Roche executives have insisted that they haven’t given up on anti-TIGIT checkpoint inhibitors, even as they dodged questions about whether their candidate has flunked yet another phase 3 trial.
Tiragolumab already notched two notable late-stage trail failures last year. The publication this morning of documents (PDF) tied to Roche’s first-quarter earnings results revealed that another phase 3 study, dubbed SKYSCRAPER-08, would continue to its final analysis. The news sparked speculation among industry analysts that the trial had been unable to demonstrate overall survival at an interim look—a sign that the drug may have failed yet again.
On a call with analysts this morning, executives walked a verbal tightrope between advising participants not to rush to the assumption of a clinical failure without hinting that the drug had demonstrated success.
The TIGIT space is “intensively competitive,” recently appointed Roche CEO Teresa Graham said, when asked why executives couldn't be more precise about how the drug had fared in the trial.
“We have a very robust clinical trial program that we're currently running,” Graham added. “And we are also aware that it is an extremely competitive space. So I think as we receive data that is meaningful and material, we will share it.”
Once hailed as the future of immuno-oncology, TIGITs have fallen wide of the mark. Roche’s trials last year were unable to demonstrate that tiragolumab could match the progression-free survival achieved by Tecentriq alone in patients with non-small cell lung cancer. More recently, Merck & Co. has also struggled.
One of Roche's failed lung cancer trials, dubbed SKYCRAPER-01, is due to produce a final analysis in the third quarter, Graham pointed out, adding that “there are several other data sets that will read out later this year as well.”
“So I think the story on TIGIT is far from fully written,” the CEO added. “There's a lot we still don't know and we will need to wait for the clinical trial data to read out.”
SKYSCRAPER-08 was designed to compare the impact of a treatment regimen of tiragolumab, Tecentriq and chemo compared with chemo alone in 461 patients with metastatic esophageal squamous cell carcinoma. The study wrapped up in February, according to ClinicalTrials.gov.
Whatever the outcome of the trial—which is expected to read out toward the end of the year—Graham’s comments on the call made it clear that Roche’s TIGIT explorations are far from over.
“We continue to be really interested in the TIGIT pathway,” Graham said. “We continue to think that this has a lot of mechanistic and biologic rationale and could still potentially be something that helps redefine what cancer immunotherapy treatment looks like going forward.”
“In addition to the trials that we're currently running, we do continue to signal-seek in different combinations and in different tumour types,” she added. “You will likely see us announce additional trials and additional phase 3 starts.”