766P Levels of Serum EGF Concentration As Biomarker of Response of CIMAvax-EFG Vaccine: Survival Evaluation of Advanced NSCLC Patients Treated in Primary Health Care Scenario

Previous studies have shown that baseline concentrations of EGF in serum could be considered a biomarker of the efficacy of the therapeutic vaccine CIMAVax-EGF. The objective of this study is to evaluate the serum EGF concentration as biomarker of response of CIMAvax-EGF vaccine for the treatment of advanced NSCLC patients in primary health care scenario. A phase IV clinical trial (Public Registry RPCEC00000205; Dec 14, 2015) was conducted in 121 policlinics and 24 hospitals in Cuba during 5 years. The database cutoff was performed in December 2021. A total of 741 advanced NSCLC patients were included without other treatment options due to progressive disease or comorbidities. CIMAvax-EGF was administered by intramuscular injection in four sites of administration (4 subdoses of 0.25 ml), every 2 weeks the first 4 doses and after this induction phase, monthly reinmunizations were given. Serum EGF concentrations was determined at baseline, before vaccine administration. The median overall survival time (mOS) for all vaccinated patients with EGF concentrations <870 pg/mL (n = 438) was 7.3 months and with EGF concentrations ≥870 pg/mL ( n = 211) was 6.2 months (p = 0.07). For patients who received at least 4 doses of CIMAvax-EGF (per protocol population, N=489), the mOS for EGF<870 pg/mL (n=334) was 10.2 months and with EGF ≥870 pg/mL (n = 155) was 8.9 months (p = 0.13). For patients who respond to the first line of oncospecific treatment, the mOS for EGF < 870 pg/mL (n = 216) was 12.6 months and for those with EGF ≥ 870 pg/mL was 11.8 months (p = 0.82). The subgroup of patients with ECOG 0 or 1, achieved survivals of 15.0 months for EGF<870pg/mL (n=65) and 14.9 for EGF ≥870 pg/mL (n=17), p=0.44. The results showed that patients with high baseline serum EGF concentrations and poor prognosis, achieve comparable survival to those with low baseline serum EGF concentrationsa and better prognosis of the disease in terms of survival. Patients who received at least 4 doses of treatment, achieved response to first-line onco-specific treatment, and had ECOG between 1 and 2, received the greatest benefit.