The patients were randomized to receive investigator’s choice of platinum-based chemotherapy or treatment tailored according to messenger RNA (mRNA) expression of two molecular markers – excision repair cross complementation 1 (ERCC1) and thymidylate synthase (TS).
There was no significant difference in overall survival or recurrence-free survival between the treatment approaches. However, toxicity was less common among patients who received customized treatment.
These results, from the phase 3 ITACA trial, were presented at the 2020 World Conference on Lung Cancer (Abstract 1820), which was rescheduled to January 2021.
“There is a clear need to define patients most likely to derive survival benefit from adjuvant therapy and spare patients who do not need adjuvant chemotherapy due to the toxicity of such therapy,” said presenter Silvia Novello, MD, PhD, of the University of Turin in Italy. “mRNA expression of different genes has been correlated with the sensitivity or resistance to specific anticancer agents.”
With this in mind, Dr. Novello and colleagues conducted the ITACA trial. The researchers’ primary goal was to determine whether an adjuvant pharmacogenomic-driven approach was able to improve overall survival in completely resected NSCLC.
Patients and treatment
The researchers randomized 773 NSCLC patients within 5-8 weeks after radical surgery. Genomic analyses were performed soon after surgery, and patients were randomly assigned to investigator’s choice of platinum-based chemotherapy or to tailored treatments defined by mRNA levels of ERCC1 and TS.
Patients with high ERCC1 mRNA expression who were randomized to tailored treatment received single-agent docetaxel if their TS level was high or pemetrexed monotherapy if their TS level was low.
Patients with low ERCC1 mRNA expression who were randomized to tailored treatment received cisplatin-gemcitabine if their TS level was high or cisplatin-pemetrexed if their TS was low.
The most frequent doublets used in control patients were cisplatin-gemcitabine and cisplatin-vinorelbine.
The demographic characteristics of the 384 patients randomized to tailored therapy and the 389 control subjects were well-balanced, Dr. Novello said. Two-thirds of patients had stage II disease, 11% were never smokers, and the vast majority had a lobectomy as the resection method.
Results
At a median follow-up of 28.2 months, the median overall survival was 96.4 months in the tailored therapy arm and 83.5 months in the control arm. The median recurrence-free survival was 64.4 months and 41.5 months, respectively.
“Adjuvant chemotherapy customization based on the primary tumor tissue mRNA expression of ERCC1 and TS did not significantly improve overall survival or recurrence-free survival,” Dr. Novello said. “There was a non–statistically significant trend for overall survival favoring the customized arm.”
Dr. Novello noted that, when the final analysis was performed, the study was underpowered, as only 46% of expected events were collected. Assuming the same hazard ratio point estimate and that the expected 336 events were collected, the hazard ratio estimate would be 0.76 (P = .012).
Grade 3/4 toxicities occurred in 32.6% of patients in the tailored therapy arm and 45.9% of those in the control arm (P < .001).
“It is important to underline that the treatment customization significantly improved the toxicity profile without compromising the efficacy,” Dr. Novello said.
She added that “more comprehensive and high-throughput diagnostic techniques will be needed in order to tailor adjuvant chemotherapy, with or without immunotherapy, in completely resected NSCLC.”
“The ITACA study is the largest adjuvant study tailored to ERCC1/TS status, and the results have been long-awaited,” said Tetsuya Mitsudomi, MD, a professor at Kindai University in Japan and president of the International Association for the Study of Lung Cancer.
“This trial should be praised for the mandated genomic analysis that was accomplished within a reasonably short time frame before random assignment. In addition, this trial confirmed that there is no biomarker strong enough to predict the efficacy of cytotoxic chemotherapy. However, the concept of customizing adjuvant therapy according to the genomic status of patients’ tumors is valid, leading to the recent demonstration in the ADAURA study of the superiority of osimertinib in delaying the postoperative recurrence of disease in patients with EGFR-mutated NSCLC.”
The ITACA study was funded by University of Turin and Eli Lilly. Dr. Novello disclosed relationships with Eli Lilly, Amgen, AstraZeneca, Bohringer Ingelheim, Beigene, Pfizer, Roche, Merck, Bristol-Myers Squibb, Takeda, and Sanofi. Dr. Mitsudomi disclosed relationships with Eli Lilly, AstraZeneca, Boehringer-Ingelheim, Chugai, Pfizer, Merck, Ono Pharmaceutical, Bristol-Myers Squibb, Novartis, ThermoFisher, Guardant, Eisai, Amgen, and Johnson & Johnson.