Doug Williamson
Analyst · Cantor Fitzgerald. Please go ahead
Thank you, Brendan. I'd now like to update you on the continued progress of our clinical programs, starting with Pimavanserin as a potential treatment for the negative symptoms of schizophrenia on Slide 15. As Steve mentioned, we've now completed enrollment on schedule in advance two, our second study of Pimavanserin in negative symptoms of schizophrenia and are on track for high-level results in the first quarter of 2024. I want to remind you of the opportunity that we're pursuing in this program. Predominant negative symptoms remain one of the largest unmet needs in schizophrenia, and as of today, there are still no approved treatments for these symptoms. Let's first understand the distinction between treating the positive and negative symptoms of schizophrenia. The positive or psychotic symptoms of schizophrenia are characterized by hallucinations, delusions, and thought disorders. They typically resolve with appropriate anti-psychotic treatment over a period of weeks and often occur in discrete episodes. The negative symptoms of schizophrenia are characterized by social withdrawal, lack of motivation, and blunted affect. Negative symptoms often persist following acute episodes of psychosis and continue to worsen between episodes. These symptoms can lead to greatly diminished social functioning, increased caregiver burden, poor occupational outcome, and long-term disability. Drugs that treat the positive symptoms, including drugs approved to treat schizophrenia today, may also show a benefit on negative symptoms during the acute treatment phase, but thereafter fail to resolve the chronic, persistent, and significant negative symptoms affecting approximately 700,000 patients in the U.S. Our late-stage Adjunctive Pimavanserin program is designed to treat these patients whose positive psychotic symptoms are adequately controlled, but who still suffer from persistent and uncontrolled negative symptoms inhibiting their ability to lead a normal, productive life. In order to demonstrate utility in this population and obtain an FDA approval for treatment of negative symptoms, it's necessary to study patients with predominant negative symptoms whose positive symptoms are under control and for a sufficient period of time, usually several months. Please turn to the next slide. Let me just highlight a few key elements of our now fully-enrolled Phase 3 clinical trial, ADVANCE-2, to treat the negative symptoms of schizophrenia. Negative symptoms of schizophrenia have proven to be an exceedingly difficult drug development challenge, with multiple industry failures over several decades. Therefore, with our previous positive ADVANCE-1 study of Pimavanserin, we achieved something very rare in this population. In our second pivotal study, ADVANCE-2, we're following the same design as our positive ADVANCE-1 study with two key differences, both of which are aimed at improving the probability of success. First, in the ADVANCE-1 trial, we studied patients on a flexible dose range of 20 to 34 milligrams, and while the primary endpoint of improvement in all patients was met, we clearly saw that the patients on 34 milligrams had a meaningfully stronger response, so as a result, in ADVANCE-2, we're only treating patients with the 34 milligram dose, the same dose for which NUPLAZID is approved for Parkinson's patients without dementia. Secondly, ADVANCE-2 is being conducted solely in sites outside the U.S. It's well understood in our industry, as well as by the FDA, that separating from placebo has become more difficult in US schizophrenia trials over the past couple of decades, largely because of differences in the way schizophrenia patients are treated and the way clinical trials are run here. Therefore, because we already have all the U.S. patients we need, ADVANCE-2 is being run solely outside the U.S. Again, having recently completed enrollment, we remain on track to announce top-line results from this study in the first quarter of 2024. Please turn to Slide 17 to discuss our program in Prader-Willi syndrome. In early June, we announced the addition of our Phase 3 development candidate, ACP-101, for the treatment of hyperphasia in Prader-Willi syndrome, or PWS. ACP-101 in PWS reinforces our ongoing strategy to increase our footprint in rare disease. Prader-Willi syndrome is a rare genetic neurobehavioral syndrome that affects approximately 8,000 to 10,000 patients in the United States and represents a significant unmet need. There are currently no therapies approved to treat the characteristic hyperphasia in patients with PWS. ACP-101 is an intranasal formulation of carbatocin, which is a synthetic analog of the naturally occurring hormone oxytocin. Oxytocin deficiency is believed to play a particularly important role in PWS, resulting in increased appetite and behavioral symptoms such as anxiousness. However, oxytocin has a very short half-life, is usually administered intravenously or by eye and injection, and accordingly is not a viable treatment for PWS. Carbatocin has improved drug qualities relative to oxytocin, including a much greater half-life which allows for three times daily dosing. It also has greater seal activity for oxytocin receptors compared to off-target vasopressin receptors, reducing the risk of anti-diuretic effects