FORWARD I: A Randomized, Open Label Phase 3 Study to Evaluate the Safety and Efficacy of Mirvetuximab Soravtansine (IMGN853) Versus Investigator's Choice of Chemotherapy in Women With Folate Receptor Alpha Positive Advanced Epithelial Ovarian Cancer, Primary Peritoneal Cancer or Fallopian Tube Cancer

Trial ID # NCT02631876; FORWARD I
Phase III
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 Liposomal doxorubicin, Mirvetuximab Soravtansine, Paclitaxel, Topotecan
Eligible Participant

Platinum resistant ovarian cancer with 1-3 prior therapies and FRalpha medium/high by 10X score

Patients Enrolled


Therapy Setting


Study Design

Open-Label, Randomized


ORR, PFS, OS, evaluated per RECIST




Mir vs Chemotherapy Treatment of Physician's Choice (TPC) (liposomal doxorubicin, paclitaxel or topotecan):

All patients (n=366):
ORR: 22 vs 12%, p=0.015
PFS: 4.1 vs 4.4 months, HR: 0.981
OS: HR: 0.815

FRalpha high (by 10X score; n=218):
ORR: 24 vs 10% (p=0.014)
PFS: 4.8 vs 3.3 months, HR: 0.693 (p=0.049)
OS: 16.4 vs 12.0 months, HR: 0.618 (p=0.033)

Exploratory analysis: FRalpha by PS2+ score (score method from prior trials):
FRalpha high (n=116): ORR: 26 vs 6%; PFS: 5.6 vs 3.2 months, HR: 0.549; OS: 16.4 vs 11.4 months, HR: 0.678

Clinically Significant Adverse Events

Mir vs TPC:
Serious AE:
Grade 3-4 AE: any (46 vs 61%)


Mirvetuximab soravtansine has favorable tolerability and benefit-risk profile compared to chemotherapy in FRalpha high patients


Moore KN et al. FORWARD I (GOG 3011): A phase III study of mirvetuximab soravtansine, a folate receptor alpha (FRa)-targeting antibody-drug conjugate (ADC), versus chemotherapy in patients (pts) with platinum-resistant ovarian cancer (PROC). ESMO (2019) Abstr 992O

ImmunoGen Presents Full Data from Phase 3 FORWARD I Study or Mirvetuximab Soravtansine in Ovarian Cancer at ESMO, press release 9/29/2019