New Combination for HER2+ Breast Cancer Meets Phase 3 Trial Goal

A phase 3 clinical study for anbenitamab (KN026) used with a special form of docetaxel (HB1801) successfully met its main goal for patients with HER2-positive early or locally advanced breast cancer, CSPC Pharmaceutical Group Limited has announced via a news release.

The pharmaceutical group, alongside partners Shanghai JMT-BIO Technology Co., Ltd. and Jiangsu Alphamab Oncology Co., Ltd., conducted the multicenter study to find better options for patients to receive before surgery. This announcement follows the achievement of a primary endpoint that showed the combination treatment was effective in clearing cancer signs before surgical intervention. While the drug is being developed internationally, it has already caught the attention of regulators in the United States, where anbenitamab has been granted Orphan Drug Designation by the U.S. Food and Drug Administration (FDA) for certain related conditions.

Main data that support the findings

The study focused on HER2-positive breast cancer, a subtype that accounts for approximately 20% to 30% of all breast cancer cases. For many patients, the cancer is found at an early or locally advanced stage. In these cases, the primary goal of treatment is to reach a radical cure through surgery combined with therapy given before or after the operation.

The main measurement of success in this trial was the total pathological complete response, often called tpCR. This occurs when no signs of cancer remain in the breast tissue or lymph nodes after treatment is finished but before surgery is performed. Reaching this milestone is very important for patients with cancer. Data show that patients who achieve a total pathological complete response have significantly improved event-free survival and overall survival. This is especially true for those with the HER2-positive subtype.

Currently, the standard treatment given before surgery for this type of cancer is a combination of Herceptin (trastuzumab), Perjeta (pertuzumab) and chemotherapy. However, only about half of the patients who receive this standard care reach a total pathological complete response. This trial showed that the combination of anbenitamab and HB1801, with or without the addition of carboplatin, significantly improved the rates of total pathological complete response compared to that existing standard. These results are considered highly significant for both clinical practice and the patients who need more effective options to help facilitate earlier surgery.

Trial details

The phase 3 study, known as Neo-Healer or KN026–004, was an open-label, multicenter trial that randomly assigned approximately 520 patients to different groups. The trial compared the new combination of anbenitamab and HB1801 against the current standard of care. Some patients in both groups also received carboplatin.

Anbenitamab is a HER2 bispecific antibody. It is designed to target the HER2 protein in a specific way to help treat the cancer. Multiple clinical studies are currently looking at how anbenitamab works as a first-line treatment for breast cancer and as a therapy used both before and after surgery.

Safety

A major part of this study involved a new way to deliver the chemotherapy drug docetaxel. The version used in this trial, HB1801, is albumin-bound. Traditional docetaxel can be difficult to administer because it does not dissolve easily in water. Because of this, standard formulations must use solvents like polysorbate 80 and ethanol. These solvents are known to cause severe allergic reactions in some patients. They also require the medication to be dripped into the vein very slowly and at low concentrations. Furthermore, the standard version requires medical staff to use special infusion bags that do not contain certain plastics.

HB1801 changes this by wrapping the docetaxel in human serum albumin. Because it does not contain the usual solvents, it offers several safety benefits for patients with cancer. One of the most important findings is that no hypersensitivity or allergic reactions occur with this version. Patients do not need to take hormone or steroid pretreatment before their infusion, which is usually a requirement for standard docetaxel.

The albumin-bound version can be given to the patient quickly and at higher concentrations. This makes the treatment more convenient and may help patients stay on their treatment schedule more easily. Early clinical results across different stages of testing showed that HB1801 was better at reaching the goal of reducing toxicity while increasing the effectiveness of the drug compared to the older docetaxel injection. This improved safety profile is a key part of the ongoing pivotal trials for both breast and gastric cancers.

Final detailed data from the Neo-Healer study will be presented at an upcoming international conference.

Editor's note: This article is for informational purposes only and is not a substitute for professional medical advice, as your own experience will be unique. Use this article to guide discussions with your oncologist. Content was generated with AI, reviewed by a human editor, but not independently verified by a medical professional.

References

1. “PHASE III CLINICAL STUDY OF ANBENITAMAB (KN026) IN COMBINATION WITH DOCETAXEL (ALBUMIN-BOUND) (HB1801) FOR NEOADJUVANT TREATMENT OF HER2+ BREAST CANCER MEETS PRIMARY ENDPOINT.” News release. CSPC Pharmaceutical Group Limited. March 31, 2026.

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