Longboard Pharmaceuticals Announces Positive Interim Analysis Results from the Open-Label Extension (OLE) of the Phase 1b/2a PACIFIC Study Evaluating Bexicaserin in Participants with Developmental and Epileptic Encephalopathies (DEEs)

Rhea-AI Summary

Longboard Pharmaceuticals (LBPH) announced positive interim results from the open-label extension (OLE) of its PACIFIC Study evaluating bexicaserin in Developmental and Epileptic Encephalopathies (DEEs). Key findings include:

1. 57.7% median reduction in countable motor seizures over ~9 months
2. Sustained efficacy for both bexicaserin-treated (58.2% reduction) and placebo-to-bexicaserin groups (57.3% reduction)
3. Favorable safety and tolerability profile
4. 92.7% participant retention in the ongoing study

The company plans to initiate a global Phase 3 program later this year, with full 12-month OLE data expected in early 2024. Bexicaserin has received Breakthrough Therapy designation, highlighting its potential as a transformative treatment for DEEs.

Positive

• Bexicaserin achieved a 57.7% median reduction in countable motor seizures over ~9 months
• High participant retention rate of 92.7% in the ongoing open-label study
• Sustained efficacy observed in both bexicaserin-treated and placebo-to-bexicaserin groups
• Favorable safety and tolerability profile maintained
• Bexicaserin received Breakthrough Therapy designation
• Global Phase 3 program planned to initiate later this year

Negative

• One participant discontinued due to adverse event of lethargy
• Two participants discontinued by withdrawal of consent or other reasons

Medical Research Analyst

The interim analysis of the PACIFIC OLE Study for bexicaserin in DEE patients shows promising results. The 57.7% median reduction in countable motor seizures over 9 months is clinically significant. This efficacy is consistent across both previously treated and placebo groups, suggesting robust and durable effects.

The safety profile appears favorable, with a high retention rate of 92.7%. Common adverse events are mostly mild and expected. The low discontinuation rate due to adverse events (1 out of 41) is encouraging for long-term tolerability.

These results support bexicaserin's potential as a best-in-class therapy for DEEs, a group of severe epilepsies with high unmet need. The planned Phase 3 program and Breakthrough Therapy designation could accelerate its path to market, potentially offering a new treatment option for patients with alternatives.

Financial Analyst

This positive interim data could significantly boost Longboard Pharmaceuticals' (LBPH) market position. The strong efficacy and safety profile of bexicaserin in DEEs, a challenging therapeutic area, may translate to substantial market potential if approved.

The Breakthrough Therapy designation could accelerate the regulatory process, potentially leading to earlier market entry and revenue generation. This could positively impact LBPH's valuation and investor interest.

However, investors should note that full 12-month data and successful Phase 3 trials are still pending. The company's financial runway and ability to fund the upcoming global Phase 3 program will be important factors to monitor. Overall, this news presents a positive outlook for LBPH's near-term prospects and long-term value proposition in the neurology space.

Neurology Specialist

The interim results of bexicaserin in DEEs are clinically impressive. A 57.7% median seizure reduction over 9 months is substantial for these difficult-to-treat epilepsies. The consistency of effect across different DEE types (Dravet, Lennox-Gastaut and others) suggests broad applicability.

The safety profile is particularly noteworthy. DEE patients often experience significant side effects from current treatments, impacting quality of life. The low discontinuation rate and mostly mild adverse events indicate a favorable risk-benefit ratio.

If these results are confirmed in Phase 3 trials, bexicaserin could become a valuable addition to the arsenal of treatments for DEEs. Its potential to offer sustained seizure control with good tolerability could significantly improve patient outcomes and quality of life in this challenging patient population.

• Bexicaserin achieved an overall median seizure reduction of 57.7% in countable motor seizures over an approximate 9-month treatment period
• Favorable safety and tolerability results continue to be observed
• Data to be presented at the 15^th European Epilepsy Congress in Rome, Italy
• Full 12-month OLE dataset expected early next year

LA JOLLA, Calif.--(BUSINESS WIRE)-- Longboard Pharmaceuticals, Inc. (Nasdaq: LBPH), a clinical-stage biopharmaceutical company focused on developing novel, transformative medicines for neurological diseases, today announced positive interim results from its ongoing 52-week open-label extension of the PACIFIC Study evaluating bexicaserin (LP352) in participants ages 12-65 years old with Developmental and Epileptic Encephalopathies (DEEs).

