Real-World Treatment Patterns in Patients With HER2-Amplified Metastatic Colorectal Cancer: A Clinical-Genomic...

Area of Science:

• Oncology
• Gastroenterology
• Genomics

Background:

• HER2 amplification (HER2+) affects about 3% of metastatic colorectal cancer (mCRC) patients.
• NCCN Guidelines now include HER2-directed therapies, but FDA-approved options were historically limited.
• This study investigates real-world treatment shifts in HER2+ mCRC patients before and after 2018.

Purpose of the Study:

• To examine real-world treatment patterns in patients with HER2-positive metastatic colorectal cancer (mCRC).
• To evaluate treatment evolution in HER2+ mCRC before and after increased awareness of HER2-directed therapies.
• To assess real-world time to next treatment (rwTTNT) based on therapy type.

Main Methods:

• Retrospective observational study using the GuardantINFORM database (claims data with Guardant360 genomic testing).
• Included 142 patients (≥18 years) diagnosed with mCRC (Jan 2014–Sep 2020) and confirmed ERBB2 amplification.
• Analyzed treatment patterns and calculated rwTTNT.

Main Results:

• Treatment patterns were heterogeneous and changed post-2018.
• Before 2018, anti-VEGF therapy (with or without chemotherapy) was most common (31.6%).
• After 2018, HER2-directed therapies became most common (36.5%).
• Median rwTTNT was 8.4 months; numerically longer with HER2-directed therapy (11.0 months) vs. non-HER2-directed (7.2 months).

Conclusions:

• Despite NCCN guideline inclusion, many HER2+ mCRC patients do not receive HER2-directed therapy.
• Heterogeneous treatment patterns indicate an undefined standard of care and underutilization of targeted therapy.
• Increased awareness and new therapies are needed to improve targeted treatment strategies for HER2+ mCRC.