Results from AMPACT1 trial of Keyzilen (esketamine hydrochloride)a proposed treatment for peripheral tinnitus.- Auris Medical Holding AG

AMPACT1 is the second of two open-label extension studies with Keyzilen that were conducted in response to a request from the FDA for safety data from chronic intermittent use of Keyzilen for up to 12 months. Participants who completed the TACTT2 trial were offered the option to roll over into AMPACT1, while still blinded to the treatment allocation. Patients were given the choice to receive up to three treatment cycles with each cycle comprising three intratympanic administrations of Keyzilen, followed by a treatment-free observation period of 12 weeks.TACTT2 and AMPACT1 were primarily conducted in North America. Patients enrolled in TACTT2 within three months from tinnitus onset, i.e. during the acute stage. Of the 316 patients who completed the TACTT2 trial, 257 patients rolled over into AMPACT1 and provided safety data; 228 of these patients provided exploratory efficacy data. At the time of enrollment into AMPACT1, all patients were in the post-acute stage. The primary safety endpoint of AMPACT1 was the incidence of clinically relevant hearing deterioration five weeks after the start of a treatment cycle. In line with the results from previous trials with Keyzilen, such incidence was low (6%), with no signs of treatment-related effects. Over the course of AMPACT1, the hearing threshold at the average of 4, 6 and 8 kHz showed only little change. The vast majority of adverse events that were considered related to the study drug or treatment procedure were rated as either mild or moderate in intensity. Three patients experienced a total of four non-fatal, serious adverse events, none of which was considered related to the study drug.

Confirming previous data, about 93% of tympanic membranes were already closed at the time of the first follow-up visit. Exploratory efficacy analyses of AMPACT1 show improvements in the Tinnitus Functional Index (TFI) as well as other tinnitus metrics. The TFI decreased on average by 8.2 points (95% confidence interval 6.2 to 10.1; baseline of 42.7 points) to the last follow-up visit. The more treatment cycles the patients received, the larger the reduction in the TFI was; the difference between three cycles and one cycle reached statistical significance. Similar results were achieved on subjective tinnitus loudness and tinnitus annoyance. In addition, 41% of AMPACT1 participants achieved a reduction in their tinnitus severity (extreme-severe-moderate-mild-none) by at least one grade and 28% reported that their tinnitus severity had improved "much" or "very much" compared to baseline.

Auris Medical expects to announce results from TACTT3, the European placebo-controlled sister trial to TACTT2, in early 2018. The trial has been extended to recruit an additional 60 patients in each of the acute and post-acute strata (i.e. up to three months and between three and six months from onset), and enrollment is ongoing.