Mirvetuximab soravtansine (MIRV), a new form of therapy to treat patients diagnosed with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, has been shown to target and contribute to greater tumor reduction.
However, with this treatment comes treatment-related adverse events (TRAEs)—including ocular events. Identifying and mitigating these symptoms are key for eyecare professionals (ECPs).
Tell me about MIRV.
Mirvetuximab soravtansine (MIRV) is a first-in-class, antibody-drug conjugate (ADC)—an anti-cancer drug made of a monoclonal target-specific antibody that delivers anticancer agents to tumor cells with limited damage to healthy cells— focusing on a cell-surface protein called folate receptor alpha (FRα).
While FRα is typically limited in normal tissue, it is overexpressed in most cases of epithelial ovarian cancer (EOC).
How is it being marketed in the US?
Mirvetuximab soravtasine-gynx (Elahere; Immuogen) is an injection indicated for intravenous use in adult patients with FRα-positive, platinum-resistant ovarian cancer who have received one to three prior systemic treatment regimens.
To note, the FDA granted Elahere accelerated approval in November 2022 following clinical trials that demonstrated anti-cancer activity with a differentiated safety profile (largely low-grade, resolvable gastrointestinal and ocular AEs).
What is this approval contingent on?
The approval is based on tumor objective response rate (ORR) and the durability of a patient’s response; it’s contingent on verification of the therapy’s proven clinical benefits in a confirmatory trial.
The therapy is also the first ADC to be approved with an ovarian cancer indication.
What’s the dosage regimen?
Prior to infusion, patients are to receive a baseline ophthalmic exam consisting of best-corrected visual acuity (BCVA) and a slit lamp exam. After the exam, they are to begin a regimen of prophylactic ophthalmic topical steroids and preservative-free artificial tears.
Elahere should be administered as a 6 mg/kg dose via an intravenous infusion on Day 1 of each 3-week treatment cycle, continuing until the cancer progresses or unacceptable systemic toxicity is noted.
Patients are to be monitored via eye exams every second cycle of the first eight cycles of treatment, or every 6 weeks (with three exams).
Now talk about some research.
A pooled exposure-response analysis of 464 patients from three clinical trials on Elahere—NCT01609556; NCT02631876; and NCT04296890—suggested an association between MIRV and an increased occurrence of ocular AEs.
What kind of ocular AEs?
Blurred vision, superficial punctate keratopathy (SPK; dry eye), and keratopathy were noted.
Keratopathy occurred in 36% of patients and was characterized by microcyst-like epithelial changes (MECs); 26% of patients reported dry eye symptoms; and 49% of patients experienced vision impairment during at least one time-point in the study.
Anything else?
There were no reports of corneal ulcers or permanent ocular sequela; >1% of patients discontinued Elahere use due to ocular AEs.
How can these be prevented or managed?
According to investigators, a combination of ECP monitoring (eye exams) is key as well as patient education on eyelid margin hygiene practices; use of sunglasses in the daylight; and avoiding contact lenses (unless an ECP indicates otherwise) are advisable.
There is a need for ECPs to appropriately educate and deliver proper expectations on common risk factors to patients, particularly for dry eye, to proactively mitigate the signs and symptoms.