A Phase 1, First-in-Human Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of IMGN853 in Adults With Ovarian Cancer and Other FOLR1-Positive Solid Tumors

Trial ID # NCT01609556
Phase I
Drug Class Antibody Drug Conjugates: FRalpha
Drug Name Mirvetuximab Soravtansine
Alternate Drug Names Anti-FOLR1-mab Maytansinoid Conjugate, IMGN853, M9346A-sulfo-SPDB-DM4
Drugs in Trial Mirvetuximab Soravtansine
Eligible Participant

FRalpha+ platinum resistant cancer; ≤ 5 prior therapies; IHC: ≥ 25% tumor cells at ≥ 2+ intensity

Patients Enrolled

205 (46 ovarian)

Therapy Setting


Study Design

Open-Label, Non-randomized


ORR, PFS, RP2D, evaluated per RECIST


FRalpha protein


RP2D: 6.0mg/kg q3w
ORR: 26% (1CR, 11PR, n=46)
PFS: 4.8 months (3.9-5.7)

Exploratory analysis # of prior therapies:
>3 previous therapies (n=23): ORR: 13%; PFS: 3.9 months (2.6-5.4)
≤3 previous therapies (n=23): ORR: 39%; PFS: 6.7 months (3.9-8.7)

Exploratory analysis FORWARD I criteria (Pt-R, ≤3 previous therapies, ≥ 50% of tumor cells with ≥ 2+ FRalpha expression, n=37):
ORR: 47%; PFS: 6.7 months (4.1-8.3)

Clinically Significant Adverse Events

Serious AE: overall (22%)
Grade 3-4 AE: any (26%)
41% of patients experienced low grade ocular AEs


Promising activity in platinum-resistant FRalpha+ patients


Moore KN et al. Safety and Activity of Mirvetuximab Soravtansine (IMGN853), a Folate Receptor Alpha-Targeting Antibody-Drug Conjugate, in Platinum-Resistant Ovarian, Fallopian Tube, or Primary Peritoneal Cancer: A Phase I Expansion Study. J Clin Oncol (2017) 35(10):1112-1118

Moore KN et al. Mirvetuximab soravtansine (IMGN853), a folate receptor alpha (FR⍺)-targeting antibody-drug conjugate (ADC), in platinum-resistant epithelial ovarian cancer (EOC) patients (pts): Activity and safety analyses in phase I pooled expansion cohorts. J Clin Oncol (2017) 35 (suppl; abstr 5547)