Exact Sciences' Patent for Cologuard Screening Kit Declared Invalid by Patent Board

Exact Sciences' patent for Cologuard colorectal cancer screening kits has been invalidated by the Patent Trial and Appeal Board. The patent covered methods for collecting and preserving stool samples using separate buffers for blood and DNA tests. Shares of Exact Sciences are down 3% to $53.68 following the ruling.

PDS Biotechnology Corporation (NASDAQ: PDSB) has announced significant progress in its clinical trial for PDS01ADC, a novel antibody drug conjugate targeting metastatic colorectal cancer. The company's Phase 2 trial, conducted in collaboration with the National Cancer Institute (NCI), has successfully completed Stage 1 recruitment and met the predetermined efficacy threshold, achieving objective responses in at least 6 of 9 participants per RECIST criteria. This milestone triggers enrollment expansion to 22 participants in the colorectal cancer cohort, with completion targeted for Q4 2025 [1].

The trial, led by Dr. Jonathan Hernandez of the NCI, is an open-label, single-center, non-randomized study with three cohorts: metastatic colorectal cancer, cholangiocarcinoma, and adrenocortical cancer. The colorectal cancer cohort will now expand from 9 to 22 participants, following the successful completion of Stage 1. The trial combines PDS01ADC with floxuridine (FUDR) administered via hepatic artery infusion pump, a specialized approach for liver metastases common in colorectal cancer [1].

Meanwhile, Exact Sciences Corporation (NASDAQ: EXAS) saw its shares drop 3% to $53.68 following a ruling by the Patent Trial and Appeal Board (PTAB) invalidating its patent for Cologuard colorectal cancer screening kits. The patent covered methods for collecting and preserving stool samples using separate buffers for blood and DNA tests. The invalidation of this patent may impact Exact Sciences' market position in the colorectal cancer screening market [2].

These developments highlight the contrasting fortunes of two biotech companies operating in the colorectal cancer space. While PDS Biotechnology advances its clinical pipeline, Exact Sciences faces a setback in its intellectual property portfolio. Both companies will continue to navigate the complexities of clinical development and regulatory challenges in their respective markets.

References:
[1] https://www.stocktitan.net/news/PDSB/pds-biotech-announces-colorectal-cancer-cohort-of-phase-2-clinical-xjyk9xc3qaiy.html
[2] https://www.stocktitan.net/news/EXAS/exact-sciences-colorectal-cancer-screening-patent-invalidated-2025.html