Markovic, Svetomir

e21054 Background: Up to 50% of patients undergoing resection for advanced melanoma experience recurrence. Identification of preoperative prognostic biomarkers is needed to ascertain risk of relapse and guide postoperative management. Lactate dehydrogenase (LDH) represents a strong prognostic factor in unresectable metastatic (stage IV) melanoma, but its relevance in patients with resected stage III or IV disease remains unknown. Methods: We retrospectively analyzed data from patients with stage III and IV melanoma who had undergone complete resection of disease and received follow-up treatment at Mayo Clinic, Rochester between January 1, 2000 and January 31, 2012. Clinical data were collected from electronic records. Survival data were estimated using the Kaplan-Meier method. Associations of preoperative LDH with time to relapse and death were evaluated using Cox proportional hazards regression models and summarized with hazard ratios and 95% confidence intervals. Results: A total of 154 subjects with resectable stage III or IV melanoma were included in the study. Median age at the time of resection was 58; 54 (35.1%) were female. One-hundred sixteen (75.3%) patients were classified as stage III and 38 (24.7%) stage IV. Adjuvant systemic treatment was administered in 75 (48.7%) patients and adjuvant radiation in 32 (20.7%). Median duration of follow-up was 4.0 years. Sixteen (10.3%) patients had preoperative LDH above the upper limit of normal. Each 50-unit increase in LDH was associated with a 15% increased risk of relapse (HR 1.15; p = 0.040) and 23% increased risk of death (HR 1.23; p = 0.001). After adjusting for age, gender, stage, number of sites, adjuvant systemic treatment, and adjuvant radiation, preoperative LDH remained associated with time to death (HR 1.25; p = 0.002). Preoperative LDH greater than the upper limit of normal was associated with increased hazard of death, both with univariate (HR 2.44; p = 0.005) and multivariate (HR 2.17; p = 0.017) analyses. Conclusions: This study supports the role of elevated preoperative LDH as a predictor of inferior outcomes in patients with advanced melanoma. Further study to correlate LDH to outcomes in the era of adjuvant immunotherapy is required.

Abstract Background The treatment of metastatic melanoma has been revolutionized by developments in targeted therapy and immunotherapy. BRAF/MEK inhibitors, blockade of cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death (PD-1/L1) receptor have shown durable anti-melanoma effects. The optimal sequence strategy of targeted therapy and immunotherapy in metastatic BRAF-mutated melanoma patients (pts) is unknown and no treatment guidelines exist. Therefore, we report a single-institution experience of different treatment approaches using targeted therapy and immunotherapy and its impact on outcomes. Methods Pts with BRAF-mutated metastatic melanoma treated with targeted therapy and immunotherapy from 2012 to2017 were analyzed. Six groups were identified based on treatment strategy: (1) 1st line BRAF/MEK inhibitors followed by 2nd line immunotherapy; (1.1) 1st line BRAF/MEK inhibitors followed by 2nd line immunotherapy in combination with BRAF/MEK inhibitors (triple therapy);(1.2) same as group 1 followed by triple therapy as 3rd line; (2) 1st line immunotherapy followed by 2nd line BRAF/MEK inhibitors; (2.1) 1st line immunotherapy followed by 2nd line triple therapy; (2.2) same as group2 followed by triple therapy as 3rd line. All time-to-event analysis was calculated using the Kaplan-Meier method and Wilcoxon test. Results Forty four pts were included. The median age at diagnosis was 49 years (range 21-73), 24 (54%) pts were females and 19 (43%) developed brain metastases during their disease course. BRAF V600 mutation was seen in all pts except in 1 pt with p.N581S mutation. The preferred 1st line targeted therapy was dabrafenib/trametinib used in 17 (94%) out of 18 pts, while ipilimumab was the preferred 1st immunotherapy used in 11 (42%) out of 26 pts. For 2nd line therapy, DT was used in 19 (90%) out of 21 pts, while pembrolizumab was used in 16 (69%) out of 23 pts. For 3rd line, DT was used in 5 (83%) out of 6 pts, while pembrolizumab was used in 6 (100%) out of 6 pts. DT was usually the first choice for patients with high burden disease or brain metastases. The most common approach strategy was immunotherapy followed by targeted therapy (group 2), the median duration of treatment was 11 and 19 weeks respectively; for pts started on targeted therapy followed by immunotherapy (group 1), the median duration of treatment was 17 and 14 weeks respectively. (Table 1) Time-to-next therapy (TTNT) following 1st line treatment was similar in pts treated with targeted therapy (median 23 weeks [95% CI: 15-31]) or immunotherapy (median 26 weeks [95% CI: 10-33], p=0.94). Following 2nd line treatment, the TTNT for pts treated with targeted therapy was 18 weeks (95% CI: 4-38), immunotherapy 18 weeks (95% CI: 13-19) and triple therapy 22 weeks (95% CI: 13-41), p=0.48. A trend towards better overall survival (OS) from frontline therapy was seen in pts who received immunotherapy (1st line) followed by targeted therapy (2nd line) (median 7 years [95% CI: 2.7-7.08]) compared to those who received targeted therapy (1st line) followed by immunotherapy (2nd line) (median 2.3 years [95% CI: 1.3-NR], p=0.09. Interestingly, patients who received salvage chemotherapy had significant longer OS in those treated initially with immunotherapy (median 7 years [95% CI: 3.2-7.08]) (n=6) compared to patients started on targeted therapy (median 2 years [95% CI: 0.6-2.4], p=0.03) (n=5). Conclusion A trend towards longer OS was seen in pts treated with 1st line immunotherapy followed by 2nd line targeted therapy with a median therapy time of 11 and 19 weeks respectively. No difference in TTNT was seen with the use immunotherapy, targeted therapy or triple therapy when used as 1st or 2nd line. The significant longer OS benefit with f 1st line immunotherapy was only seen in patients who received chemotherapy later in their treatment course. Table 1.Treatment Characteristics by GroupMedian duration of therapy in weeksGroup(n)1st line therapy(median)2nd line therapy(median)3rd line therapy(median)Totalmedian (range)Chemotherapy (n)1(n=9)Targeted therapy(17)Immunotherapy (14)N/A52 (13-134)51.1(n=7)Targeted therapy(25)Triple therapy (19)Any*(43)69 (22-118)11.2(n=2)Targeted therapy(60)Immunotherapy (16)Triple therapy (21)96 (81-111)12(n=18)Immunotherapy(11)Targeted therapy(19)Any*(24)48 (16-120)52.1(n=4)Immunotherapy(17)Triple therapy (16)Any*(9)41 (25-69)02.2(n=4)Immunotherapy(19)Targeted therapy(16)Triple therapy (19)61 (54-73)1* include any treatment regimen such as immunotherapy, targeted therapy or chemotherapy Citation Format: Jesus Vera-Aguilera, Jonas Paludo, Narjust Duma, Marcella Tschautscher, Cecilia Yu, Svetomir Markovic. A clinical insight into therapeutic sequence in advanced melanoma [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-A32.

