Health Canada Approves Durvalumab Monotherapy for Limited-Stage Small Cell Lung Cancer

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Health Canada has granted a notice of compliance for durvalumab (Imfinzi) as monotherapy for the treatment of patients with limited-stage small cell lung cancer (LS-SCLC) whose disease has not progressed following platinum-based chemoradiation therapy.1

The approval was based on findings from the phase 3 ADRIATIC trial, which were first presented at the 2024 ASCO Annual Meeting and subsequently published in the New England Journal of Medicine.2,3 In the trial durvalumab led to a median overall survival (OS) of 55.9 months (95% CI, 37.3-not evaluable) vs 33.4 months (95% CI, 25.5-39.9) with placebo (HR, 0.73; 95% CI, 0.57-0.93; P = .0104). The median progression-free survival (PFS) was also improved at 16.6 months (95% CI, 10.2-28.2) with durvalumab vs 9.2 months (95% CI, 7.4-12.9) with placebo (HR, 0.76; 95% CI, 0.61-0.95; P =.0161).

“With this approval, we can now offer immunotherapy treatment to people living with LS-SCLC, which is almost always fatal, even in patients with limited disease burden,” Shantanu Banerji, BSc (Med), MD, FRCPC, director of Precision Oncology and Advanced Therapeutics, CancerCare Manitoba, stated in a news release.1 “The ADRIATIC trial demonstrated that [durvalumab] can offer improved survival and greater odds of cure for these patients, the first major advance for this disease in close to 40 years.”

This approval joins that of the FDA and European Commission approvals, which were granted in December 2024 and March 2025, respectively, for the same indication.4,5

The double-blinded, international trial enrolled patients with stage I to III LS-SCLC, including those with stage I/II inoperable disease.2 Patients were required to have a World Health Organization performance status of 0 or 1, and they could not have progressed after concurrent chemoradiation. Prophylactic cranial irradiation was allowed before randomization.

Patients (n = 730) were randomly assigned to one of three arms: single-agent durvalumab at 1500 mg every 4 weeks; placebo every 4 weeks; or durvalumab at 1500 mg every 4 weeks plus tremelimumab (Imjudo) at 75 mg every 4 weeks for 4 doses, followed by durvalumab monotherapy given at 1500 mg every 4 weeks (n = 200). Treatment was administered until disease progression, unacceptable toxicity, or up to 24 months.

The dual primary end points were OS and PFS by blinded independent central review (BICR) and RECIST 1.1 criteria with durvalumab alone vs placebo. Key secondary end points include OS and PFS by BICR and RECIST 1.1 criteria with durvalumab plus tremelimumab vs placebo.

Additional efficacy data indicated that the 3-year OS rates were 56.5% with durvalumab and 47.6% with placebo. The 2-year PFS rates were 46.2% and 34.2% with durvalumab and placebo, respectively.

Regarding safety, any-grade adverse effects (AEs) occurred in 94.3% of evaluable patients who received durvalumab (n = 262) vs 88.3% of those given placebo (n = 265); these effects were grade 3/4 in severity for 24.4% and 24.2% of patients, respectively. Serious AEs occurred in 29.8% of those given durvalumab vs 24.2% of those given placebo.

The most common AEs that occurred in at least 10% of patients in the durvalumab arm were pneumonitis or radiation pneumonitis, decreased appetite, hypothyroidism, cough, pruritus, nausea, dizziness, fatigue, diarrhea, pneumonia, rash, constipation and hyperthyroidism.1

AEs led to treatment discontinuation for 16.4% and 10.6% of patients, respectively; they resulted in death for 2.7% and 1.9% of patients, respectively.2

“This approval is great news for people living with this form of lung cancer and their families,” Shem Singh, executive director, Lung Cancer Canada, stated in the news release.1 “The opportunity to live longer and with better outcomes is a significant advancement and a critical new treatment option for this aggressive disease, which has traditionally been known for its high rates of recurrence.”

References

1. Health Canada approves Imfinzi (durvalumab) as the first and only immunotherapy regimen for adult patients with limited-stage small cell lung cancer (LS-SCLC). News release. BioSpace. April 10, 2025. Accessed April 11, 2025. https://www.biospace.com/press-releases/health-canada-approves-imfinzi-durvalumab-as-the-first-and-only-immunotherapy-regimen-for-adult-patients-with-limited-stage-small-cell-lung-cancer-ls-sclc
2. Spigel DR, Cheng Y, Chul Cho B, et al. ADRIATIC: durvalumab (D) as consolidation treatment (tx) for patients (pts) with limited-stage small-cell lung cancer (LS-SCLC). J Clin Oncol. 2024;42(suppl 17):LBA5. doi:10.1200/JCO.2024.42.17_suppl.LBA5
3. Cheng Y, Spigel DR, Chul Cho B, et al. Durvalumab after chemoradiotherapy in limited-stage small-cell lung cancer. N Engl J Med. 2024;391(14):1313-1327. doi:10.1056/NEJMoa2404873
4. Imfinzi approved in the US as first and only immunotherapy regimen for patients with limited-stage small cell lung cancer. News release. AstraZeneca. December 5, 2024. Accessed April 11, 2025. https://www.astrazeneca.com/media-centre/press-releases/2024/imfinzi-approved-in-us-for-limited-stage-sclc.html
5. Imfinzi approved in the EU as first and only immunotherapy for limited-stage small cell lung cancer. News release. March 17, 2025. Accessed April 11, 2025. https://www.astrazeneca.com/media-centre/press-releases/2025/imfinzi-approved-in-eu-for-limited-stage-sclc.html