FDA approves first immunotherapy for extensive SCLC

Atezolizumab (Tecentriq^®) plus chemotherapy (carboplatin and etoposide) was recently approved by the FDA for first-line treatment of extensive-stage small-cell lung cancer (ES-SCLC). It is the first immunotherapy approved for the initial treatment of ES-SCLC, as well as the first drug approved by the FDA for the treatment of this disease in more than 20 years.

According to study researchers, ES-SCLC was “especially difficult to treat” prior to the approval of the new regimen. “Until now, there have been limited treatment advances for this disease, and we are excited to bring a potential new standard of care to patients that has been shown to improve survival compared to chemotherapy,” said Sandra Horning, MD, chief medical officer and head of global product development, Roche.

Tecentriq is a monoclonal antibody that binds programmed death-ligand 1 (PD-L1) expressed on tumor cells and tumor-infiltrating immune cells. This drug could activate T-cells by inhibiting PD-L1, and may be useful as a core foundational treatment with cancer immunotherapies, targeted drugs, and other chemotherapies for a gamut of cancers.

Findings from IMpower133—a phase 3, multicenter, double-blinded, randomized, placebo-controlled study that assessed the efficacy and safety of Tecentriq in combination with chemotherapy vs chemotherapy alone in chemotherapy-naïve adult patients with ES-SCLC (n=403)—supported the FDA’s approval of Tecentriq.

In this study, patients were randomized in a 1:1 ratio to receive either Tecentriq plus chemotherapy or chemotherapy alone. During the treatment-induction phase, patients received treatment on 21-day cycles for 4 cycles, proceeded by maintenance with Tecentriq or placebo until progressive disease (PD) as assessed by the researchers. The researchers were able to continue treatment until they detected persistent radiographic PD or symptomatic deterioration.

According to the findings, patients taking the Tecentriq combination lived significantly longer vs chemotherapy alone (median overall survival [OS]: 12.3 vs 10.3 months; hazard ratio [HR]: 0.70; 95% CI: 0.54–0.91; P=0.0069). Patients on the combination also experienced decreased risk of disease worsening or death compared with those treated with chemotherapy alone (progression-free survival: 5.2 vs 4.3 months; HR: 0.77; 95% CI: 0.62–0.96; P=0.017).

Overall, the safety of the Tecentriq and chemotherapy combination was comparable to that of Tecentriq alone. Serious adverse reactions were noted in 37% of patients treated with Tecentriq plus chemotherapy vs 35% in those who received chemotherapy alone. Reactions observed in patients who received the combination therapy included fatigue/asthenia (39%), nausea (38%), hair loss (37%), and decreased appetite (27%), as well as constipation (26%) and vomiting (20%).

In the United, States, Tecentriq is currently used in combination with nab-paclitaxel as first-line treatment for PD-L1–positive metastatic triple-negative breast cancer. It is also used in combination with bevacizumab (Avastin^®) and chemotherapy in the first-line treatment of metastatic non-squamous non-small-cell lung cancer. Finally, it is approved to treat patients with metastatic urothelial carcinoma who are not eligible for cisplatin chemotherapy, or who have had disease progression during or following platinum-containing therapy.