Survival Story: Enhertu

Sometimes, it’s best to let the results speak for themselves. In June 2022, Good Morning America¹ ran a segment about a drug being described as a cancer treatment breakthrough. ABC News’ medical correspondent, Jennifer Ashton, joined host Lara Spencer to explain that a new study published in The New England Journal of Medicine revealed that Enhertu, a cancer drug co-developed by AstraZeneca and Daiichi Sankyo, could help patients suffering from some types of breast cancer to live longer.² While Ashton makes it clear that the drug is not a cure, she stresses that it does give patients more time.

What the study found in these 500 or so women is [that] it got them more time,” says Ashton during the segment. “They got an additional five months of progression-free survival—which means without their cancer progressing and spreading further. They got an additional six months. They lived six months longer (vs. standard chemotherapy). So, it’s about time for these women that really didn’t have a lot of options.”

Enhertu treats patients suffering from HER2-low metastatic breast cancer. It first received accelerated approval from FDA in 2019 for adult patients with HER2-positive breast cancer who had already received two or more treatment regimens. However, the drug was later designated as a breakthrough drug by the agency. This led to more studies being conducted. On May 4, 2022, FDA approved Enhertu for patients who had only received one prior treatment for HER2-positive breast cancer.

Finally, in August 2022, the agency cleared the use of Enhertu for the treatment of HER2-low breast cancer for patients who had already received chemotherapy treatment.

This came after the previously mentioned study in NEJM that showed Enhertu resulted in a longer progression-free period in patients and also contributed to a longer overall survival rate.

On the AstraZeneca webpage for Enhertu, the company’s chief medical officer and oncology chief development officer, Cristian Massacesi, says, “The progression-free survival and overall survival results for Enhertu alongside the continued robust and durable tumor responses seen with further follow-up underscore the potential value of this important medicine for patients with HER2-expressing cancers who currently have no targeted treatment options. With a high unmet need in these cancers, we are working with health authorities to bring Enhertu to patients with HER2-expressing cancers that could potentially benefit from this medicine as quickly as possible.”

Due to its nature as a treatment for a potentially fatal form of cancer, there was no massive advertising campaign for the relaunch of Enhertu as a treatment for HER2-low breast cancer. Instead, it relied on news segments describing its effectiveness.

The Enhertu website presents a very straightforward description of the drug and its treatment purposes. Aside from a single image of a woman standing next to a waterfall (with the tagline “I stand determined”), the page simply presents information about HER2 breast cancer and the Enhertu treatment process (patients receive an intravenous infusion once every three weeks). It’s notable that the website still only lists Enhertu as a treatment for HER2-positive, as opposed to its new designation as a treatment for HER2-low as well.

In March, AstraZeneca announced the results of the trial, DESTINY-PanTumor02, which showed that Enhertu was effective across multiple HER2 tumors.

On the AstraZeneca page for Enhertu, Daiichi Sankyo’s global head of oncology development, Mark Rutstein, says, “These updated results from the DESTINY-PanTumor02 trial are important as we work to reshape the clinical landscape in HER2-expressing advanced cancers, where patients currently have limited treatment options and face a poor prognosis. The overall survival demonstrated by Enhertu in these patients is a significant step forward in the potential to advance current standards of care and offer new options for patients with HER2-expressing cancers.”

Enhertu has been called a breakthrough in breast cancer treatment. While it doesn’t cure HER2 breast cancer, research shows that it provides patients with more time. According to the National Library of Medicine, the five-year survival rate for patients with HER2-low breast cancer is 32–45%.³ Providing these patients with more time is an important step forward for cancer treatment. Not only does it allow doctors and researchers to spend more time researching potential treatments and cures for the patients, but it also allows those suffering from these diseases to spend more quality time with their loved ones. When a drug can offer that possibility, it markets itself.

References

1. Cancer Drug Could Help Women with Metastatic Breast Cancer Live Longer, Study Says. Good Morning America. June 7, 2022. https://www.youtube.com/watch?v=TaUu4mdZo0M
2. Modi, S.; Jacot, W.; Yamashita, T.; et al. Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer. N Engl J Med. July 7, 2022. https://www.nejm.org/doi/full/10.1056/NEJMoa2203690
3. Holthius, E.I.; Vondeling, G.T.; Kuiper, J.G.; et al. Real-World Data of HER2-Low Metastatic Breat Cancer: A Population-Based Cohort Study. Breast, National Library of Medicine. 2022. 66 (12), 278-284. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9663525/