Background
The treatment landscape of non-small cell lung cancer (NSCLC) has shifted substantially with the emergence of immunotherapy treatments; in turn, these have simultaneously reshaped the biomarker testing landscape, with PD-L1 testing rapidly adopted and becoming part of the diagnostic requirement to select the most appropriate treatment. With the evolution of PD-(L)1 therapy approvals also comes the need for physicians to familiarize themselves with updated PD-L1 expression requirement guidelines.
Methods
Ipsos’ Global Oncology Monitor is a multi-stakeholder, physician-reported patient record database. A total of 3,172 cancer-treating physicians (US=1,362, EU4+UK=1,810) were screened for seniority and caseload and submitted data on 154,571 patients (US=58,325, EU4+UK=96,246). Data were collected online from April 2023 to March 2024.
Results
95% of the physician-reported first line metastatic NSCLC patients in the US and EU4+UK were tested for PD-L1 expression. Of these first line tested patients, 32% in the US and 36% in the EU4+UK were categorized by the physicians as PD-L1-negative. Among reported patients considered PD-L1-negative, 31% in the US and 32% in the EU4+UK had TPS 1-49%. Additionally, 18% and 26% of the physicians in the US and EU4+UK, respectively, classified patients with a TPS of between 1-49% as a mix of positive and negative. In the US subset, 47% of first line patients classified as PD-L1-negative with TPS 1-49% received a PD-(L)1 therapy, and 39% received cytotoxic treatment. At a regional level, the proportion of this patient cohort recorded as receiving cytotoxic therapy were as follows: Spain, 82%; Italy, 52%; UK, 48%; France, 47%. In Germany, only 17% of the 1-49% patients received cytotoxic only treatment.
Conclusions
The high PD-L1 testing rate in this study suggests that PD-L1 has become one of the most important decision-making tools available for physicians when deciding on an appropriate upfront therapy for their NSCLC patients. However, the decision-making can be complicated by different thresholds that physicians may adopt for low-expressor patients that are also compounded by differing regional prescribing realities. These differences could be a consequence of the evolution and changes in the approvals of PD-(L)1 inhibitors, especially in NSCLC. These observations highlight the importance of understanding that treating physicians may have varying benchmarks in mind when labelling PD-L1 status as positive or negative, which in turn can cause variation in their treatment approach. The availability of a clear definition and labelling of PD-L1 ranges would help align physicians’ prescribing, ensuring an optimized treatment plan for individual patients.