Alex A. Adjei, MD, PhD, discusses frontline treatment options for patients with advanced non–small cell lung cancer, as well as some of the nuances of selecting the optimal therapy.
Immunotherapy, often in combination with chemotherapy, has transformed the frontline treatment of patients with advanced non–small cell lung cancer (NSCLC) who do not harbor actionable alterations, said Alex A. Adjei, MD, PhD.
“[The frontline treatment of patients with] stage IV [NSCLC] has become very complex in terms of treating patients without druggable genomic alterations. We have to look at histology in terms of the chemotherapy backbone, and then we have to look at PD-L1 expression.”
During a 2020 OncLive® Institutional Perspectives in Cancer webinar on lung cancer, Adjei, professor of oncology and pharmacology and a consultant in the Division of Medical Oncology and Department of Oncology at Mayo Clinic, discussed frontline treatment options for patients with advanced NSCLC, as well as some of the nuances of selecting the optimal therapy.
In the phase 3 KEYNOTE-024 and KEYNOTE-042 trials, pembrolizumab (Keytruda) demonstrated a statistically significant improvement in overall survival (OS) compared with chemotherapy as first-line treatment for patients with stage IV NSCLC.1,2
Specifically, in KEYNOTE-042, the OS benefit was observed in patients with any level of PD-L1 expression (≥ 1%). However, upon further analysis, the OS improvement appeared to be largely driven by patients with a tumor proportion score (TPS) of 50% or greater. In this population, the median OS was 20.0 months with pembrolizumab vs 12.2 months with chemotherapy (HR, 0.69; 95% CI, 0.56-0.85; P = .0003). In the group of patients with a TPS of 1% to 49%, the median OS was 13.4 months vs 12.1 months, respectively (HR, 0.92; 95% CI, 0.77-1.11).
“Even though, theoretically, we could use single-agent pembrolizumab in patients whose tumors have less than 50% PD-L1 expression, it is not ideal,” explained Adjei. “Sometimes patients have a poor performance status, and we want to give them single-agent [immunotherapy], but it is not a great treatment in terms of efficacy.”
Based on the results of the phase 3 IMpower110 trial, atezolizumab (Tecentriq) also emerged as a potential single-agent option for patients with high PD-L1 expression (TPS ≥ 50%).3 The median OS with atezolizumab versus chemotherapy was 20.2 months and 13.1 months, respectively (HR, 0.59; 95% CI, 0.40-0.89; P = .0106). The median progression-free survival (PFS) was 8.1 months and 5 months, respectively (HR, 0.63; 95% CI, 0.45-0.88).
Additionally, the chemotherapy-free regimen of nivolumab (Opdivo) and ipilimumab (Yervoy) demonstrated encouraging efficacy in the phase 3 CheckMate 227 trial for patients with stage IV or recurrent NSCLC.4
In part 1a of the study, patients with at least 1% PD-L1 expression were randomized to nivolumab plus ipilimumab, chemotherapy alone, or nivolumab alone. The 24-month OS rates were 40%, 33%, and 36%, respectively. The 24-month PFS rates were 22%, 7%, and 14%, respectively.
Part 1b of CheckMate-227 randomized patients with less than 1% PD-L1 expression to nivolumab plus ipilimumab, nivolumab plus chemotherapy, or chemotherapy alone. The 24-month OS rates were 40%, 35%, and 23%, respectively.
“PD-L1 expression did not seem to significantly affect the responses,” said Adjei. “It appears that the ipilimumab and nivolumab combination is very effective [irrespective] of PD-L1 expression, so it is something to think about if you want to decide which agent to pick in the crowded field.”
Notably, findings from the phase 2 CCTG BR.34 study did not demonstrate an OS improvement with the addition of durvalumab (Imfinzi) to tremelimumab plus chemotherapy compared with durvalumab/tremelimumab alone in patients with stage IV squamous or nonsquamous NSCLC.5 The median OS was 16.6 months vs 14.1 months, respectively (stratified HR, 0.88; 95% CI, 0.67-1.16; log-rank P = .46).
