Effect of Esketamine Nasal Spray on Olfactory Function and Nasal Tolerability in Patients with Treatment-Resistant Depression: Results from Four Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase III Studies

Abstract

Background: Intranasal drug delivery offers a non-invasive and convenient dosing option for patients and physicians, especially for conditions requiring chronic/repeated-treatment administration. However, in some cases such delivery may be harmful to nasal and olfactory epithelia.

Objective: The aim of this study was to assess the potential impact of long-term intermittent treatment with esketamine nasal spray, taken in conjunction with an oral antidepressant (AD), on olfactory function and nasal tolerability in patients with treatment-resistant depression (TRD).

Methods: A total of 1142 patients with TRD participated from four multicenter, randomized, double-blind, phase III studies: three short-term studies (two in patients aged 18-64 years, one in patients ≥65 years), and one long-term maintenance study of esketamine nasal spray + AD versus placebo nasal spray + AD. Across the four studies, assessments were performed at 208 sites in 21 countries. Olfactory function was measured using the 40-item University of Pennsylvania Smell Identification Test (UPSIT®) and the single-staircase Snap & Sniff® Odor Detection Threshold Test (S&S-T). Nasal tolerability, including nasal examinations and a quantitative, self-administered nasal symptom questionnaire (NSQ), was also assessed. Data were analyzed using analyses of covariance.

Results: Of 1142 participants, 734 were women (64.3%). The mean age of all participants ranged from 45.7 to 70.0 years across the studies. Overall, 855 patients received esketamine nasal spray + AD and 432 received placebo nasal spray + AD. Objective evaluation of nasal function showed no evidence of an adverse impact following esketamine administration. Based on the UPSIT® and S&S-T results, intranasal administration of esketamine had no effect on the odor identification or threshold test scores compared with placebo nasal spray + oral AD. Similarly, repeated administration with esketamine nasal spray had no meaningful impact on assessments of nasal function. No dose-response relationship was observed between esketamine doses and the olfactory test scores. Esketamine nasal spray was well tolerated, as indicated by responses on the NSQ and negative nasal examination findings.

Conclusion: Findings from this analysis indicate that there was no evidence of adverse effect on either olfactory or nasal health measures with repeated intermittent administration of esketamine nasal spray at any dose over the course of short-term (4 weeks) or long-term (16-100 weeks) studies.

Clinical trial registration: TRANSFORM-1: NCT02417064, date of registration: 15/04/2015; TRANSFORM-2: NCT02418585, date of registration: 16/04/2015; TRANSFORM-3: NCT02422186, date of registration: 21/04/2015; SUSTAIN-1: NCT02493868, date of registration: 10/07/2015.

Conflict of interest statement

All the authors, except Dr. Doty, Ms. Wylie and Dr. Singh, are employees of Janssen Research & Development, LLC and shareholders of Johnson & Johnson. Dr. Doty is President and major shareholder of Sensonics International, the manufacturer and distributor of smell and taste tests, including the tests used in these studies. He is a consultant to Acorda Therapeutics, Eisai Co., Ltd., Merck Pharmaceuticals, The Michael J. Fox Foundation for Parkinson’s Research, and Johnsons & Johnson. He receives royalties from Cambridge University Press, Johns Hopkins University Press, and John Wiley & Sons, Inc. Ms Wylie was employed at Sensonics International and the Smell and Taste Center at the Hospital of University of Pennsylvania when this study was conducted. Jaskaran Singh worked on the clinical development program of esketamine for treatment-resistant depression during his employment by Janssen Research & Development, LLC; he is currently employed by Neurocrine Biosciences, San Diego, CA.

© 2021. The Author(s).

Figures

Fig. 1

Study designs and nasal function tests. *age 18–64 years, #age ≥ 65 years; †responders from TRANSFORM-3 study did not enter in SUSTAIN-1 study. AD antidepressant, DB double-blind, ESK esketamine, IND induction, MA maintenance, OL open-label, OP optimization, UPSIT® University of Pennsylvania Smell Identification Test. References: SUSTAIN-1 [14]; TRANSFORM-1 [15]; TRANSFORM-2 [16]; TRANSFORM-3 [17]