US-based biopharmaceutical company AbbVie will acquire biotechnology company Stemcentrx for nearly $5.8bn.
AbbVie will take over Stemcentrx along with its major late-stage asset rovalpituzumab tesirine (Rova-T), which at present is in registrational trials for small cell lung cancer, also known as small-cell carcinoma (SCLC).
Rova-T is a biomarker-specific therapy and obtained from cancer stem cells and targets delta-like protein 3 (DLL3), which is expressed in more than 80% of SCLC patient tumours and is not present in healthy tissue.
The biopharmaceutical company will fund about $2bn of the total transaction amount in cash while the remaining portion will be funded with stock.
AbbVie chairman and CEO Richard A. Gonzalez said: "The addition of Stemcentrx and its late-stage compound Rova-T provide AbbVie with a unique platform in solid tumour therapeutics and complement our leadership position in hematologic oncology.
"We believe the acquisition of Stemcentrx will strengthen and accelerate our ability to deliver innovative therapies that will have a remarkable impact on patients’ lives."
Expected to close in the second quarter of this year, the transaction is dependent on customary closing conditions and expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act.
In Phase 1/2 studies of relapsed SCLC patients who have earlier failed one or more standard therapies, Rova-T exhibited overall response rates of 44% in the patients who are detected with high expression of DLL3.
The expression of DLL3 suggests that Rova-T might also prove helpful for a wide range of tumour types, including glioblastoma multiforme, metastatic melanoma, pancreatic, prostate and colorectal cancers.
In such cases DLL3 expression varies from 50% to 80%.
Rova-T not only combines a targeted antibody that supplies a cytotoxic agent directly to the DLL3-expressing cancer cells, but also reduces toxicity to healthy cells.
Currently, Rova-T has been submitted to the US Food and Drug Administration (FDA) for Breakthrough Therapy designation, and is being examined as a third-line treatment in SCLC, which so far has no approved therapy.
Memorial Sloan Kettering Cancer Centre Thoracic Oncology Service chief Charles Rudin said: "Rova-T is the first predictive biomarker-based therapy associated with drug efficacy in small cell lung cancer, and that is a big deal for this difficult disease."
Stemcentrx has four other compounds in clinical trials across many solid tumour indications such as triple-negative breast cancer, non-small cell lung cancer and ovarian cancer.
Image: Micrograph of small cell lung cancer. Photo: courtesy of Nephron.