A Phase 2 Study of Panobinostat (PAN) in Combination with Bortezomib (BTZ) in Patients with Relapsed/Refractory Peripheral T-Cell Lymphoma (PTCL) or NK/T-Cell Lymphoma (NKL)
Authors: Goh Yeow-Tee , Hwang William YK , Diong Colin Phipps , Hsien Yap chun , Tay Kevin , Lim Soon Thye , Lee Yuh Shan , Ng Soo Chin , Fadilah S , Kim Won Seog , Tan Daryl 
Published: October 2019

Abstract
Background
Relapsed/refractory PTCL and NKL after conventional chemotherapy carry a poor prognosis and there is currently no proven salvage treatment available. Numerous preclinical studies have demonstrated synergistic interactions between proteasome and histone deacetylase (HDAC) inhibitors. PAN inhibits the aggresome pathway of protein degradation, which is upregulated when the proteasome pathway is inhibited by BTZ. Primary end point of this phase II multi-center open-label clinical study (NCT00901147) is the objective response rate (ORR) according to the Revised Response Criteria (Cheson 2007) among eligible patients (pts) treated with this novel combination of BTZ and PAN. Secondary end points include the evaluation of the progression-free survival (PFS) and the assessment of the safety and tolerability of the combination. We report the final clinical results of our study exploring this novel combination.
Methods
Pts with histologically confirmed PTCL or NKL who failed or were refractory to 1 or more prior systemic therapy, and had measurable disease and ECOG performance status 0–2 were eligible. Pts were accrued according to a 2-stage Gehan design. Pts receive thrice weekly oral PAN (20 mg) and twice weekly BTZ (IV 1.3 mg/m2), both for 2 of 3 weeks for up to 8 cycles. CT scanning and/or FDG-PET were performed after every two cycles.
Results:
Among 25 pts enrolled, histologies included: angioimmunoblastic T-cell lymphoma (AITL) n=8, PTCL (unspecified) n=11, Anaplastic large cell lymphoma, ALK+ and ALK- n=1 and 2 respectively, NKL, nasal type n=2 and subcutaneous panniculitis-like T-cell lymphoma n=1. The median age was 59 (35-79) years, and 64% were male. Outcomes are available on 23 patients as 2 patients withdrew consent before any response assessment could be made. The ORR (CR+PR) was 43% (10/23) with 22% (5/23) attaining a CR. Median time to response was 6 weeks. Five pts (22%) had stable disease while 8 pts developed progressive disease (35%) while on study. Pts received a median of 2 prior therapies (range 1-4); 28% had prior autologous stem cell transplantation (SCT). Common treatment-related grade 3/4 adverse events included thrombocytopenia (68%), neutropenia (36%), diarrhoea (28%) and asthenia/fatigue (16%). Peripheral neuropathy of any grade was observed in 40%. 5 pts successfully underwent subsequent allogeneic SCT. Updated survival analysis will be presented.
Conclusions
The study regimen is generally well tolerated and shows encouraging activity across different T/NK-cell lymphomas. The novel combination could successfully serve as a bridge to allogeneic SCT for many transplant-eligible patients who have failed conventional chemotherapy. These results form the basis for further validation studies on proteasome and HDAC inhibition in PTCL or NKL. Ongoing correlative studies are designed to determine if the study regimen is more active in diseases with up-regulation of NF-kappa B activity or transcription factors/ co-regulators known to be modified by acetylation.

Disclosures
Goh: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Jannsen Pharmaceuticals: Honoraria, Research Funding, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Kim:Novartis, Celgene, Takeda: Research Funding. Tan:JANSEN: Honoraria, Research Funding; NOVARTIS: Research Funding.