for this newly approved sublingually absorbed second-generation antipsychotic. Int J Clin Pract. 2009;63(12):1762–1784.
2.    Citrome L. Iloperidone: chemistry, pharmacodynamics, pharmacokinetics and metabolism, clinical efficacy, safety and tolerability, regulatory affairs, and an opinion. Expert Opin Drug Metab Toxicol. 2010;6(12):1551–1564
3.    Citrome L. Iloperidone redux: a dissection of the drug approval package for this newly commercialised second-generation antipsychotic. Int J Clin Pract. 2010;64(6):707–718
4.    Citrome L. Iloperidone for schizophrenia: a review of the efficacy and safety profile for this newly commercialised second-generation antipsychotic. Int J Clin Pract. 2009;63(8):1237–1248.
5.    Volavka J, Citrome L. Oral antipsychotics for the treatment of schizophrenia: heterogeneity in efficacy and tolerability should drive decision-making. Expert Opin Pharmacother. 2009;10(12):1917–1928.
6.    Citrome L. Lurasidone for schizophrenia: a review of the efficacy and safety profile for this newly approved second-generation antipsychotic. Int J Clin Pract. (In press) Available on-line early at doi: 10.1111/j.1742-1241.2010.02587.

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Category: Bipolar Disorder, Past Articles, Psychiatry, Psychopharmacology, Schizophrenia, Trend Watch

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