A Phase 1b/2 Randomized, Controlled Study of AVB-S6-500 in Combination With Pegylated Liposomal Doxorubicin (PLD) or Paclitaxel (Pac) in Patients With Platinum-resistant Recurrent Ovarian Cancer

Trial ID # NCT03639246
Phase Ib/II
Drug Class Growth Factor Inhibitors: Gas6
Drug Name Batiraxcept
Alternate Drug Names anti-AXL fusion protein AVB-S6-500, AVB-S6-500, AVB-500
Drugs in Trial Batiraxcept, Liposomal doxorubicin, Paclitaxel
Eligible Participant

Platinum resistant ovarian cancer

Patients Enrolled

53; AVB-S6-500+Pac: 23, median 2 prior therapies, 56% w/ prior Bev; AVB-S6-500+PLD: 30, median 1 prior therapy; 40% w/ prior Bev

Therapy Setting


Study Design

Double Blind, Randomized


ORR, DCR, PFS, evaluated per RECIST


Exploratory: AVB-S6-500 levels in relation to minimal efficacious concentration (MEC)


RP2D for AVB-S6-500: 15 mg/kg Q2W (84% of patients achieves MEC)

AVB-S6-500+Pac vs AVB-S6-500+PLD:
ORR: 36.8 (2CR, 5PR, n=19) vs 16.0% (4PR, n=25)
DCR: 68.4 (2CR, 5PR, 6SD) vs 60.0% (4PR, 11SD)
PFS: 3.6 vs 3.6 months

Exploratory analysis, prior Bev, AVB-S6-500 serum trough levels, serum sAxl/Gas6 ratio:
AVB-S6-500+Pac; no prior Bev vs prior Bev:
ORR: 66.7 (2CR, 4PR, n=9) vs 10.0% (1PR, n=10)
DCR: 88.9 (2CR, 4PR, 1SD) vs 60% (1PR, 5SD, n=10)
PFS: 7.7 vs 2.8 months
OS: 19.3 vs 9.2 months

AVB-S6-500+Pac; PFI<3 months vs 3≤PFI<6 months:
ORR: 60 vs 40%

AVB-S6-500+Pac; trough levels above MEC vs below MEC:
ORR: 50 (2CR, 3PR, n=10) vs 22% (2PR, n=9)
PFS: 7.5 vs 2.8 months

Clinically Significant Adverse Events

AVB-S6-500+Pac vs AVB-S6-500+PLD:
Serious AE:
Grade 3-4 AE: overall (17.4 vs 6.7%)


AVB-S6-500+paclitaxel or liposomal doxorubicin is safe; the combination of AVB-S6-500+paclitaxel is most effective and best response is seen in patients without prior bevacizumab


Fuh KC et al. Phase 1b study of GAS6/AXL inhibitor (AVB-500) in recurrent, platinum-resistant ovarian carcinoma. J Clin Oncol (2021) 39 (suppl 15; abstr 5566)

Fuh KC et al. Poster

Fuh KC et al. Phase 1b study of AVB-500 in combination with paclitaxel or pegylated liposomal doxorubicin platinum-resistant recurrent ovarian cancer. Gynecol Oncol (2021) 163(2):254-261

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