‘A curious regulatory issue’
The Food and Drug Administration has approved Amgen’s trastuzumab-anns as a trastuzumab biosimilar for the treatment of HER2-positive breast cancer and gastric cancer.
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This biosimilar, to be marketed as Kanjinti, is the fifth trastuzumab biosimilar to be approved by the agency, according to the FDA.
Approval was based in part on the LILAC study, which demonstrated that the biosimilar, previously called ABP-980, had similar efficacy and comparable cardiac safety with trastuzumab.
In the phase 3 study, 725 patients with HER2-positive early breast cancer were randomized to neoadjuvant treatment with trastuzumab-anns or trastuzumab, plus paclitaxel, for four cycles following four cycles of chemotherapy. The primary pathological complete response endpoint was achieved in 48% of those in the biosimilar arm, compared with 40.5% in the trastuzumab arm. Patients then went on to receive adjuvant treatment with ABP 980 or trastuzumab every 3 weeks for up to 1 year following surgery.
Grade 3 or worse adverse events during the neoadjuvant phase occurred in 15% of patients in the ABP 980 group and 14% in the trastuzumab group. The most frequent grade 3 event in both study arms was neutropenia. In the adjuvant phase, grade 3 or worse adverse events occurred in 9% of those continuing ABP 980 and in 6% of those continuing trastuzumab. The most frequent events in both arms were infections, infestations, and neutropenia.
Trastuzumab-anns is indicated for adjuvant treatment of HER2-overexpressing node positive or node negative breast cancer, first-line treatment of HER2-overexpressing metastatic breast cancer, and first-line treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma. The FDA indicates patients should be selected based on an FDA-approved companion diagnostic for a trastuzumab product.
The biosimilar includes a boxed warning for cardiomyopathy, infusion reactions, embryo-fetal toxicity, and pulmonary toxicity.