Combined immunotherapy in melanoma patients with brain metastases: A multicenter international study

BACKGROUND

Ipilimumab plus nivolumab (COMBO) is the standard treatment in asymptomatic patients with melanoma brain metastases (MBM). We report a retrospective study aiming to assess the outcome of patients with MBM treated with COMBO outside clinical trials.

METHODS

Consecutive patients treated with COMBO have been included. Demographics, steroid treatment, Central Nervous System (CNS)-related symptoms, BRAF status, radiotherapy or surgery, response rate (RR), progression-free (PFS) and overall survival (OS) have been analyzed.

RESULTS

376 patients were included: 262 received COMBO as first-line and 114 as a subsequent line of therapy, respectively. In multivariate analysis, Eastern Cooperative Oncology Group (ECOG) (≥1 vs 0) [HR 1.97 (1.46-2.66)], extracerebral metastases [HR 1.92 (1.09-3.40)], steroid use at the start of COMBO [HR 1.59 (1.08-2.38)], CNS-related symptoms [HR 1.59 (1.08-2.34)], SRS (Stereotactic radiosurgery) [HR 0.63 (0.45-0.88)] and surgery [HR 0.63 (0.43-0.91)] were associated with OS. At a median follow-up of 30 months, the median OS (mOS) in the overall population was 21.3 months (18.1-24.5), whilst OS was not yet reached in treatment-naive patients, steroid-free at baseline. In patients receiving COMBO after BRAF/MEK inhibitors(i) PFS at 1-year was 15.7%. The dose of steroids (dexamethasone < vs ≥ 4 mg/day) was not prognostic. SRS alongside COMBO vs COMBO alone in asymptomatic patients prolonged survival. (p = 0.013). Toxicities were consistent with previous studies. An independent validation cohort (n = 51) confirmed the findings.

CONCLUSIONS

Our results demonstrate remarkable long-term survival in treatment-naïve, asymptomatic, steroid-free patients, as well as in those receiving SRS plus COMBO. PFS and OS were poor in patients receiving COMBO after progressing to BRAF/MEKi.

Sinonasal mucosal melanomas: defining profiles for better survival outcomes

BACKGROUND

Sinonasal mucosal melanoma is an aggressive malignancy with a 5-year survival rate ranging from 20% to 39%. Despite the evolving surgical and radiotherapy techniques, and introduction of immune-checkpoint inhibitor therapy, overall survival rates remain poor.

METHODOLOGY

A retrospective cohort study was conducted at the Hospital Clinic de Barcelona and the Hospital de la Santa Creu i Sant Pau between 1984 and 2020; primary outcome measures were 3 and 5-year melanoma-specific survival (MSS). Kaplan-Meier survival analysis and Cox proportional hazards model were performed to identify predictors of survival.

RESULTS

Fifty patients were included, the mean age was 70.4, MSS at 3 and 5 years was 51.2%, and 29.5%, respectively. The median follow-up was 39.6 months during which 46% presented locoregional recurrence and 36%, metastasis. The univariate and multivariate analyses found as survival predictors the N category, the treatment received, the surgical margins and the mitotic index.

CONCLUSIONS

We found an overall 5-year MSS of 29.5%. Those patients with intention-to-cure (stages III and IVa) treated by surgery that were N0 at diagnosis, with < 10 mitoses per HPF showed a 5-year MSS rate of 74.1%. More studies will be needed to adequately define the patients' profiles that will benefit from a better survival outcome.

FOCUS phase 3 trial results: Percutaneous hepatic perfusion (PHP) with melphalan for patients with ocular melanoma liver metastases (PHP-OCM-301/301A)

9510

Background: Ocular melanoma, the most common intraocular malignancy, frequently metastasizes to the liver but to date there is no established standard of care for hepatic-dominant ocular melanoma patients. The FOCUS trial began as a randomized, Ph 3 trial (301) comparing PHP with best alternative care (BAC). The trial was subsequently amended (301A) to halt the BAC arm due to enrollment concerns. Methods: Eligible patients with hepatic-dominant ocular melanoma were randomized 1:1 to receive PHP or BAC (investigator’s choice of TACE, pembrolizumab, ipilimumab, or dacarbazine) on the 301 trial. All eligible patients received PHP on the 301A trial. PHP patients could receive up to 6 PHP treatments, repeated every 6-8 weeks with melphalan dosed at 3.0mg/kg ideal body weight (IBW). Patients with progressive disease (PD) were discontinued from study treatment and all patients are followed until death. Patientswere imaged every 12 (±2) weeks until PD. The primary endpoint, ORR (per RECIST 1.1) as assessed by Independent Review Committee, was characterized by the point estimate and 95% CI for each group (PHP and BAC). Results: 144 patients were enrolled overall; 102 were assigned to PHP (301: n = 43; 301A: n = 59) and 42 were assigned to BAC. 91 PHP patients received treatment (301: n = 40; 301A: n = 51) and 32 BAC patients received treatment. ORR among PHP patients was 35.2% (32/91; 95% CI: 25.44-45.88%). ORR among BAC patients was 12.5% (4/32; 95% CI: 3.51-28.99%; p= 0.0154). The median DOR was 14 months for PHP patients and not calculable for BAC patients. The DCR among PHP patients was 73.6% (67/91; 95% CI: 63.35-82.31%) and among BAC patients was 37.5% (12/32; 95% CI: 21.10-56.31%; p= 0.0002). The median PFS was 9.03 months (95% CI: 6.34-11.56) among PHP patients and was 3.12 months (95% CI: 2.89-5.65) among BAC patients ( p= 0.0007). The median OS was 20.53 months (95% CI: 16.59-24.35) among PHP patients and was 14.06 months (95% CI: 9.99-19.78) among BAC patients. With the last treatment occurring in May 2021, the OS, DOR, and PFS data continues to mature as patients are still being followed for survival. Among the 94 patients assessed for safety after treatment with PHP, 42.6% of patients experienced a serious treatment-emergent adverse event, the majority of which were hematological, transient in nature, and resolved without sequelae. There were no treatment related deaths in the trial. Conclusions: In this analysis of data from the FOCUS trial, PHP demonstrates superior ORR, DOR, DCR, PFS, and OS in comparison with BAC in the treatment of hepatic metastases from ocular melanoma. This therapy offers a potential option for patients with this rare indication that is associated with a poor prognosis and few treatment options. Clinical trial information: NCT02678572.

