China Accepts NDA for KN026, the First Domestically Developed HER2 Bispecific Antibody, for Breast Cancer Indications

On August 4, 2026, regulators in Beijing accepted a new drug application that could reshape how doctors treat HER2-positive breast cancer in China. The filing, bearing reference number CXSS2600114, marks the latest milestone for KN026—a bispecific antibody designed to attack the cancer-promoting HER2 protein from two angles simultaneously.

Just one month earlier, China's Center for Drug Evaluation had fast-tracked two additional uses of the drug: first-line treatment of unresectable or metastatic HER2-positive breast cancer in combination with albumin-bound docetaxel, and neoadjuvant therapy for early or locally advanced cases with the same backbone plus or minus carboplatin. The accelerated review signals Beijing's growing urgency to expand treatment options for the roughly 20% of breast cancers driven by HER2 overexpression.

Developed by Alphamab Oncology, KN026 binds to two non-overlapping sites on the HER2 receptor, effectively shutting down the signaling pathways that fuel tumor growth. In August 2021, CSPC Pharmaceutical Group's subsidiary Shanghai Jinmente Biotechnology Co., Ltd. secured exclusive rights to commercialize the drug in mainland China for breast and gastric cancer indications in a deal valued at RMB 1 billion (approximately $140 million USD).

A First for China

The drug already has one approval under its belt. In May 2026, the National Medical Products Administration (NMPA) approved KN026 through the priority review pathway for use in combination with chemotherapy to treat patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma who had previously received at least one trastuzumab-containing regimen. It became the first domestically developed HER2 bispecific antibody to reach the Chinese market.

The regulatory nod came after the drug earned breakthrough therapy designation from the CDE on November 4, 2023—a status reserved for treatments that show substantial improvement over existing options for serious conditions.

Full-Cycle Ambitions in Breast Cancer

CSPC and Alphamab are not stopping at gastric cancer. The partners have launched three Phase III clinical trials in HER2-positive breast cancer, covering first-line therapy, neoadjuvant treatment, and adjuvant care—a comprehensive approach they call "full-cycle management."

The adjuvant trial, registered as NCT07441460, aims to enroll 1,800 patients and is currently in the recruitment phase. The neoadjuvant study, NCT067477338, has already completed enrollment with 521 participants, slightly exceeding its 520-patient target. The first-line trial, NCT05938066—known internally as the Healer study—has also reached full enrollment with 880 patients. All three trials compare KN026 plus albumin-bound docetaxel (HB1801) against the standard combination of trastuzumab and pertuzumab with docetaxel.

A Crowded Competitive Landscape

KN026 does not have the HER2 bispecific space to itself. Globally, only two such drugs have won regulatory approval: zanidatamab, developed by Zymeworks and BeiGene, which gained global approval on November 20, 2024, and received the green light in China on February 27, 2025, for biliary tract cancer; and KN026 itself, approved in China on May 27, 2026.

But competition is closing in. Chia Tai Tianqing Pharmaceutical Group's TQB2930 is advancing through Phase III trials for HER2-positive breast cancer, with additional studies underway in solid tumors and colorectal cancer. As of July 2025, TQB2930 had reached its highest development stage—a position that makes it the most advanced domestic challenger to the current market leaders.

The race for HER2 dominance in China is far from over. With KN026 now seeking to expand its footprint into breast cancer—the most commonly diagnosed cancer among Chinese women—the coming trial results will determine whether Alphamab and CSPC can translate their first-mover advantage into lasting market leadership.