A Phase 1b/2 Study to Evaluate the Safety, Tolerability and Pharmacokinetics of Mirvetuximab Soravtansine (IMGN853) in Combination With Bevacizumab, Carboplatin, Pegylated Liposomal Doxorubicin, Pembrolizumab, or Bevacizumab+Carboplatin in Adults With Folate Receptor Alpha Positive Advanced Epithelial Ovarian Cancer, Primary Peritoneal Cancer or Fallopian Tube Cancer

Trial ID # NCT02606305
Phase Ib/II
Drug Class Immunotherapy: Checkpoint Inhibitors/PD-1
Drug Name Pembrolizumab
Alternate Drug Names Keytruda, Lambrolizumab, SCH 900475, MK3475, MK-3475
Drugs in Trial Mirvetuximab Soravtansine, Pembrolizumab
Eligible Participant

Platinum-resistant FRalpha-positive ovarian cancer; IHC: ≥ 25% tumor cells at ≥ 2+ intensity

Patients Enrolled

56; median 3 prior therapies (2-7)

Therapy Setting


Study Design

Open-Label, Non-randomized


ORR, PFS, RP2D, evaluated per RECIST


FRalpha protein


RP2D: Pem 200mg + Mir 6mg/kg q3w
ORR: 30% (n=54)
DoR: 6.9 months (4.2-8.3)
PFS: 4.2 months (2.8-5.9)

Exploratory analysis; medium/high FRalpha: ≥ 50% of tumor cells with ≥ 2+ FRalpha expression:
ORR: 31% (n=39)
DoR: 8.1 months (4.2-NR)
PFS: 5.5 months (2.8-6.3)

Clinically Significant Adverse Events

Serious AE: one treatment-related death (encephalitis)
Grade 3-4 AE: overall (45%)


Encouraging activity in FRalpha-positive patients


Matulonis UA et al. Initial safety and activity findings from a phase 1b escalation study of mirvetuximab soravtansine, a folate receptor alpha (Frα)-targeting antibody-drug conjugate (ADC), in combination with pembrolizumab in platinum-resistant epithelial ovarian cancer patients. SGO (2018) Abstract 74

Matulonis UA et al. Mirvetuximab soravtansine, a folate receptor alpha (Frα)-targeting antibody-drug conjugate (ADC), with pembrolizumab in platinum-resistant ovariancancer (PROC): Initial results of an expansion cohort from FORWARD II, a Phase Ib study. Ann Oncol (2018) 29 Suppl_8, Abstract 949P, Poster