186 Background: The optimal sequence strategy of BRAF/MEK inhibitors, anti-PD- 1/PDL-1 and anti-CTLA-4 in metastatic BRAF-mutated melanoma patients (pts) is unknown and no treatment guidelines exist. Therefore, we report a single-institution experience of different treatment approaches using targeted therapy (TT) and immunotherapy and its impact on outcomes. Methods: BRAF-mutated metastatic melanoma pts treated with TT and immunotherapy from 2012 to2017 were analyzed. Six groups were identified based on treatment strategy. All time-to-event analyses were calculated using the Kaplan-Meier method and Wilcoxon test. Results: Forty-four pts were identified. The median age at diagnosis was 49 years (range 21-73), 54% pts were females and 43% developed brain metastases during disease course. The most common approach strategy was immunotherapy followed by TT, the median duration of treatment was 11 and 19 weeks, respectively. Time-to-next therapy (TTNT) following 1st line treatment was similar in pts treated with TT (median 23 weeks [95% CI: 15-31]) or immunotherapy (median 26 weeks [95% CI: 10-33], p = 0.94). A trend towards better overall survival (OS) was seen in pts who received immunotherapy followed by TT (p = 0.09); patients who received salvage chemotherapy (carboplatin/paclitaxel) had significantly longer OS (median 7 years [95% CI: 3.2-7.08]) ( p = 0.03). Conclusions: No differences in TTNT were seen with immunotherapy, TT or combined (triple therapy) when used as 1st or 2nd line. The significant longer OS benefit with 1st line immunotherapy was only seen in patients who received chemotherapy later in their treatment course. [Table: see text]

Abstract Metastatic melanoma (MM) is the most aggressive type of skin cancer contributing to approximately 80% of all skin cancer related deaths. In 2016, it was estimated that more 76,000 cases would be diagnosed in the United States. The high metastatic potential and aggressive clinical behavior of this disease makes it a major health problem. As a consequence there has been notable development in for novel targeted (i.e. BRAF inhibitors) and immune therapies (i.e. anti-PD1 and CTLA4 inhibitors). However, despite improvements in patient outcomes, most patients develop resistance within 6-11 months on dual BRAF/MEK inhibition, and 5 months on immune therapy, highlighting the need to identify new therapies that improve disease management and patient survival. Increased expression of CyclinD1 has been reported to occur as a mechanism of resistance to BRAF inhibition, resulting in reactivation of the canonical activating pathway in melanoma, MAPK. Thus, we hypothesize that combined inhibition of CDK4/6 and MAPK signaling will provide a novel anti-tumor synergy drug combination superior to current standard of care in BRAF mutant patient-derived preclinical models. Using MM human tissue from patients we developed 3 BRAF mutant preclinical models investigating a novel triple therapy drug combination BRAFi/MEKi/CDK4/6i. Protein analysis and drug proliferation assays were used to design the novel combination. In vivo, we found statistically significant differences in tumor inhibition between the novel combination and the current standard of care. The triple therapy also showed promising results, in vivo, when assessed as a salvage therapy following tumor escape from BRAFi/MEKi combination treatment. Citation Format: Antoneicka L. Harris, Michael Thompson, Svetomir Markovic, William Durham, Louis Dawson, Daniel Small, John A. Copland. Tumor regression in novel triple therapy BRAF mutant metastatic melanoma patient-derived preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-130. doi:10.1158/1538-7445.AM2017-LB-130