Ovarian cancer is the deadliest form of gynecological cancer that kills an estimated 12,700 women each year in the United States. Since 70% of all new cases are diagnosed at advanced stages, the risk of death within 5 years is quite high (60% at stage III and 83% at stage IV).
The standard first-line treatment for advanced ovarian cancer is surgery (if possible), followed by chemotherapy using platinum-based drugs like Carboplatin. While the majority of patients respond positively to treatment, the chances of recurrence are incredibly high (up to 75%).
In many cases, the cancer can progress rapidly into a treatment-resistant stage – folate receptor alpha (FRα)-positive platinum-resistant ovarian cancer (PROC). At this stage, the disease may stop responding to the drugs, significantly raising the chances of death within 12 to 16 months.
The good news is that newer treatment options are emerging, thanks to recent advances in precision oncology. A great example is AbbVie’s ELAHERE, whose Phase 3 MIRASOL clinical trials yielded encouraging results in March 2025.
A Smart Bomb Delivery System That Targets Cancer Cells
ELAHERE is the brand name of a drug called mirvetuximab soravtansine-gynx. Developed by Chicago-based biopharmaceutical firm AbbVie, it belongs to a special category of targeted cancer therapies called antibody-drug conjugate (ADC).
An ADC is like a smart bomb delivery system – a potent chemotherapy drug chemically attached to a monoclonal antibody. In the case of ELAHERE, the monoclonal antibody is Mirvetuximab. It has one purpose – to target folate receptor alpha (FRα) – a glycoprotein.
In healthy epithelial cells, FRα is essential for absorbing Folate or Vitamin B9. This vitamin plays an important role in DNA repair and synthesis. Healthy cells only require FRα proteins at very low levels.
Ovarian cancer cells produce an excessively high amount of FRα because cancer needs large quantities of folate for aggressive tumor growth. Some studies also indicate that high levels of FRα might help the cancer evade traditional therapies.
Since 80% of all late-stage ovarian cancer cases show high levels of FRα, mirvetuximab is an excellent targeting system. The deadly payload in ELAHERE is soravtansine (DM4), a cytotoxin derived from a plant-based natural compound called maytansine.
DM4 is an extremely toxic drug that kills cells by blocking the essential process of mitosis. Combining it with the monoclonal antibody ensures that the toxin only attacks the cancer cells, reducing the risk of adverse side effects.
The Promising Results of the MIRASOL Study
MIRASOL was a randomized Phase 3 trial for ELAHERE that commenced in December 2019. As an advanced clinical trial, it had quite strict eligibility requirements for the participants. The researchers were looking for PROC patients who also had high levels of FRα in their tumors.
An additional requirement was exposure to first-line chemotherapy – only patients who had already completed up to three regimens of treatment for PROC were selected for the study. By the start of trial, MIRASOL had 453 participants who fulfilled the requirements.
The five-year-long trial pitted ELAHERE against standard chemotherapy treatments like paclitaxel, PEGylated liposomal doxorubicin, and topotecan. Since PROC is by nature resistant to platinum-based drugs, carboplatin and others were not included in the trial.
After primary data collection and a follow-up phase with a median of 30.5 months, MIRASOL yielded the following main results:
A Clear Reduction in Risk of Tumor Progression and Death
ELAHERE reduced the risk of tumor progression and death by 37%, with an increase in median progression-free survival (PFS) from 3.98 months to 5.59 months when compared to the standard chemotherapy drugs.
A higher percentage of patients had a positive reaction to ELAHERE – the objective response rate was 41% versus just 15% for the other drugs. The patients also survived three months longer on average (median of 16.85 months versus 13.34 months), a 32% reduction in mortality risk.
Those numbers indicate that ELAHERE demonstrates a “clear survival advantage over standard chemotherapy” for patients with FRα-positive PROC, according to Dr. Toon Van Gorp, MD, PhD, and the presenting author of the MIRASOL study.
As the Professor of Gynecologic Oncology at the University of Leuven and an expert on ovarian cancers, Dr. Van Gorp was particularly impressed by the consistent results ELAHERE displayed across a broad range of patient sub-groups.
“Beyond confirming its role in the current treatment paradigm for FRα-positive disease, MIRASOL opens the door to exploring ELAHERE in earlier lines of therapy,” explains Dr. Van Gorp.
Although Side Effects Exist, the Safety Profile is Still Superior
Around 20% of patients treated with ELAHERE in the study experienced a range of side effects including blurred vision, dry eyes, fatigue, nausea, keratopathy, abdominal pain, diarrhea, and constipation. However, when compared to the control group drugs, ELAHERE performed well with overall lower rates of side effects (both minor and severe).
Fewer patients were forced to discontinue treatment with ELAHERE due to adverse side effects. Certain side effects like vision problems can be deeply distressing for cancer patients. Tashanna Myers, MD, Division Chief of Gynecologic Oncology at Baystate Health highlights this often-overlooked psychological aspect of cancer care.
“For patients living with a difficult diagnosis, efficacy alone isn’t enough. It’s equally important that treatment allows them to maintain a sense of normalcy and function in their daily lives,” says Dr. Myers.
Although some ocular side effects were frequently reported in MIRASOL, they didn’t significantly affect patients’ overall quality of life.
In the opinion of Dr. Myers, the findings help contextualize the overall risk-benefit profile of ELAHERE. While side effects are present, they are manageable and do not detract from the therapy’s meaningful survival benefits, making ELAHERE an important option for women navigating a challenging stage of the disease.
Current Legal Status of ELAHERE and Future Prospects
In 2024, ELAHERE received full approval from the US FDA and the European Union regulators for the treatment of several advanced forms of gynecological cancers. In the US, patients who fulfill the following criteria may be eligible for this therapy:
- Are suffering from folate receptor-alpha positive ovarian cancer, fallopian tube cancer, or primary peritoneal cancer
- Are no longer responding to platinum-based therapy
- Have already received 1 to 3 prior types of chemotherapy
The MIRASOL study results in 2025 represent a significant milestone in our fight against terminal ovarian cancer. ELAHERE has shown that there is still hope for thousands of women who battle this odious illness. According to Dr. Van Gorp, the implications are manifold:
“These results underscore the potential of antibody-drug conjugates (ADCs) to reshape how we treat platinum-resistant ovarian cancer. ELAHERE not only delivers improved survival outcomes but does so with a more manageable safety profile compared to traditional chemotherapy. Beyond confirming its role in the current treatment paradigm for FRα-positive disease, MIRASOL opens the door to exploring ELAHERE in earlier lines of therapy.”