such as hyponatremia. In addition, ACP-101's intranasal administration of carbatocin provides direct delivery of the drug to the brain and greatly reduces systemic exposure, further reducing the potential for side effects. On this slide, we've laid out the design of a Phase III Global Multicenter Randomized Double Blind 12-Week placebo-controlled study evaluating the efficacy and safety of ACP-101 in approximately 170 prior-release patients. In this study, we will evaluate 3.2 milligrams of ACP-101 compared to placebo. The primary efficacy endpoint is improvement of hyperphagia as measured by the Hyperphagia Questionnaire for Clinical Trials, or HQCT, scale. This was the same primary endpoint on which the 3.2 milligram dose group achieved statistically significant separation from placebo in the previous Phase III study conducted by Levo Therapeutics. Those patients who complete the study will be eligible to enroll in an open label long-term extension study. I'd like to provide some additional perspective regarding the 3.2 milligram dose. Prior to ACADIA's acquisition, LIVO conducted a Phase 3 multi-center, randomized, double-blind, eight-week placebo control study evaluating two doses of ACP-101, 3.2 milligrams and 9.6 milligrams, versus placebo. The study was underpowered and the 9.6 milligram dose while it demonstrated improvement compared to placebo did not achieve statistical significance. However, top-line results showed that ACP-101 demonstrated statistically significant efficacy at the 3.2 milligram dose. With regard to safety and tolerability, 3.2 milligrams of ACP-101 had a very clean profile with no serious adverse events of concern, both in the LIVO Phase 3 study and an open-label extension study that followed. If data from this Phase 3 study is positive, we plan to submit a new drug application for the treatment of hyperphagia in PWS to the FDA. We look forward to working with the Prada-Willie community and clinical experts as we continue to advance development of this program. We know that patients and their families are waiting for a treatment. On Slide 18, let's shift now to ACP-204, our next-generation 5-HT2A compound which we're developing as a potential treatment for Alzheimer's disease psychosis. ACP-204 continues to make excellent progress and we believe has a potentially exciting future. ACP-204 works primarily as an inverse agonist at the 5-HT2A receptor. Our experience with time of answering suggests that this mechanism is very well suited for elderly populations with multiple comorbidities and concoctions providing anti-psychotic efficacy with a highly tolerable safety profile and a low drug-drug interaction liability. With ACP-204, we're seeking to build on those learnings. As Steve mentioned, we have completed a comprehensive Phase 1 program for ACP-204 involving over 100 subjects including both adult and elderly volunteers. This Phase 1 effort reflects our goal of characterizing ACP-204 as fully as possible early in development in order to accelerate late-stage development. Our work completed to date supports our target product profile for 204, a profile that could represent a significant improvement over an already strong product profile for Pimavanserin. Firstly, we wanted to mitigate or eliminate a QTC signal. This was an important goal as it limited the dose of Pimavanserin. To-date, we've seen no signals of risk of QT prolongation that planned doses in our studies with ACP-204. Next, we wanted to explore doses of ACP-204 higher than the equivalent of 34 mg of Pimavanserin. We believe the 30 mg and 60 mg doses of ACP-204 we are taking through to Phase 2 development represent up to twofold that dose. Finally, we wanted ACP-204 to have a faster onset of action. ACP-204 has a shorter half-life than Pimavanserin and it reaches a steady state in less than half the time, roughly five days compared to around 12 days. In addition, in our Phase 1 studies, ACP-204 demonstrates a very favorable safety and tolerability profile with a low propensity for drug-drug interactions similar to Pimavanserin. Please turn to Slide 19. Armed with this strong data from Phase 1, we're preparing to start our Phase 2 study of over 300 patients for ACP-204 in the fourth quarter. We've designed Phase 2 so that if successful, it could be considered a pivotal registration study. As we previously described, we recently met with the FDA to get alignment on our Phase 2-3 development plan and be able to move seamlessly from Phase 2 into 2 Phase 3 studies. With this accelerated development plan, we can move seamlessly from Phase 2 to two Phase 3 studies with the same sites continuously enrolling patients. As each site completes their Phase 2 site allocation, they will move directly into enrolling patients for one of the Phase 3 studies. Once the full study allocation of patients for Phase 2 is complete, we will analyze and report Phase 2 results, by which time the two Phase 3 studies will already be underway. This plan will ultimately provide three potential pivotal studies for submission. Overall, we're very excited with the progress of this program, and we've already begun exploring a potentially rich life cycle plan for 204, which will comprise other indications where 5-HT2A inhibition plays a significant role. And now, I'll turn it over to Mark for a financial update on Slide 20