"Optimized Herceptin" Margenza Head-to-Head Phase 3 Study Results Announced

Compilenewborn

On September 7, Zai Lab's partner MacroGenics announced the final overall survival (OS) results of the key phase 3 SOPHIA study (NCT02492711) of the HER2 targeted blocking antibody drug Margenza (margetuximab) for the treatment of adult patients with metastatic HER2-positive breast cancer.

.

The study was carried out in patients who had previously received anti-HER2 targeted therapy, and compared Margenza + chemotherapy regimens with trastuzumab + chemotherapy regimens
.

Among the enrolled patients, all patients had previously received trastuzumab treatment, except for one patient, all received Perjeta (perturbation, Pertuzumab) treatment, and 91% of the patients had received Kadcyla (ado -trastuzumab emtansine, T-DM1) treatment

The final OS analysis of the ITT population showed that: compared with patients receiving trastuzumab + chemotherapy, patients receiving Margenza + chemotherapy did not show a statistically significant advantage in OS (HR=0.
95; 95%CI: 0.
77-1.
17; P=0.
62)
.

In the entire ITT population, the median OS of patients in the Margenza+ chemotherapy group (N=266) was 21.

A pre-specified, non-alpha assignment exploratory analysis evaluated the effect of CD16A allelic variation on Margenza activity
.

Among patients carrying the CD16A 158F allele in the trial (approximately 82% of the study patients, 437 out of 536 patients), the median OS of the Margenza+ chemotherapy group was prolonged compared with the trastuzumab+ chemotherapy group 2.

In addition, a numerical OS advantage was observed in the subgroup of CD16A 158F homozygous patients ("F/F" patients, accounting for approximately 35.
8% of the study population), which is in favor of Margenza + chemotherapy (HR=0.
72; 95%CI: 0.
52- 1.
00; nominal P=0.
05)
.

In this subgroup, patients who received Margenza + chemotherapy (102 of 266 patients) had a median OS of 23.

In the subgroup of CD16A F/V patients, patients who received Margenza + chemotherapy (119 of 266 patients) had a median OS of 21.
3 months, while those who received trastuzumab + chemotherapy (126 of 270 patients) had a median OS of 21.
3 months.
The median OS was 22.
0 months (HR=0.
96; 95%CI: 0.
71-1.
30; nominal P=0.
78)
.

In a small subgroup of CD16A V/V patients, the OS of trastuzumab + chemotherapy was greater than Margenza + chemotherapy (HR=1.
77; 95%CI: 1.
01-3.
12; nominal P=0.
04)
.

In this subgroup, patients who received Margenza + chemotherapy (37 of 266 patients) had a median OS of 22.

The safety of the SOPHIA study in the final OS analysis is similar to the previous report, and is consistent with the existing FDA-approved label of the product
.

Among patients treated with Margenza+ chemotherapy, adverse reactions that occurred more than 20% were consistent with existing product labels

Margenza's active pharmaceutical ingredient margetuximab is an immune-enhancing monoclonal antibody optimized for the Fc domain, which targets the HER2 protein to block
.

Margetuximab has HER2 binding and anti-proliferative effects similar to trastuzumab, and its engineered Fc domain can increase the participation of the immune system

In November 2018, Zai Lab reached a cooperation with MacroGenics to obtain the development and commercialization rights of margetuximab in Greater China
.

In December 2020, the US FDA approved Margenza combined chemotherapy for the treatment of adult patients with metastatic HER2-positive breast cancer, specifically: have previously received 2 or more anti-HER2 regimens, at least one of which is used to treat metastatic breast cancer Disease patients

Although the OS results of the ITT population in the SOPHIA study were disappointing, in the subgroup of CD16A 158F homozygous patients (“F/F” patients, which accounted for about 40% of all HER2-positive breast cancer patients, it accounted for the majority of the entire study population in the SOPHIA study.
A higher OS benefit was observed in 35.
8%), which is consistent with the enhancement observed in the engineered Fc region of Margenza
.

Therefore, further research is needed to determine the effect of Margenza on HER2-positive breast cancer patients with different CD16A allelic variants, including an ongoing researcher-sponsored neoadjuvant study investigating the effect of Margenza and trastuzumab on the expression of CD16A Effects of F allelic variants in patients
.

Reference source: MacroGenics Announces Final Overall Survival Results from SOPHIA Study of MARGENZA™ in Patients with HER2-Positive Metastatic Breast Cancer