For the second time this month, the FDA has given an approval to Genentech’s PD-L1 inhibitor, Tecentriq.
On March 18, 2019, the FDA awarded the immunotherapy agent, Tecentriq (atezolizumab; Genentech), in combination with chemotherapy (carboplatin and etoposide), approval for the first-line treatment of adults with extensive-stage small-cell lung cancer (ES-SCLC).
As evidence of the rapidity with which the immunotherapy field is gaining ground in cancer treatment, this new approval comes only 10 days after the drug received an accelerated approval (in combination with nab-paclitaxel) for the treatment of triple-negative breast cancer. Not only is this the second approval for atezolizumab in close succession to the first, but it is the first novel treatment in 2 decades for ES-SCLC, an aggressive and deadly malignancy.
This latest approval was based on data from the phase 3 IMpower133 trial, which was the first study to show that initial treatment with the immunotherapy-based combination significantly improved overall survival (OS) in patients with ES-SCLC. The study, sponsored by the Swiss drug manufacturer Roche, enrolled 403 patients with ES-SCLC and randomized them equally among the combination treatment and chemotherapy alone.
Median OS was 12.3 months with atezolizumab plus chemotherapy compared with 10.3 months with chemotherapy alone, and median progression-free survival was 5.2 months with atezolizumab plus chemotherapy versus 4.3 months with chemotherapy alone. In addition, the combination treatment significantly lowered the risk of death or worsening disease when compared with chemotherapy alone. Approximately half the patients who received the combination of atezolizumab plus chemotherapy in the IMpower133 study were alive 1 year after treatment, compared with 38% in those who received chemotherapy only.
The American Cancer Society estimates that approximately 228,000 Americans will be diagnosed with lung cancer this year. Most will be diagnosed with the far more prevalent type, non–small-cell lung cancer. Approximately 13% will be diagnosed with small-cell lung cancer; 70% of these will have ES-SCLC. Patients at any stage of lung cancer have an estimated 5-year survival rate of approximately 18%. Even a small gain in OS is significant for patients with ES-SCLC, for whom there are few treatment options.
The most frequent adverse reactions reported in ≥20% of patients treated with atezolizumab were fatigue/asthenia, nausea, alopecia, constipation, and decreased appetite.
For patients with ES-SCLC, the recommended dose of atezolizumab is 1200 mg intravenously over 60 minutes every 3 weeks. When administered on the same day as chemotherapy, atezolizumab should be administered first. If the first infusion is tolerated, all subsequent infusions may be delivered over 30 minutes.
Lung cancer kills more people than any other cancer, and globally takes approximately 1.76 million lives each year.