Playing catchup in cancer, AstraZeneca posts PD-L1 data, pins hopes on combos

AstraZeneca

AstraZeneca ($AZN) has posted an update on a Phase I/II trial of its anti-PD-L1 monoclonal antibody durvalumab in non-small cell lung cancer (NSCLC). The readout represents another small milestone on route to data from a trial pairing durvalumab to CTLA-4 drug tremelimumab, which AstraZeneca sees belatedly giving it a seat at the immuno-oncology table.

To date, AstraZeneca has been a spectator as Bristol-Myers Squibb ($BMY) and Merck ($MRK) have carved up and reshaped the cancer market. AstraZeneca gave up hope of winning the quickie approval for durvalumab it needed to stay within touching distance late last year. The failure to join the first wave of immuno-oncology drugs has ratcheted up the pressure of the combination therapies AstraZeneca sees as its way into the market.

AstraZeneca arrived at ESMO without new clinical data on its headline combination of durvalumab and tremelimumab. But, with Bristol-Myers’ competing combination of Opdivo and Yervoy not set to post pivotal data until 2018, AstraZeneca thinks it is on track to bring a first-line NSCLC combination therapy to market ahead of its rival.

“It is possible, provided that the data supports filing, that we would be first,” AstraZeneca CMO Sean Bohen told Bloomberg. AstraZeneca is aiming to file for approval next year.

With the data AstraZeneca needs to support that filing still some way off, attention at ESMO was on a couple of its other trials. Investigators presented follow-up data from a Phase I/II trial of durvalumab as a monotherapy in advanced NSCLC. Durvalumab achieved an overall response rate (ORR) of 26% in patients with high PD-L1-expressing tumors. Second-line median overall survival (OS) in those patients was 17.8 months. For comparison, a Phase III trial of Tecentriq, Roche’s ($RHHBY) PD-L1 drug, had a median second-line survival of 20.5 months in patients with high expressing tumors.

The other data AstraZeneca discussed at ESMO came from a Phase Ib/IIa clinical trial that is giving durvalumab alongside drugs designed to tackle immunosuppression in the tumor microenvironment.

In the safety and dose-finding stage of the advanced solid tumor trial, AstraZeneca gave eleven patients a combination of durvalumab and an antisense oligonucleotide against STAT3. That cohort featured two partial responses and five cases of stable disease. In another 20 patients who received durvalumab plus a CXCR2 antagonist, there was one complete response, two partial responses and five cases of stable disease.