Can Enhertu Treat Ovarian Cancer? All the Data, None of the Hype.

Last updated: 15 January 2024

Enhertu (fam-trastuzumab deruxtecan-nxki) was first approved by the FDA in 2019 ¹. At that point, it was indicated for the treatment of HER2-positive breast cancer. Since then, Enhertu has been approved for more indications. These include HER2-positive gastric cancer, HER2-low breast cancer, and HER2-mutant non-small cell lung cancer. There's even been talk of ambitions for treatment approval across all HER2-positive tumours⁵.

In this context, Enhertu has gathered a lot of media attention. As a natural consequence of the hype, cancer patients everywhere are wondering whether Enhertu can also be applicable to them.

As always, we're here to cut through the noise and look at the available data. In this article, we'll review all there is to know about Enhertu for ovarian cancer.

What type of cancer does Enhertu treat?

Patients everywhere have been wondering if Enhertu can cure all cancer. Unfortunately, that's not the case. And it's not the case by design. Enhertu is a targeted therapy specifically for:

Tumors with a HER-2 expression. HER-2 is a protein found on the surface of different types of cells in the body. It helps with normal cell growth. However, in certain cancers, it can become overactive due to gene changes or mutations. HER2 overexpression affects between 2% and 66% of ovarian cancer cases ⁵.
Tumors that have spread to other parts of the body and/or are inoperable ⁴. Future clinical trials may involve Enhertu at earlier stages of cancer treatment ⁶. However, this is currently not the case.

How effective is Enhertu for ovarian cancer?

The ongoing phase 2 DESTINY-PanTumor02 trial is focused on testing Enhertu's activity in various HER2-positive solid cancers. One of them is ovarian cancer. The interim results of the trial were shared in June 2023, and are showing some promise.

For ovarian cancer patients, the key preliminary outcomes of the trial are:

Overall response rate was 45.0%. Meaning that 45% of patients treated with Enhertu had their tumours shrink. For patients with a HER2 status of IHC 3+, the overall response rate was 63.6%. For those with IHC 2+ status, the response rate was 36.8% ³.
10% of ovarian cancer patients had a complete response. In other words, their tumour completely disappeared ³.
After 12 months, 45.8% of ovarian cancer patients with tumors that decreased in size or disappeared still reported experiencing this benefit³.
The median duration of response in ovarian cancer patients was 11.3 months³.

Overall, these results can be considered encouraging. The long duration of responses is a particularly notable result, according to Dr. Meric-Bernstam (Chair of the Department of Investigational Cancer Therapeutics at the USA MD Anderson Cancer Center) ³.

Based on these clinical study results, the FDA in the USA granted Enhertu a Breakthrough Therapy designation. This designation helps speed up the development and review of medicines for serious conditions, for which initial clinical evidence indicates a substantial improvement over other available therapies ².

When will Enhertu be approved for ovarian cancer?

There's no clear timeline for the potential approval of Enhertu for the treatment of HER2-positive ovarian cancer.

The DESTINY-PanTumor02 trial is ongoing, with final results expected in April 2027 ⁷. However, this doesn't necessarily mean that ovarian cancer patients have to wait until then for the FDA's approval decision on Enhertu.

The medicine has Breakthrough Therapy status in the USA. This makes it possible for the FDA to decide earlier on allowing Enhertu's use in ovarian (and other) cancers. Time, and additional trial results will tell if that happens.

In the meantime, what role could Enhertu play in ovarian cancer treatment?

Can my doctor prescribe Enhertu for ovarian cancer?

The best answer currently is, maybe.

Enhertu has not yet been approved anywhere for the treatment of HER2-positive ovarian cancer. However, your doctor has the authority to prescribe the medicine for this indication anyway. They could do this based on the preliminary results of the DESTINY-PanTumor02 clinical trial, and on the specifics of your case.

When a doctor prescribes a medicine for treating a disease it's not approved for (yet), that's called off-label use. An off-label use prescription may be difficult to fill in some countries, depending on local regulations and availability. However, it's always possible to fill it using the Named Patient Import regulation.

Has your doctor made the decision to prescribe Enhertu for the treatment of your ovarian cancer? Our team at www.everyone.org can help you access the medicine. We specialize in sourcing and delivery of prescribed medicines unapproved or unavailable in a patient's country. Contact us, so we can help you.

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