Spectrum Pharmaceuticals, Inc. (NasdaqGS: SPPI), a biotechnology company with fully integrated commercial and drug development operations with a primary focus in hematology and oncology, today announced preliminary poziotinib data from the University of Texas, MD Anderson Cancer Center Phase 2 non-small cell lung cancer (NSCLC) study which were released today during an oral presentation at the IASLC 19th World Conference on Lung Cancer hosted by the International Association for the Study of Lung Cancer. The MD Anderson study is the single largest data set of patients with an exon 20 mutation in EGFR or HER2.
“There are currently no approved targeted therapies for this hard-to-treat population,” said John Heymach, M.D., Ph.D., Chairman and Professor, Department of Thoracic/Head and Neck Medical Oncology, University of Texas, MD Anderson Cancer Center. “For this reason, it is especially exciting to observe that poziotinib is highly active, with a manageable safety profile, in these heavily pre-treated patients. The study is ongoing with nineteen EGFR patients remaining on treatment, six of which have been on drug for longer than a year. Poziotinib may offer a much needed option to NSCLC patients with exon 20 mutations in EGFR or HER2.”
In the interim analysis presented at the WCLC, the following observations were made:
This phase II study demonstrates high anti-tumor activity for poziotinib in metastatic, heavily pretreated EGFR exon 20 mutant NSCLC, a group for which no targeted agents have proven effective to date (other than patients bearing T790M or S768I mutations) with best response of PR in 55% of evaluable patients (43% confirmed ORR to date; 19 patients remain on treatment).
Median PFS 5.5m; durable responses observed with 6 treated for >1year thus far.
Compares favorably to historical ORR rates of <8% approved TKIs and <19% for standard of care 2L agents (docetaxel, PD-1/PD-L1 inhibitors).
Significant activity also observed in HER2 exon 20-mutant NSCLC with initial responses observed in 50% (6/12) evaluable patients and median PFS 5.1m.
EGFR-related toxicities (including rash, diarrhea, & paronychia) were manageable and required dose reductions in 60%. Discontinuation due to poor tolerance was rare (3%).
Encouraging activity has prompted a confirmatory, international, multicenter study in EGFR and HER2 exon 20 mutant NSCLC patients which is currently enrolling (NCT03318939), including a first-line cohort, and development of a separate pan-tumor basket study.
The poziotinib NSCLC clinical program for patients with EGFR or HER2 exon 20 insertion mutations currently consists of a Phase 2 investigator-initiated study at The University of Texas, MD Anderson Cancer Center and a Phase 2 pivotal, Spectrum-sponsored, multi-center, global study (ZENITH20) with active sites in the United States and future centers planned in Canada and Europe. The overall poziotinib clinical development program is focused on four pillars, including previously treated NSCLC, first-line treatment of NSCLC, combination therapy and treatment of other solid tumors.
Poziotinib is a novel, orally available Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR TKI) that inhibits the tyrosine kinase activity of EGFR as well as HER2 and HER4. Importantly this, in turn, leads to the inhibition of the proliferation of tumor cells that overexpress these receptors. Mutations or overexpression/amplification of EGFR family receptors have been associated with a number of different cancers, including non-small cell lung cancer (NSCLC), breast cancer, and gastric cancer. Spectrum received an exclusive license from Hanmi Pharmaceuticals to develop, manufacture, and commercialize worldwide, excluding Korea and China. Poziotinib is currently being investigated by Spectrum and Hanmi in several mid-stage trials in multiple solid tumor indications.