HONOLULU – Treatment with the pan-HER tyrosine kinase inhibitor neratinib leads to durable responses and disease control in heavily pretreated metastatic patients with HER2-mutant cervical cancer, preliminary efficacy results from the phase 2 SUMMIT basket trial suggest.
Of 11 trial subjects evaluable for efficacy, 3 (27%) had objective confirmed responses and 6 others had stable disease for at least 16 weeks (clinical benefit rate, 55%). Median progression-free survival was 7 months, Anishka D’Souza, MD, reported at the Society of Gynecologic Oncology’s Annual Meeting on Women’s Cancer.
Study subjects included HER2-mutant metastatic cervical cancer patients. Most (89%) had adenocarcinoma and 11% had squamous cell carcinoma, saidof the University of Southern California, Los Angeles.
The median number of total prior regimens was two, with a range of one to four, she said. Patients received oral neratinib at a dose of 240 mg once daily.
The treatment was generally well tolerated; the most common adverse event was diarrhea, with only one grade 3/4 case occurring, she said, noting that high-dose loperamide prophylaxis was mandatory during cycle 1 because of the high incidence of diarrhea.
Though preliminary, the findings are notable as somatic HER2 (ERBB2) mutations, observed in about 5% of metastatic cervical cancer cases, are associated with poor prognosis, she explained, noting that there are limited treatment options and few long-term durable responses.
“There is a great need for additional treatment options,” she said.
Neratinib has been shown to have single-agent clinical activity in multiple HER2‑mutant cancers, so Dr. D’Souza and her colleagues are assessing its safety and efficacy as either monotherapy or in combination with other treatments across multiple tumor types. The current analysis focuses on the cohort of patients who received neratinib monotherapy.
Neratinib use in this cohort led to durable responses and disease control in heavily pretreated metastatic patients with HER2-mutant cervical cancer, she said, adding that “this is an ongoing study and we are continuing to enroll patients to expand our dataset.”
Dr. D’Souza reported having no financial disclosures.
SOURCE: D’Souza A et al. SGO 2019, .