Abstract 2319
Background
The number of new anal cancer (SCCA) cases in the US has been rising annually; 20% of patients (pts) will develop metastatic (met) disease, which presents an unmet medical need. A large population-based study showed 88% of SCCA were HPV+ and 73% had HPV-16 (Hoots et al IJC 2009). ADXS11-001 (ADXS) is an irreversibly attenuated Listeria monocytogenes immunotherapy that targets HPV-associated cancers. It is bioengineered to secrete an antigen-adjuvant protein fused to the E7 peptide of HPV-16. It allows the generation of tumor antigen specific cytotoxic T cells that infiltrate and destroy tumor cells. This is the 1st P2 trial to assess the efficacy/safety of ADXS in met SCCA.
Methods
This multicenter, open-label, 2-stage design trial (NCT02399813) includes pts ≥ 18 yrs with histologically confirmed, measurable SCCA and previous ≥ 1 line of therapy for advanced disease. Pts received IV ADXS monotherapy (1x109 colony forming units) every 3 weeks for ≤ 2 years or until a discontinuation criterion was met. Tumor assessments (RECIST 1.1) were every 9 wks. Interim analysis was planned on enrollment of 31 evaluable pts (≥ 1 post-baseline scan). An objective response rate (ORR) ≥ 10% or a 6-month progression free survival (PFS) ≥ 20% with tolerable safety would allow proceeding to Stage 2.
Results
Preliminary Stage 1 results are reported with data from 29 of the planned 31 evaluable pts. Median age 60 yrs, range 43-77; 27 F/2 M; median follow-up time 191 days. One pt (3.5%) had a durable partial response lasting > 6 months (after progression on prior anti-PD-1 therapy) and 7 pts had stable disease (24%). Disease control rate was 28%. The current KM 6-month PFS estimate is 22%. Common (≥ 30%) treatment related AEs (TRAEs) were grade 1-2 chills/rigors, fever, hypotension and vomiting. Grade 3 TRAEs of cytokine related syndrome (n = 1; SAE), infusion related reactions (n = 2; 1 SAE) and hypotension (n = 2; 1 SAE) were reported.
Conclusions
ADXS monotherapy showed promising activity and met the predefined 6-month PFS rate. Treatment was well-tolerated with mostly grade 1-2 infusion related AEs that resolved successfully with standard care. Further investigation is ongoing in this population.
Clinical trial identification
NCT02399813
Legal entity responsible for the study
Advaxis, Inc
Funding
Advaxis, Inc
Disclosure
C. Eng: Consulting agreement with Advaxis. All other authors have declared no conflicts of interest.