Management of infliximab-refractory immune checkpoint inhibitor gastrointestinal toxicity: A multicenter case series

2665

Background: Immune checkpoint inhibitor (ICI) GI tox (gastritis, enteritis, colitis) is a major cause of morbidity and treatment-related death. Guidelines agree steroid-refractory cases warrant infliximab (IFx); however not all pts respond and best management of IFx-Refractory ICI GI toxicity (IRIGItox) is not clear. Methods: We conducted an international multi-centre retrospective case series. IRIGItox was defined as failure of symptom resolution ≤ Gr 1 (CTCAE v5.0) following ≥ 2 IFx doses or failure of symptom resolution ≤ Gr 2 after 1 dose. Data were extracted regarding demographics, steroid use, response and survival. Tox was graded at symptom onset and time of IFx failure. Efficacy of IFx refractory therapy was assessed by symptom resolution, time to resolution and steroid wean. Results: 78 pts were identified; med age 60 yrs (95% CI 56-65), 56% male. 70 (90%) had melanoma, 55 (71%) had advanced-stage, 60 (77%) received anti-CTLA-4 (with anti-PD1 50, single agent 10). Most had colitis (N=75, 96%) and ≥ Gr 3 tox (N=74, 95%) at symptom onset. Pre-IFx investigation varied: imaging 37%; faecal calprotectin 29%; endoscopy 59%. All pts received Med time to steroid initiation was 3 days (95% CI 2-4). 46 (59%) had primary steroid refractory disease,. Med time from symptom onset to IFx was 18 days (95% CI 12-23), a med 2 (range 1-6) doses of IFx were given, 69 (88%) pts received > 1 IFx dose. Across 78 pts, 105 post IFx treatments were given: calcineurin inhibitors (ciclosporin, tacrolimus, 32); antimetabolites (mycophenolate, azathioprine, 26); non-TNF-α MABs (vedolizumab, ustekinumab, 20); non-targeted anti-inflammatory (mesalazine, 16); non-pharmacological (colectomy 5, faecal transplant 1, photophoresis 1). 4 pts did not receive therapy for IRIGItox. Of these, 2 died of melanoma prior to resolution of tox; 1 had resolution after 4 doses IFx, 1 had recurrent melanoma and flare of tox on PD1 re-challenge. IRIGItox outcomes by post IFx treatment are shown in Table. Conclusions: This retrospective case series confirms heterogeneous management of IRIGItox. Non-pharmacological interventions and calcineurin inhibitors appear most likely to result in tox resolution. Calcineurin inhibitors have the shortest time to resolution in responders. Further details on post-IFx management and oncological outcomes will be examined. [Table: see text]

Phase II study SECOMBIT (sequential combo immuno and target therapy study): A subgroup analysis with a longer follow-up

9535

Background: To investigate the best sequential strategy, we started the SECOMBIT study, a randomized three parallel arms phase 2 study (NCT02631447). We used the combination of encorafenib/binimetinib (E+B) as targeted therapy (T-T) and the combination of ipilimumab/nivolumab (I+N) as immunotherapy (I-O). We explored the two different sequences and the “sandwich” strategy with a short course of target therapy, switched by combo immunotherapy at the best response, and not at progression of disease. In our previous report we have observed a trend in favor of the arms where I-O was given as first, confirmed by the first report of the DreamSeq study, a phase III study which compared the two different sequences with T-T and I-O. Here we updated the study data with a subgroup analysis. Methods: From Nov 2016 to May 2019, 37 centers in 9 countries enrolled 251 patients with untreated, metastatic BRAFV600 melanoma. Patients were randomized to Arm A [E+B until PD, followed by I+N], or Arm B (I+N until PD, followed by E+B) or Arm C (E+B for 8 weeks, followed by I+N until PD, followed by E+B). The overall survival (OS) is the primary endpoint of the study. Secondary endpoints included total progression-free survival (tPFS), 2- and 3-years survival rate, best overall response rate, duration of response, biomarkers evaluation. Results: The study primary endpoint was met in each arm with at least 30 patients alive at 24 months. The median follow-up estimated with the reverse Kaplan-Meier method was 37.1 months (IQR: 32.8-46.4). The OS at 2 and 3 years was calculated in the three arms for all patients, and in the subgroups normal or elevate LDH level and < 3 or ≥ 3 metastatic sites. OS and tPFS rates at 2 and 3 years are shown in the table. Conclusions: With a 37.1 months median follow-up, 2 and 3-years OS as well as tPFS rates are higher in Arm B and C. In line with recent findings, the SECOMBIT results confirm a better trend in favor of Arm B and C treatment sequence. The analysis of the secondary endpoints is ongoing. Clinical trial information: NCT02631447. [Table: see text]

Nivolumab (NIVO) + relatlimab (RELA) versus NIVO in previously untreated metastatic or unresectable melanoma: OS and ORR by key subgroups from RELATIVITY-047

9505

Background: In the phase 2/3 RELATIVITY-047 trial, NIVO + RELA as a fixed-dose combination (FDC) significantly improved the primary endpoint of progression-free survival (PFS) versus NIVO in patients (pts) with previously untreated metastatic or unresectable melanoma. Secondary endpoints showed a clinically meaningful improvement in overall survival (OS), although not statistically significant, and a higher objective response rate (ORR). As previously reported, PFS and OS favored NIVO + RELA over NIVO across prespecified stratification factors (LAG-3 expression, PD-L1 expression, BRAF V600 mutation status, and metastasis stage). Here we report the first disclosure of ORR analyzed by prespecified stratification factors and OS and ORR in additional subgroups. Methods: Pts were randomized 1:1 to receive NIVO 480 mg + RELA 160 mg FDC or NIVO 480 mg intravenously Q4W. The primary endpoint was PFS per RECIST v1.1 assessed by blinded independent central review (BICR). Secondary endpoints were OS and ORR by BICR, tested in hierarchy. Exploratory analyses were performed for PFS, OS, and ORR by prespecified subgroups. Results: PFS continued to favor NIVO + RELA over NIVO across key subgroups. OS and ORR also favored NIVO + RELA over NIVO across key subgroups including those associated with poor prognosis (Table). ORR favored NIVO + RELA over NIVO for pts with LAG-3 expression ≥ 1% (47% vs 35%) and < 1% (31% vs 24%), PD-L1 expression ≥ 1% (53% vs 45%) and < 1% (36% vs 24%), and BRAF wild-type (43% vs 34%) and mutant (43% vs 31%) melanoma, respectively. Additional key prespecified subgroups will be presented. In all treated pts, NIVO + RELA maintained a manageable safety profile with no new or unexpected safety signals. Conclusions: NIVO + RELA was favored over NIVO across key subgroups for PFS, OS, and ORR, and findings appeared consistent with outcomes in the overall population. NIVO + RELA had a favorable benefit-risk profile. Clinical trial information: NCT03470922. [Table: see text]

