A Phase 1 Open-Label, Safety, Pharmacokinetic and Preliminary Efficacy Study of STRO-002, an Anti-Folate Receptor Alpha (FolRα) Antibody-Drug Conjugate (ADC), in Patients With Advanced Epithelial Ovarian Cancer (Including Fallopian Tube or Primary Peritoneal Cancers) and Endometrial Cancers

Platinum resistant or refractory ovarian cancer

31 patients in dose escalation; 44 patients in dose expansion, median 3 prior therapies (1-3)

Recurrence

Open-Label, Non-randomized

CBR, ORR, DCR, DoR, PFS, evaluated per RECIST

Results from dose escalation, doses 2.9 mg/kg and above:

ORR: 32% (1CR, 4PR, 5uPR, n=31)
DCR (4 months): 61%
CBR: 55%
DCR (1 year): 16%
PFS: 7.2 months

Results from expansion at 4.3 mg/kg and 5.2 mg/kg:
ORR: 31.7% (13PR, n=41)
DCR: 78%
DoR: 5.4 months
PFS: 4.3 months (n=44)

Exploratory analysis, FRalpha expression by TPS %, dosing 4.3 mg/kg or 5.2 mg/kg:
Doses 4.3 mg/kg and 5.2 mg/kg:
TPS ≤ 25% (n=9): ORR: 11.1% (1PR); DoR: 2.9 months; PFS: 3.8 months
TPS > 25% (n=32): ORR: 37.5% (12PR); DCR: 81.3%; DoR: 5.5 months; PFS: 6.1 months
TPS > 25% and 4.3 mg/kg (n=16): ORR: 31.3%; DoR: 13 months; PFS: 6.1 months
TPS > 25% and 5.2 mg/kg (n=16): ORR: 43.8%; DoR: 5.4 months; PFS: 6.6 months 

Serious AE: febrile neutropenia (n=1)
Grade 3-4 AE: overall (86%), neutropenia (71%), arthralgia (18%), anemia (14%) - only 1 pt required therapeutic corticosteroid eyedrops

Luveltamab tazevibulin (STRO-002) is well tolerated with evidence of anti-tumor activity in heavily pretreated patients across a broad range of FRα expression levels. No ocular toxicity signals have been observed.

Naumann RW et al. Phase 1 dose-escalation study of STRO-002, an antifolate receptor alpha (FRα) antibody drug conjugate (ADC), in patients with advanced, progressive platinum-resistant/refractory epithelial ovarian cancer (EOC). J Clin Oncol (2021) 39 (suppl 15; abstr 5550)
https://meetinglibrary.asco.org/record/197364/abstract

Naumann RW et al. Poster
https://www.clearityfoundation.org/wp-content/uploads/2021/06/STRO-002-poster-ASCO-2021-scaled.jpeg

Oaknin A et al. Luveltamab tazevibulin (STRO-002), an anti-folate receptor alpha (FolRα) antibody drug conjugate (ADC), safety and efficacy in a broad distribution of FolRα expression in patients with recurrent epithelial ovarian cancer (OC): Update of STRO-002-GM1 phase 1 dose expansion cohort. J Clin Oncol 41, 2023 (suppl 16; abstr 5508)
https://ascopubs.org/doi/10.1200/JCO.2023.41.16_suppl.5508

Oaknin A et al. Slide from presentation
https://www.clearityfoundation.org/wp-content/uploads/2023/06/Luveltamab-tazevibulin-slide-ASCO-2023.jpeg