Survival Success with Durvalumab Immunotherapy in Stage 3 Lung Cancer Treatment

When the tumor cannot be surgically removed, stage 3 non-small cell lung cancerhas been a condition we have struggled to treat for years while seeking the ideal treatment. For patients with inoperable stage 3 lung cancer, standard treatmentis chemotherapy together with radiotherapy (chemoradiotherapy). Despite using chemotherapy and radiotherapy together, our two most important treatments, lung cancer usually recurs (for lung cancers diagnosed at stage 3, the 5-year survival rate is around %15). In this situation, the first and only treatment reducing recurrence risk after chemoradiotherapy was the immunotherapy durvalumab (brand name Imfinzi), approved by the FDA on 16 February 2018. All previous immunotherapy approvals in lung cancer had been for advanced (stage 4 = metastatic) disease. Although durvalumab was approved for use after chemoradiotherapy in stage 3 lung cancer, its contribution to overall survival had not been clearly established until now. A study presented at the 19th World Conference on Lung Cancer and simultaneously published in NEJMshowed durvalumab's long-term survival results.

PACIFIC was a phase 3 clinical trial involving 26 countries and 235 cancer centers. It enrolled 713 stage 3 non-small cell lung cancer patients in a 2-to-1 ratio. All received chemoradiotherapy, after which 2/3 received durvalumab at 10 mg/kg every two weeks for 12 months; the other group received placebo (a medicine without an active ingredient).

Note: The comparison was against placebo because there was no other standard treatment after chemoradiotherapy for this stage of lung cancer.

As of 22 March 2018, according to results at a median follow-up of 25 months;

• The 2-year overall survival rate was %66 in durvalumab recipients versus %55 in placebo recipients.

• Durvalumab immunotherapy reduced the risk of death by %32 compared with placebo.
• The time disease was kept under control with treatment (progression-free survival) was the same as previously reported: 17.2 versus 5.6 months.
• Median time to death or distant metastasis was 28.3 months in durvalumab recipients versus 16.2 months in placebo recipients.
• In durvalumab recipients, %30.5, and in placebo recipients, %26.1, experienced serious (grade 3 and 4) side effects.
• Rates of treatment discontinuation for any reason were %15.4 in durvalumab recipients and %9.8 in placebo recipients.

In conclusion, this study clarified the efficacy of the immunotherapy durvalumab, the first treatment approved to reduce the risk of progression in inoperable stage 3 non-small cell lung cancer.

• What Are the Side Effects of Immunotherapy Drugs, and How Are They Treated?