Nov 2023: Pembrolizumab (Keytruda, Merck) was granted approval by the Food and Drug Administration (FDA) as a neoadjuvant treatment in combination with platinum-containing chemotherapy and as a post-surgical adjuvant treatment for resectable non-small cell lung cancer (NSCLC) tumours measuring 4 cm or more in diameter, when combined with platinum-containing chemotherapy.
KEYNOTE-671 (NCT03425643), a multicenter, randomized, double-blind, placebo-controlled trial involving 797 patients with AJCC 8th edition resectable Stage II, IIIA, or IIIB NSCLC who had not been previously treated, assessed the drug’s efficacy. Patients undergoing platinum-based chemotherapy were randomized (1:1) to receive pembrolizumab or a placebo every three weeks for four cycles (neoadjuvant treatment).
Subsequently, for a maximum of thirteen cycles (adjuvant treatment), patients were administered either continued single-agent pembrolizumab or a placebo every three weeks. The surgical window and chemotherapy specifics are available at the link to the drug label above.
The primary outcome measures of efficacy were investigator-assessed event-free survival (EFS) and overall survival (OS). The median OS for those receiving placebo was 52.4 months (95% CI: 45.7, NE) and was not attained in the pembrolizumab arm (95% CI: not estimable [NE], NE]; p-value=0.0103). The risk ratio [HR] was 0.72 [95% CI: 0.56, 0.93]; p-value=0.0103]. The median EFS in the placebo arm was 17 months (95% CI: 14.3, 22.0) compared to 17 months in the pembrolizumab arm (95% CI: 34.1 months, NE) (HR 0.58 [95% CI: 0.46, 0.72]; p-value=0.0001).
The adverse reactions most frequently reported by 20% or more of the patients in KEYNOTE-671 were as follows: nausea, fatigue, neutropenia, anaemia, constipation, decreased appetite, decreased white blood cell count, musculoskeletal pain, rash, congestion, vomiting, diarrhoea, and dyspnea.
A comparatively lower rate of adverse reactions prevented surgery for 6% of patients in the pembrolizumab arm who received neoadjuvant treatment, as opposed to 4.3% in the placebo arm. In addition, 3.1% of patients who received neoadjuvant treatment and surgery in the pembrolizumab arm experienced surgical delays as compared to 2.5% in the placebo arm. The safety information pertaining to the neoadjuvant and adjuvant phases can be found in the drug label link provided above.
Pembrolizumab is prescribed at a dosage of 200 mg every 3 weeks or 400 mg every 6 weeks. When administered on the same day as chemotherapy, pembrolizumab should be administered beforehand.
