Tempus AI has entered into a definitive agreement to acquire Personalis for approximately $1.5 billion, expanding the company’s presence in the rapidly growing molecular residual disease (MRD) testing market.
The transaction is expected to close in late 2026 or early 2027, pending shareholder and regulatory approvals.
The acquisition builds on a partnership launched in 2023, when Tempus invested in Personalis and began commercially offering the company’s NeXT Personal MRD assay.
“MRD is a large and rapidly growing market with the potential to truly transform how cancer patients are monitored,” said Tempus CEO Eric Lefkofsky in a press release.
The deal is the second major acquisition within the last 12 months by Tempus within the clinical lab market. The Dark Report noted that Tempus’ $81.25 million acquisition of Paige last September signaled a market correction in digital pathology, where high development costs, reimbursement barriers, and workflow challenges have tempered earlier enthusiasm for AI-powered diagnostics.
The earlier deal also suggested that digital pathology companies may increasingly seek partnerships or buyers with stronger data, commercial, and precision medicine platforms to support wider adoption.
MRD testing gains commercial momentum
Personalis’ tumor-informed test analyzes circulating tumor DNA to help clinicians monitor treatment response, identify residual cancer, and detect recurrence earlier. The assay currently has Medicare coverage for three clinical indications, with additional coverage anticipated.
By combining the test with Tempus’ artificial intelligence capabilities, multimodal patient data, and commercial infrastructure, the companies hope to expand access to longitudinal cancer monitoring and support biomarker discovery.
The deal also reflects growing diagnostics industry investment in MRD and liquid biopsy testing. Tempus estimates the emerging MRD market represents a $20 billion opportunity as cancer survival improves and more patients require long-term monitoring.
Personalis reported preliminary second-quarter revenue of $22.4 million. The company performed 10,384 clinical tests during the quarter, a 33% increase from the previous quarter.
For clinical laboratories and pathology groups, the acquisition illustrates how MRD testing is becoming more closely integrated with broader precision oncology platforms. As reimbursement and clinical adoption expand, laboratories may see increased demand for highly sensitive circulating tumor DNA testing throughout the cancer care continuum.