“We are thrilled that bexicaserin is continuing to demonstrate a sustained, durable response in seizure reduction and a favorable safety and tolerability profile across a broad range of DEE patients. These data provide further support to bexicaserin’s potential to offer a highly differentiated and best-in-class profile,” stated Dr. Randall Kaye, Longboard’s Chief Medical Officer.

“Given the tremendous unmet need in patients living with DEEs, we are committed to rapidly advancing the development of bexicaserin. We expect to provide a full analysis of participants with 12-month data early next year as they complete the OLE Study and transition to our Expanded Access Program,” Dr. Kaye continued. “With Breakthrough Therapy designation granted, we remain on track to initiate our global Phase 3 program for bexicaserin later this year.”

PACIFIC OLE Study Interim Analysis:

The PACIFIC OLE Study is a 52-week Phase 2, open-label, long-term safety study of bexicaserin in participants with a range of DEEs including Dravet syndrome (n=3), Lennox-Gastaut syndrome (n=20) and DEE Other (n=18), who completed the PACIFIC Study (n=41). The study objectives are to investigate the safety and tolerability of multiple doses of bexicaserin in participants with DEEs, and to analyze the effect of bexicaserin on the frequency of observed countable motor seizures and other seizure types. The interim analysis was conducted when participants reached the approximate 9-month point in the OLE Study.

Summary of Efficacy Results:

The median change in countable motor seizure frequency for participants in the OLE Study over an approximate 9-month treatment period was a decrease of 57.7% (n=40) from their baseline entering the PACIFIC Study.

The median change in countable motor seizure frequency from baseline for:

• participants randomized to the bexicaserin-treated group in the PACIFIC Study was a decrease of 58.2% (n=31)
• participants randomized to the placebo group in the PACIFIC Study that transitioned to bexicaserin in the OLE was a decrease of 57.3% (n=9)

Summary of Safety and Tolerability Results:

Continued favorable safety and tolerability results were observed in this study. 100% of PACIFIC Study completers elected to enroll in the OLE with 92.7% (38 out of 41) remaining in the ongoing open-label study. Through the approximate nine-month period, one participant discontinued due to the adverse event (AE) of lethargy and two participants discontinued by withdrawal of consent or other (relocation). The most common treatment emergent AEs in the overall group (n=41) occurring in >5% of participants were upper respiratory tract infections, COVID-19, pneumonia, sinusitis, decreased appetite, pyrexia, and weight decrease.

ABOUT THE PACIFIC STUDY AND THE OLE STUDY

The PACIFIC Study is a Phase 1b/2a double-blind, placebo-controlled clinical trial to assess the safety, tolerability, efficacy and pharmacokinetics of bexicaserin (LP352) in 52 participants between the ages of 12 and 65 years old with DEEs at 34 sites across the United States and Australia. Following a 5-week screening period and baseline evaluations, study participants initiated a dose titration over a 15-day period and subsequently continued on the highest tolerated dose throughout the maintenance period of 60 days. Following the maintenance period, participants were then titrated down, and eligible participants were given the opportunity to enroll in the 52-week open-label extension study.

ABOUT LONGBOARD PHARMACEUTICALS

Longboard Pharmaceuticals, Inc. is a clinical-stage biopharmaceutical company focused on developing novel, transformative medicines for neurological diseases. Longboard is working to advance a portfolio of centrally acting product candidates designed to be highly selective for specific G protein-coupled receptors (GPCRs). Longboard’s small molecule product candidates are based on more than 20 years of GPCR research. Longboard plans to advance bexicaserin (LP352), an oral, centrally acting 5-hydroxytryptamine 2C (5-HT2C) receptor superagonist, with no observed impact on 5-HT2B and 5-HT2A receptor subtypes, into a global Phase 3 program. The FDA has granted Breakthrough Therapy designation for bexicaserin for the treatment of seizures associated with Developmental and Epileptic Encephalopathies (DEEs) for patients two years of age and older. Earlier this year, Longboard reported positive topline data from a Phase 1b/2a clinical trial (the PACIFIC Study) evaluating bexicaserin in participants with DEEs. Longboard is also evaluating LP659, an oral, centrally acting, sphingosine-1-phosphate (S1P) receptor subtypes 1 and 5 modulator, which is in development for the potential treatment of rare neuroinflammatory conditions. Longboard recently completed a Phase 1 single-ascending dose (SAD) clinical trial for LP659 in healthy volunteers.

Bexicaserin and LP659 are investigational compounds that are not approved for marketing by the U.S. Food and Drug Administration (FDA) or any other regulatory authority.

