John Heymach, MD, PhD: Based on the initial promising result that was seen in the single center MD Anderson study for exon 20 EGFR and HER2, an international study has now been opened. That study is sponsored by Spectrum. It’s got slightly different eligibility criteria. In that study, everybody must have received prior systemic therapy. So, there are no first-line patients in that study. But again, the study looks at both EGFR and HER2 exon 20. The study is currently enrolling. It’s open in a number of sites across the country and is enrolling well thus far. The study looks at the same regimen of poziotinib, 16 mg daily, as the prior study. The goal is to see if the same level of activity that we saw in our single-center study can be seen across the country for both patients with EGFR and HER2.
Poziotinib is also being studied for HER2-mutant or HER2-amplified breast cancer. In breast cancer, HER2 amplifications are much more common than HER2 mutations. But both of them do occur. For HER2 amplifications, there are very active drugs like trastuzumab and T-DM1. HER2 mutations are much more of an unmet need. So, that’s one application for poziotinib that’s currently undergoing investigation. There are also plans to open what’s called a basket study to look across all of the different diseases outside of lung cancer that have EGFR or HER2 exon 20 mutations. We’re very excited to see that get going. Just because lung cancer patients with EGFR or HER2 exon 20 may respond to the drug doesn’t mean that somebody with glioblastoma or colorectal cancer or adenoid cystic cancer, who’s got the same mutation, will have the same response.
We do have cases where a drug may work extremely well in one disease but not another, when the same exact mutation is present—like BRAF in melanoma versus BRAF in colorectal cancer. So, it remains to be seen whether HER2 and EGFR exon 20 mutations in those other diseases will be as responsive as in lung cancer. But we’re certainly hopeful. We expect the basket study to start up in the upcoming year, and that’s sponsored by Spectrum.
Transcript Edited for Clarity