Study was terminated due to low recruitment.

This is a prospective, randomized, single-site, open-label Phase II trial of neoadjuvant pembrolizumab (3 cycles) followed by surgery, versus concomitant neoadjuvant pembrolizumab with platinum doublet chemotherapy (3 cycles) followed by surgery for participants with Stage IA3, IB and IIA non-small-cell lung cancer (NSCLC). Participants will be offered pembrolizumab (6 cycles), and standard of care adjuvant chemotherapy (4 cycles) if applicable.

The use of ctDNA levels and resolution in relation to treatment response has been studied in various types of cancer, notably melanoma, colorectal and pancreatic cancers. In pancreatic cancer, it was particularly noted to be useful for the prediction of recurrence and survival patterns. In NSCLC, there is a growing need to identify patients who are more likely to respond to immunotherapies given the rates of recurrence, and ctDNA was described to be a useful tool in the prediction of pathological response in this population. In fact, ctDNA was shown to correlate with disease resolution in NSCLC and higher levels of ctDNA in non-responding patients.

The central research question of this trial is focused on the ability to predict the occurrence of a pCR based on resolution of ctDNA detectability in early stage NSCLC. The biomarker collection plan will provide tumor and plasma samples from which whole exome sequencing will be performed to monitor disease response. The endpoint is focused on the elimination of ctDNA (both replicates = 0%) at the completion of systemic therapy, prior to surgical resection. All patients will be re-tested for ctDNA levels 30 days post-surgery to determine if those patients who did not experience ctDNA resolution after systemic therapy will experience resolution with the addition of surgery.

With the ctDNA treatment response arc, the investigators will be able to address the primary objective of the study: to establish ctDNA levels in early stage NSCLC as a reliable measure of local disease burden in the context of systemic therapy, with the lower end of the detection limit correlating to the extent of pathological response. The investigators hypothesize that in a cohort of patients with stage IA3, IB and IIA NSCLC, pre-operative pembrolizumab with or without histology-specific chemotherapy will cause resolution of ctDNA detectability that correlates with a pathological complete response (pCR) to therapy.

Inclusion Criteria:

• Previously untreated, histologically confirmed (by core biopsy) NSCLC and histologically confirmed stages IA3, IB and IIA NSCLC (AJCC 8th edition).
• Able to undergo protocol therapy, including necessary surgery.
• If female: may participate if no active pregnancy, not breastfeeding, and at least one of the following: is not a woman of childbearing potential (WOCBP), or is a WOCBP using contraceptive methods.
• If male: must agree to refrain from donating sperm, and must either be abstinent or agree to use contraception.
• ECOG 0-1
• Available formalin-fixed paraffin embedded (FFPE) tumor tissue samples

Exclusion Criteria:

• Has one of the following tumor locations/types: NSCLC involving the superior sulcus, large cell neuroendocrine cancer (LCNEC) or sarcomatoid tumor.
• History of immunodeficiency, HBV, HCV, HIV. No HBV, HCV or HIV testing is required unless mandated by local health authority.
• Has a history of (non-infectious) pneumonitis/interstitial lung disease.
• Has an active infection requiring systemic therapy.
• Has had an allogenic tissue/solid organ transplant.
• Has a known severe hypersensitivity (≥ Grade 3) to pembrolizumab, its active substance and/or any of its excipients. (Refer to the respective Investigator's Brochure for a list of excipients.)
• Has a known severe hypersensitivity (≥ Grade 3) to any of the study chemotherapy agents and/or to any of their excipients.
• Has an active autoimmune disease that has required systemic treatment in past 2 years (ie, with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (eg, thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic treatment and is allowed.
• Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the participant's participation for the full duration of the trial, or is not in the best interest of the participant to participate, in the opinion of the treating investigator.
• Has known psychiatric or substance abuse disorders that would interfere with cooperating with the requirements of the trial.
• Has received colony-stimulating factors (eg, G-CSF, GM-CSF or recombinant erythropoietin) within 2 weeks before randomization
• Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent or with an agent directed to another co-inhibitory T-cell receptor (eg, CTLA-4, OX-40, CD137).
• Has received prior systemic anticancer therapy including investigational agents for the current malignancy prior to randomization/allocation.
• Has received prior radiotherapy within 2 weeks of start of trial treatment. Participants must have recovered from all radiation-related toxicities, not require corticosteroids, and not have had radiation pneumonitis.
• Has received a live or live attenuated vaccine within 30 days prior to the first dose of trial drug. Note: killed vaccines are allowed.
• Is currently participating in or has participated in a trial of an investigational agent or has used an investigational device within 4 weeks prior to the first dose of trial treatment.
• Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy (dose exceeding 10 mg daily of prednisone equivalent) or any other form of immunosuppressive therapy within 7 days prior the first dose of trial drug.
• Has a known additional malignancy that is progressing or requires active treatment within the past (5 years).