Summary of Cancellation for Gefapixant (*Lyfnua)

Review decision

The Regulatory Decision Summary explains Health Canada’s decision for the product seeking market authorization. The Regulatory Decision Summary includes the purpose of the submission and the reason for the decision.


Product type:

Drug

Medicinal ingredient(s):

Gefapixant

Therapeutic area:

Cough and Cold Preparations

Type of submission:

New Drug Submission (New Active Substance)

Control number:

255697

Decision issued:

No final decision was issued by Health Canada. The company cancelled its submission before a final decision was issued.

Date of cancellation:

2024-06-12

What was the purpose of this submission?

Lyfnua (gefapixant) is a new active substance and first-in-class drug. This New Drug Submission (NDS) was filed to seek authorization for use of gefapixant in the treatment of adults with refractory chronic cough (RCC) or unexplained chronic cough (UCC).

A Notice of Deficiency (NOD) was issued on October 18, 2022 due to concerns identified regarding the reliability and accuracy of the cough count data obtained from the VitaloJAK cough recording system and the manual cough counting process used in the analyses of the primary and key secondary efficacy endpoints in the two pivotal studies. There were also concerns regarding the robustness and clinical relevance of the available efficacy data and regarding the submitted QTc analyses. Other objections were also included in the NOD to be addressed by the Sponsor.

A response to NOD (NOD-R) was submitted on July 28, 2023.

What did the company submit to supports its submission?

The sponsor submitted drug quality, pre-clinical and clinical packages as well as labelling information and a post-market Risk Management Plan to support the Lyfnua submission. Two pivotal Phase 3, 52-week, multicenter, randomized, double-blind, placebo-controlled studies were filed to support the proposed indication (P027 and P030). Studies P027 and P030 evaluated the efficacy and safety of two doses of gefapixant (15 mg BID and gefapixant 45 mg BID) in adult patients with RCC or UCC in 732 and 1,317 patients, respectively. The choice of gefapixant doses for the Phase 3 chronic cough studies was based on modeling and simulation using data from Phase 1 and 2. The primary endpoint for both pivotal studies was the relative reduction in 24-hour cough counts (in coughs per hour) from baseline to Week 12 (in P027) and Week 24 (in P030) compared to placebo.

What was the status of the submission when it was cancelled? What was Health Canada’s assessment of the submission at the time of cancellation?

At the time of the cancellation, Health Canada was finalizing its review of the response to the Notice of Deficiency (NOD). Health Canada still had concerns regarding the robustness and clinical relevance of the efficacy data despite the additional information provided in the response to NOD.

What consequences does the cancellation have for patients accessing the drug under the Special Access Programme (SAP), or via clinical trials?

Lyfnua (gefapixant) has not been accessed via SAP. There is no expected impact for patients in clinical trials.

*Proposed Brand Name:

Lyfnua

Manufacturer:

Merck Canada Inc.

Drug Identification Numbers issued:

N/A

Date filed:

2021-08-12