Imfinzi Combination Treatment Successful in Late-Stage Lung Cancer

AstraZeneca announced that its cancer drug Imfinzi, also known as durvalumab, in combination with chemotherapy and tremelimumab improved progression-free survival (PFS) in late-stage lung cancer patients. According to reports, AstraZeneca shares went up by up to 2% following the company’s news.

The revelation comes on the heels of the phase III POSEIDON trial, which included previously untreated stage IV (metastatic) non-small cell lung cancer (NSCLC) patients.

“The POSEIDON trial provides evidence of the efficacy of Imfinzi in patients with Stage IV non-small cell lung cancer,” said José Baselga, executive vice president, Oncology R&D, stated in a press release. “Clinical benefit was observed in a trial population that included a high proportion of patients with squamous disease and multiple choices of chemotherapy regimens. Additionally, the potential to add tremelimumab to Imfinzi and chemotherapy may present an important treatment approach in this challenging setting, especially taking into consideration the [favorable] safety profile.”

PFS was one of the study’s primary endpoints. Patients in POSEIDON were treated with either a combination of durvalumab plus tremelimumab plus chemotherapy, durvalumab plus chemotherapy, or chemotherapy alone.

Patients aged ≥18 years with stage IV NSCLC were eligible for inclusion. Tumor PD-L1 status had to be established prior to study randomization. Other eligibility criteria included:

• Tumors without activating EGFR mutations and ALK fusions
• No history of chemotherapy or any systematic therapy for metastatic NSCLC
• World Health Organization/Eastern Cooperative Oncology Group performance status of 0 to 1
• No history of immunemediated therapy exposure (except therapeutic anticancer vaccines)

Patients were excluded based on the following criteria:

• Mixed small-cell lung cancer and NSCLC histology, sarcoamtoid variant
• Current or history of autoimmune or inflammatory disorders
• Unstable brain metastases or spinal cord compression
• Active infection (tuberculosis, hepatitis B or C, or HIV)

The primary outcomes were PFS up to three years and overall survival (OS) up to four years. According to a press release from the company, “The triple combination of Imfinzi plus tremelimumab and chemotherapy also demonstrated a statistically significant and clinically meaningful PFS improvement vs. chemotherapy alone as a key secondary endpoint. The safety and tolerability of Imfinzi was consistent with its known safety profile. The triple combination delivered a broadly similar safety profile to the Imfinzi and chemotherapy combination and did not result in increased discontinuation of therapy.”

The study remains ongoing in 153 centers spanning 28 countries, including the U.S., as well as others in Europe, South America, Asia, and South Africa.

Imfinizi is currently approved in the U.S. and 52 other countries in the treatment of unresectable stage III NSCLC, as well as previously treated advanced bladder cancer patients in 10 countries plus the U.S.

The announcement proved to be a hit on competitors, according to Reuters: “Shares of Merck & Co Inc, whose drug Keytruda is a dominant treatment for advanced lung cancer, dropped as much as 2% after the data.”