One additional Phase 3 trial, along with previously completed Phase 2 trial, would be acceptable to support an efficacy claim for a New Drug Application filing
Company on track to initiate Phase 3 program, including efficacy and open-label long-term safety trials, by the end of 2020
BOSTON--(BUSINESS WIRE)-- Karuna Therapeutics, Inc. (NASDAQ:KRTX), an innovative clinical-stage biopharmaceutical company committed to developing novel therapies with the potential to transform the lives of people with disabling and potentially fatal neuropsychiatric disorders and pain, today announced next steps in the clinical program evaluating KarXT for the treatment of acute psychosis in patients with schizophrenia following the completion of a successful End-of-Phase 2 meeting with the U.S. Food & Drug Administration (FDA). The outcome of the meeting supports the progression of KarXT into Phase 3 development. The Company remains on track to initiate the Phase 3 program by the end of 2020.
“We look forward to progressing KarXT into Phase 3 clinical development for the treatment of schizophrenia following a constructive End-of-Phase 2 meeting with the FDA,” said Andrew Miller, Ph.D., chief operating officer and founder of Karuna Therapeutics. “Our team is dedicated to truly advancing the standard of care in schizophrenia, and we believe our planned Phase 3 program sets us on course to potentially offer a new, unique and mechanistically differentiated treatment option relative to current therapies. We are pleased to be working closely with the FDA as we prepare to advance our lead clinical program into Phase 3 by the end of the year.”
The End-of-Phase 2 discussion was supported by pre-clinical and clinical efficacy data, including results from the previously completed positive Phase 2 trial evaluating KarXT in patients with schizophrenia. In the Phase 2 trial, KarXT demonstrated robust efficacy on primary and key secondary outcome measures and was generally safe and well tolerated.
The Company and FDA aligned on key elements of the Phase 3 program to support a New Drug Application (NDA) filing, including the initiation of additional trials evaluating the efficacy and long-term safety of KarXT. The formal minutes from the meeting confirmed that the completed Phase 2 trial, along with one successful Phase 3 efficacy and safety trial, and additional safety data to meet regulatory requirements, would be acceptable to support an NDA filing.
The Company plans to initiate two five-week inpatient trials evaluating the efficacy and safety of KarXT for the treatment of acute psychosis in adults with schizophrenia. Both trials will share key characteristics of the completed Phase 2 trial, such as duration of treatment, patient population and primary outcome measure, among other aspects. The first Phase 3 trial is expected to commence by the end of 2020. This five-week, 1:1 randomized, flexible-dose, double-blind, placebo-controlled, inpatient trial will enroll approximately 250 adults in the U.S. and evaluate the change in Positive and Negative Syndrome Scale total score at Week 5 of KarXT versus placebo as the primary outcome measure. Details of the second efficacy trial will be finalized by the end of 2020, with initiation expected in the first half of 2021.
In conjunction with the short-term efficacy and safety trials, the Company will collect long-term, open-label data to assess the safety and tolerability of KarXT in patients for up to one year in an outpatient setting. Following the five-week, double-blind, inpatient phase in both efficacy trials, patients may enter a 52-week open-label safety and tolerability extension in which all patients will receive active treatment. The Company currently plans to also conduct a separate 52-week open-label trial evaluating the long-term safety of KarXT in adults with schizophrenia who have not been enrolled in the inpatient trials. This trial is expected to begin the first half of 2021. Data from these trials will be used to support regulatory safety requirements for an NDA filing.
As previously shared, the Company is well capitalized, with sufficient funding to support development activities for the NDA filing. Additional details regarding the development plan, including anticipated completion timelines, will be shared in the second half of 2020.