- The Food and Drug Administration on Friday approved the first immunotherapy regimen to target a hard-to-treat type of metastatic breast cancer, granting an accelerated OK to a combination of Roche's Tecentriq and an older chemotherapy called Abraxane.
- Patients with so-called triple-negative breast cancer and whose tumors express a biomarker known as PD-L1 are eligible to receive the Tecentriq regimen under the label cleared by the FDA. The FDA's approval, however, is contingent on further study to confirm the benefit Roche observed in the Phase 3 study supporting its application.
- In that trial, called IMpassion 130, treatment with Tecentriq and Abraxane extended progression-free survival by a little over two months versus Abraxane alone in previously untreated patients. Data on survival, however, were not yet analyzable.
Triple-negative breast cancer, or TNBC, is the third tumor type Roche's Tecentriq (atezolizumab) is cleared to treat in the U.S. Unlike bladder and lung cancers, however, Tecentriq is the sole immunotherapy approved.
Tecentriq's approval in bladder cancer is also under an accelerated OK that the FDA later limited to only patients whose tumors express high levels of PD-L1.
More notably, the FDA OK adds a new treatment option for TNBC, for which commonly used breast cancer treatments like Herceptin (trastuzumab) or Ibrance (palbociclib) aren't effective.
Breast cancers classified as triple negative lack expression of estrogen and progesterone receptors, and don't overexpress HER2. Chemotherapies like are Abraxane (nab-paclitaxel) can be used but median survival is still estimated to be less than 18 months.
Tecentriq plus Abraxane are only cleared for PD-L1 positive patients, a group thought to account for roughly 40% of the broader TNBC population.
In Roche's IMpassion 130 study, the combination regimen cut the risk of disease worsening or death by 40% versus Abraxane alone. That risk reduction, however, doesn't translate into dramatically longer progression-free survival, with median times checking in at 7.4 months for the combo and 4.8 months for the control.
Roche also measured Tecentriq regimen's efficacy in the intent-to-treat population of the trial. Among that larger group, the combination delivered a lesser 20% risk reduction over Abraxane.
When measured across the study population overall, the difference in survival between the two groups wasn't statistically significant (although a numerical advantage was observed.)
Among PD-L1-positive patients, those given the combination lived a median of 10 months longer than those on the control arm, but that result wasn't formally tested because the survival difference in the overall study didn't pass the statistical threshold for success.
Safety results from IMpassion 130 were generally consistent with the known profile of both medicines, and no new side effects were observed, Roche said.
While Tecentriq might be the first approved, Roche's drug isn't the only immmunotherapy being studied in TNBC. Rival Merck & Co. is testing its PD-1 inhibitor Keytruda (pembrolizumab) in three Phase 3 studies across several lines of treatment. Results are expected this year.