A Study to Assess the Efficacy and Safety of Firmonertinib Versus Placebo for Adjuvant Treatment in Participants With Stage IB - IIIB NSCLC With Uncommon Epidermal Growth Factor Receptor (EGFR) Mutations, Following Complete Surgical Resection With or Without Adjuvant Chemotherapy（FIRMOST）

Phase 3

Recruiting

• Conditions: NSCLC; Adjuvant Treatment
• Interventions: Drug: Firmonertinib; Drug: Placebo

• Registration Number: NCT07010419
• Lead Sponsor: Allist Pharmaceuticals, Inc.

Brief Summary

This is a Phase 3, global, double-blind, randomized, controlled multicenter clinical study to assess the efficacy and safety of adjuvant treatment with firmonertinib versus placebo in participants with Stage IB-IIIB NSCLC with uncommon EGFR mutations (exon 20 insertions, PACC and classical-like mutations) after complete surgical resection with or without adjuvant chemotherapy.

About 338 eligible participants will be enrolled and randomized in a 1:1 ratio to receive either firmonertinib 240 mg QD or placebo QD in 21-day treatment cycles. Before randomization, the participant must have undergone complete surgical resection (R0 resection), must have sufficiently recovered from surgery, and must have completed adjuvant chemotherapy (if applicable). The participants will receive firmonertinib or placebo as adjuvant treatment until unacceptable toxicity, withdrawal of informed consent, disease recurrence, initiation of new antitumor treatment, completion of treatment, or other end of treatment reason is met.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2025-05-20
• Study Start: 2025-05-28
• Status Verified: 2025-06
• Study First Submitted QC: 2025-06-05
• Last Update Submitted: 2025-06-05
• Study First Posted: 2025-06-08
• Last Update Posted: 2025-06-08
• Primary Completion: 2028-10-31
• Study Completion: 2032-04-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 338

Inclusion Criteria

1. Sign the Informed Consent Form (ICF).
2. Aged ≥ 18 years old. Participants from Japan/Taiwan aged ≥ 20 years old.
3. Histologically confirmed diagnosis of primary non-small cell lung cancer (NSCLC) of predominantly non-squamous histology.
4. Underwent complete surgical resection of primary lung cancer and systematic lymph node dissection (R0 resection).
5. Classified post-operatively as Stage IB, II, IIIA, or IIIB (T3N2M0 only) on the basis of pathologic criteria, with the disease staging following the 9th Edition TNM Staging Classification: Lung Cancer issued by Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC).
6. Documented results of the presence of uncommon EGFR mutations (exon 20 insertion mutations, PACC mutations, and/or classical-like mutations, either as single mutations or as co-mutations), in tumor tissue or blood via a validated NGS or validated PCR assay.

Exclusion Criteria

A participant would be excluded from the study if he/she meets any of the following:

1. NSCLC with EGFR Exon 19 deletion or L858R or C797S mutation.

2. Incomplete resection (R1/R2) or segmentectomy or wedge resection only.

3. Prior treatment with any of the following:

   1. Prior treatment with any antineoplastic therapy other than standard platinum-based doublet adjuvant chemotherapy.
   2. prior treatment with neoadjuvant therapy.

4. Concurrent malignant tumors other than the primary tumor; participants with cancers that can be treated locally and cured may be eligible.

5. Previous ILD (including drug-induced ILD) or active ILD/active radiation pneumonitis.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Firmonertinib	Firmonertinib	Firmonertinib: 240 mg, QD, orally
Placebo	Placebo	Placebo: 240 mg, QD, orally

Primary Outcome Measures

Name	Time	Method
Disease free survival (DFS)	Up to 3 years	DFS as assessed by the investigator in Stage II- IIIB. DFS defined as the time from the date of randomization to the first observation of disease recurrence (by pathological diagnosis or imaging) or death caused by any reason, whichever occurs first.

Secondary Outcome Measures

Name	Time	Method
Disease free survival (DFS)	Up to 3 years	DFS as assessed by the investigator in Stage IB-IIIB; DFS as assessed by the BICR in Stage IB-IIIB
Disease free survival rates	Up to 5 years	2-, 3-, and 5-year DFS rates as assessed by the investigator and BICR in Stage II-IIIB and in Stage IB-IIIB
Overall survival (OS)	Up to 5 years	OS defined as the time from the date of randomization to the date of death due to any cause, in Stage II-IIIB and in Stage IB-IIIB
Overall survival rates	Up to 5 years	2-, 3-, and 5-year OS rates in Stage II-IIIB and in Stage IB-IIIB
Adverse event (AE)	Up to 5 years	Incidence and severity of AEs, with severity as determined according to National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0 (NCI CTCAE v5.0)

Trial Locations

Locations (2)

Peking University People's Hospital; 🇨🇳 BeiJing, Beijing, China

Sun Yat-sen University Cancer Center; 🇨🇳 Guangdong, Guangzhou, China