Next steps
Analyses of other cohorts in the ZENITH20 trial will be reported at upcoming conferences as the data mature, Dr. Le noted. Cohorts 2-4 include patients with previously treated HER2 exon 20 insertions and treatment-naive patients with EGFR and HER2 exon 20 insertions, respectively.
Additionally, three new cohorts are being added, including one with patients who have EGFR or HER2 exon 20 insertions, one with EGFR patients who failed prior osimertinib treatment, and one with patients who have atypical EGFR or HER2 mutations.
Rather than the once-daily dosing used in cohorts 1-4, twice-daily dosing will be evaluated in these cohorts, Dr. Le said, explaining that the half-life of poziotinib is about 8 hours.
“Recent pharmacological modeling showed that a [twice-daily] regimen would reduce the maximal serum concentration and increase trough, which could lead to optimized drug coverage,” she said. “This may potentially reduce toxicity and improve patient compliance and efficacy.”
ZENITH20 is sponsored by Spectrum Pharmaceuticals Inc. Dr. Le disclosed relationships with Spectrum as well as Eli Lilly, AstraZeneca, EMD Serono, and Boehringer Ingelheim. Dr. Owonikoko disclosed relationships with many companies, not including Spectrum.
SOURCE: Le X et al. AACR 2020, Abstract CT081.