Imfizi (durvalumab) has become the first approved immunotherapy in the United States for patients with advanced non-small cell lung cancer that has stabilized.
The U.S. Food and Drug Admnistration authorization applies to NSCLC patients who are unable to have surgery and whose disease has not progressed after platinum-based chemotherapy and radiation therapy. AstraZeneca and MedImmune developed the therapy.
Imfinzi is a human monoclonal antibody that binds to the programmed cell death 1 receptor, unleashing immune T-cells to attack cancer cells.
The FDA approval was based on the results of the Phase 3 PACIFIC clinical trial (NCT02125461). Researchers randomized patients to receive either Imfinzi or a placebo every two weeks for up to 12 months.
It took three times as long for Imfinzi-treated patients’ disease to progress — 16.8 months versus 5.6 for the placebo group. This equated to Imfinzi patients’ risk of disease progression or death being half that of the control group’s.
The finding was independent of whether tumor cells contained the programmed death-ligand 1 protein. Tumors containing PD-L1 usually respond better to immunotherapies that target the protein.
As for safety, researchers said the frequency and severity of treatment-related adverse events in the trial were comparable between the Imfinzi and placebo patients.
Imfinzi’s developers are continuing the PACIFIC trial to see if the therapy can extend patients’ overall survival.
Researchers published the trial results in the New England Journal of Medicine. The article is titled “Durvalumab after Chemoradiotherapy in Stage III Non–Small-Cell Lung Cancer.”
“The approval of Imfinzi in this earlier stage of non-small cell lung cancer is a truly meaningful milestone for patients who, until now, had no FDA-approved treatment options following chemoradiation therapy,” Dave Fredrickson, executive vice president and head of the Oncology Business Unit at AstraZeneca, said in a press release. “Globally, approximately 30 percent of patients with NSCLC” have a Stage III disease. “We are excited to launch the first immunotherapy into this setting.”
Stage III is the second most advanced form of the disease, with only Stage IV being higher.
“Until now, treatment guidelines have recommended that patients with unresectable Stage III lung cancer” — cancer that can’t be surgically removed — “undergo a period of active surveillance following chemoradiation therapy until disease progression,” said Dr. Scott J. Antonia, chair of the Thoracic Oncology Department at the H. Lee Moffitt Cancer Center and Research Institute in Tampa.
“Given that up to 89 percent of patients will progress to metastatic disease [one that spreads to other parts of the body], it is important that there is now a new option that can give patients more time without disease progression,” said Antonia, one of the trial investigators. “The PACIFIC trial data supporting today’s approval of Imfinzi will change how we treat these patients.”
The National Comprehensive Cancer Network’s Clinical Practice Guidelines in Oncology added Imfinzi as an NSCLC treatment option in September 2017. It applies to patients with stage 3 NSCLC who are unable to have surgery and whose disease has failed to progress after two or more cycles of radiation and chemo.
Several clinical trials are investigating Imfinzi as a first-line treatment for advanced NSCLC patients whose disease has spread. They are looking at Imfinzi as a stand-alone therapy and in combination with other immunotherapies.
The trials include the MYSTIC (NCT02453282), NEPTUNE (NCT02542293), PEARL (NCT03003962), and POSEIDON (NCT03164616) Phase 3 studies. The Phase 3 ADJUVANT trial (NCT02273375) in Canada is investigating Imfinzi as an add-on therapy for NSCLC patients who have had surgery.