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; FORWARD II-2
Phase Ib/II
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 Bevacizumab, Mirvetuximab Soravtansine
Eligible Participant

Recurrent FRalpha+ ovarian cancer; IHC: ≥ 50% tumor cells at ≥ 2+ intensity

Patients Enrolled

60 patients, median 2 prior therapies (1-4); 47% Pt-S, 53% Pt-R

Therapy Setting

Recurrence

Study Design

Open-Label, Non-randomized

Endpoints

ORR, evaluated per RECIST

Biomarkers

FRalpha+

Efficacy

ORR: 47%
FRalpha medium (IHC: ≥ 50% tumor cells at ≥ 2+ intensity, n=27): ORR: 26%
FRalpha high (IHC: ≥ 75% tumor cells at ≥ 2+ intensity, n=33): ORR: 64%

Exploratory analysis, Pt-status in FRalpha high patients:
Pt-S (n=16): ORR: 69%
Pt-R (n=17): ORR: 59%

Clinically Significant Adverse Events

Serious AE:
Grade 3-4 AE: hypertension (12%), myelosuppression (10%)

Conclusion

The combination of mirvetuximab soravtansine with bevacizumab demonstrates an encouraging ORR in platinum sensitive patients with high FRalpha expression

Reference

Gilbert L et al. Mirvetuximab soravtansine, a folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC), in combination with bevacizumab in patients (pts) with platinum-agnostic ovarian cancer. J Clin Oncol (2020) 38: (suppl; abstr 6004)
https://ascopubs.org/doi/abs/10.1200/JCO.2020.38.15_suppl.6004

Gilbert L et al. Slide from presentation
https://www.clearityfoundation.org/wp-content/uploads/2020/06/MirvBev-ASCO-2020.pdf