On Friday, Mersana Therapeutics Inc. MRSN launched preliminary knowledge from the Section 1 dose escalation and backfill cohorts for emiltatug ledadotin.
Emi-Le was usually properly tolerated, with no Grade 4 or 5 treatment-related opposed occasions reported.
At intermediate doses within the trial (38.1 mg/m2 to 67.4 mg/m2), the confirmed goal response fee amongst evaluable sufferers was 23% (6 of 26 sufferers) throughout all B7-H4 excessive tumors and 23% (3 of 13 sufferers) with B7-H4 excessive TNBC, all of whom had beforehand been handled with at the least one topo-1 ADC.
Within the ASCENT Section 3 trial of sacituzumab govitecan, the ORR with standard-of-care single-agent chemotherapy in relapsed/refractory TNBC was roughly 5%, with progression-free survival of roughly seven weeks.
Based mostly on these encouraging Emi-Le knowledge at intermediate doses, Mersana has superior a dose of 67.4 mg/m2 each 4 weeks into an growth cohort in sufferers with TNBC who’ve acquired one to 4 prior remedy strains.
At excessive doses above 76 mg/m2, the confirmed ORR amongst evaluable sufferers was 22% (2 of 9) throughout all B7-H4 excessive tumors.
Moreover, 78% (7 of 9 sufferers) had ≥30% tumor discount in goal lesions.
At these excessive dose ranges, goal responses in a number of evaluable sufferers with B7-H4 excessive tumors weren’t confirmed after protocol-mandated dose delays for proteinuria.
Mersana is implementing proteinuria mitigation efforts and continues to look at greater doses in dose escalation and backfill cohorts to determine a second dose for the growth portion of the trial.
Concurrently, the FDA granted an extra Quick Observe designation to Mersana Therapeutics’ XMT-1660.
The corporate additionally introduced that the World Well being Group has authorised emiltatug ledadotin (abbreviated as Emi-Le) as XMT-1660’s worldwide nonproprietary identify.
The brand new Quick Observe designation is for superior or metastatic breast most cancers in sufferers with human epidermal development issue receptor 2 (HER2) low (IHC 1+ or IHC 2+/ISH–) or HER2-negative (IHC 0) illness, together with triple-negative breast most cancers (TNBC), who’ve acquired a previous topoisomerase-1 inhibitor ADC.
Moreover, hormone-receptor optimistic sufferers must also have acquired or be ineligible for endocrine remedy.
Value Motion: MRSN inventory is down 36.6% at $0.8245 ultimately examine Friday.
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