Obsidian Therapeutics has enrolled the first patient in the registration-enabling cohort of its phase 1/2 Agni-01 study evaluating amsoki-cel in advanced melanoma.
The move follows discussions with the FDA, after which the company opted for a single-arm design intended to support a future BLA submission.
The cohort builds on earlier phase 1/2 results showing a 67% ORR at the recommended phase 2 dose, including two complete responses, in patients with difficult-to-treat advanced melanoma.
Parameswaran Hari, Chief Medical Officer of Obsidian, said: “We have obtained alignment with the FDA across key trial design and manufacturing considerations, including drug potency assay, to proceed with the registration-enabling cohort in support of the single-arm accelerated approval pathway for amsoki-cel in advanced melanoma.
“Enrolling the first patient in this cohort is an important step toward bringing a patient-centric TIL treatment regimen to patients with difficult-to-treat ICI-resistant advanced melanoma.”
He added: “We believe amsoki-cel has the potential to serve a broad patient population given its IL2-free regimen, option for less-invasive core needle biopsy tumor tissue procurement, and exclusively low-dose lymphodepletion compatible with outpatient administration.
“We anticipate reporting topline data from the registration-enabling cohort by year-end 2027.”
The Agni-01 study is assessing safety and efficacy of amsoki-cel at the recommended phase 2 dose in ICI-resistant advanced melanoma, with ORR as the primary endpoint measured by blinded independent central review. Enrollment is expected to finish by the end of Q1 2027.
Initiation of the cohort follows earlier data showing strong efficacy and a favourable safety profile, with no dose-limiting toxicities, treatment-related mortality or ICU transfers.
Obsidian is also studying amsoki-cel in non-small cell lung cancer, with phase 1 data expected in the first half of 2027.
