Robert Iannone
Analyst · Jefferies.
Yes, happy to. And so I would agree, Bruce, that the endpoints that we prioritize as primary, not only the most meaningful to patients, but endorsed by FDA. And on those endpoints, we have confidence from the TCOM trial. And I would just add to that, in the current Phase IIb trial with a new once-daily formulation, we've been able to push that dose to exposures that would be higher than in the TCOM trial itself because we have 10, 20 and 30-milligram doses in that trial. So we think based on that, we're positioned for success.
And then coming back to the question on JACOB and GEA, the key point I'd like to make is we really believe that Zanidatamab is differentiated from even the combination of Herceptin and PERJETA. As we presented at our R&D Day, we stepped through some important data that were published in Nature Communications, showing how Zanidatamab is differentiated with 2 epitopes necessarily buying to distinct receptors, causing more effective receptor clustering and internalization and have demonstrated better immune function, for example, complement fixation. And so in that paper head-to-head and preclinical experiments better than Herceptin and PERJETA and the clinical data bear that out without going into great detail, if you look at the BTC data, where the response rates are over 40% and duration of response greater than 12 months, that compares very favorably to prior data with the combination of Herceptin and PERJETA.
And of course, we have data in breast cancer showing activity of Zanidatamab even after patients have failed frontline therapy with Herceptin and PERJETA as part of a [ CLIA patch ] regimen. So that in combination with the data that you referred to, Zani, chemo and then separately, a cohort of Zani, chemo, tislelizumab shown very promising not only response rates, but very, very durable responses. That's what gives us confidence that our Phase III trial will be successful.