“Immunotherapy is more complex than we think. Just a PD-1/PD-L1 [plus] CTLA-4 combination may not always be a one-size-fits-all [option],” explained Adjei.
For eligible patients, the combination of a checkpoint inhibitor and chemotherapy has also shown utility in the frontline setting, Adjei explained.
For example, pembrolizumab plus pemetrexed and carboplatin or cisplatin followed by pembrolizumab plus pemetrexed demonstrated superior median OS (not reached) compared with placebo plus pemetrexed plus carboplatin or cisplatin followed by placebo and pemetrexed (11.3; HR, 0.49; 95% CI, 0.38-0.64; P < .001) in patients with treatment-naïve stage IV nonsquamous NSCLC, according to findings from the phase 3 KEYNOTE-189 trial.6 Moreover, the benefit was observed irrespective of PD-L1 status.
Similar results were observed in the phase 3 KEYNOTE-407 trial but in patients with squamous histology. The median OS with pembrolizumab plus carboplatin and paclitaxel or nab-paclitaxel (Abraxane) was 15.9 months vs 11.3 months with placebo plus chemotherapy. The benefit was observed across PD-L1 expression cohorts.7
However, findings from the phase 3 IMpower131 evaluating atezolizumab plus chemotherapy did not yield positive results for patients with advanced squamous NSCLC.8
The phase 3 IMpower150 randomized patients with stage IV or recurrent metastatic nonsquamous NSCLC to atezolizumab plus carboplatin and paclitaxel (arm A), atezolizumab plus carboplatin, paclitaxel, and bevacizumab (Avastin; arm B), or carboplatin, paclitaxel and bevacizumab alone (arm C).9
Looking at arms B and C, the median PFS was 8.3 months with the addition of atezolizumab versus 6.8 months with chemotherapy alone (HR, 0.59; 95% CI, 0.50-0.70; P < .0001). The median OS was 19.2 months versus 14.7 months, respectively (HR, 0.78; 95% CI, 0.64-0.96; P = .0164).
Notably, benefit was observed across all subgroups analyzed, including PD-L1 expression, presence of liver metastases, and EGFR/ALK positivity. Moreover, patients with an EGFR mutation had a median OS that was not estimable with atezolizumab versus 17.5 months with the control regimen (HR, 0.54).
“The is a hotly debated area,” said Adjei. “At this point, based on these data, we tend to use this combination when we have a patient with an EGFR [mutation] who has gone through all options.”
Adjei closed out his presentation by highlighting the role of chemotherapy plus dual immunotherapy, such as was explored in the CheckMate 9LA trial.10
In the study, patients with stage IV or recurrent NSCLC were randomized to nivolumab plus ipilimumab and chemotherapy or chemotherapy alone.
The median OS was 15.6 months with the chemoimmunotherapy combination compared with 10.9 months with chemotherapy alone (HR, 0.66; 95% CI, 0.55-0.80). Notably, this benefit was observed across histologies (nonsquamous vs squamous) and PD-L1–expression level (< 1%, ≥ 1%, 1-49%, and ≥ 50%).
Secondary end points were also intriguing, said Adjei. The overall response rates were 38% with chemoimmunotherapy versus 25% with chemotherapy alone. Nine percent and 13% of patients experienced progressive disease, respectively. Finally, the median duration of response was 11.3 months with nivolumab/ipilimumab/chemotherapy versus 5.6 months with chemotherapy alone.
Toxicity is one potential caveat of the CheckMate-9LA regimen, said Adjei. The rate of treatment-related select adverse effects, including skin, endocrine, gastrointestinal, hepatic, renal, pulmonary, and hypersensitivity/infusion reaction events, were observed with chemoimmunotherapy. Grade 3/4 events occurred in 4%, 3%, 6%, 4%, 2%, 2%, and 1% of patients, respectively.
What is the appropriate first-line treatment for a 70-year-old patient with stage IV ocarcinoma and 75% PD-L1 expression on tumor cells?
What is the appropriate first-line treatment for a 60-year-old man with stage IV squamous cell carcinoma with unknown PD-L1 expression on tumor cells?