Decision for Retifanlimab Approval Deferred for SCAC Treatment by ODAC

The Oncologic Drugs Advisory Committee has decided to wait until more results from a clinical trial of retifanlimab are available to make a final decision about approval in squamous cell carcinoma of the anal canal.

Approval of retifanlimab for the treatment of advanced or metastatic squamous cell carcinoma of the anal canal (SCAC) following progression on or intolerance of platinum-based chemotherapy will be deferred, according to a decision by the Oncologic Drugs Advisory Committee (ODAC) of the FDA as it awaits further results to support efficacy.1

This decision to defer approval of the biologics license application (BLA) was based on a 13-4 vote from the ODAC to wait until more efficacy data from the phase 3 POD1UM-303 trial (NCT04472429) of retifanlimab plus carboplatin/paclitaxel or matched placebo are available, announced the developer of the intravenous PD-1 inhibitor, Incyte, in a press release.

“While we are disappointed by the outcome of today’s ODAC vote, we will continue to work closely with the FDA as it completes its review of the BLA for retifanlimab,” said Lance Leopold, MD, Group Vice President, Immuno-Oncology Clinical Development at Incyte, said in a press release. “Patients with advanced SCAC who have progressed after first-line platinum-based chemotherapy currently have no FDA-approved treatments available to them and face an extremely poor prognosis. We continue to believe that retifanlimab can provide an additional, much-needed option for these patients based on the favorable benefit/risk shown in our trial.”

Previously, retifanlimab earned priority review for this indication based on the results of the open-label, single-arm phase 2 POD1UM-202 trial (NCT03597285), which evaluated 94 previously treated patients with advanced or metastatic SCAC. Patients were given 500 mg of retifanlimab intravenously every 4 weeks for 2 years.2

The primary end point of this study was objective response rate (ORR). Secondary end points were duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS), along with safety and pharmacokinetics.

The ORR with retifanlimab monotherapy was 13.8%, including 1 complete response and 12 partial responses, with 33 (35.1%) cases of stable disease. Of note, responses were observed regardless of PD-1 status, liver metastases, age, or HIV-positive status. The median DOR of 9.5 months.

The median PFS was 2.3 months (95% CI, 1.9-3.6) and median OS was 10.1 months (95% CI, 7.9-NE). Responses were associated with longer PFS and OS.

Adverse effects (AEs) of grade 3 or higher were reported in 11.7% of the patients and immune-related AEs were reported in 6.4%. The most common AEs reported were fatigue and diarrhea, occurring in less than 20% each.

The FDA previously granted retifanlimab Orphan Drug Designation for the treatment of anal cancer.

Reference

1. Incyte Announces Outcome of FDA Oncologic Drugs Advisory Committee (ODAC) Meeting Reviewing Retifanlimab as a Treatment for Patients with Squamous Cell Carcinoma of the Anal Canal (SCAC). News Release. June 24, 2021. Accessed June 25, 2021. https://bit.ly/2SWOg77

2. Incyte announces acceptance and priority review of BLA for retifanlimab as a potential treatment for patients with squamous cell carcinoma of the anal canal (SCAC). News release. Incyte. Published January 21, 2021. Accessed June 25, 2021. https://bit.ly/3jfuePQ