AZ looks for advantage over Merck in lung cancer trial

AstraZeneca has set itself tougher goals in a key lung cancer drug trial, after strong efficacy data generated by its cancer immunotherapy, durvalumab.

The company needs to catch up with the frontrunners in the field, and AZ wants to gain advantage over Merck & Co’s emerging market leader Keytruda.

Keytruda (pembrolizumab) is the first cancer immunotherapy approved in the lucrative first-line non-small cell lung cancer indication, after Bristol-Myers Squibb’s rival, Opdivo, failed to show benefit in this group.

Now AZ is after a piece of this market and hopes that setting itself a tougher goal in the MYSTIC trial of its immunotherapy hopeful, durvalumab, could give it an advantage over Keytruda if approved.

The FDA approved Keytruda in first line lung cancer, with high levels of PD-L1 expression, on the basis of progression-free survival data, with overall survival among secondary endpoints.

But AZ has said it will measure effectiveness of durvalumab monotherapy, and the durvalumab and tremelimumab combination against the tougher overall survival (OS) goal, as well as progression free survival (PFS) primary endpoints.

AZ’s statement suggests an increased focus on the monotherapy element of the trial – and a potential showdown with Keytruda should it get to market.

The MYSTIC trial was initially designed to assess the benefit of durvalumab monotherapy and durvalumab and tremelimumab (durva + treme) combination therapy versus standard-of-care (SoC) chemotherapy, focused on progression-free survival (PFS).

The trial will now assess PFS and OS endpoints in patients with PDL1-expressing tumours for both durvalumab monotherapy and the combination of durva + treme, as well as in ‘all comers’ for the combination of durva + treme, versus SoC chemotherapy.

AZ has predicted peak sales in the region of $6.5 billion for durvalumab, and said it had made the decision based on “recent internal and external data” including strong efficacy and in monotherapy presented at medical meetings and “significant opportunities in the competitive landscape”.

PFS data will be ready in mid-2017 and final OS data will be ready at the latest in 2018.

The phase 3 NEPTUNE trial will be expanded to support a filing of the durva + treme combination in China in first-line NSCLC, without delaying the anticipated OS data readout in 2018 from the global cohort, which is approaching full recruitment.

AZ has also begun the phase 3 PEARL trial of durvalumab monotherapy versus SoC chemotherapy in first-line NSCLC patients whose tumours express PD-L1. The PEARL trial focuses on Asian countries, primarily China, due to the high prevalence of NSCLC in the region.

Sean Bohen, AZ’s chief medical officer, said: “We continue to follow the science through both internal and external sources for the benefit of patients and look forward to sharing our first pivotal data in mid-2017.”

Nevertheless, AZ will still have a mountain to climb to compete with Keytruda. Last week Merck filed Keytruda for use in frontline NSCLC treatment in combination with chemotherapy, a development which gave its share price a huge boost.

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