Abstract 4758
Background
HPV induces many alterations in CDK4-Cyclin D-Rb and apoptotic pathways such as up-regulation of p16, loss of Rb and p53 functions in SCCHN carcinogenesis. Loss of p16 expression is known as a poor prognostic marker in SCCHN for survival. Palbociclib is a highly selective inhibitor of CDK4/6 by blocking Rb phosphorylation with radiosensitizing activity in preclinical studies. Addition of palbociclib to cetuximab and IMRT provides a strong rationale to improve efficacy of treatment in locally advanced SCCHN, especially in p16/HPV-negative tumour.
Methods
This is a phase I study designed to determine the maximum tolerated dose (MTD) and toxicity of palbociclib, cetuximab, and IMRT, using a classical 3 + 3 design (NCT03024489). The study included locally advanced SCCHN of oral cavity, oropharynx, larynx, and hypopharynx. Palbociclib dose was escalated with 3 dose levels (DLs), starting from 75 to 125 mg/d orally for 21 day-on and 7 day-off for 2 cycles. For all DLs, cetuximab was administered at 400 mg/m2IV on day -7 and then 250 mg/m2weekly for 7 weeks. IMRT was delivered 5 day-on and 2 day-off with a total dose of 70 Gy for 33 fractions. MRI and PET scans pre- and post-treatment was used to evaluate preliminary efficacy.
Results
A total of 13 eligible patients were enrolled in the dose escalation cohort. No MTD was observed. One DLT, febrile neutropenia (FN) was reported in 1 of 7 patients who received 125 mg of palbociclib (DL3) at the 6thweek of IMRT. The FN recovered without G-CSF support within 7 days after discontinuation of palbociclib. Overall, toxicities were related to cetuximab and IMRT. Complete response was observed in 7 of 10 evaluable patients (70%), while overall objective response was demonstarted in 9 of 10 patients (90%).
Conclusions
The recommended phase 2 dose was palbociclib 125 mg/d for 21 days on and 7 days off with full standard dose of cetuximab and IMRT for locally advanced SCCHN. MTD was not achieved. The combination was well tolerated with promising preliminary efficacy. The expansion cohort of palbociclib 125 mg/d is currently accruing up to 15 locally advanced p16-negative SCCHN patients.
Clinical trial identification
NCT#03024489.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Pfizer.
Disclosure
N. Ngamphaiboon: Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): AstraZeneca; Honoraria (self), Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Eisai; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Amgen; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: MSD; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Novartis; Advisory / Consultancy: Boehringer Ingelheim; Travel / Accommodation / Expenses: Merck; Travel / Accommodation / Expenses: Taiho. T. Siripoon: Travel / Accommodation / Expenses: Pfizer; Travel / Accommodation / Expenses: Roche; Travel / Accommodation / Expenses: Boehringer Ingelheim. S. Lukerak: Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): MSD; Research grant / Funding (institution): AstraZeneca. N. Sankaseam: Research grant / Funding (institution): Roche; Research grant / Funding (institution): MSD; Research grant / Funding (institution): AstraZeneca. E. Sirachainan: Honoraria (self), Travel / Accommodation / Expenses: MSD; Honoraria (self): Sanofi/Aventis; Honoraria (self): Merck; Honoraria (self), Travel / Accommodation / Expenses: Amgen; Honoraria (self), Travel / Accommodation / Expenses: Roche; Travel / Accommodation / Expenses: Mundipharma; Honoraria (self), Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZeneca; Honoraria (self): LF Asia; Honoraria (self): Diethelm Keller Logistics; Honoraria (self): BMS; Honoraria (self): Boehringer Ingelheim. All other authors have declared no conflicts of interest.
Resources from the same session
1802 - Evaluation of the anti-tumor efficacy and immune effects of N-809, a novel IL-15 superagonist/anti-PD-L1 bispecific agent
Presenter: Kristin Hicks
Session: Poster Display session 3
Resources:
Abstract
3190 - GI101, a novel triple-targeting bispecific CD80-IgG4-IL2variant fusion protein, elicits synergistic anti-tumor effects in preclinical models
Presenter: Jae Chan Park
Session: Poster Display session 3
Resources:
Abstract
4062 - Phase 1b, open-label, dose-escalation study of M9241 (NHS-IL12) plus avelumab in patients (pts) with advanced solid tumors
Presenter: Julius Strauss
Session: Poster Display session 3
Resources:
Abstract
5777 - THOR-707, a novel not-alpha IL-2, promotes all key immune system anti-tumoral actions of IL-2 without eliciting vascular leak syndrome (VLS)
Presenter: Marcos Milla
Session: Poster Display session 3
Resources:
Abstract
5047 - A phase I clinical trial of malignant pleural mesothelioma treated with locally delivered autologous anti-FAP-targeted CAR T-cells
Presenter: Alessandra Curioni
Session: Poster Display session 3
Resources:
Abstract
1679 - HPV16 E6-specific TCR-T armored with checkpoint blockade in the treatment of cervical cancer
Presenter: Paul Bryson
Session: Poster Display session 3
Resources:
Abstract
1133 - the Mutant Neoantigen Specific T Cell Is a Personalized Immunotherapy in Refractory Solid Tumor
Presenter: Qi Song
Session: Poster Display session 3
Resources:
Abstract
3338 - NY-ESO-1 and LAGE1A –an emerging target for cell therapies in solid tumours
Presenter: Ioanna Eleftheriadou
Session: Poster Display session 3
Resources:
Abstract
3089 - Targeting myeloid-derived suppressor cells and T cells: combination treatment with MTL-CEBPA and PD-1 antibody in a mouse syngeneic CT26 model
Presenter: Mikael Sodergren
Session: Poster Display session 3
Resources:
Abstract
5991 - Master Checkpoint Cbl-b Inhibition: Anti-tumor Efficacy in a Murine Colorectal Cancer Model Following siRNA-based Cell Therapy
Presenter: Kathrin Thell
Session: Poster Display session 3
Resources:
Abstract