5692 - FPA150 (B7-H4 antibody) Phase 1 Update in Advanced Solid Tumors: Monotherapy and in Combination with Pembrolizumab

Background

FPA150 is a fully human antibody against B7-H4 (a transmembrane protein of the B7 family) blocking negative regulatory function in T cells. FPA150 additionally exhibits enhanced antibody-dependent cell-mediated cytotoxicity and in vivo synergizes with anti-PD1 agents. We initiated a phase Ia/Ib evaluation of safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and activity in monotherapy (mono) and with anti-PD1 (combo). A current update of this ongoing trial is provided.

Methods

Trial design (see table)Table:

1198P

Results

At 3/15/2019 data snapshot, 29 pts with solid tumors (12 ovarian, 7 GI, 3 GYN, 3 head/neck, 2 GU, and 2 other) received FPA150 in dose escalation (n = 21) and dose exploration (n = 8). FPA150 demonstrated ∼ dose-proportional exposure at doses ≥0.3 mg/kg and half-life of 1-2 weeks. To date, no dose-limiting toxicities, treatment-related serious adverse events or treatment-related adverse events (TRAEs) leading to drug discontinuation have been identified (1 Grade 3 TRAE of decreased lymphocyte count); others were Grade 1-2, with most common being diarrhea (16.7%), and fatigue (13.8%). Enrollment to phase Ib mono and phase Ia combo is ongoing. Expanded safety, PD and activity from phase Ib mono and phase Ia combo will be presented.

Conclusions

FPA150 RD for phase Ib mono identified as 20 mg/kg (Sachdev, ASCO 2019). Mono appears well tolerated during dose escalation/exploration allowing evaluation in combination therapy. Sachdev, J et al. Phase Ia/1b study of first-in-class B7-H4 antibody, FPA150, as monotherapy in patients with advanced solid tumors. Proc Am. Soc. Clin. Oncol 2019.

Clinical trial identification

NCT03514121.

Editorial acknowledgement

Legal entity responsible for the study

Five Prime Therapeutics, Inc.

Funding

Five Prime Therapeutics, Inc.

Disclosure

Z.A. Wainberg: Advisory / Consultancy: Bristol Meier Squibb; Advisory / Consultancy: Five Prime Therapeutics; Advisory / Consultancy: Merck; Advisory / Consultancy: Eli Lilly; Advisory / Consultancy: Novartis; Advisory / Consultancy: Bayer. J.C. Sachdev: Honoraria (self): Celgene; Honoraria (self): Novartis; Honoraria (self): Puma Technology; Honoraria (self): Tempus; Honoraria (self): Ipsen; Advisory / Consultancy: Celgene; Research grant / Funding (institution): Celgene; Travel / Accommodation / Expenses: Celgene; Advisory / Consultancy: Five Prime Therapeutics. T. Bauer: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses, institution: Ignyta; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Guardant Health; Advisory / Consultancy, Research grant / Funding (institution): Loxo; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Self and institution: Pfizer; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Moderna Therapeutics; Speaker Bureau / Expert testimony, Research grant / Funding (institution): Bayer; Research grant / Funding (institution): Daiichi Sankyo; Research grant / Funding (institution): Medpacto; Research grant / Funding (institution): Incyte; Research grant / Funding (institution): Mirati Therapeutics; Research grant / Funding (institution): MedImmune; Research grant / Funding (institution): AbbVie; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): MabVax; Research grant / Funding (institution): Stemline Therapeutics; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Eli Lilly; Research grant / Funding (institution): Glaxo Smith Kline; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): Immunogen; Research grant / Funding (institution): Deciphera; Research grant / Funding (institution): Merimack; Research grant / Funding (institution): Immunogen. S. Pant: Advisory / Consultancy: Mirati Therapeutics; Advisory / Consultancy: Eli Lilly; Advisory / Consultancy: Red hill Biopharma Ltd; Advisory / Consultancy: Xencor; Advisory / Consultancy: Five Prime Therapeutics; Advisory / Consultancy: Novartis; Advisory / Consultancy: Rgenix; Advisory / Consultancy: Sanofi-Aventis; Advisory / Consultancy: Arqule; Advisory / Consultancy: Bristol-Myers Squibb; Advisory / Consultancy: Onco Response; Advisory / Consultancy: Sanofi US Services Inc; Advisory / Consultancy: GlaxoSmith Kline; Speaker Bureau / Expert testimony: Tyme, Inc; Speaker Bureau / Expert testimony: 4-D Pharma. S. Chawla: Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Amgen; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Roche; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: GlaxoSmithKline; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Threshold Pharmaceuticals; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: CytRx; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Ignyta; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Immune Design; Honoraria (self), Speaker Bureau / Expert testimony: TRACON Pharma; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Karyopharm Therapeutics; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Sarcoma Alliance for REsearch Through Collaboration; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Janssen. N. Marina: Full / Part-time employment: Five Prime Therapeutics. H. Xiang: Full / Part-time employment: Five Prime Therapeutics. W. Deng: Full / Part-time employment: Five Prime Therapeutics. M. Schmidt: Full / Part-time employment: Five Prime Therapeutics. A. Patnaik: Advisory / Consultancy: Bayer; Advisory / Consultancy: Novartis; Advisory / Consultancy: Genentech; Advisory / Consultancy, Research grant / Funding (institution): Merck; Advisory / Consultancy: Seattle Genetics; Advisory / Consultancy: Bristo-Myers Squibb; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Eli Lilly; Research grant / Funding (institution): Plexxikon; Research grant / Funding (institution): Corvus Pharmaceuticals; Research grant / Funding (institution): Tesaro; Research grant / Funding (institution): Forty-seven; Research grant / Funding (institution): Five Prime Therapeutics; Research grant / Funding (institution): Infinity Pharmaceuticals; Research grant / Funding (institution): Proximagen; Research grant / Funding (institution): Pieris; Research grant / Funding (institution): Surface Oncology; Research grant / Funding (institution): Livson; Research grant / Funding (institution): Vigeo Therapeutics; Research grant / Funding (institution): Astella Pharma. P. LoRusso: Advisory / Consultancy: AbbVie; Advisory / Consultancy: Agios; Advisory / Consultancy: Alexion; Advisory / Consultancy: Ariad; Advisory / Consultancy: Five Prime Therapeutics; Advisory / Consultancy: GenMab; Advisory / Consultancy: Glenmark; Advisory / Consultancy: Halozyme; Advisory / Consultancy: Menarini; Advisory / Consultancy: Novartis; Advisory / Consultancy: Roche-Genentech; Advisory / Consultancy: Genentech; Advisory / Consultancy: CytomX; Advisory / Consultancy: Omniox; Advisory / Consultancy: Ignyta; Advisory / Consultancy: Takeda; Advisory / Consultancy: SOTIO; Advisory / Consultancy: Cybrexa; Advisory / Consultancy: Agenus; Advisory / Consultancy: Tyme.