Praxis Precision Medicines Reports Positive Results of PRAX-628 Study Evaluating Photo Paroxysmal Response (PPR) Achieving 100% Response in Treated Patients

Rhea-AI Impact
Rhea-AI Sentiment
Rhea-AI Summary
Praxis Precision Medicines, Inc. (NASDAQ: PRAX) reports positive results from Phase 2a study of PRAX-628 in epilepsy patients with PPR, showing high complete response rates in both 15mg and 45mg cohorts. Safety profile remains favorable, paving the way for an efficacy study in focal onset epilepsy in the second half of 2024.
  • None.
  • None.

The recent update from Praxis Precision Medicines on their Phase 2a proof of concept study for PRAX-628 is a significant milestone in the development of treatments for central nervous system disorders, particularly epilepsy. The complete response rates observed in the 45 mg cohort and the high combined response rates are indicative of PRAX-628's potential efficacy. The safety profile aligning with previous studies suggests a manageable risk profile, an essential factor in the progression of clinical trials.

From a research perspective, the use of PPR studies to measure EEG signatures is a credible approach to assessing anti-seizure efficacy. This is especially relevant for focal onset epilepsy, which can be resistant to current treatments. The anticipation of an efficacy study in the second half of 2024 indicates a strategic progression in the drug's development timeline, potentially accelerating its path to market, pending successful outcomes.

For investors and stakeholders, the development of a precision sodium channel modulator like PRAX-628 could represent a substantial advancement in the epilepsy treatment landscape. The specificity of such treatments can lead to better patient outcomes and possibly command premium pricing in the market. However, it is important to consider the competitive landscape, regulatory hurdles and the long-term data required for approval when evaluating the potential impact on Praxis's financials and stock performance.

The update on PRAX-628's clinical trial results is a positive indicator for Praxis's investment potential. The 100% response rates in clinical trials are rarely seen and suggest a strong therapeutic potential for PRAX-628. This level of efficacy could position the drug as a leader in the epilepsy treatment market, which is valued at billions of dollars globally.

Investors should note the timelines for the upcoming efficacy study. While the initiation of the study is planned for the second half of 2024, the actual market entry of PRAX-628, if approved, would still be several years away. This introduces a time-to-market risk, which is typical in the biopharmaceutical industry. The financial implications for Praxis will depend on the continued success of clinical trials, the ability to secure regulatory approvals and the eventual uptake of the drug in the market.

Short-term stock movements may reflect investor optimism, but the long-term trajectory will hinge on execution and the competitive dynamics of the epilepsy market. It is also worth monitoring the company's cash burn rate and fundraising activities, as clinical trials are capital-intensive. Praxis's ability to manage these financial aspects will be critical for sustaining operations until potential product launch.

The pharmacological profile of PRAX-628 as a precision sodium channel modulator represents a novel approach in epilepsy treatment. Sodium channels are critical in the generation and conduction of electrical signals in the nervous system and their dysfunction is implicated in several types of epilepsy. By targeting these channels with precision, PRAX-628 may offer a more targeted and potentially more effective treatment option compared to broader-spectrum anti-seizure medications.

The consistency of therapeutic exposures and the favorable safety profile observed are encouraging from a pharmacological standpoint. These factors contribute to the drug's potential for a favorable benefit-risk ratio, an important consideration in the treatment of chronic conditions like epilepsy. The partial responses in the 15 mg cohort also suggest a dose-responsive effect, which is beneficial for individualizing treatment regimens.

Looking ahead, the design and outcomes of the planned efficacy study will be critical. It will need to demonstrate not just seizure control but also improvements in patient quality of life and long-term safety. The pharmacological data will be key in determining the drug's positioning in the epilepsy treatment algorithm and its potential for market differentiation.

