Tecentriq Improves Survival in Trial of Subset of Patients With Advanced Lung Cancer
Jason M. Broderick
According to recent findings from a phase 3 trial, the immunotherapy Tecentriq (atezolizumab) improved survival compared with docetaxel in patients with advanced non–small cell lung cancer (NSCLC) following the failure of platinum-based chemotherapy.
The survival benefit was observed regardless of PD-L1 status, Genentech, the manufacturer of the PD-L1 inhibitor, reported in a statement. The company also noted that the safety profile for Tecentriq in the phase 3 OAK trial was consistent with previously reported adverse event (AE) data for the drug. Genentech plans to present the complete results from the study at a medical meeting this year.
“These results add to the growing body of evidence that supports the role of Tecentriq as a potential new treatment for specific types of advanced NSCLC,” Sandra Horning, M.D., chief medical officer and head of Global Product Development at Genentech, said in a statement. “This is very encouraging news for people living with this disease because lung cancer is the leading cause of cancer deaths around the world. We hope to bring this treatment option to patients as soon as possible.”
The international, open-label randomized OAK trial included 1,225 patients with locally advanced or metastatic NSCLC who progressed during or after platinum-containing chemotherapy. Patients were randomized in a one-to-one ratio to 75 mg/m2 of intravenous docetaxel or 1200 mg of intravenous Tecentriq every three weeks.
The coprimary endpoints of the trial were overall survival in the entire study population and in a PD-L1–defined subgroup. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR) and duration of response. The primary efficacy assessment included only the initial 850 randomized patients, and the secondary efficacy analysis will include data from all 1,225 randomized patients.
In April 2016, the FDA granted a priority review to Tecentriq for the treatment of patients with locally advanced or metastatic NSCLC who express PD-L1 and have progressed after a platinum-containing regimen. Under the expedited priority program, the FDA will issue a final decision on approval by October 19, 2016.
The priority review is based on data from multiple clinical trials, including the phase 2 BIRCH study, in which responses were observed in up to 27 percent of previously treated patients with NSCLC who had the highest levels of PD-L1 expression.
The open-label, single-arm phase 2 BIRCH study enrolled 667 patients with stage 3B/4 or recurrent NSCLC who did not have active central nervous system metastases. Patient characteristics were balanced across cohorts; the median age was 64 years, 35 percent were ECOG PS 0, 28 percent had squamous NSCLC, and 17 percent of patients were never-smokers. EGFR and KRAS mutations were identified in 327 and 177 patients overall, respectively.
All patients had disease that expressed PD-L1 as measured on tumor cells (TC) and tumor-infiltrating immune cells (IC) by Roche’s investigational IHC test. An IHC score of TC2/3 or IC2/3 was the inclusion criteria established by the trial design.
Tecentriq was administered at 1200 mg IV at 3-week intervals as frontline therapy to 142 patients (cohort 1), as second-line to 271 patients who had progressed after 1 prior platinum therapy (cohort 2) and to 254 patients who had undergone 2 or more prior chemotherapy regimens (cohort 3).
Overall response rate was the primary endpoint, with secondary outcome measures including duration of response, PFS, OS and safety.
Among the 659 evaluable patients, the median treatment duration across all cohorts was 4.2 months (ranging from 0 to 15). The ORR in cohort 1 was 19 percent and 17 percent in cohorts 2 and 3 in patients with TC2/3 or IC2/3 expression. Stronger response was seen in patients with higher expression; ORR rates were 26 percent, 24 percent and 27 percent in cohorts 1, 2 and 3 in patients with PD-L1 expression of level TC3 or IC3.
At a median follow-up of 8.8, 7.9 and 8.6 months, median overall survival was 14 months, not reached (NR) and NR, across cohorts 1, 2 and 3, respectively. Six-month overall survival was achieved by 82 percent, 76 percent and 71 percent of patients TC2/3 or IC2/3 expression levels in cohorts 1, 2, and 3, respectively, and by 79 percent, 80 percent and 75 percent of patients in cohorts 1, 2 and 3 having TC3 or IC3 expression levels.
Six-month PFS rates were 46 percent, 29 percent and 31 percent at the PD-L1 expression level of TC2/3 and IC2/3 and 48 percent, 34 percent and 39 percent in patients with TC3 or IC3 expression levels in cohorts 1, 2, and 3, respectively.
The safety data for Tecentriq in BIRCH were similar to those observed in other trials. The most commonly reported AEs were fatigue (18 percent) and nausea (10 percent). Grade 3/4 treatment-related AEs occurred in 11 percent of patients overall and 6 percent of patients discontinued therapy due to a treatment-related AE. All-cause grade 3/4 AEs occurred in 38 percent of patients.
Results with Tecentriq in NSCLC from the phase II POPLAR trial were also previously reported.The study randomized 287 patients with previously treated NSCLC to receive Tecentriq (n = 144) or docetaxel (n = 143). Intravenous Tecentriq was administered at 1200 mg every three weeks and docetaxel was used at 75 mg/m2 every three weeks.
In the overall study population, the results did not significantly favor Tecentriq; however, as in the BIRCH trial, PD-L1 expression was strongly associated with Tecentriq's efficacy in POPLAR.
In high PD-L1 expressing tumors (TC/IC 3), the median PFS was 7.8 versus 3.9 months, for Tecentriq and docetaxel, respectively. The ORR was 38 percent and 13 percent, respectively.
In patients without PD-L1 expression (TC/IC 0), a difference was not observed between the two groups. Across all expression levels, the ORR was 15 percent with both treatments. In this group, the median OS was 12.6 and 9.7 months and the median PFS was 2.7 and 3.0 months, for Tecentriq and docetaxel, respectively.
In the study, fewer grade 3 to 5 adverse events were experienced by patients treated with Tecentriq compared with docetaxel (44 percent vs 56 percent). There was a higher incidence of respiratory side effects with immunotherapy versus chemotherapy. Tecentriq was associated with aspartate and alanine aminotransferase increases (4 percent each), colitis (1 percent), hepatitis (1 percent) and pneumonitis (2 percent).
Based on early-stage studies, Tecentriq received a breakthrough therapy designation from the FDA in February 2015 as a potential treatment for patients with PD-L1–positive NSCLC following progression on prior therapy, including chemotherapy and targeted therapies. According to Genentech, there are eight ongoing phase 3 lung cancer studies examining single-agent Tecentriq or in combination regimens.
Tecentriq is currently approved by the FDA as a treatment for patients with locally advanced or metastatic urothelial carcinoma whose disease progressed during or after platinum-based chemotherapy, or within 12 months of receiving platinum-containing chemotherapy, either before or after surgery.