New ADC drug introduced…expands treatment options

and heats up the competition in the field

Datroway under review for breast cancer in Korea

AbbVie Applies for marketing authorization of Elahere... indicated for platinum-resistant ovarian cancer

New global drugs are awaiting entry into Korea’s antibody-drug conjugate (ADC) market one after another.

 

Following Daiichi Sankyo Korea's application for domestic approval of the ADC anticancer drug ‘Datroway,’ AbbVie Korea is also proceeding with the approval process for its ovarian cancer-targeted ADC ‘Elahere.’ The industry anticipates that the commercialization of these two new drugs will significantly accelerate the competitive landscape for ADCs in Korea.

 

According to industry sources on the 25th, Daiichi Sankyo Korea has completed its application for the domestic approval of its ADC anticancer drug Datroway and is awaiting approval.

 

The indication is for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer.

 

The company expects approval early next year.

 

ADC anticancer drug Datroway

Dartroway is an ADC being co-developed by Daiichi Sankyo and AstraZeneca.

 

AstraZeneca has prior experience commercializing the HER2-targeted ADC ‘Enhertu’ with Daiichi Sankyo.

 

Previously, AstraZeneca secured the development and sales rights for Enhertu through a total USD 6.9 billion (KRW 8.418 trillion) contract with Daiichi Sankyo.

 

In 2020, AstraZeneca paid Daiichi Sankyo USD 1 billion (KRW 1.22 trillion) as an upfront payment to obtain the development rights for Datroway.

 

The total contract value, including development milestones and commercialization milestones, amounts to USD 6 billion (KRW 7.32 trillion).

 

TROP2, which Datroway targets, is rapidly emerging as a global ADC target.

 

The TROP2 protein is overexpressed in various cancers, including breast cancer and non-small cell lung cancer.

 

Datroway binds to this protein and delivers a cytotoxic drug into cancer cells, inducing cell death.

 

It maintains the efficacy of existing cytotoxic anticancer drugs while reducing damage to normal cells.

 

The first novel drug to reach commercialization with this mechanism was Gilead's Trodelvy.

 

Trodelvy has been approved as a TROP2-targeted breast cancer treatment in the US, Europe, and South Korea.

 

Subsequently, Datroway entered the market, adding indications for breast cancer and non-small cell lung cancer.

 

Datroway demonstrated efficacy in the Phase III TROPION-BREAST01 clinical trial.

 

This study was a randomized 1:1 trial comparing the Datroway group with the investigator-selected chemotherapy group (eribulin, vinorelbine, capecitabine, or gemcitabine) in patients with previously treated, unresectable or metastatic hormone receptor-positive (HR+/HER2-) breast cancer.

 

The study included 723 patients with a median age of 56 years.

 

Key endpoints included progression-free survival (PFS), defined as the time without disease progression as assessed by blinded independent central review (BICR) per RECIST 1.1, and overall survival (OS), defined as the time from treatment initiation to death.

 

Results showed the median PFS in the Datroway group was 6.9 months.

 

This was longer than the 4.9 months observed in the chemotherapy group.

 

Although the OS data were immature, a trend favoring Datoray was observed.

 

AbbVie's first ADC ‘Elahere nears domestic commercialization

ADC anticancer drug Elahere

AbbVie is also awaiting approval for a new ADC.

 

AbbVie has applied for domestic approval of ‘Elahere’ targeting the ovarian cancer indication.

 

AbbVie acquired Elahere in November 2023 by purchasing the US biotechnology company Immunogen for USD 10.1 billion (approximately KRW 13.1 trillion).

 

Elahere is an ADC targeting ovarian cancers expressing FRα (folate receptor alpha).

 

Its mechanism involves delivering the potent cytotoxic drug DM4 into cancer cells to destroy the tumor.

 

It is particularly gaining attention as a new option for ovarian cancer patients resistant to platinum-based anticancer drugs.

 

This treatment was also designated as an orphan drug in Korea this January.

 

For epithelial ovarian cancer, which accounts for 90% of ovarian cancers, taxane-based drugs like paclitaxel and platinum-based anticancer drugs like carboplatin and cisplatin are primarily used.

 

However, for recurrent ovarian cancer resistant to platinum-based drugs, response rates to standard chemotherapy have generally been low, significantly limiting improvements in survival rates.

 

Elahere demonstrated its potential as a new alternative through the Phase III MIRASOL study, conducted in patients with platinum-resistant ovarian cancer.

 

The confirmatory Phase III MIRASOL study enrolled 453 patients with platinum-resistant epithelial ovarian cancer.

 

The trial compared the Elahere group with the standard chemotherapy group.

 

At a median follow-up of 30.5 months, Elahere demonstrated an improvement in median PFS of 5.59 months compared to 3.98 months in the standard therapy group.

 

This represented a 37% reduction in the risk of disease progression or death.

 

The objective response rate (ORR), which measures the proportion of patients with tumor size reduction over a set period, was also higher in the Elahere group at 41.9%, compared to 15.9% in the standard therapy group.

 

Overall survival (OS) was also longer with Elahere at 16.85 months, reducing the risk of death by 32% compared to 13.34 months in the standard therapy group.

 

Regarding safety, eye-related adverse events, fatigue, and abdominal pain were reported, but these were generally considered manageable.

 

Based on these results, Elahere received full approval in the United States in March of last year and obtained marketing authorization in Europe in November of the same year.