Artios Pharma has secured $115 million in Series D funding to advance its pipeline of next-generation DNA damage repair inhibitors for cancer treatment, the company announced Monday. The financing will support expanded clinical development of two lead programs targeting novel pathways beyond the established PARP inhibitor class.
The funding round was co-led by founding investor SV Health Investors and new backer RA Capital Management, with participation from Janus Henderson Investors and more than a dozen other venture firms including Sofinnova Partners, Novartis Venture Fund, and EQT Life Sciences.
Lead ATR Inhibitor Shows Promise in ATM-Negative Tumors
The majority of proceeds will support alnodesertib, Artios' lead ATR (ataxia telangiectasia and Rad3-related protein) inhibitor currently in testing for second-line pancreatic cancer and third-line colorectal cancer. Data presented in April demonstrated significant activity in patients with compromised DNA repair systems.
When combined with low-dose irinotecan, alnodesertib achieved a 50% confirmed overall response rate in patients with advanced or metastatic solid tumors who were ATM-negative. In the broader subgroup of patients with low ATM expression, the response rate was 22%.
"ATM-negative pancreatic and colorectal tumors are two areas of very high unmet need," said CEO Mike Andriole. The company plans to use the new funding to enroll more ATM-negative patients in both cancer cohorts, capitalizing on the drug's apparent selectivity for tumors with compromised DNA repair mechanisms.
Polymerase Theta Program Targets PARP Resistance
The Series D proceeds will also enable Artios to initiate a Phase II trial for ART6043, a DNA polymerase theta inhibitor being developed for patients with BRCA-mutant HER2-negative breast cancer. Data presented at the 2025 Congress of the European Society for Medical Oncology in September supported a once-daily dosing profile and highlighted the drug's potential for combination with AstraZeneca and Merck's PARP inhibitor Lynparza.
Safety findings pointed to a "benign" tolerability profile, according to the company. Andriole explained that most patients on PARP inhibitors eventually progress due to drug resistance that restores tumor DNA repair capabilities. Adding a polymerase theta blocker might prevent this resistance mechanism, potentially leading to better and more durable responses.
"Of course, the only way to prove that is in a randomized study," Andriole noted. The company plans to start a randomized trial next year testing whether the combination of ART6043 and a PARP inhibitor is superior to PARP therapy alone.
Expanding Beyond PARP Inhibitors
Artios is developing drugs that treat cancer by blocking proteins involved in DNA damage repair, building on the success of PARP inhibitors, which have become widely used cancer treatments. The company has been searching for the "next generation" of pathways that might deliver similar clinical impact.
Several other companies, including AstraZeneca, Merck KGaA, and Repare Therapeutics, have been developing ATR inhibitors, though none have yet received regulatory approval. Merck KGaA previously discontinued work on an earlier ATR blocker and pivoted to a newer candidate now in mid-stage testing.
Pipeline Expansion and Future Plans
Beyond its two lead programs, Artios is conducting preclinical research on an antibody-drug conjugate targeting DNA damage repair mechanisms, with plans to name a lead candidate from this work in 2026.
The Series D funding brings Artios' total raised capital to more than $320 million and provides runway into 2027, when the company expects to have data from both top programs. "The right decision for now was to continue to stay private and advance these two programs with this financing," Andriole said. "We'll explore what comes next when we've got data in hand."
The fundraising reflects continued investor interest in oncology innovation, joining other significant 2025 biotech financings including Isomorphic Labs' $600 million round, Odyssey Therapeutics' $213 million Series D, and Kriya Therapeutics' $313.3 million raise.
