AbbVie has announced plans to snap up privately held US cancer drugmaker Stemcentrx in a deal potentially worth $9.8 billion, in a move designed to expand its solid tumour development pipeline.

Stemcentrx’ lead asset is rovalpituzumab tesirine (Rova-T), an antibody drug conjugate targeting the cancer stem cell protein DLL3, which is expressed in more than 80 percent of small cell lung cancers. The drug is currently in registrational studies, and thus far data has shown an overall response rate of 44 percent.

Rova-T has been submitted for Breakthrough Therapy designation in the US as a third-line therapy for SCLC, where no current approved treatment exists, but it is also being evaluated as an earlier line of treatment as well as in other types of solid tumours including melanoma, thyroid cancer and glioblastoma, among others.

Commercialisation for SCLC is expected in 2018 and, with a multi-billion dollar peak potential, the drug is expected to be a significant contributor to AbbVie’s long-term growth, the firm said.  

Stemcentrx also adds four early-stage clinical compounds in solid tumours and a portfolio of preclinical assets, with several advancing toward clinical trials later this year.

Under the terms of the deal, AbbVie will acquire Stemcentrx for around $5.8 billion in cash and stock, with Stemcentrx investors eligible to receive up to $4 billion for additional, success-based milestone payments for the achievement of certain regulatory and clinical developments.