Despite having an impressive roster of high-profile supporters, including AbbVie, BMS, J&J, Novartis and Pfizer, PARP-focused Ribon has called it quits after nearly a decade in business.
Ribon Therapeutics, which was working to target novel enzyme families that could become pathologic under stress conditions, has ceased operations after nearly 10 years in business.
The closure was first publicly announced in May 2024 via a video conference but was reported by Endpoints News on Friday. Ribon said at the time that it had “discontinued all material operations” and held an online auction of “substantially all of the assets,” primarily consisting of intellectual property and other assets connected with its clinical development programs.
Ribon at the time put up for sale its “interest in certain deferred and contingent milestone payments” owed it by Boehringer Ingelheim under an existing transaction. Rock Creek Advisors, on behalf of Ankara Trust Company, was scheduled to conduct the sale.
Founded in 2015, Ribon was a clinical-stage biotech that was advancing three PARP inhibitors for various indications. Its most mature candidate was RBN-2397, which the company was developing for squamous cell lung carcinoma in combination with Merck’s Keytruda (pembrolizumab). Ribon initiated a Phase Ib/II study for RBN-2397 in March 2022.
The oral drug candidate was designed to block the PARP7 protein, concentrations of which spike in cells as a response to stress. PARP7 dampens the activity type I interferon and halts the cellular stress response. By inhibiting PARP7, RBN-2397 aimed to stop cell proliferation and restore the body’s innate and adaptive anti-tumor activity.
Phase I data, which were presented at the 2021 American Society of Clinical Oncology Annual Meeting, showed that the drug candidate was generally safe and well-tolerated and could elicit an increase in type I interferon response and immune cells. In a highly heterogeneous study sample of heavily pretreated patients, RBN-2397 achieved one partial response, while nine patients had stable disease for more than four months.
Ribon was also working on the PARP14 inhibitor RBN-3143, which it was developing for moderate-to-severe atopic dermatitis. The biotech touted RBN-3143 as a potential first-in-class therapy that worked by lowering levels of cytokines and disease-causing immune cells.
Before shutting down, Ribon amassed an impressive group of backers. In January 2023, the biotech secured a $ 25 million equity investment from Pfizer. In November 2022, Ribon licensed to Boehringer Ingelheim its preclinical CD38 program.
In July 2021, Ribon closed a $65 million round of financing, which included among its participants AbbVie Ventures, Bristol Myers Squibb, Johnson & Johnson Innovation, Novartis Venture Fund and Takeda Ventures.
