The CRO allegedly involved in errors that occurred during two of Acelyrin’s trials of izokibep, an interleukin-17A inhibitor, has pushed back against the biopharma’s claims in an SEC filing.

Last Monday, Acelyrin issued a press release disclosing trial execution errors in its ongoing psoriatic arthritis (PsA) trial of izokibep. These mistakes, which stemmed from an incorrectly programmed protocol, were allegedly the fault of the trial’s CRO, Fortrea, and a vendor it worked with, the release said.

“Acelyrin’s team recently identified clinical trial execution errors involving its CRO and one of the vendors engaged by the CRO. Acelyrin has confirmed that the protocol, which outlined dosing sequence, was correct,” the biopharma alleged. “However, Acelyrin’s protocol was programmed incorrectly by the vendor, resulting in a sequencing error that went further unidentified through the providers’ testing processes.”

The now-resolved PsA trial issue, while it caused participants to receive placebo and the investigational drug in random order rather than an alternating pattern as directed by the protocol, did not lead to any safety risks, and no patients received more of the trial drug than was already specified in the protocol, the company clarified.

The press release also implied that “certain confounding factors” in Acelyrin’s hidradenitis suppurativa (HS) trial, which is evaluating the same drug, led to quality control measures beyond standard protocol and may have involved the CRO as well.

Now, Fortrea is standing by its performance in the two trials as it commits to seeing the analysis of the PsA trial through and supporting Acelyrin with its next steps.

“Fortrea objects to the implications that Fortrea’s study conduct impacted the trial outcomes. Fortrea stands behind its conduct of the HS clinical trial in accordance with the protocol and applicable regulatory requirements,” the CRO said in its SEC filing. Additionally, it “object[s] to the statements related to ‘the provider’s testing processes’ and who uncovered the third-party error. Furthermore, the sequencing issue is isolated to two arms of the PsA trial and is not related to the HS trial.”