ImmunityBio tries again in papillary bladder cancer

ImmunityBio’s attempt last year to file Anktiva in a new bladder cancer use based on uncontrolled data was met with a refuse to file letter from the FDA – now the group is set to try again, and believes it won’t need to carry out a new trial.

The company’s approach stands in contrast to another bladder cancer contender, Johnson & Johnson, which previously indicated that it’s waiting for readout of the controlled Sunrise-5 trial of its therapy Inlexzo before filing in the same setting, BCG-unresponsive papillary non-muscle invasive bladder cancer. This is despite Inlexzo producing similar data to Anktiva in this use.

ImmunityBio's stock opened up 18% on Tuesday.

Papillary only

Both therapies are already FDA approved for BCG-unresponsive NMIBC with carcinoma in situ (CIS), with or without papillary tumours – Inlexzo as monotherapy, and Anktiva in combination with BCG.

And both companies hope to expand into papillary-only disease. CIS accounts for only about 10% of BCG-unresponsive disease, while the less aggressive papillary form makes up the rest. Standard of care for papillary-only disease is chemotherapy.

Last April, ImmunityBio filed the IL-15 agonist Anktiva with the FDA for BCG-unresponsive papillary NMIBC, based on cohort B of the phase 2/3 Quilt-3.032 trial, which tested Anktiva plus BCG.

But the agency issued a refuse to file letter in May, apparently saying the study wasn’t sufficient to support a regulatory review. This came after J&J told ApexOnco that the FDA had indicated they weren’t going to accept non-randomised data in the papillary population for Inlexzo, a gemcitabine-eluting product then known as TAR-200.

No new trial needed?

Now ImmunityBio reckons it’s found a path forward. The company said on Tuesday that the FDA recommended the company provide “additional information” that could support resubmission of the sBLA.

This “does not include the initiation or design of any new clinical trials”, ImmunityBio added. The company plans to submit the new information to the agency within 30 days.

The group highlighted long-term results from Quilt-3.032, which were recently published in The Journal of Urology. These show 12-month DFS and PFS rates of 58% and 95% respectively with Anktiva plus BCG, with 92% of patients avoiding bladder removal surgery (cystectomy) at one year.

ImmunityBio called these results “unprecedented”, but they look similar to those seen with Inlexzo in cohort 4 of the uncontrolled Sunrise-1 trial, which were last updated at the Society of Urologic Oncology (SUO) meeting in December.

But J&J is waiting for data from ongoing Sunrise-5 trial, which is testing Inlexzo versus chemotherapy in BCG-treated, papillary-only NMIBC. The primary endpoint of that trial is DFS; J&J hasn’t said when it might read out, but noted last April that it was almost fully enrolled.

With the companies taking different approaches, the response from the FDA will be watched with interest.

Cross-trial comparison in BCG-unresponsive papillary NMIBC

Note: *primary endpoint. Source: The Journal of Urology Jan 2026 & SUO 2025.