Dabrafenib (D) and trametinib (T) plus spartalizumab (S) in patients (pts) with previously untreated BRAF V600–mutant unresectable or metastatic melanoma: Three-year overall survival (OS) data from the randomized part 3 of the phase III COMBI-i trial

9527

Background: Combination of immune checkpoint inhibitors and targeted therapy may produce durable and deep response in a higher proportion of pts with BRAF V600–mutant unresectable or metastatic melanoma. A recent report from the randomized, double-blind, placebo (PBO)-controlled Part 3 of the Phase 3 COMBI-i trial (NCT02967692) failed to show a statistically significant progression-free survival (PFS) benefit (hazard ratio (HR) of 0.82 (95% CI, 0.66‒1.03, p=.042)). Here, we report 3-year OS data from COMBI-i part 3. Methods: Eligible pts were randomized 1:1 to receive either S+D+T (n = 267; S 400 mg IV Q4W + D 150 mg orally BID + T 2 mg orally QD) or PBO+D+T (n = 265), until progression or unacceptable toxicity. Although the primary endpoint of PFS was not met, exploratory OS and safety analyses were performed. OS was summarized descriptively using Kaplan–Meier methods and HR was estimated using a stratified cox regression model. Results: As of October 19, 2021 (median follow-up, 42.8 months), the median OS was not reached in S+D+T arm and was 40.4 months with PBO+D+T (HR 0.796; 95% CI, 0.615‒1.029). There were 113 (42.3%) deaths in the S+D+T and 126 (47.5%) in the PBO+D+T. Estimated 2-year and 3-year OS rates were 67.7% (95% CI 61.6‒73.1) and 60.1% (95% CI 53.8‒65.8) with S+D+T vs 61.9% (95% CI 55.6‒67.5) and 52.9% (95% CI 46.6‒58.9) with PBO+D+T, respectively. An OS benefit was observed with S+D+T in these prespecified subgroups – Eastern Cooperative Oncology Group Performance Status (ECOG PS) 1 (HR 0.50; 95% CI, 0.32‒0.8), age ≥65 years (HR 0.58; 95% CI, 0.36‒0.94), PD-L1 negative ( < 1%) (HR 0.62; 95% CI, 0.42‒0.91), sum of lesion diameters ≥ 66 mm at baseline (HR 0.63; 95% CI, 0.43‒0.91) and metastatic sites ≥ 3 (HR 0.66; 95% CI, 0.47‒0.94). Adverse events (AEs) irrespective of study treatment relationship were observed in 99.3% of pts in S+D+T vs 97.3% in PBO+D+T. The most common AEs (in > 30%; all grades) were pyrexia, diarrhea, and nausea. Grade ≥3 treatment-related AEs (TRAEs) occurred in 56.9% vs 35.2% of pts treated with S+D+T vs PBO+D+T, respectively. Dose reductions of D and T due to AEs were more frequent in the S+D+T arm than PBO+D+T arm (47.2% vs 25.4% and 45.7% vs 25.4%, respectively), contributing to a lower relative dose intensity; the TRAEs leading to discontinuation of all 3 study drugs occurred in 13.5% vs 8% of pts, respectively. Conclusions: Results from this landmark 3-year OS analysis from COMBI-i- part 3 was consistent with the primary analysis, while the PBO+D+T showed a higher OS rate than previously observed for D+T alone in COMBI D/V studies, with a longer median follow-up. Subgroup analyses showed that ECOG PS 1, age ≥65 years, negative PD-L1 status and high tumor burden were associated with better OS in S+D+T in terms of HR. Clinical trial information: NCT02967692.

Relatlimab and nivolumab versus nivolumab in previously untreated metastatic or unresectable melanoma: Overall survival and response rates from RELATIVITY-047 (CA224-047)