FORWARD-LOOKING STATEMENTS

Certain statements in this press release are forward-looking statements that involve a number of risks and uncertainties. In some cases, you can identify forward-looking statements by words such as “to be presented”, “expect”, “focus”, “potential”, “committed to”, “on track to”, “objective”, “working to”, “designed to”, “plans” or the negative, plural or other tenses of these words, references to future dates or time periods, or other comparable language, and they may include, without limitation, statements about the following: Longboard’s product candidates (including their potential and design), clinical and preclinical programs (including initiation of clinical trials, data from clinical trials, and participants’ enrollment in or completion of studies), plans, focus and work. For such statements, Longboard claims the protection of the Private Securities Litigation Reform Act of 1995. Actual events or results may differ materially from Longboard’s expectations. Factors that could cause actual results to differ materially from those stated or implied by Longboard’s forward-looking statements include, but are not limited to, the following: topline or interim data may not accurately reflect the complete results of a particular study or trial, and final data may differ materially from topline or interim data; PACIFIC Study participants’ diagnoses are as of time of screening and are subject to change; results of clinical trials and other studies are subject to different interpretations and may not be predictive of future results; risks related to Longboard’s limited operating history, financial position and need for additional capital; Longboard will need additional managerial and financial resources to advance all of its programs, and you and others may not agree with the manner Longboard allocates its resources; risks related to the development and commercialization of Longboard’s product candidates; Longboard’s product candidates are in the early to middle phases of a lengthy research and development process, the timing, manner and outcome of research, development and regulatory review is uncertain, and Longboard’s product candidates may not advance in research or development or be approved for marketing; the standard for Breakthrough Therapy designation is not the same as the standard for drug approval, the clinical evidence supporting Breakthrough Therapy designation is preliminary, and not all drugs designated as Breakthrough Therapies ultimately will be shown to have substantial improvement over available therapies; the FDA may later decide to rescind a Breakthrough Therapy designation if it determines the designation is no longer supported by subsequent data; enrolling participants in Longboard’s ongoing and intended clinical trials is competitive and challenging; risks related to unexpected or unfavorable new data; nonclinical and clinical data is voluminous and detailed, and regulatory agencies may interpret or weigh the importance of data differently and reach different conclusions than Longboard or others, request additional information, have additional recommendations or change their guidance or requirements before or after approval; macroeconomic events and their impact on Longboard’s clinical trials and operations, the operations of Longboard’s suppliers, partners, collaborators, and licensees, and capital markets; risks related to relying on licenses or collaborative arrangements; other risks related to Longboard’s dependence on third parties; competition; product liability or other litigation or disagreements with others; government and third-party payor actions, including relating to reimbursement and pricing; risks related to regulatory compliance; and risks related to Longboard’s and third parties’ intellectual property rights. Additional factors that could cause actual results to differ materially from those stated or implied by Longboard’s forward-looking statements are disclosed in Longboard’s filings with the Securities and Exchange Commission (SEC). These forward-looking statements represent Longboard’s judgment as of the time of this release. Longboard disclaims any intent or obligation to update these forward-looking statements, other than as may be required under applicable law.

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CORPORATE CONTACT:

Megan E. Knight

VP, Head of Investor Relations

IR@longboardpharma.com

858.789.9283

Source: Longboard Pharmaceuticals, Inc.

FAQ

What were the key results of Longboard Pharmaceuticals' (LBPH) PACIFIC Study OLE for bexicaserin?

The PACIFIC Study OLE for bexicaserin showed a 57.7% median reduction in countable motor seizures over ~9 months, with sustained efficacy and a favorable safety profile in patients with Developmental and Epileptic Encephalopathies (DEEs).

When will Longboard Pharmaceuticals (LBPH) release the full 12-month data for the bexicaserin PACIFIC Study OLE?

Longboard Pharmaceuticals expects to provide a full analysis of participants with 12-month data from the bexicaserin PACIFIC Study OLE early next year (2024).

What is the next step for Longboard Pharmaceuticals (LBPH) in developing bexicaserin for DEEs?

Longboard Pharmaceuticals plans to initiate a global Phase 3 program for bexicaserin in DEEs later this year, following the positive interim results and Breakthrough Therapy designation.

What was the retention rate in Longboard Pharmaceuticals' (LBPH) PACIFIC Study OLE for bexicaserin?

The retention rate in the PACIFIC Study OLE for bexicaserin was 92.7%, with 38 out of 41 participants remaining in the ongoing open-label study after approximately nine months.