Gilead Sciences plans to acquire all remaining worldwide rights to its breast cancer drug Trodelvy through a new agreement announced Monday.
The deal with Everest Medicines, a Chinese biotechnology company, will hand Gilead development and commercialization rights to Trodelvy across a large swath of Asia, including Greater China, South Korea, Singapore and Indonesia. In exchange, Everest will receive $280 million upfront and be eligible for as much as $175 million in additional payments that hinge on the drug achieving certain regulatory and commercial goals.
The companies expect their transaction to close sometime later this year.
The deal coincided with another announcement from Gilead, which said Trodelvy appeared to have a “statistically significant and clinically meaningful” impact on survival rates in a closely watched study testing it in patients with a certain hard-to-treat form of breast cancer. The company didn’t provide any additional details, but said overall survival data will be presented at an upcoming medical conference.
According to analysts, that data will be critical to Trodelvy’s commercial future. The drug is already approved in the U.S. and elsewhere to treat a rarer, aggressive type of breast cancer called “triple negative” because it doesn’t have any of three proteins — known for short as ER, PR and HER2 — often found on breast tumors.
Gilead, though, hopes to also secure approval in a much more common type, in which tumors still don’t have HER2 but are positive for at least one, if not both, of the ER and PR proteins. Some analysts have argued such an approval would put Trodelvy, which generated $305 million over the first half of this year, on track to becoming a multibillion-dollar product.
In March, Gilead revealed high-level results from that key study, saying that Trodelvy had hit the main goal by reducing the risk of death or cancer progression compared to physician’s choice of chemotherapy. The company offered up more specific data in early June, showing that Trodelvy-treated patients went a median of 5.5 months without dying or having their cancer progress, versus 4 months for chemotherapy-treated patients.
On the measure of overall survival, the study had by that time shown no significant difference between the two groups, with respective median survival rates of 13.9 months and 12.3 months.
However, Gilead said Monday that a more recent analysis found a more meaningful benefit.
With the data presentation likely months away, analysts are now left to guess how large Trodelvy’s impact on survival will end up being in the study, and whether it can stack up to recent, practice-changing results from Enhertu, a rival breast cancer therapy developed by AstraZeneca and Daiichi Sankyo. Enhertu was this month approved for patients with low, but still detectable levels of the HER2 protein. Many of those patients would previously have been characterized as HER2-negative.
Brian Abrahams of RBC Capital Markets wrote in a note to clients that his team estimates a 2- to 2.4-month survival benefit in the Trodelvy study. Abrahams noted how, in other breast cancer drug trials, the change in overall survival has often been larger than the change in survival without disease progression. While the exact patient populations differed, he wrote that the trend can be seen in the testing that supported approvals for Trodelvy and Enhertu.
Abrahams added that, based on a survey RBC conducted with 36 breast cancer specialists, doctors would view a 2.3- to 2.5-month overall survival benefit in the Trodelvy study as warranting use of the drug in this patient setting.
Enhertu, though, may continue to cast a shadow over Trodelvy. In June, shortly after fresh Enhertu data were presented at a major cancer meeting, Raymond James analysts lowered their forecast for peak Trodelvy sales from breast cancer indications by $2.5 billion in recognition of the greater competition.