Astra knocks another hole in J&J's Mariposa plan

Johnson & Johnson investors face a nervous wait for results of the Mariposa study, and today they have something else to worry about. Astrazeneca’s Flaura2 trial has been toplined positive, suggesting – depending on the extent of the hit, of course – that even a convincing win in Mariposa might not count for much. That scenario already looked uncertain since Mariposa passed an interim analysis without being halted for efficacy, suggesting that any benefit might be smaller than hoped for. Flaura2 and Mariposa comprise front-line lung cancer patients with a specific EGFR mutation, a space effectively owned by Astra’s Tagrisso. In Mariposa J&J wants to beat Tagrisso with its Rybrevant plus lazertinib combo, but Flaura2 puts a fly in the ointment: 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 no doubt prompt cross-trial comparisons to tease out any effect seen in Mariposa, and nothing is yet known about overall survival. Things will become clearer by the end of 2023.