What is the success rate of Elahere?

In the Phase 3 MIRASOL study, people receiving Elahere had a median of 5.6 months without the advanced ovarian cancer growing or spreading compared to 4 months in the standard chemotherapy group. People receiving Elahere also lived longer - a median of 16.5 months compared to 12.7 months with chemotherapy.

What is Elahere approved for?

Elahere (mirvetuximab soravtansine-gynx), from ImmunoGen, is approved to treat adults with FRα (folate receptor-alpha) positive ovarian, fallopian tube, or primary peritoneal cancer, who have received 1 to 3 prior systemic treatment regimens. These patients have advanced disease, and have not responded, or are no longer responding to platinum-based chemotherapy.

Your doctor will test you to be sure you can receive Elahere. Eligible patients are determined via a companion diagnostic tool, the VENTANA FOLR1 RxDx IHC Assay.

Elahere is given as an intravenous (IV) infusion every 3 weeks until the cancer progresses or you have intolerable side effects. Your dose is based on your ideal body weight and will be determined by your physician.

Elahere studies

Approval of Elahere was based on the Phase 3 MIRASOL study, a two-arm, randomized, open-label, active-controlled study in 453 patients with FRα (folate receptor-alpha) positive ovarian, fallopian tube, or primary peritoneal cancer. Enrolled patients could have had up to 3 prior lines of systemic treatment.

There were 227 patients randomized to the Elahere group and 226 to chemotherapy. The median age was 63 years (range: 29 to 88 years) and 66% of participants were White, 12% Asian and 3% Black or African American.

Patients received either Elahere 6 mg/kg (dose based on adjusted ideal body weight) as an IV infusion every 3 weeks or the investigators choice of chemotherapy (weekly paclitaxel, pegylated liposomal doxorubicin, or topotecan).

Elahere demonstrated a statistically significant improvement in progression-free survival (PFS), overall response rate (ORR) and overall survival (OS) in studies when compared to groups receiving standard chemotherapy.

Results

Primary endpoint: Progression-free survival (PFS)

The primary endpoint to determine Elahere success was median progression-free survival (PFS) as determined by the investigator.

Median progression-free survival (PFS) is defined as the length of time during and after the treatment that a patient lives with the disease but the tumor does not continue to grow or get worse.

The PFS was reported as a median of 5.6 months for the group receiving Elahere and 4 months for the chemotherapy treatment group. “Median” indicates that one half of patients had a PFS less than 5.6 months in length and one half had a PFS longer than 5.6 months.

This represented a 35% reduction in the risk of tumor progression in the Elahere group compared to chemotherapy treatment (HR 0.65; 95% CI 0.52, 0.81).

Overall Response Rate (ORR)

The key secondary endpoints to evaluate Elahere success were overall response rate (ORR) and overall survival (OS).

The ORR is defined as the number of people who had either a complete response or a partial response to treatment. In the study 42% of people had an overall response, with 5% achieving a complete response and 37% had a partial response. 0% of patients in the chemotherapy group had a complete response, while 16% had a partial response.

A complete response means that these people had no evidence of a tumor during a follow-up imaging test (but it does not mean they were cured). Partial response means that the tumor shrank by at least 30%.

Overall survival (OS)

Overall survival (OS) was also evaluated in the Elahere studies. Median overall survival is the length of time that half of the people were alive after starting treatment.

In the Elahere group, the median OS was found to be 16.5 months long compared to 12.7 months in the chemotherapy group.

This represented a 33% reduction in the risk of death (HR=0.67) in the group using Elahere compared to the traditional chemotherapy group.

How does Elahere work in ovarian cancer?

Elahere is an antibody-drug conjugate (ADC) that works by targeting folate receptor-alpha (FRα), a cell-surface protein highly expressed in ovarian cancer. It was the first FDA-approved ADC for platinum-resistant disease.

It is composed of a folate receptor alpha-binding antibody, cleavable linker, and the maytansinoid payload DM4, a potent tubulin inhibitor designed to kill the targeted cancer cells.

Elahere safety

Elahere carries a Boxed Warning, the FDA’s most prominent safety warning, for severe ocular toxicity, including visual impairment, keratopathy, dry eye, photophobia, eye pain, and uveitis. Patients should have an eye examination, including visual acuity and slit lamp exam, prior to treatment and every other cycle for the first 8 cycles, and as clinically indicated.

Warnings and precautions include peripheral neuropathy, pneumonitis and harm to an unborn baby.

The most common side effects (in at least 20% of patients) included: vision impairment, fatigue, elevated liver enzyme, diarrhea, blurred vision, nausea, decreased platelets, cornea damage, abdominal pain, decreased lymphocytes, and peripheral neuropathy, among others.

Learn more: Elahere Precautions, Warnings and Side Effects (in more detail)

This is not all the information you need to know about Elahere for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.