AstraZeneca, Daiichi Drug Approved as New First-Line Therapy for Tough Type of Breast Cancer

A Daiichi Sankyo and AstraZeneca drug is now approved as a first-line treatment for a particularly difficult-to-treat type of breast cancer, bringing a new targeted therapy to patients that’s positioned at an advantage over a Gilead Sciences product from the same class of medicines.

The FDA’s Friday regulatory decision for the drug, Datroway, covers the treatment of triple negative breast cancer (TNBC). It’s named for the lack of three receptors found in other types of breast cancer, which means that therapies for those targets won’t work. Chemotherapy is the first line of treatment for TNBC. The Merck immunotherapy Keytruda is also approved for this setting alongside chemotherapy. But not all TNBC patients are eligible for immunotherapy, which highlights the need for new treatment options.

Datroway is an antibody drug conjugate (ADC) designed to target TROP2, a protein abundant on the surface of many cancer cells, including most triple negative breast cancers. The FDA submission was based on Phase 3 results showing Datroway reduced the risk of disease progression or death by 43% compared to chemotherapy. For patients with metastatic TNBC who were not candidates for immunotherapy, Datroway led to median progression-free survival of 10.8 months compared to 5.6 months for the chemo arm; median overall survival was 23.7 months for Datroway-treated patients versus 18.7 months for those who received chemo. The objective response rate was 64% for the study drug versus 30% for chemotherapy. The clinical trial results were presented last fall during the European Society of Medical Oncology meeting.

The first TROP2-targeting ADC for TNBC was Gilead Sciences’ Trodelvy, approved in 2020 as a third-line or later treatment. Gilead aims to bring this drug into earlier lines of treatment. In patients ineligible for immunotherapy, Phase 3 results presented at the same ESMO meeting showed a 38% reduction in the risk of disease progression or death. The Gilead drug led to a median 9.7 month improvement in progression-free survival versus 6.9 months for the chemo arm; overall survival data were not yet mature.

For now, Datroway has the edge over Trodelvy in TNBC. This ADC was discovered and developed by Daiichi Sankyo. In 2019, the company began an alliance with AstraZeneca focused on Enhertu, a HER2-targeting ADC. The following year, AstraZeneca paid $1 billion up front to begin a collaboration on DS-1062, which became Datroway. Up to $5 billion more is tied to the achievement of regulatory and commercial milestones for Datroway, which has racked up three approvals in the past 18 months.

Datroway was first approved last year for HR positive and HER2 negative breast cancer and then for EGFR-mutated non-small cell lung cancer. The TNBC regulatory decision is an accelerated FDA approval based on the objective response rate the duration of response. Continued approval in this indication may require additional data from a confirmatory study.

Here’s a recap of other recent regulatory developments:

More Cancer Drug Approvals

—BeOne Medicines received FDA approval for Beqalzi as a treatment for the rare blood cancer mantle cell lymphoma. While the Beqalzi addresses the same target as Venclexta, a blockbuster blood cancer drug from AbbVie and Genentech, BeOne’s drug is designed with properties intended to give it safety advantages.

—Veppanu, a drug developed by partners Arvinas and Pfizer, received FDA approval for treating ER-positive, HER2-negative breast cancers carrying an ESR1 mutation. It’s the first approval in a class of drugs that leverage a mechanism called targeted protein degradation. Veppanu will be commercialized by Rigel Pharmaceuticals, which paid $85 million up front for global rights to the small molecule.
—Daiichi Sankyo and AstraZeneca drug Enhertu expanded its FDA approval with two new indications. The first is as a neoadjuvant treatment (before surgery) for HER2-positive stage II or III breast cancer. The second is as an adjuvant (after surgery) treatment for HER2-positive breast cancer patients who have residual invasive disease following neoadjuvant treatment.

—Bizengri, a drug from Partner Therapeutics, expanded its label to include the treatment of cholangiocarcinoma driven by NRG1 gene fusions. Partner licensed U.S. rights Bizengri from Merus, which steered the fusion protein to a 2024 FDA approval for treating pancreatic adenocarcinoma and non-small cell lung cancer positive for NRG1 gene fusions.

—Taiho Pharmaceutical drug Inqovi expanded its approval to include use alongside the AbbVie and Genentech drug Venclexta as a treatment for adults with newly diagnosed acute myeloid leukemia. The Taiho oral small molecule was first approved by the FDA in 2020 as a treatment for myelodysplastic syndromes, including chronic myelomonocytic leukemia.

New Drugs for Inflammation & Immunology

—AstraZeneca lupus drug Saphnelo is now approved in a once-weekly formulation developed for self-administration by autoinjector pen. Saphnelo was first approved for lupus in 2021. That version of the antibody drug is administered as an intravenous infusion.

—Incyte received FDA approval for Jakafi XR, an extended-release version of its oral inhibitor of JAK 1 and JAK 2 proteins. This drug may now be used to treat the same myelofibrosis, polycythemia vera, and acute graft-versus-host disease indications as Jakafi, but with once-daily versus twice-daily dosing of the original drug.

—Bristol Myers Squibb immunology drug Sotyktu received European Commission approval as a treatment for active psoriatic arthritis in adults. The drug first reached patients in Europe in 2023, approved for treating moderate-to-severe plaque psoriasis.

—AstraZeneca’s Breztri Aerosphere expanded its FDA approval to maintenance treatment of asthma. The inhalable triple combination therapy was first approved in 2020 for treating chronic obstructive pulmonary disease.

Regulatory Setbacks

—The FDA placed a full clinical hold on Aardvark Therapeutics’ ARD-101, which had reached Phase 3 testing as a treatment for Prader-Willi syndrome, a rare metabolic disease that leads to excessive overeating. Aardvark voluntarily paused the study in February after a cardiac safety signal emerged in a healthy volunteer study. The company said it will now unblind the trial data to find a path forward for the small molecule.

—Following a patient death, the FDA paused enrollment of new patients at U.S. sites testing evenamide, a Newron Pharmaceuticals drug in development for treatment-resistant schizophrenia. The death, which occurred at a site outside the U.S., was deemed by a trial investigator as unrelated to the study drug, Newron said.

Decisions for Rare Disease Drugs

—X4 Pharmaceuticals received European Commission approval for Xolremdi as a treatment for WHIM syndrome, an ultra-rare primary immunodeficiency. Norgine holds European rights to the drug. The FDA approved Xolremdi in 2024.

—The European Commission approved Palsonify, a Crinetics Pharmaceuticals pill developed to treat acromegaly, a rare endocrine disorder. The FDA approved Palsonify last September.

—Argenx drug Vyvgart and the injectable version Vyvgart Hytrulo expanded their approvals to include the treatment of all adults with generalized myasthenia gravis (gMG), a rare neuromuscular disorder. Vyvgart’s initial approval in 2021 covered only the treatment of gMG patients whose disease is driven by one particular antibody, the AChR antibody.

Other FDA Approvals

—AstraZeneca landed FDA approval for Baxfendy, first in a new class of hypertension medicines. The once-daily pill came from AstraZeneca’s 2023 acquisition of CinCor Pharma for $1.3 billion.

—Axsome Therapeutics drug Auvelity expanded its label to include the treatment of agitation associated with Alzheimer’s disease. The twice-daily pill was initially approved in 2022 for treating major depressive disorder.

Public domain image by the National Cancer Institute