360385

Background: RELATIVITY-047, a global, randomized, double-blind, phase II/III study, met its primary endpoint of progression-free survival (PFS). Relatlimab and nivolumab (RELA + NIVO) as a fixed-dose combination (FDC) demonstrated a significant PFS benefit (median PFS was 10.1 months [mo]; 95% CI, 6.4–15.7) with RELA + NIVO vs. 4.6 mo (95% CI, 3.4–5.6) with NIVO; hazard ratio (HR) 0.75 (95% CI, 0.6–0.9; p = .0055), with a manageable safety profile, compared to NIVO alone in patients with previously untreated metastatic or unresectable melanoma (Lipson EJ et al. J Clin Oncol 2021;39[15_suppl]:9503P). Here we report updated PFS and the first disclosure of secondary endpoints, overall survival (OS), and overall response rate (ORR). Methods: Patients were randomized 1:1 to receive RELA 160 mg + NIVO 480 mg FDC or NIVO 480 mg alone, given intravenously every 4 weeks, as previously described (Lipson EJ et al. J Clin Oncol 2021;39[15_suppl]:9503P). The primary endpoint of PFS per RECIST v1.1 was assessed by blinded independent central review (BICR). Secondary endpoints were OS and ORR by BICR, to be tested hierarchically. The OS boundary for statistical significance was p < .04302 (2-sided) based on 69% power for a target HR of 0.75. Results: Patients (714 patients) were randomly selected to receive RELA + NIVO (355 patients) or NIVO (359 patients). Median follow-up was 19.3 mo. Updated median PFS was 10.2 mo (95% CI, 6.5–14.8) with RELA + NIVO vs. 4.6 mo (95% CI, 3.5–6.4) with NIVO (HR 0.78; 95% CI, 0.6–0.9). Median OS was not reached (NR; 95% CI, 34.2–NR) with RELA + NIVO vs. 34.1 mo (95% CI. 25.2–NR) with NIVO (HR 0.80; 95% CI, 0.6–1.0; p = .0593). OS rates at 12 mo were 77.0% (95% CI, 72.2–81.1) vs. 71.6% (95% CI, 66.6–76.0) and at 24 mo were 63.7% (95% CI, 58.1–68.7) vs. 58.3% (95% CI, 52.7–63.4) with RELA + NIVO vs. NIVO, respectively. Subsequent systemic therapy rates and types were generally similar between treatment groups. Confirmed ORR per BICR was 43.1% (95% CI, 37.9–48.4) with RELA + NIVO vs. 32.6% (95% CI, 27.8–37.7) with NIVO. Complete responses were observed in 16.3% of patients on RELA + NIVO vs. 14.2% on NIVO. Grade 3/4 treatment-related adverse events (TRAEs) were observed in 75 (21.1%) patients on RELA + NIVO and 40 (11.1%) on NIVO. There were four treatment-related deaths in the RELA + NIVO group and two in the NIVO group. TRAEs (any grade) leading to treatment discontinuation were observed in 54 (15.2%) patients on RELA + NIVO and 26 (7.2%) on NIVO. Conclusions: RELA + NIVO continued to demonstrate a PFS benefit vs. NIVO alone in patients with previously untreated metastatic or unresectable melanoma, consistent with the primary analysis. RELA + NIVO demonstrated a 20% reduction in risk of death and numerically improved OS rates vs. NIVO, although statistical significance was not reached for this secondary endpoint. ORR was higher with RELA + NIVO vs. NIVO. The safety profile of RELA + NIVO remained manageable with no new or unexpected safety signals. Clinical trial information: NCT03470922.

389 Phase II of CD40 agonistic antibody sotigalimab (APX005M) in combination with nivolumab in subjects with metastatic melanoma with confirmed disease progression on anti-PD-1 therapy

Background

A significant number of melanoma patients treated with anti-PD-1 alone or in combination with anti-CTLA-4 have transient or no response to treatment. Sotigalimab is a CD40 agonist antibody with unique epitope specificity and Fc receptor binding profile for optimal therapeutic application. Preclinical studies suggest that sotigalimab can be combined with PD-1 blockade to trigger effective anti-tumor immunity. We conducted a multi-center, open label, Phase Ib-parallel arm phase II trial (NCT03123783) to evaluate the combination of sotigalimab with nivolumab in subjects with anti-PD-1/PD-L1 refractory metastatic melanoma.

Methods

The study objective was to evaluate the efficacy and safety of sotigalimab in combination with nivolumab in anti-PD-1/PD-L1 refractory advanced melanoma patients. Subjects received sotigalimab (0.3mg/kg) combined with nivolumab (360mg) every 3 weeks. Thirty-eight subjects with unresectable or metastatic melanoma who had confirmed progressive disease during treatment with anti-PD-1 therapy (documented by 2 consecutive tumor assessments) were enrolled (evaluable for safety) and 33 subjects were evaluable for efficacy.

Results

Six subjects had PR (including one unconfirmed PR) for an ORR of 18%. The mDOR was 18.7 months. Two subjects with PR received treatment for >2 years. Three of the six responding subjects remain off all therapy for ≥26 months, and one patient required stereotactic radiosurgery to a single brain lesion ten months after stopping therapy and has not required additional local or systemic therapy since. Three additional subjects had prolonged SD (12.6, 7.6, 6.2 months). The DCR was 48% and 33% of subjects experienced reduction in target lesions. Efficacy was observed in patients regardless of their tumor PD-L1 expression. The overall safety profile of the combination is consistent with the profiles of individual agents. The majority of AEs observed were of mild to moderate intensity (CTCAE Grade ≤2). The most commonly observed AEs were: pyrexia, chills, nausea, fatigue, pruritus, transaminitis, headache, asthenia, myalgia, rash, vomiting and arthralgia. There were no Grade 4 or 5 AEs related to study drugs. There were no treatment discontinuations due to AEs.

Conclusions

The combination of sotigalimab and nivolumab demonstrated treatment benefit (tumor response or prolonged disease control) in anti-PD-1/PD-L1 refractory melanoma patients with an overall favorable safety and tolerability profile. Notably, a subset of patients remain in response off treatment for ≥26 months. These results warrant further study of this combination in advanced, refractory melanoma.

Acknowledgements

We extend our gratitude to the patients and their families who made this trial possible and the clinical study teams involved in this trial. We thank BMS for providing the nivolumab for this study.

Trial Registration

NCT03123783

Ethics Approval

This study was approved by the Institutional Review Boards at Yale University (#20170300), University of Nebraska Medical Center (#543-18-CB) and The Hospital Regional de Málaga (#19.03.1341E1-GHM).

Lenvatinib (len) plus pembrolizumab (pembro) for patients (pts) with advanced melanoma and confirmed progression on a PD-1 or PD-L1 inhibitor: Updated findings of LEAP-004