In the 45 mg cohort, 100% of patients achieved a complete response

In the 15 mg cohort, 80% of patients achieved a complete response and 20% achieved a partial response

Safety was consistent with prior dose escalation study and PK analysis confirmed therapeutic exposures

Praxis plans to initiate an efficacy study in focal onset epilepsy in the second half of 2024

BOSTON, March 26, 2024 (GLOBE NEWSWIRE) -- Praxis Precision Medicines, Inc. (NASDAQ: PRAX), a clinical-stage biopharmaceutical company translating genetic insights into the development of therapies for central nervous system (CNS) disorders characterized by neuronal excitation-inhibition imbalance, today provided an update on its Phase 2a proof of concept study evaluating PRAX-628 in epilepsy patients with PPR. PPR studies measure electroencephalogram (EEG) signatures after intermittent photic stimulation and are used as an indicator of anti-seizure efficacy.

“The strength and consistency of response across both study arms, combined with a continued positive tolerability and safety profile, build on our earlier conviction that PRAX-628 has the potential to be the first precision sodium channel modulator for focal epilepsy patients. With such a clear response, we have advanced our planning of the focal epilepsy efficacy study for PRAX-628, expected to begin in the second half of 2024. We extend our thanks to the patients who participated in this PPR study,” said Marcio Souza, president and chief executive officer of Praxis.

Summary of Response
CohortPartial Response RateComplete Response RateTotal Response
15mg20% (1)80% (4)100% (5)
45mg--100% (3)100% (3)
Combined12% (1)88% (7)100% (8)

About the Phase 2a PPR Study

  • Patient EEG signatures were assessed at defined measurement points over a 24-hour period after receiving placebo or PRAX-628, and results were compared to baseline.
  • Patients must have demonstrated PPR during screening and baseline to be evaluable.
    • A total of six patients were baselined in the 15 mg cohort, of whom five were evaluable. One patient in the 15 mg cohort did not present adequate PPR at baseline to be evaluated.
    • Four patients were baselined in the 45 mg cohort, of whom three were evaluable. One patient in the 45 mg cohort was not evaluable due to lack of eligibility.
    • Three patients from the 15mg cohort participated in the 45mg cohort after a washout period of >100 days.
    • Three patients were on background anti-seizure medications (ASMs).
  • Response Assessment
    • Complete: Reduction to zero in the number of generalized PPR events at any assessment period vs. baseline.
    • Partial: Reduction, other than to zero, in the number of generalized PPR events at any assessment period vs. baseline.
  • Safety and PK samples were collected during the entire observation period.

PRAX-628 for Focal Epilepsy:

  • The Phase 2a study builds on positive results from animal studies and the Phase 1 dose escalation study in healthy volunteers.
    • PRAX-628 demonstrated unprecedented pre-clinical efficacy in the maximal electroshock seizure (MES) model.
    • PRAX-628 was generally well-tolerated at all tested doses in the Phase 1 study.
    • Pharmacokinetic data from the Phase 1 study demonstrated dose-dependent exposure supporting once-daily dosing without titration to achieve potentially therapeutically effective drug concentration levels.
    • Further analysis of patients in the Phase 1 study using quantitative EEG data showed a pharmacodynamic effect at all dose levels and was significantly different from placebo.

Praxis will host a call on Tuesday, March 26 at 8:00 am ET to discuss the study results, and will be joined by Dr. Daniel Friedman, Professor of Neurology at NYU Grossman School of Medicine. To register for the call, please click here.

The live webcast and replay will be available through the Events & Presentations page of the Investors and Media section of the company’s website at

About PRAX-628
PRAX-628 is a next-generation, functionally selective small molecule targeting the hyperexcitable state of sodium-channels in the brain that is currently being developed as a once daily, oral treatment for adult focal onset epilepsy. Preclinical data demonstrates PRAX-628 is differentiated from standard of care, with the potential to be best-in-class for focal epilepsy. In vitro, PRAX-628 has demonstrated superior selectivity for disease-state NaV channel hyperexcitability. In vivo studies of PRAX-628 have demonstrated unprecedented potency in the MES model, a highly predictive translational model for efficacy in focal epilepsy. Data from the PRAX-628-101 study demonstrated that PRAX-628 can be safely dosed in healthy subjects to greater than 15 times the predicted human equivalent of the rodent MES EC50.

