The study includes a screening period (not more than 28 days after the subject signs informed consent to before the first medication), treatment period (including Almonertinib treatment in 6-8 weeks after enrollment\ctDNA testing and radiographically imaging assessment\ctDNA guiding sequential Envafolimab immunotherapy) and follow-up period (including survival and safety) .~Eligible subjects receive 110 mg of Almonertinib once a day for 6-8 consecutive weeks of treatment，and receive ctDNA testing and radiographically imaging assessment again. According to test results, there are two types:~EGFR mutation is positive, subjects subsequent treament is up to the investigator (continue to receive 110 mg of Almonertinib once a day or combination therapy regimen), follow up every 6 weeks.~EGFR mutation is negative and achieve stable radiographically deep response after 6-8 weeks treatment with Almonertinib, subjects will stop Almonertinib treatment，and receive sequential Envafolimab immunotherapy (ctDNA dynamic monitoring guided treatment，every 6 weeks test ctDNA once, if it is negative, subjects continue to receive Envafolimab immunotherapy until ctDNA EGFR turns positive; if ctDNA EGFR is positive, subjects stop Envafolimab immunotherapy and receive Almonertinib 110 mg once a day again until ctDNA EGFR turns negative).~The treatment will continue until disease progression assessed by the investigator according to RECIST 1.1 criteria, or withdrawal or termination criteria are reached.
This is a prospective, single-arm, open-label, interventional clinical study, aimed at exploring the efficacy and safety of sequential Envafolimab immunotherapy after patients with ctDNA EGFR mutation clearance and achieved stable radiographically deep esponse after first line treatment with Almonertinib in EGFR-Mutant, PD-LI positive non-small-cell lung cancer.