9504

Background: Initial results of the open-label, single-arm, phase 2 LEAP-004 study (NCT03776136) showed that len and pembro in combination had promising efficacy and manageable safety in pts with unresectable stage III-IV melanoma and confirmed PD on a PD-(L)1 inhibitor given alone or in combination. ORR was 21.4% with a 6.3-mo median DOR; ORR was 31.0% in patients with PD on prior anti–PD-1 + anti–CTLA-4. We present updated data from LEAP-004 and additional ORR subgroup analyses. Methods: Eligible pts with PD confirmed per iRECIST within 12 wk of the last dose of a PD-(L)1 inhibitor given alone or with anti–CTLA-4 or other therapies for ≥2 doses received len 20 mg/d once daily plus ≤35 doses of pembro 200 mg Q3W until PD or unacceptable toxicity. Primary end point is ORR per RECIST v1.1 by blinded independent central review (BICR). Secondary end points are PFS and DOR per RECIST v1.1 by BICR, OS, and safety. ORR was calculated for pts with PD on prior anti–PD-1 + anti–CTLA-4, pts whose only prior anti–PD-(L)1 was in the adjuvant setting, pts with primary resistance (ie, best response of SD or PD to prior anti–PD-(L)1 in the advanced setting) and pts with secondary resistance (ie, PD following best response of CR or PR on prior anti–PD-(L)1 in the advanced setting). Results: 103 pts were enrolled. Median age was 63 y, 68.0% of pts had stage M1c/M1d disease, 55.3% had LDH > ULN (20.4% ≥2 × ULN), 58.3% received ≥2 prior treatments, 94.2% received therapy for advanced disease, and 32.0% received BRAF ± MEK inhibition. With median study follow-up of 15.3 mo (range 12.1-19.0), 17.5% of pts were still receiving study drug. ORR by BICR remained 21.4% (95% CI 13.9-30.5), although the number of CRs increased from 2 to 3. DCR was 66.0%. Median DOR increased to 8.2 mo, and the KM estimate of DOR ≥9 mo was 37.2%. ORR was 33.3% in pts with PD on prior anti–PD-1 + anti–CTLA-4 (n = 30), 18.2% in pts whose only prior anti–PD-1/L1 was in the adjuvant setting (n = 11), 22.6% in pts with primary resistance (n = 62), and 22.7% in pts with secondary resistance (n = 22). Median (95% CI) PFS and OS in the total population were 4.2 mo (3.8-7.1) and 14.0 mo (95% CI 10.8-NR); 12-mo PFS and OS estimates were 17.8% and 54.5%. Incidence of treatment-related AEs was as follows: 96.1% any grade, 45.6% grade 3-4, 1.0% grade 5 (decreased platelet count), 7.8% led to discontinuation of len and/or pembro, and 56.3% led to len dose reduction. Conclusions: The combination of len and pembro continues to show clinically meaningful, durable responses in pts with advanced MEL with confirmed progression on a prior PD-(L)1 inhibitor, including those with PD on anti–PD-1 + anti–CTLA-4 therapy, and regardless of primary or secondary resistance to prior anti–PD-(L)1 therapy. The safety profile was consistent with prior studies of len + pembro. These data support len + pembro as a potential regimen for this population of high unmet need. Clinical trial information: NCT03776136.

KEYNOTE-555 Cohort B: Efficacy, safety, and PK of pembrolizumab (pembro) 400 mg every 6 weeks (Q6W) as 1L therapy for advanced melanoma

9541

Background: In KEYNOTE-555, a model-based approach suggested expected drug exposure with pembro 400 mg Q6W is similar to that observed with approved doses of pembro 200 mg or 2 mg/kg Q3W. The pembro Q6W dose is now approved. We present interim efficacy, safety and PK of 1L pembro 400 mg Q6W for patients (pts) with advanced melanoma in KEYNOTE-555 Cohort B (NCT03665597). Methods: Eligible pts had unresectable stage III or IV melanoma, ECOG PS ≤1, and no prior systemic therapy for advanced disease.Pts received pembro 400 mg Q6W for up to 18 cycles (≈2 years).The primary efficacy endpoint was ORR per RECIST v1.1 by blinded independent central review (BICR). Secondary endpoints included PFS by BICR per RECIST v1.1 and safety. PK profile and exposure were evaluated for cycle 1 and steady state (cycle 4). Results: Between May 2019 and Jan 2020, 101 pts were enrolled and received ≥1 dose of pembro. Baseline characteristics were generally similar to pt cohorts of historical pembro studies in advanced melanoma. As of the data cutoff date of August 6, 2020, all pts had ≥6 mo of follow-up and 40.6% of pts had discontinued study treatment. Median (range) duration of treatment and doses administered were 8.2 mo (1 day–13.9 mo) and 6 (1–11) doses, respectively. Observed exposure with pembro 400 mg Q6W had lower variability than model predictions and was within PK parameters from clinical experience with other pembro regimens (Table). ORR was 50.5% (95% CI 40.4–60.6). 12.9% of pts had CR and 37.6% had PR. Median PFS was 13.8 mo (95% CI 3.0–not reached). Estimated PFS rates were 56.5% at 6 mo and 54.3% at 12 mo. Treatment-related AEs of any grade occurred in 79.2% of pts (grade 3–4: 6.9% of pts; no deaths due to a treatment-related AE). The most common immune-mediated AEs were hyperthyroidism (6.9%) and hypothyroidism (6.9%). Conclusions: 1L treatment with pembro 400 mg Q6W yielded a clinically meaningful ORR in pts with advanced melanoma. PK, efficacy and safety results from KEYNOTE-555 Cohort B support prior findings from the model-based assessment and indicate that the benefit-risk profile for the more practical pembro 400 mg Q6W regimen is consistent with that of 200 mg or 2 mg/kg Q3W regimens. Clinical trial information: NCT03665597. [Table: see text]

Two dosing regimens of nivolumab (NIVO) plus ipilimumab (IPI) for advanced (adv) melanoma: Three-year results of CheckMate 511

9516

Background: NIVO 1 mg/kg plus IPI 3 mg/kg (NIVO1 + IPI3) is approved for treatment (tx) of unresectable/adv melanoma, with demonstrated durable clinical benefit on long-term follow-up. Analysis of the phase 3b/4 CheckMate 511 study (NCT02714218) at 1 y showed that NIVO 3 mg/kg plus IPI 1 mg/kg (NIVO3 + IPI1) improves the safety profile of the combination; efficacy with the 2 regimens was similar in descriptive analyses. Here we present 3-y safety/efficacy results. Methods: Patients (pts) ≥ 18 y of age with previously untreated unresectable stage III/IV melanoma were randomized 1:1 to receive NIVO3 + IPI1 Q3W × 4 (N = 180) or NIVO1 + IPI3 Q3W × 4 (N = 178), both followed by NIVO 480 mg Q4W until progression/unacceptable toxicity. The primary endpoint was the incidence of grade (gr) 3–5 tx-related adverse events (TRAEs); secondary endpoints (descriptive analyses) included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The study was not powered to formally demonstrate noninferiority for efficacy endpoints. Results: At a median follow-up of 44.4 and 43.9 mo in the NIVO3 + IPI1 and NIVO1 + IPI3 groups, respectively, TRAEs led to tx discontinuation in 26% and 39% of pts; 57% and 42% of pts had received maintenance therapy. Gr 3–5 TRAE incidence remained significantly lower with NIVO3 + IPI1 than NIVO1 + IPI3 (33.9% vs 48.3%; odds ratio 0.55 [95% CI 0.36–0.84]). The most frequent TRAEs (any gr) were diarrhea (27%), fatigue (26%), and pruritus (26%) with NIVO3 + IPI1 and diarrhea (31%), pruritus (29%), and rash (27%) with NIVO1 + IPI3. In descriptive analyses, efficacy results were similar to those observed at 1 y. OS and tx-free–analysis outcomes were numerically similar in the 2 groups (table). Conclusions: At 3-y follow-up, NIVO3 + IPI1 continued to demonstrate an improved safety profile compared with NIVO1 + IPI3. In descriptive analyses, both groups demonstrated high 3-y OS rates that were numerically similar. This study provides important information regarding the benefit–risk profile of both dosing regimens of NIVO + IPI in pts with adv melanoma. Clinical trial information: NCT02714218. [Table: see text]

