NCI-MATCH Trial Subprotocol: T-DM1 in HER2-Positive Salivary Gland Tumors
Posted: Friday, January 24, 2020
Ado-trastuzumab emtansine (T-DM1) showed clinical activity in salivary gland tumors that overexpress HER2. These results represent ‘Arm Q’ of the National Cancer Institute–Molecular Analysis for Therapy Choice trial (NCI-MATCH). Komal Jhaveri, MD, FACP, of Memorial Sloan Kettering Cancer Center, New York, published the work she completed with colleagues in the Annals of Oncology.
“The benefit lasted 2 years in the patient with squamous cell cancer of the parotid gland and 9 months in the case of mucoepidermoid carcinoma of the parotid gland,” said Dr. Jhaveri in an ECOG-ACRIN press release. “This is a hint of activity that needs to become the focus of a larger trial.”
This study enrolled 38 patients with HER2 amplification at a copy number greater than 7 based on next-generation sequencing. Those who had prior trastuzumab, pertuzumab, or T-DM1 treatment were excluded.
There were 36 patients included in the efficacy analysis. These patients had a median of 3 prior therapies in the metastatic setting, and the median copy number of HER2 was 17. This group had multiple unique histologies, excluding breast and gastric cancers. There were 17 patients (47%) who had stable disease for a duration of 4.6 months. The overall 6-month progression-free survival rate was 23.6%. There was a trend toward tumor shrinkage with higher levels of HER2 copy numbers identified via next-generation sequencing.
Partial responses were noted in two patients (5.6%): one with mucoepidermoid carcinoma of the parotid gland and one with parotid gland squamous cell carcinoma. Of note, the copy number in the squamous cell carcinoma was 129, and the mucoepidermoid carcinoma had a copy number of 21. These patients saw shrinkage of their tumors by at least 30%.
Although the regimen was well tolerated, common toxicities included fatigue, anemia, fever, and thrombocytopenia. This protocol did not find any new toxicities associated with T-DM1.
Disclosure: For full disclosures of the study authors, visit academic.oup.com.