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）

Launched by ALLIST PHARMACEUTICALS, INC. · Jun 5, 2025

Keywords

ClinConnect Summary

This clinical trial, called FIRMOST, is studying a new treatment called firmonertinib for patients who have early-stage non-small cell lung cancer (NSCLC) with specific rare mutations in a gene called EGFR. After surgery to remove the cancer, some patients might receive firmonertinib while others will receive a placebo, which is a dummy treatment with no active ingredients. The goal is to see if firmonertinib can help prevent the cancer from coming back after surgery. About 338 people will take part in this study, and they will be closely monitored for any side effects or changes in their health.

To be eligible for the trial, participants must be at least 18 years old, have had surgery for NSCLC, and have specific unusual mutations in their cancer. They should also be recovering well from their surgery and may have received chemotherapy beforehand. If someone joins the study, they will take firmonertinib or the placebo daily for a certain period, unless they experience bad side effects or their cancer returns. This study is currently recruiting participants, and it aims to provide valuable information about a potential new treatment option for this type of lung cancer.

Gender

ALL

Eligibility criteria

• 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.