Relatlimab (RELA) plus nivolumab (NIVO) versus NIVO in first-line advanced melanoma: Primary phase III results from RELATIVITY-047 (CA224-047)

9503

Background: Immune checkpoint inhibitor therapy has revolutionized the treatment of patients with advanced melanoma. However, novel combinations are needed to optimize the benefit-risk profile. Lymphocyte-activation gene 3 (LAG-3) regulates an immune checkpoint pathway, which inhibits T-cell activity, and is upregulated in many tumor types including melanoma. Relatlimab (RELA), a human IgG4 LAG-3-blocking antibody, restores effector function of exhausted T cells. RELA in combination with nivolumab (NIVO; anti-programmed death [PD]-1) modulates potentially synergistic immune checkpoint pathways and can enhance antitumor immune responses. RELATIVITY-047 is a global, randomized, double-blind, phase II/III study evaluating a novel immune checkpoint inhibitor combination of RELA+NIVO as a fixed-dose combination (FDC) treatment in first-line advanced melanoma. Methods: Patients with previously untreated advanced melanoma were randomized 1:1 to receive RELA 160 mg + NIVO 480 mg FDC intravenously (IV) every 4 weeks (Q4W) or NIVO monotherapy 480 mg IV Q4W, stratified by LAG-3 expression, programmed death ligand 1 expression, BRAF mutation status, and AJCC (v8) M stage. The primary endpoint was progression-free survival (PFS) per RECIST v1.1 as assessed by blinded independent central review. Secondary endpoints were overall survival and objective response rate. PFS in prespecified subgroups and safety were additional objectives. Results: 714 patients were randomized to RELA+NIVO FDC (n = 355) or NIVO (n = 359). Patient characteristics were well balanced between treatment groups. Median follow-up was 13.2 months. Median PFS in the RELA+NIVO FDC group (10.1 months [95% CI, 6.4–15.7]) was significantly longer than in the NIVO group (4.6 months [95% CI, 3.4–5.6]; hazard ratio, 0.75 [95% CI, 0.6–0.9]; P = 0.0055). PFS rates at 12 months were 47.7% (95% CI, 41.8–53.2) and 36.0% (95% CI, 30.5–41.6) for RELA+NIVO FDC and NIVO, respectively. PFS favored RELA+NIVO FDC across key prespecified subgroups. The incidence of grade 3/4 treatment-related adverse events (TRAEs) was higher in the RELA+NIVO FDC group (18.9%) versus NIVO (9.7%). There were 3 treatment-related deaths with RELA+NIVO FDC and 2 with NIVO. TRAEs (any grade) led to treatment discontinuation in 14.6% and 6.7% of patients in the RELA+NIVO FDC and NIVO groups, respectively. Conclusions: First-line treatment with RELA+NIVO FDC demonstrated a statistically significant PFS benefit compared to NIVO monotherapy in patients with advanced melanoma. RELA+NIVO FDC was well tolerated with a manageable safety profile and without unexpected safety signals. This is the first phase III study of a novel FDC to demonstrate a clinically meaningful benefit by dual inhibition of the LAG-3 and PD-1 pathways. Clinical trial information: NCT03470922.

Percutaneous hepatic perfusion (PHP) with melphalan for patients with ocular melanoma liver metastases: Preliminary results of FOCUS (PHP-OCM-301/301A) phase III trial

9510

Background: Ocular melanoma, the most common intraocular malignancy, frequently metastasizes to the liver but to date there is no established standard of care for hepatic-dominant ocular melanoma patients. The FOCUS trial began as a randomized, phase III trial (301) comparing PHP with best alternative care (BAC). The trial was subsequently amended (301A) to remove the BAC arm due to enrollment concerns. Methods: Eligible patients with hepatic-dominant ocular melanoma were randomized 1:1 to receive PHP or BAC (investigator’s choice of TACE, pembrolizumab, ipilimumab, or dacarbazine) on the 301 trial. All eligible patients received PHP on the 301A trial. PHP patients could receive up to 6 PHP treatments, repeated every 6-8 weeks with melphalan dosed at 3.0mg/kg ideal body weight (IBW). Patients with progressive disease (PD) were discontinued from study treatment and all patients are followed until death. Patientswere imaged every 12 (±2) weeks until PD. The primary endpoint, ORR (per RECIST 1.1) as assessed by Independent Review Committee, will be characterized by the point estimate and 95% CI for each group (PHP and BAC). Categorical efficacy variables will be presented as frequency counts and percentages and 95% CI. Time-to-event variables will be summarized using Kaplan-Meier methods (median and 95% CI). Results: 144 patients were enrolled overall; 102 were assigned to PHP (301: n=43; 301A: n=59) and 42 were assigned to BAC. 91 PHP patients received treatment (301: n=40; 301A: n=51) and 32 BAC patients received treatment. At the time of this analysis, 4 PHP patients were still ongoing on study treatment with a minimum follow-up of 24 weeks. 79 PHP-treated patients and 29 BAC-treated patients were evaluable for response. ORR among PHP patients was 32.9% (26/79; 95% CI: 22.75-40.40%). ORR among BAC patients was 13.8% (4/29; 95% CI: 3.89-31.66%). The median PFS was 9.03 months (95% CI: 6.24-11.83) among PHP patients and was 3.06 months (95% CI: 2.69-5.65) among BAC patients; this difference was statistically significant ( p=0.0004). Among the 94 patients assessed for safety after treatment with PHP, 40.4% of patients experienced a serious treatment-emergent adverse event, the majority of which were hematological and resolved without sequelae. There were no treatment related deaths in the trial. Conclusions: In this analysis of preliminary data from the FOCUS trial, PHP demonstrates a statistically superior ORR and significantly prolonged PFS in comparison with BAC in the treatment of hepatic metastases from ocular melanoma. The data is encouraging as efficacious treatments for hepatic metastases from ocular melanoma are desperately needed. These early data show an improvement over the previous phase III study in terms of both efficacy (ORR and PFS) as well as toxicity using second generation filters. Clinical trial information: NCT02678572.

