Roche's I-O contender Tecentriq misses again, failing combo colorectal cancer trial

Roche's Tecentriq, in combination with Cotellic, couldn't outdo Bayer's Stivarga at extending overall survival in CRC patients. (Roche)

After a couple of lung cancer wins, Roche’s Tecentriq has stumbled again.

Thursday, the Swiss drugmaker said that a combination of its immuno-oncology med and fellow Roche cancer-fighter Cotellic had come up short in a head-to-head trial against Bayer’s Stivarga in heavily pretreated colorectal cancer (CRC) patients. The combo failed to extend patients' lives better than the Bayer med did alone.

Solo Tecentriq didn’t beat Stivarga, either. That result was less of a surprise, though: More than 95% of patients enrolled in the trial—dubbed IMblaze370—had so-called microsatellite stable tumors, and “based on the available data, checkpoint inhibitors as monotherapy have not demonstrated clinically meaningful efficacy” in that group of CRC patients, it explained in a release. The drugs tend to work better in patients with microsatellite instability-high tumors, which are rare tumors identified with genetic testing.

The flop follows news from last month that the company had paused enrollment for a phase 2 study examining the same combo as a maintenance therapy for first-line, metastatic CRC. The enrollment went on hold after more patients died in the study's experimental arm than in the control group, a spokeswoman said at the time.

RELATED: Bristol-Myers Squibb's Opdivo nabs MSI-H colorectal cancer nod, but it can't match Keytruda's umbrella approval

Had the IMblaze 370 data come up positive, Roche could have made inroads in a CRC field where its two biggest competitors—Merck and Bristol-Myers Squibb—have only narrow CRC approvals for their respective PD-1/PD-L1 meds, Keytruda and Opdivo. Both drugs bear FDA go-aheads to treat CRC patients with microsatellite instability-high tumors, which affect only about 5% of metastatic CRC sufferers, Bristol has said.

And Roche could stand to make up some ground when it comes to immuno-oncology. Right now, Tecentriq is approved in just bladder cancer and non-small-cell lung cancer, where it’s battling both of those rival blockbusters. And in bladder cancer, the cancer type most crowded with PD-1/L1 checkpoint drugs, Tecentriq last year failed to prove it could actually extend patients’ lives.

RELATED: Roche's Tecentriq triumphs in squamous lung cancer. Can it make its mark against Merck?

On the bright side, though, Roche is coming off a pair of Tecentriq victories in lung cancer that could help it play catch-up. Earlier this week, Roche’s Tecentriq-Avastin-chemo cocktail snagged an FDA priority review as a treatment for previously untreated patients with advanced lung cancer. And in March, a phase 3 study showed a Tecentriq-chemo combo could top solo chemo at cutting the risk of disease worsening or death in previously untreated patients with the squamous form of the disease.

Meanwhile, Roche isn’t giving up on finding new options for CRC. “We have a number of studies evaluating medicines in colorectal cancer that could play an important role in the treatment of people with this disease in the future,” Sandra Horning, Roche’s chief medical officer and head of global product development, said in a statement.

It’s still pushing full speed ahead on new uses for Tecentriq, too, with more than 50 studies ongoing across cancer types including kidney, skin, breast, colorectal, prostate, ovarian, blood and liver.