Benzinga | Dec 6, 2021 07:04AM EST

Spectrum Pharmaceuticals Submits New Drug Application For Poziotinib

Spectrum Pharmaceuticals (NASDAQ:SPPI), a biopharmaceutical company focused on novel and targeted oncology therapies, today announced that it has submitted its New Drug Application (NDA) for poziotinib to the U.S. Food and Drug Administration (FDA) for use in patients with previously treated locally advanced or metastatic non-small cell lung cancer (NSCLC) with HER2 exon 20 insertion mutations. The NDA submission is based on the positive results of Cohort 2 from the ZENITH20 clinical trial, which assessed the safety and efficacy of poziotinib. The product has received Fast Track designation and there is currently no treatment specifically approved by the FDA for this indication.

"The NDA submission for poziotinib marks an important step in achieving a first treatment for patients with HER2 exon 20 insertion mutations in lung cancer," said Joe Turgeon, President and CEO of Spectrum Pharmaceuticals. "I want to thank the patients, investigators and our internal staff who have passionately worked to achieve this important milestone in an area of high unmet medical need."

ZENITH20 Cohort 2 Clinical Results Summary

Results for Cohort 2 of the ZENITH20 clinical trial have been published in the Journal of Clinical Oncology (November 29, 2021), and can be accessed by clicking here.

Cohort 2 enrolled 90 patients who received an oral once daily dose of 16 mg of poziotinib. The intent-to-treat analysis demonstrated a confirmed objective response rate (ORR) of 27.8% (95% Confidence Interval (CI), 18.9%-38.2%). The observed lower bound of 18.9% exceeded the pre-specified lower bound of 17%. The median duration of response was 5.1 months and the median progression free survival was 5.5 months. In this cohort, 87% of patients had drug interruptions with 11 patients (12%) permanently discontinuing due to adverse events. 13 patients (14%) had treatment-related serious adverse events. As previously announced, the company had a successful pre-NDA meeting with the FDA which resulted in an agreement to submit an NDA for poziotinib. During the meeting, Spectrum confirmed with the FDA that Cohort 2 data could serve as the basis of an NDA submission. The company will continue to work with the FDA as appropriate, while the agency conducts its review.

About the ZENITH20 Clinical Trial

The ZENITH20 study consists of seven cohorts of NSCLC patients. Cohorts 1 (EGFR) and 2 (HER2) in previously treated NSCLC patients with exon 20 mutations and Cohort 3 (EGFR) in first-line patients have completed enrollment. Cohort 4 (HER2) in first-line NSCLC patients with exon 20 mutations is still enrolling patients. Cohorts 1- 4 are each independently powered for a pre-specified statistical hypothesis and the primary endpoint is objective response rate (ORR). Cohort 5 includes previously treated or treatment-na?ve NSCLC patients with EGFR or HER2 exon 20 insertion mutations. Cohort 6 includes NSCLC patients with classical EGFR mutations who progressed while on treatment with first-line osimertinib and developed an additional EGFR mutation. Cohort 7 includes NSCLC patients with a variety of less common mutations in EGFR or HER2 exons 18-21 or the extracellular or transmembrane domains.