Astra places its bet in oestrogen receptor degradation
Astrazeneca had boasted two selective oestrogen receptor degraders (Serds), but one of these, AZD9496, has been discontinued, it revealed on today’s fourth-quarter call. However, the second, AZD9833, has just moved into phase III, meaning that there are now four pivotal-stage Serds battling for a breast cancer niche some think is worth $2-3bn a year. Sanofi’s most important first-half event is readout of amcenestrant’s potentially registrational phase II Ameera-3 trial, though this targets second-line use. The first-line Ameera-5 study will not read out for some time, but Asco could see phase I data from yet another study, Ameera-1, that Sanofi last week said “gave us confidence to kick off ... the pivotal trial”. Radius Health’s elacestrant will be the first to yield pivotal data, but does not appear to target the front-line setting. Roche, meanwhile, is now on its third Serd, having scrapped two Seragon-derived assets. Astra said AZD9496 was canned based on initial safety and efficacy results, but called AZD9833 a next-generation Serd that forms an integral part of its breast cancer strategy. The group developed the first ever Serd, Faslodex, a drug that struggled with poor bioavailability, and will not give up this market without a fight.
|Serds in phase III development for ER+ve/Her2-ve breast cancer|
|Elacestrant||Radius Health/ Menarini||Emerald||2nd-line, postmenopausal, vs SoC||PFS in ESR1-mut & PFS in all-comers||Reads out Q4 2021|
|Amcenestrant (SAR439859)||Sanofi||Ameera-5||1st-line, vs Femara||PFS||First patient in Q4 2020|
|Giredestrant (RG6171)||Roche||BO41843||1st-line, Ibrance combo vs Femara + Ibrance||PFS||First patient in Q4 2020|
|Camizestrant (AZD9833)||Astrazeneca||Serena-4||1st-line, Ibrance combo vs Arimidex + Ibrance||PFS||First patient in Q1 2021|