Abstract
e14171 Background: We previously reported that aPD1 agents could be safely administered IL in patients (pts) with metastatic MEL with superficial lesions, providing local and bystander tumor response (Samoylenko, I., et al. (ASCO-SITC 2018)). We present results from an interim 6 mos analysis of RFS and ORR for IL neo aPD1 therapy. Methods: Pts with unresectable stage IIIC/D/IVM1a-c MEL (safety cohort, N = 7) and resectable stage IIIC/D/IVM1a (expansion cohort, N = 18), with ≥ 1 injectable cutaneous, subcutaneous, or nodal lesions ≥ 10 mm were allocated to 6 doses/12 of nivolumab or pembrolizumab before surgery (surg). aPD1 was given at scale-based dosing regimen reported previously. Tumor sampling for biomarker analysis and pCR confirmation (or core-needle biopsy, CNB) was performed prior to treatment and at week 13-18. The analysis was conducted on the ITT basis to estimate RFS at 6 mos and ORR. An RFS event was defined as disease progression or death due to any cause after surg and assessed in the expansion cohort. ORR for the both cohorts was evaluated. Results: Since Apr 2016 to Dec 2018 25 pts were enrolled. Baseline characteristics are summarized in Table. ORR was 47,6% (10/21 pts assessed), with 5 (24%) clinical CR and 4 pathological CR (19%). Among 18 pts considered for surg 2 refused from surg when CNB confirmed no residual tumor. 89% of pts (16/18 pts) from the expansion cohort remained recurrence free at 6 mos FU. Baseline immune phenotype of tumor infiltrating lymphocytes (TILs) was available for 20 of 21 pts assessed. Baseline percent of TILs assessed by flow cytometry (FCT) was higher in responders vs non-responders (7.54±7.51% vs 1.51±2.93, p < .05), whereas CD3-CD16+CD56+ and CD4+CD25+ values were lower in responders vs non-responders (0.94±1.45% vs 7.88±6.84, p < .05, and 6.68±3.46% vs 20.50±16.79, p < 0.05, respectively). PD1, PDL-1 and PDL-2 expression in tumor cells and TILs assessed by FCT did not differ significantly between responders and non-responders. Conclusions: We demonstrated the potential clinical efficacy of IL aPD1 in melanoma pts. Further studies are needed to determine if unsuccessful IL administration could predict failure to adjuvant treatment. Primary analysis of RFS at 1-yr is expected. Clinical trial information: NA. [Table: see text]
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