About Praxis
Praxis Precision Medicines is a clinical-stage biopharmaceutical company translating insights from genetic epilepsies into the development of therapies for CNS disorders characterized by neuronal excitation-inhibition imbalance. Praxis is applying genetic insights to the discovery and development of therapies for rare and more prevalent neurological disorders through our proprietary small molecule platform, Cerebrum™, and antisense oligonucleotide (ASO) platform, Solidus™, using our understanding of shared biological targets and circuits in the brain. Praxis has established a diversified, multimodal CNS portfolio including multiple programs across movement disorders and epilepsy, with four clinical-stage product candidates. For more information, please visit and follow us on Facebook, LinkedIn and Twitter/X.

Forward-Looking Statements 
This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995 and other federal securities laws, including express or implied statements regarding Praxis’ future expectations, plans and prospects, including, without limitation, statements regarding the anticipated timing of Praxis’ clinical trials, the development of Praxis’ product candidates and the potential therapeutic effects of Praxis’ product candidates, as well as other statements containing the words “anticipate,” “believe,” “continue,” “could,” “endeavor,” “estimate,” “expect,” “anticipate,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will” or “would” and similar expressions that constitute forward-looking statements under the Private Securities Litigation Reform Act of 1995. 

The express or implied forward-looking statements included in this press release are only predictions and are subject to a number of risks, uncertainties and assumptions, including, without limitation: uncertainties inherent in clinical trials; the expected timing of clinical trials, data readouts and the results thereof, and submissions for regulatory approval or review by governmental authorities; regulatory approvals to conduct trials; and other risks concerning Praxis’ programs and operations as described in its Annual Report on Form 10-K for the year ended December 31, 2023 and other filings made with the Securities and Exchange Commission. Although Praxis’ forward-looking statements reflect the good faith judgment of its management, these statements are based only on information and factors currently known by Praxis. As a result, you are cautioned not to rely on these forward-looking statements. Any forward-looking statement made in this press release speaks only as of the date on which it is made. Praxis undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future developments or otherwise.


What is the ticker symbol for Praxis Precision Medicines, Inc.?

The ticker symbol for Praxis Precision Medicines, Inc. is PRAX.

What are the complete response rates in the 15mg cohort?

In the 15mg cohort, 80% of patients achieved a complete response.

When does Praxis plan to initiate an efficacy study in focal onset epilepsy?

Praxis plans to initiate an efficacy study in focal onset epilepsy in the second half of 2024.

What do PPR studies measure?

PPR studies measure electroencephalogram (EEG) signatures after intermittent photic stimulation and are used as an indicator of anti-seizure efficacy.

What did the PK analysis confirm?

PK analysis confirmed therapeutic exposures.

Praxis Precision Medicines, Inc.


PRAX Rankings

PRAX Latest News

PRAX Stock Data

Pharmaceutical Preparation Manufacturing
United States of America

About PRAX

praxis precision medicines, inc., a clinical-stage biopharmaceutical company, develops therapies for central nervous system disorders characterized by neuronal imbalance. its lead product candidates include prax-114, an extrasynaptic-preferring gabaa receptor positive allosteric modulator that is in phase iia clinical trial for the treatment of major depressive disorder and perimenopausal depression; and prax-944, a selective small molecule inhibitor of t-type calcium channels, which is in phase iia clinical trial for the treatment of essential tremor. the company is also developing prax-562, a persistent sodium current blocker that is in phase i clinical trial to treat severe pediatric epilepsy and adult cephalgia; prax-222, an antisense oligonucleotide for patients with gain-of-function (gof) scn2a epilepsy; and kcnt1 program for the treatment of kcnt1 gof epilepsy. it has a cooperation and license agreement with rogcon inc.; a license agreement purdue neuroscience company; and a res