Results of phase II randomized study of intermittent versus continuous schedule of vemurafenib plus cobimetinib in BRAF-mutated advanced melanoma

9528

Background: Combination of vemurafenib plus cobimetinib is approved for the treatment of BRAF-mutated advanced melanoma. Although patients initially respond to treatment, resistance emerges before 18 months in most cases. One of the key pre-clinical observations that supported an intermittent schedule was that resistant tumors suffer a fitness deficit in the absence of the drug, so modulation of the drug pressure through an intermittent dosing could delay the emergence of resistance. Methods: GEM1501 is a randomized phase 2 study comparing the activity of the combination of vemurafenib 960 mg every 12 h/d plus cobimetinib 60 mg/d in a standard (arm A) versus intermittent schedule (arm B). Arm A: four-week (w) cycles of daily vemurafenib for 4w plus cobimetinib for 3w-on and 1w-off-treatment. Arm B: first three cycles according to the standard schedule, followed by 6w-cycle with 2w-off vemurafenib & 3w-off cobimetinib. Primary endpoint was progression free survival (PFS) and secondary were objective response (OR) and treatment-related adverse events (TAEs). Results: 70 treatment-naïve patients were included. Results in arms A and B: median PFS 16.2 (95%CI 9.5, 24.1) vs 6.9 months (95%CI 5.2, 9.3) (p = 0.079); OR in 25 (71.4%) (8 complete -23%-) vs 21 (60%) patients (5 complete -14%-); G3-4 TAEs 42.8% vs 40.0%, respectively. Analysis of BRAFV600 mutation in tumoral cell free DNA (cfDNA) was performed in serial plasma samples in 41 patients. Twenty-one (51%) patients had detectable BRAFV600 mutation in pretreatment cfDNA (preBRAF+). Significant differences in PFS were found according to preBRAF V600: 8.2 months (95%CI 5.2, 13.6) in preBRAF+ vs non-reached (NR) (95%CI 2.8, NR) in preBRAF- (p = 0.017). In arm A, median PFS was 13.3 months (95% CI 4.6, NR) in preBRAF+ vs NR (95% CI 2.3, NR) in preBRAF-. In arm B, median PFS was 6.2 months (95% CI 0.3-8.3) in preBRAF+ vs NR (95%CI 2.8, NR) in preBRAF- (p = 0.003). BRAFV600 mutation became undetectable in cfDNA after treatment initiation in all preBRAF+ patients. Different kinetic of BRAFV600 mutation in cfDNA was found according to treatment arm. At progression, BRAFV600 reappeared in cfDNA in all (5/5) cases treated in arm B, but only in 50% (3/6) of cases in arm A. NGS analysis of cfDNA at progression suggested different resistance mechanisms. Conclusions: The results of this study do not support the use of an intermittent schedule of vemurafenib plus cobimetinib in advanced melanoma. BRAFV600 detection in pretreatment cfDNA is a prognostic factor of poor survival that it is independent of treatment schedule, although most striking differences favoring continuous arm vs intermittent arm were found in patients with detectable BRAFV600 mutation on pretreatment cfDNA. Further research is required to determine the clinical value of the analysis of resistance mechanisms in cfDNA. Clinical trial information: 2014-005277-36.

Five-year overall survival (OS) in COLUMBUS: A randomized phase 3 trial of encorafenib plus binimetinib versus vemurafenib or encorafenib in patients (pts) with BRAF V600-mutant melanoma

9507

Background: Combined BRAF/MEK inhibitor therapy has demonstrated benefits on progression-free survival (PFS) and OS and is standard of care for the treatment of advanced BRAF V600-mutant melanoma. Here we report a 5-year update from the COLUMBUS trial. Methods: In Part 1 of COLUMBUS, 577 pts with advanced/metastatic BRAF V600-mutant melanoma, untreated or progressed after first-line immunotherapy, were randomized 1:1:1 to encorafenib 450 mg QD + binimetinib 45 mg BID (COMBO450), encorafenib 300 mg QD (ENCO300), or vemurafenib 960 mg BID (VEM). An updated analysis including PFS, OS, objective response rate (ORR; by blinded independent central review), and safety was conducted after minimum follow-up of 65.2 months (mo). Data are as is; study is ongoing. Results: At data cut-off (Sep 15, 2020), there were 131 (68%), 117 (60%), and 145 (76%) deaths in the COMBO450, ENCO300, and VEM treatment arms, respectively. The median OS (95% CI) and 5-year OS rate (95% CI) with COMBO450 were 33.6 (24.4–39.2) mo and 34.7% (28.0–41.5), respectively (median follow-up: 70.4 mo). The 5-year OS rate (95% CI) in COMBO450 pts who had normal lactate dehydrogenase (LDH) levels at baseline was 45.1% (36.5–53.2). Median OS and 5-year OS rates for ENCO300 and VEM, as well as for pts with normal and high LDH levels and > 3 organs involved at baseline, are shown in the table. For COMBO450, ENCO300, and VEM, the 5-year PFS rate was 22.9%, 19.3%, and 10.2%; ORR (95% CI) was 64.1% (56.8–70.8), 51.5% (44.3–58.8), and 40.8% (33.8–48.2); and the median duration of response (DOR) was 18.6, 15.5, and 12.3 mo, respectively. Safety results were consistent with the known tolerability profile of COMBO450. Additional efficacy and updated safety analyses will be presented. Following study drug discontinuation, the most common subsequent treatment in all arms was checkpoint inhibitors. Conclusions: Updated OS and DOR results with COMBO450 demonstrate continued long-term benefits in pts with BRAF V600-mutant melanoma. Clinical trial information: NCT01909453. [Table: see text]

