- A combination of AstraZeneca's cancer drug Imfinzi and another experimental immunotherapy extended survival in people with previously untreated liver cancer that can't be removed by surgery, the British drugmaker said Friday.
- According to AstraZeneca, summary results of a Phase 3 trial called HIMALAYA showed Imfinzi together with tremelimumab significantly lengthened survival versus an older liver cancer drug called Nexavar. Imfinzi alone was judged "non-inferior" to Nexavar, but the difference in survival was not large enough to also be statistically significant.
- The results from HIMALAYA are a rare dataset in support of tremelimumab, which AstraZeneca has spent years unsuccessfully developing, with a handful of negative readouts across several other trials and cancer types. One other Phase 3 study, called POSEIDON, also showed a survival benefit adding tremelimumab to Imfinzi in patients with non-small cell lung cancer.
AstraZeneca's Imfinzi is one of seven approved immunotherapies that work by blocking proteins dubbed PD-1 or PD-L1. While Merck & Co.'s Keytruda, Bristol Myers Squibb's Opdivo and Roche's Tecentriq account for much of the immunotherapy market, AstraZeneca has found some success with its drug as a treatment for earlier-stage non-small cell lung cancer.
Tremelimumab, which also works by directing the immune system against tumors but in a different way, was meant to complement Imfinzi, much in the same way Bristol Myers has used its drug Yervoy in combination with Opdivo.
That strategy has largely not panned out, with several trial failures in metastatic lung cancer as well as bladder and head and neck cancers.
HIMALAYA, along with the earlier result in POSEIDON, are two exceptions, though they used different dosing regiments of tremelimumab.
In HIMALAYA, which enrolled 1,324 patients with unresectable, advanced hepatocellular carcinoma, participants were randomized to receive either Imfinzi alone, Imfinzi plus a single, high dose of tremelimumab, or Nexavar.
The single, high dose regimen of tremelimumab differs from a lower, once every four week dosing schedule used in POSEIDON and other studies.
HIMALAYA met its goal by showing a significant survival advantage to the combination over Nexavar, although AstraZeneca did not disclose specific details, which will be needed to assess how useful the combination might be in practice. Detailed data will be presented at an upcoming medical meeting, the company said.
Currently, Roche's Tecentriq is approved to treat advanced liver cancer in the first-line setting, although other immunotherapies like Keytruda and Opdivo are still in testing. The Food and Drug Administration last year rejected Merck and partner Eisai's combination of Keytruda and Lenvima for that use, as Roche's approval closed off the regulatory path for an accelerated OK.