ASCO 2026: A Second PFS Benefit Says Earlier Is Better

Research evidence excerpt

ASCO 2026: A Second PFS Benefit Says Earlier Is Better

Pharmaceuticals (Major) & Large Cap Biotechnology

Biotechnology-Large Cap - Market Weight

ASCO 2026: A Second PFS Benefit Says Earlier Is Better June 2, 2026

Gilead Sciences (GILD)

The Wolfe Byte

Addtl. findings from ASCENT-03/04 further support Trodelvy as a compelling 1L TNBC therapy, with debate

shifting to how best to sequence ADCs. A contentious discussion session also left some questioning the validity of

the studies due to a potentially unreliable endpoint.

Quick reminders. ASCENT-03 and ASCENT-04 evaluated sacituzumab govitecan (SG, commercialized Trodelvy), a

TROP2-directed ADC in 1L mTNBC, extending its use earlier than the approved 2L+ indication.

●ASCENT-04 enrolled PD-L1+ mTNBC patients eligible for immunotherapy. Adding SG to pembro reduced

progression risk by 35% (mPFS 11.2 vs 7.8 mos; 0.65 HR) with a higher ORR (60% vs 43%) and mDOR (16.5

vs 9.2 mos).

●ASCENT-03 enrolled 1L mTNBC patients ineligible for PD-L1 inhibitors and randomized to SG or chemotherapy

(chemo). SG showed a 38% reduction in progression risk vs chemo (mPFS 9.7 vs 6.9 mos; 0.62 HR) with notably

more durable responses (DOR 12.2 vs 7.2 mos). OS remains immature in both trials, though early trends are

favorable. Overall safety was similar between arms and manageable.

Dubiety after primary PFS results from ESMO and ASCO 2025. For context, a challenge in interpreting 1L metastatic

trials is the crossover problem; when patients on the control arm receive experimental drug after progression and OS

benefit gets diluted, the question remains whether control patients are catching up at second line. Today at ASCO, GILD

presented follow up PFS2 (time to progression following first subsequent line of therapy) analyses with LBA 1000