Precision Medicine and Diagnostics
Jason K. Sicklick, MD, FACS
Professory of Surgery
University of California, San Diego, California, United States
Background: Malignancies are molecularly complex and become more resistant with each line of therapy. We hypothesized that offering matched, individualized combination therapies to patients with treatment-naïve, advanced cancers would be feasible and efficacious. Patients with newly diagnosed unresectable/metastatic, poor-prognosis cancers were enrolled in a cross-institutional prospective study.
Methods: A total of 145 patients were included in the study. Genomic profiling (tissue and/or circulating tumor DNA) was performed in all patients, and PD-L1 immunohistochemistry, tumor mutational burden and microsatellite status assessment were performed in a subset of patients. We evaluated safety and outcomes: disease-control rate (stable disease for ≥6 months or partial or complete response), progression-free survival (PFS), and overall survival. (OS).
Results: Seventy-six of 145 patients (52%) were treated, most commonly for non-colorectal gastrointestinal cancers, carcinomas of unknown primary, and hepatobiliary malignancies (53% women; median age, 63 years). The median number of deleterious genomic alterations per patient was 5 (range, 0–15). Fifty-four treated patients (71%) received ≥1 molecularly matched therapy, demonstrating the feasibility of administering molecularly matched therapy. The Matching Score, which reflects the percentage of targeted alterations, correlated linearly with progression-free survival (R2=0.92; P=0.01), and high (≥60%) Matching Score was an independent predictor of improved disease control rate [OR 3.31 (95%CI 1.01–10.83), P=0.048], PFS [HR 0.55 (0.28–1.07), P=0.08] and OS [HR 0.42 (0.21–0.85), P=0.02]. Serious adverse event rates were similar in the unmatched and matched groups.
Conclusions: Personalized combination therapies targeting a majority of a patient’s molecular alterations have antitumor activity as first-line treatment. These findings underscore the feasibility and importance of using tailored N-of-1 combination therapies early in the course of lethal malignancies.