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Atezolizumab (Tecentriq) Receives FDA Approval for Extensive-Stage Small Cell Lung Cancer

This week, the United States Food and Drug Administration (FDA) approved the use of atezolizumab (Tecentriq) for the initial treatment of extensive-stage small cell lung cancer (ES-SCLC) in addition to chemotherapy. The approval was based on the results from the Phase III IMpower133 trial, which was a placebo-controlled, multicenter, randomized, double-blind study. The IMpower133 study involved 403 participants. About half of these participants were randomly assigned to receive atezolizumab plus chemotherapy, while the other half received chemotherapy alone (a placebo and chemotherapy). For their chemotherapy, both groups were given carboplatin and etoposide.1

Progress for extensive-stage small cell lung cancer

“Extensive-stage small cell lung cancer is a highly aggressive form of lung cancer, which, until now, has seen limited treatment advances over the last 20 years.” –Andrea Ferris, President and CEO of LUNGevity Foundation.2,3

The results from the IMpower133 study were presented at the 2018 World Conference on Lung Cancer. They were also published in the New England Journal of Medicine at the end of 2018.4 Atezolizumab is already on the market and is approved for the treatment of certain cases of non-small cell lung cancer, breast cancer, and bladder cancer. However, it’s approval for use as a first line treatment for ES-SCLC is historic, as there have not been any new treatment options approved specifically for this group of individuals in the past 20 years.

How atezolizumab works

Atezolizumab is manufactured by Genentech, and is part of a class of medications called monoclonal antibodies. Specifically, the drug inhibits a protein called PD-L1 (programmed death ligand 1). Some tumor cells have this protein and use it to block T-cells in the body. T-cells are natural cancer fighting cells that may experience an increase in activity when PD-L1 is blocked using atezolizumab. This may allow the body’s natural cancer-fighting responses to be upregulated or heightened.

During the trial, each cycle of treatment lasted 21 days, with both groups receiving carboplatin and etoposide on day one, in addition to either atezolizumab or placebo. On days two and three, each group received etoposide again. This was continued for a maximum of four cycles. For those receiving atezolizumab, maintenance dosages were continued after the four trial cycles until lung cancer progression was noted, or until there was no longer any clinical benefit from the medication.

Study results

One of the most notable results from the study was that individuals taking atezolizumab, in addition to chemotherapy, had an increased overall survival of two months when compared to their chemotherapy only counterparts (12.3 months for atezolizumab and chemotherapy vs. 10.3 months for chemotherapy alone). Additionally, progression-free survival was also increased for those taking atezolizumab and chemotherapy together, with the median progression-free survival being 5.2 months versus 4.3 months for chemotherapy without atezolizumab. Those taking atezolizumab with chemotherapy also had a 51.7% 1-year overall survival rate as compared to 38.2% in the control group taking chemotherapy alone.

These results suggest that atezolizumab with chemotherapy may help individuals with ES-SCLC (who have not been previously treated with other methods) live longer and have a reduced risk of disease progression or death when compared to chemotherapy alone. There were no significant safety concerns of atezolizumab when compared to current chemotherapy options that would be used in addition to atezolizumab. The most commonly reported side effects of the medication were fatigue or feelings of weakness, hair loss, decreased appetite, nausea, vomiting, and constipation.1-4

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

  1. FDA Approves Atezolizumab for Extensive-Stage Small Cell Lung Cancer. United States Food and Drug Administration. Published March 18, 2019. Accessed March 21, 2019.
  2. FDA Approves Genentech’s Tecentriq in Combination with Chemotherapy for the Initial Treatment of Adults with Extensive-Stage Small Cell Lung Cancer. Genentech. Published March 18, 2019. Accessed March 21, 2019.
  3. Mulcahy N. FDA Approves Atezolizumab for Small Cell Lung Cancer. Medscape. Published March 19, 2019. Accessed March 21, 2019.
  4. Horn L, Mansfield AS, et al. First-line atezolizumab plus chemotherapy in extensive-stage small-cell lung cancer. The New England Journal of Medicine. 6 Dec 2018; 379, 2220-9.