PTC Therapeutics Inc (NASDAQ: PTCT) reported a delay in the planned submission of sepiapterin in phenylketonuria (PKU) during its Q3 earnings release.
The company originally planned to file for FDA approval in the fourth quarter, but the timeline was pushed back after the FDA requested a 26-week nonclinical mouse study before authorization.
PTC initially intended to seek approval under the 505(b)(2) pathway, utilizing data from a different reference drug to support its application. However, after acquiring the candidate from Censa Pharmaceuticals, they changed to the 505(b)(1) pathway.
In response to PTC, the FDA emphasized the importance of upright stability as a clinically meaningful endpoint. PTC has requested a meeting with the FDA to address the raised issues.
PTC executives believe that sepiapterin is better suited for the Section 505(b)(1) pathway due to its differentiated mechanism, according to William Blair.
The delay will push the filing for FDA approval to the third quarter of next year, unless the agency allows PTC to submit the mouse data during the review process. In that case, PTC could file in the second quarter of next year.
Despite the setback, analysts at William Blair view the results of the phase 3 APHENITY trial as supportive of approval and see opportunities for the drug outside the U.S., where exposure to BioMarin Pharmaceutical Inc’s (NASDAQ: BMRN) rival drug Kuvan is lower.
Additionally, PTC Therapeutics is in discussions with the FDA regarding the resumption of U.S. enrollment in the PIVOT-HD study for PTC518 for Huntington’s disease.
Enrollment for the study is currently ongoing overseas but has been on hold in the U.S. for one year. The FDA suggested that six months of clinical safety data demonstrating a similar favorable safety profile could support 12-month dosing.
Last month, PTC Therapeutics laid off 25% of its workforce, primarily in early-stage research programs and employees at the gene therapy manufacturing facility in New Jersey.
As of the last check on Friday, PTCT shares are down 22.40% at $18.60.
Reasons Behind PTC Therapeutics Stock Plunge
PTC Therapeutics Inc (NASDAQ: PTCT) is experiencing a significant drop in its stock value following a delay in the planned submission of sepiapterin in phenylketonuria (PKU). This delay is causing concern among investors and traders alike.
The FDA’s Request for a Nonclinical Mouse Study
During the company’s Q3 earnings release, PTC Therapeutics announced that the FDA has requested a 26-week nonclinical mouse study before granting authorization for sepiapterin in PKU. This unexpected requirement has pushed back the timeline for FDA approval, disappointing investors who were expecting a filing in the fourth quarter.
Change in Pathway and FDA Response
Initially, PTC Therapeutics intended to seek FDA approval under the 505(b)(2) pathway, utilizing data from a different reference drug to support its application. However, after acquiring the candidate from Censa Pharmaceuticals, they switched to the 505(b)(1) pathway. In response to PTC, the FDA highlighted the significance of upright stability as a clinically meaningful endpoint. PTC has requested a meeting with the FDA to address the concerns raised in the FDA’s written response.
Impact on Filing Timeline and Analysts’ View
As a result of the nonclinical mouse study requirement, the filing for FDA approval for sepiapterin in PKU will likely be delayed until the third quarter of next year. If the FDA allows PTC Therapeutics to submit the mouse data during the review process, there is a possibility of filing in the second quarter of next year. Although this delay is viewed as an unfortunate setback by analysts, they remain optimistic about the drug’s approval based on the results of the phase 3 APHENITY trial. Furthermore, analysts believe there are opportunities for the drug outside the U.S. market, where the exposure to BioMarin Pharmaceutical Inc’s rival drug Kuvan is lower.
Other Discussions with the FDA
In addition to the delay in PKU sepiapterin approval, PTC Therapeutics is engaged in discussions with the FDA regarding the resumption of U.S. enrollment in the PIVOT-HD study for PTC518, targeting Huntington’s disease. The enrollment process has been ongoing overseas but has been on hold in the U.S. for one year. The FDA has suggested that six months of clinical safety data demonstrating a similar favorable safety profile could support 12-month dosing, indicating a potential path forward for the study.
Recent Workforce Reduction
As part of its cost-cutting measures, PTC Therapeutics recently laid off 25% of its workforce, primarily those working on early-stage research programs and employees at the gene therapy manufacturing facility in New Jersey. This decision underscores the company’s focus on streamlining operations and maximizing efficiency.
Stock Performance
Following the news of the PKU sepiapterin delay, PTC Therapeutics stock (PTCT) experienced a significant drop, currently down 22.40% at $18.60. This decline reflects the market’s reaction to the company’s regulatory challenges and the uncertainty surrounding the drug’s future approval.
Conclusion
PTC Therapeutics is facing a setback with the delay in the planned submission of sepiapterin in PKU due to the FDA’s request for a nonclinical mouse study. This delay has caused a drop in the company’s stock value. However, analysts remain optimistic about the drug’s approval based on the positive results of the phase 3 APHENITY trial and potential opportunities outside the U.S. market. PTC Therapeutics is also in discussions with the FDA regarding the resumption of U.S. enrollment in the PIVOT-HD study for PTC518. Despite the challenges, the company continues to strategize and make decisions to streamline its operations and maximize efficiency, as reflected in recent workforce reductions. Investors and traders will closely watch the developments surrounding PTC Therapeutics’ regulatory process and anticipate further updates on the drug’s future prospects.
