On February 2, 2026 Personalis, Inc. (Nasdaq: PSNL), a leader in advanced genomics for precision oncology, reported the publication of a new study in npj Precision Oncology highlighting the power of its ultrasensitive molecular residual disease (MRD) assay, NeXT Personal, in monitoring immunotherapy response across a broad range of advanced cancers.

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The study, titled "Ultrasensitive ctDNA monitoring reveals early predictors of immunotherapy response in advanced cancer," was led by oncology researchers at UC San Diego Moores Cancer Center.

The findings reinforce the NeXT Personal test’s ability to detect circulating tumor DNA (ctDNA) at ultrasensitive levels, providing a window for earlier clinical intervention that other approaches may miss. The NeXT Personal test achieves ultrasensitive detection of small traces of ctDNA from a patient’s blood sample using a personalized approach that tracks up to ~1,800 tumor-specific variants unique to each patient’s tumor.

While immunotherapy has transformed cancer care, only ~10-40% of patients achieve durable benefit, making it critical to monitor how patients are responding to therapy. This interim analysis of the ongoing study includes 39 patients with advanced solid tumors—across nine different cancer types—treated with immune checkpoint inhibitors alone or in combination with other therapies. Key findings include:

Early identification of therapy response: Molecular response—defined by ctDNA dynamics—was detectable early, a median of 23 days after starting immunotherapy. Patients achieving an early molecular response had significantly longer progression-free survival.
Lead time over imaging: For patients whose disease progressed, NeXT Personal identified molecular progression a median of 161 days (over five months) before imaging.
Criticality of the ultrasensitive range in advanced tumors: The study found that even in advanced tumors where ctDNA shedding can be higher, 33% of positive ctDNA detections occurred in the ultrasensitive range (below 100 PPM). These are detections that could be missed with a less sensitive test.
Strong correlation with outcomes: Patients who achieved molecular complete response (ctDNA clearance) had seven times higher overall survival than patients who did not achieve ctDNA clearance.
"We continue to expand the clinical evidence that NeXT Personal can be used to monitor therapy response in advanced cancer patients on immunotherapy," said Richard Chen, M.D., M.S., Chief Medical Officer and Executive Vice President of R&D at Personalis. "This pan-cancer study builds on our recent publication in Clinical Cancer Research, similarly showing the impact of ultrasensitive ctDNA testing in late-stage cancers. With immunotherapy, an important pillar of cancer treatment in advanced cancer patients, the need for better tools to evaluate patient response is increasingly important. These findings show how NeXT Personal and ultrasensitive ctDNA testing can potentially play an important role in impacting care across a broad spectrum of solid tumors."

(Press release, Personalis, FEB 2, 2026, View Source [SID1234662413])