Reduced risk of recurrence and death by 53% compared to existing treatments... 3-year disease-free survival rate of 92.4%, expanded to include post-operative adjuvant treatment following metastatic cancer… SC formulation is in phase 1 clinical trial
Daiichi Sankyo and AstraZeneca's antibody drug conjugate (ADC) anticancer drug 'Enhertu' has been approved as a treatment for early breast cancer in the European Union (EU). As it can be used to treat metastatic cancer and prevent recurrence after surgery, opportunities for long-term commercialization of the subcutaneous injection (SC) formulation, to which Alteogen (196170) transferred its technology, have also expanded.
Daiichi Sankyo announced on the 27th that the European Commission (EC) approved Enhertu as a postoperative adjuvant therapy for adult patients with HER2-positive early breast cancer. Patients who received taxane-based anticancer drugs and HER2-targeted treatment before surgery but were confirmed to have invasive residual cancer after surgery are eligible.
This approval means that Enhertu is the first to enter the treatment of early breast cancer with the goal of cure in the EU. Previously, it was mainly used for unresectable or metastatic cancer, but it can now be prescribed to prevent recurrence in patients who have completed surgery.
1,635 patients participated in the global phase 3 clinical trial 'DESTINY-Breast05', which served as the basis for approval. The Enhertu treatment group had a 53% lower risk of invasive disease recurrence or death than the existing standard treatment, trastuzumab emtansine (T-DM1) treatment group (HR=0.47).
The 3-year invasive disease-free survival rate (IDFS) was 92.4% for Enhertu and 83.7% for T-DM1, a difference of 8.7 percentage points. Safety was generally consistent with previously known levels, and no new safety concerns were identified.
Enhertu was approved in the EU last June as a treatment for HER2-positive metastatic solid cancer, and in September as a first-line treatment for HER2-positive metastatic breast cancer. Until this early breast cancer approval, the indications have been expanded three times in the past four months.
In November 2024, Alteogen signed an exclusive technology export agreement with Daiichi Sankyo for the development and commercialization of Enhertu's SC formulation. The maximum contract size is $300 million, and sales royalties after commercialization are separate.
Enhertu SC formulation using Alteogen's 'ALT-B4' technology is currently in phase 1 clinical trials. Safety and pharmacokinetic properties are being evaluated in patients with recurrent and metastatic solid cancer.
For early breast cancer, anticancer drugs are administered repeatedly for a certain period of time to prevent recurrence after surgery. If an SC formulation that can reduce administration time compared to intravenous injection is developed, there is room to improve treatment convenience for patients and medication efficiency for medical institutions.
The currently ongoing SC clinical trial is not a study targeting patients with early breast cancer. This EU approval is also for the existing intravenous formulation and is not directly linked to Alteogen's additional profits. Depending on the scope of clinical development and approval of SC formulations in the future, early breast cancer may become a new commercial target.
