AbbVie’s Elahere wins Korean approval for platinum-resistant ovarian cancer

AbbVie Korea said its ADC therapy Elahere (mirvetuximab soravtansine) received approval from the Ministry of Food and Drug Safety (MFDS) on Friday.

It was approved as a monotherapy for adult patients with high-grade serous epithelial ovarian cancer or primary peritoneal cancer who have received one to three prior systemic therapies, are FRα-positive, and are resistant to platinum-based chemotherapy.

(Courtesy of AbbVie Korea)

Ovarian cancer is a malignant tumor that develops in the ovaries, surrounding fallopian tubes, or peritoneum. It lacks specific early symptoms and effective screening methods. As a result, about seven out of 10 patients are diagnosed at stage III or later, when the cancer has progressed. First-line treatment for advanced ovarian cancer generally consists of surgery and platinum-based chemotherapy. However, around 70 percent of patients experience recurrence after initial treatment. Repeated therapy can lead to resistance to platinum-based drugs.

One in five patients develops “platinum-resistant ovarian cancer,” which recurs within six months after platinum-based treatment. Patients with platinum-resistant ovarian cancer have limited treatment options and often have compromised overall health due to repeated prior therapies.

Patients also face significant emotional burdens, such as social isolation and hair loss from existing treatments, which can further affect prognosis. The five-year survival rate for ovarian cancer in Korea is 65.8 percent, nearly 30 percentage points lower than that for other major female cancers, such as breast cancer (94.3 percent) and endometrial cancer (89 percent).

Elahere is the first-in-class, MFDS-approved antibody-drug conjugate (ADC) for treating FRα-positive ovarian cancer. With its novel mechanism of action, it is the first new treatment option for platinum-resistant ovarian cancer in roughly a decade.

The drug targets folate receptor alpha (FRα), a protein involved in cancer growth, metastasis, and treatment resistance.

Patients are considered FRα-positive if the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay confirms membrane staining intensity of 2+ or higher in at least 75 percent of tumor cells. The test is a companion diagnostic developed by Roche Diagnostics. About 35–40 percent of ovarian cancer patients meet this criterion.

Elahere binds to the FRα receptor on the surface of tumor cells and releases a potent cytotoxic payload that kills cancer cells, including neighboring tumor cells. This mechanism has demonstrated clinical benefit, including the first statistically significant improvement in overall survival reported in platinum-resistant ovarian cancer.

Results from the phase 3 MIRASOL study showed that Elahere reduced the risk of disease progression or death by 35 percent compared with non-platinum chemotherapy in FRα-positive, platinum-resistant ovarian cancer patients with up to three prior therapies (hazard ratio 0.65; p<0.0001).

Median progression-free survival was 5.62 months with Elahere versus 3.98 months in the control group. The objective response rate was 42.3 percent compared with 15.9 percent for control (odds ratio 3.81; p<0.001).

Median overall survival was 16.46 months (95 percent confidence interval 14.46–24.57) in the Elahere group, compared with 12.75 months (95 percent confidence interval 10.91–14.36) in the control group, representing a 33 percent reduction in the risk of death (hazard ratio 0.67; 95 percent confidence interval 0.504–0.885; p=0.0046). No new safety signals were identified. All-grade adverse events occurred in 96.3 percent of patients in the Elahere group and 93.7 percent in the control group.

The Korean Society of Gynecologic Oncology recommends Elahere in its clinical guidelines with the highest level of evidence (Level I) and recommendation grade (Grade A) for patients with FRα-positive, platinum-resistant ovarian cancer.

“Platinum-resistant ovarian cancer is an area where treatment options have been severely limited, and innovative therapies are urgently needed,” said Professor Kim Jae-weon of the Department of Obstetrics and Gynecology at Seoul National University Hospital. “This approval of Elahere represents meaningful progress in treating platinum-resistant ovarian cancer after about a decade.”

“The phase 3 study demonstrated not only prolonged progression-free survival but also improved overall survival in FRα-positive patients,” Kim said. “It is particularly encouraging that the gap between the overall survival curves for the treatment and control groups widened over time, indicating sustained long-term efficacy.”

“As the first biomarker-based ADC approved in Korea for platinum-resistant patients, Elahere is expected to become an important new treatment option,” Kim added. “Because FRα expression tends to remain relatively stable from diagnosis through recurrence, confirming FRα positivity using a companion diagnostic at the time of initial tissue diagnosis is crucial to ensure timely access to treatment once platinum resistance develops.”

Kang Ji-ho, executive vice president of medical affairs at AbbVie Korea, said the approval would allow patients with platinum-resistant ovarian cancer -- a population with significant unmet needs -- to access an innovative ADC therapy.

AbbVie remains committed to developing targeted therapies for ovarian cancer and improving outcomes across disease stages, Kang added.

Elahere received accelerated approval from the U.S. Food and Drug Administration in November 2022 and final approval in March 2024. In Korea, it was designated an orphan drug in January 2025, reflecting its survival benefit in a field with limited treatment options.