Astra’s Flaura2 knocks another hole in Mariposa

Johnson & Johnson, facing a nervous wait for results of the Mariposa study, now has a fresh worry. Astrazeneca has toplined its Flaura2 trial as positive, suggesting that even a convincing win in Mariposa might not count for much. J&J investors already know that Mariposa passed an interim analysis without being halted for efficacy, suggesting that any benefit might be smaller than hoped for and making things uncertain even before the Flaura2 readout. Flaura2 and Mariposa comprise front-line lung cancer patients with a specific EGFR mutation, a space virtually owned by Astra’s Tagrisso, and in Mariposa J&J wants to beat Tagrisso with its Rybrevant plus lazertinib combo. But Flaura2 now makes things tricky: the Astra trial adds chemo on top of Tagrisso and, since this has now been said to be statistically and clinically significant for PFS, Mariposa’s Tagrisso monotherapy comparator might not stay relevant for long. Much will depend on the size of the PFS benefit, which will prompt scrutiny on a cross-trial basis to tease out any effect seen in Mariposa. Moreover, nothing is yet known about overall survival, but matters should become clearer by the end of 2023.