ECC: Lung Cancer Vaccine Trial Fails to Meet Endpoint, but Shows Benefit in Some Patients

A phase III study of the therapeutic lung cancer vaccine belagenpumatucel-L (Lucanix) failed to meet its predefined endpoint, but the vaccine showed a “considerable” increase in overall survival in patients with non–small-cell lung cancer (NSCLC). The results support further study and development, according to researchers.

Giuseppe Giaccone, MD, PhD, of the National Cancer Institute in Bethesda, Maryland, presented results of the STOP trial at the European Cancer Congress (ECC) in Amsterdam last week. Belagenpumatucel-L is comprised of four transforming growth factor (TFG)-ß2 antisense NSCLC cell lines; previous work has shown that immunosuppression and elevated TGF-ß2 correlate with poorer prognosis in NSCLC. The vaccine may stimulate immune response as well as suppress tumor production of TGF-ß2.

The study included 532 patients with NSCLC in stages IIIA (42 patients) or IIIB/IV (490 patients); all patients did not progress after first-line chemotherapy, and were randomized to either the belagenpumatucel-L (270 patients) or control group (262 patients). Randomization took place between 4 and 17.4 weeks following the end of chemotherapy.

The median overall survival, which was the primary endpoint of the study, was 20.3 months with belagenpumatucel-L and 17.8 months with placebo, for a hazard ratio of 0.94 (P = .594); thus, the trial did not meet its primary endpoint. “A predefined Cox regression demonstrated that the time elapsed between randomization and the end of frontline chemotherapy had a significant impact on survival outcomes (P = .002),” according to researchers.

Cancer stage, pretreatment radiation, and histology also were significant prognostic factors. Those patients with confirmed pretreatment radiation had a median overall survival of 40.1 months with the vaccine compared with 10.3 months for placebo patients (HR 0.45; P = .014). Patients with stage IIIB/IV non-adenocarcinoma who were randomized within 12 weeks of the completion of chemotherapy (99 patients) had a median overall survival of 19.9 months on belagenpumatucel-L, while those who received placebo had an overall survival of 12.3 months (HR 0.55; P = .036).

The study found that belagenpumatucel-L was well tolerated, with only one serious adverse event, a grade 2 allergic rash, associated with the vaccine’s administration.

“These data, along with a strong safety profile, support the continued development of belagenpumatucel-L for this indication,” the investigators concluded, in spite of the study’s failure to meet its endpoint.

Study Details

The median age of patients in the study was 61 years. Of the total cohort, 57% of patients had adenocarcinoma, 27% had squamous histology, and 6% had large cell carcinoma. The two study arms were well matched with regard to all baseline characteristics.