Pfizer and US biopharma company Arvinas have signed a collaboration agreement to jointly develop and commercialise an investigational oral protein degrader for breast cancer.
The candidate – ARV-471 – is currently in a phase 2 trial for the treatment of patients with estrogen receptor (ER) positive, human epidermal growth factor receptor 2 (HER2) negative locally advanced or metastatic breast cancer.
According to interim data from the ongoing phase 1 dose escalation study of ARV-471 in these patients, the ER protein degrader was found to promote ‘substantial’ ER degradation and also demonstrated an encouraging clinical efficacy and tolerability profile.
ARV-471 is also being studied in a phase 1b combination study alongside Pfizer’s blockbuster CDK4/6 inhibitor Ibrance (palbociclib).
Under the terms of the deal, Pfizer will pay Arvinas $650m upfront and make a $350m equity investment in the company. The companies are set to equally share the worldwide development costs as well as commercialisation expenses and profits.
Arvinas will also subsequently be eligible to receive up to $400m in approval milestones and up to $1bn in commercial milestones relating to ARV-471, while also sharing profits on the drug worldwide.
“Building on Pfizer’s established leadership position in breast cancer science and CDK4/6 inhibition, we are excited to work with Arvinas to maximise ARV-471, the first PROTAC for breast cancer with encouraging early clinical data and a potential novel hormonal therapy backbone for HR+ breast cancer,” said Jeff Settleman, chief scientific officer for oncology research and development at Pfizer.
“This partnership complements Pfizer’s robust research activities in breast cancer, including our multiple next-generation CDK inhibitors currently in early clinical development,” he added.
Pfizer and Arvinas are also planning to initiate two additional trials of ARV-471 this year, including a second phase 1b combination trial with cancer growth blocker everolimus, as well as a trial in the neoadjuvant setting.
Looking ahead to 2022, the two companies also expect to begin phase 3 studies across different lines of therapy in metastatic breast cancer, including combinations with Ibrance, followed by studies in the early breast cancer setting.