Benzinga | Mar 2, 2021 11:45AM EST

Spectrum Pharma Highlights Presentation Of Twice-Daily Dosing Data For Poziotinib At European Society for Medical Oncology Targeted Anticancer Therapies Virtual Congress 2021 being held Mar. 1-2, 2021

Spectrum Pharmaceuticals (NASDAQ:SPPI), a biopharmaceutical company focused on novel and targeted oncology therapies, today presented results from Cohort 3 and initial twice daily (BID) dosing safety and efficacy data for poziotinib from Cohort 5 of the ZENITH20 clinical trial. These preliminary data demonstrate improved tolerability with BID dosing, reduced dose interruption compared to once daily (QD) dosing, and a reduction in treatment emergent Grade 3 or higher adverse events. The preliminary data also suggest improved anti-tumor activity with 8mg BID dosing. The presentation is part of the European Society for Medical Oncology Targeted Anticancer Therapies (ESMO TAT) Virtual Congress 2021 being held March 1-2, 2021.

"As predicted by the pharmacokinetic modeling, the 8mg BID arm is showing an improved therapeutic effect and a lowered adverse event rate in this early data," said Francois Lebel, M.D., Chief Medical Officer of Spectrum Pharmaceuticals. "The data build on the positive results we have reported for Cohort 2 which will be the basis for our NDA submission later this year. We look forward to reporting additional data at AACR in April."

A copy of the ESMO presentation titled "Safety, tolerability and preliminary efficacy of poziotinib with twice daily strategy in EGFR/HER2 Exon 20 mutant non-small cell lung cancer" is available on Spectrum's website at https://investor.sppirx.com/events-and-presentations.

ZENITH20 Trial Design and Preliminary Safety and Efficacy Data for Cohort 5

Cohort 5 of the ZENITH20 trial includes previously treated NSCLC patients with EGFR or HER2 exon 20 insertion mutations. This cohort is investigating the efficacy of poziotinib with a BID dosing strategy. For the first 20 patients randomized to poziotinib 16 mg QD or 8 mg BID in Cohort 5, a trend towards improved responses was reported in the BID arm with 30% of patients reaching a partial response and two patients still too early to evaluate.

Preliminary Data on Best Overall Response

Cohort 1 Cohort 5a Cohort 5d

16mg QD 16mg QD 8mg BID

N=10 (%) N=10 (%) N=10 (%)

PR - Partial Response 2 (20) 2 (20) 3 (30)

SD - Stable Disease 5 (50) 4 (40) 2 (20)

PD - Progressive Disease 2 (20) 0 1 (10)

NE - Not Evaluable (withdrawn) 1 (10) 4 (40) 2 (20)

NA - Too Early to Assess 0 0 2 (20)

Improved tolerability was also observed, with a greater than 30% reduction in Grade 3 or higher adverse events for the BID arms relative to QD. In addition, there were 23% fewer dose interruptions for 8mg BID vs 16mg QD and 43% fewer dose interruptions for 6mg BID vs 12mg QD.

BID Dosing Exposure and Safety

Preliminary Data (study enrolling)

16mg QD 8mg BID 12mg QD 6mg BID

Enrolled 22 16 23 16

Drug Interruption, n (%) 18 (82) 10 (63) 20 (87) 8 (50)

Dose Reduction 13 (59) 8 (50) 13 (57) 6 (38)

Treatment Related AE ? Grade 3 10 (45) 5 (31) 9 (39) 3 (19)

While preliminary, these data support the hypothesis that BID dosing could improve the therapeutic effect for patients receiving poziotinib and result in better outcomes. Cohort 5 is continuing to enroll patients and a presentation of additional results is expected later this year at a medical conference.