Study shows how oncology practices change after durvalumab approval for unresectable stage III NSCLC patients

A study presented today at the IASLC 2021 World Conference on Lung Cancer suggests how oncology practices in the United States changed after 2018, when durvalumab became available for patients with unresectable Stage III non-small cell lung cancer.

In 2018, PACIFIC trial results on durvalumab were published and the U.S. Food and Drug Administration approved durvalumab for unresectable Stage III non-small cell lung cancer.

Dr. Jason Liu, City of Hope National Medical Center, Duarte, Calif., sought to assess the use of maintenance durvalumab based on patient and physician characteristics among stage III NSCLC patients in the U.S.

Dr. Liu and his co-researchers analyzed open claims, using IQVIA pharmacy and medical claims data and adjudicated closed claims from (IQVIA PharMetrics Plus Health Plan Claims Database.

IQVIA obtains pharmacy data from multiple sources, including retail, mail order, and specialty pharmacies. IQVIA currently covers approximately 90% of dispensed prescriptions in the United States. IQVIA obtains information about prescription claims, including a subset of those paid out of pocket (cash) from collaborating commercial entities. This information includes personally identifiable information (such as first and last name, sex, date of birth, and address), drug, dose, day supply, date of prescription, and date of prescription filled.

Dr. Liu found that the rate of durvalumab utilization was overall low in both the open and closed claims data sources (22.2% and 35.6% respectively). In the open claims data source, durvalumab utilization was higher for patients ≥65 years and treated in the Midwest.

Chemoradiation followed by one year of durvalumab is recommended for patients with unresectable stage 3 non-small cell lung cancer.

Dr. Liu and his colleagues filtered claims data with the following criteria: (1) claims from patients with greater than or equal to one lung cancer diagnosis code Nov 2017 – Nov 2020, (2) retain any metastatic/advanced codes, (3) exclude patient with small cell lung cancer, and (4) limit to single primary tumor looking back to November 2015. Lastly, patients must have been 18 years or older, have no lung cancer surgery codes during the observation period, and received chemoradiation after the index date and prior to May 31, 2020.

The researcher's analysis of 8071 NSCLC patient records from the open claims source revealed that 1794 (22.2%) received maintenance durvalumab. Overall, distributions of baseline characteristics were similar between durvalumab and non-durvalumab patients. Durvalumab patients had a higher probability of older age (≥65 years) (odds ratio [OR] 1.2, 95% CI 1.1 – 1.3) and being treated in the Midwest (OR 1.2, 95% CI 1.0 – 1.4), respectively.

Patient records from non-durvalumab users (N=6277), revealed that chemotherapy (n=2785; 34.5%) and pembrolizumab (n=2047; 25.4%) were most used, with 2820 (34.9%) of patients receiving no maintenance therapy. 357 NSCLC patients were included from the closed claims source; 127 (35.6%) received maintenance durvalumab.

Dr. Liu found that the rate of maintenance durvalumab utilization was overall low in both the open and closed claims data source (<40%). He found that there was a higher rate of no maintenance therapy (30%) and pembrolizumab (25%) than expected.

We found that the use of durvalumab was lower but increasing the utilization of maintenance durvalumab (standard of care treatment) would likely result in improved oncologic outcomes. We recommend future studies to better understand these current practice patterns in the U.S."

Dr. Jason Liu, City of Hope National Medical Center, Duarte, California