GSK discontinues two feladilimab trials in head and neck cancer

British drugmaker GlaxoSmithKline (GSK) has announced that it will discontinue two phase 2 trials evaluating its investigational inducible T cell co-stimulatory (ICOS) agonist feladilimab.

In a statement issued today, GSK said that following a recommendation by the Independent Data Monitoring Committee, it will stop enrolling patients in the phase 2 INDUCE-3 trial – including discontinuing treatment with the ICOS agonist.

The mid-stage study is evaluating feladilimab – GSK3359609 – plus Merck & Co’s Keytruda (pembrolizumab) compared with placebo plus Keytruda for the potential treatment of patients with PD-L1 positive advanced or metastatic head and neck squamous cell carcinoma (HNSCC).

In addition, GSK has also halted another mid-stage trial – INDUCE-4 – which is investigating feladilimab plus Keytruda and chemotherapy compared to placebo in combination with Keytruda and chemotherapy.

GSK did not say exactly why it was stopping the two mid-stage studies, but it is likely that the ICOS agonist did not yield the results that the British drugmaker was hoping for.

‘The totality of the data will be evaluated to assess the impact on the overall clinical development programme,’ commented GSK.

In the early-stage INDUCE-1 trial results, which included 34 evaluable patients who received feladilimab plus Keytruda, the overall response rate (ORR) was 24%, with responses in this cohort being durable and lasting for six months or longer.

The median progression-free survival (PFS) for the combination cohort was also found to be 5.6 months.

Based on these results, GSK initiated the INDUCE-3 trial to investigate the potential survival benefit for feladilimab with Keytruda in advanced or metastatic HNSCC patients who are PD-L1 positive.

Feladilimab aims to selectively enhance T cell function by stimulating ICOS, a protein found on the surface of certain T cells often found on a number of solid tumours.

In November 2020, Jounce Therapeutics also announced that it would not expand a phase 2 trial of its own ICOS-targeting monoclonal antibody vopratelimab after revealing less-than-stellar results.

An interim analysis of the EMERGE study found that vopratelimab in combination with Bristol Myers Squibb’s Yervoy (ipilimumab) in non-small cell lung cancer (NSCLC) patients who had previously been treated with a PD-(L)1 inhibitor did not meet the pre-specified criteria for continuation of enrolment.