Combination of radiomic and biomarker signatures as exploratory objective in a phase II trial with intratumoral BO-112 plus pembrolizumab for advanced melanoma

TPS9586

Background: Intratumoral immunotherapies are gaining interest in oncology, particularly in melanoma. These therapies, however, have faced some issues. For instance, standard response criteria do not accurately describe tumor burden, and responses may differ for injected/non injected lesions. Besides, target lesions may become non evaluable. Biomarkers provide interesting information for these therapies. In addition, some radiomic signatures have been associated with CD-8 infiltration. BO-112 is a double stranded synthetic RNA formulated with polyethyleneimine (PEI) that mimics a viral infection, mobilizing the immune system and changing tumor microenvironment. Clinical data are available from a first-in-human study, which showed ORR of 11% and DCR of 46% in patients who had developed progressive disease on immunotherapy. In patients with melanoma, this ORR was 20%. A phase 2 clinical study of BO-112 with pembrolizumab in patients with liver metastases from digestive tumors is ongoing. Both studies brought up data regarding how some biomarkers are increased after a single dose of BO-112 and correlated with responses. In this phase II study in patients with pretreated melanoma (NCT04570332), we will prospectively assess CD-8 and PD-L1 by immunohistochemistry, which will be compared with multi-parametric radiologic findings and correlated with clinical benefit. In addition, retrospective DNA sequencing will be performed. This kind of exploratory analysis in intratumoral immunotherapies might be key to identify predictive and prognostic factors. Methods: Phase 2, single arm, open label study of BO-112 with pembrolizumab in patients with advanced melanoma. BO-112 is administered once weekly (QW) in 1 to 8 tumor lesions, total dose 1-2 mg (depending on the number of injected lesions), for the first 7 weeks and then once every three weeks (Q3W); pembrolizumab 200 mg will be administered Q3W. Key eligibility criteria: advanced cutaneous or mucosal melanoma; patients must have progressed on or after treatment with an antiPD-1/L1 mAb; at least one measurable lesion amenable for weekly IT injection. Primary efficacy variable is ORR by RECIST 1.1, assessed by independent central radiologist (QUIBIM Precision platform). A 1-sided alpha of 4.19% and power of 81.8% are used. If less than 8 patients out of 40 have ORR, the study will not meet the statistical bar. Secondary endpoints include clinical activity by RECIST1.1 and iRECIST, overall survival, safety and PKs. Exploratory objectives include itRECIST and evaluation of CD-8 and PD-L1 expression by immunohistochemistry (Pangaea laboratory), which will be correlated with radiomic signatures (first order and second order) from standard-of-care computed tomography (CT) images. Enrollment is open and 1 of planned 40 patients has been enrolled. Nineteen sites are planned to participate. Clinical trial information: NCT04570332.

Analysis of patients (pts) with in-transit metastases treated with nivolumab (NIVO) or ipilimumab (IPI) in CheckMate 238

9569

Background: In the phase 3 CheckMate 238 study, NIVO has demonstrated improved recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) vs IPI in pts with resected stage IIIB–C or IV melanoma, which was sustained at the 4-y analysis. Having in-transit metastases/satellites (ITM) is a poor prognostic factor, and pts with ITM are generally omitted from clinical trials. This study was the first and only adjuvant checkpoint inhibitor trial to include pts with ITM. Here, we present post hoc outcomes in this subgroup. Methods: Pts aged ≥15 y with completely resected stage IIIB–C or IV melanoma stratified by stage and tumor PD-L1 status were randomized 1:1 to NIVO (3 mg/kg Q2W; n = 453) or IPI (10 mg/kg Q3W for 4 doses, Q12W thereafter; n = 453) for a maximum of 1 y or until disease recurrence/unacceptable toxicity. Pts with ITM, with or without synchronous nodal involvement, were included. The primary study endpoint was RFS; overall survival (OS) was a secondary endpoint; and DMFS was exploratory. Results: Each of the 2 treatment groups had 164 pts with ITM. Baseline characteristics were generally similar between treatment groups in pts with or without ITM; in pts with ITM vs without ITM, tumor ulceration was less frequent in NIVO-treated pts, and fewer IPI-treated pts had PD-L1 expression ≥5%. RFS and DMFS favored NIVO vs IPI in all ITM subgroups (table). OS was similar to the intention-to-treat (ITT) population with no differences noted between treatment groups or between ITM subgroups. Among pts with or without ITM, dominant metastatic sites were lung and lymph nodes, followed by brain, liver, and soft tissue (in varying order). Similar metastasis patterns were observed in pts with ITM regardless of nodal involvement. Treatment-related adverse events (any grade and grade 3/4) in pts with ITM were similar to those of the ITT population. Conclusions: Results of this post hoc 4-y analysis of CheckMate 238 showed that safety and efficacy were similar in pts with or without ITM, supporting the use of adjuvant NIVO in pts with ITM, regardless of nodal involvement. Clinical trial information: NCT02388906. [Table: see text]

KEYNOTE-629: Health-related quality of life (HRQoL) with pembrolizumab (pembro) in patients (pts) with locally advanced (LA) or recurrent or metastatic (R/M) cutaneous squamous cell carcinoma (cSCC)

9546

Background: KEYNOTE-629 is a single-arm phase 2 study of pembro for cSCC. At second interim analysis (IA), pembro had robust and durable antitumor activity and manageable safety in LA and R/M cohorts. At first IA, pembro maintained HRQoL in the R/M cohort; LA was not analyzed because of ongoing accrual. HRQoL of pts with LA or R/M cSCC at second IA (database cutoff July 29, 2020; additional 15-mo follow-up since IA1 for the R/M cohort) is shown. Methods: Pts with LA or R/M cSCC received pembro 200 mg IV Q3W for ≤35 cycles. HRQoL was a prespecified exploratory end point assessed using EORTC QLQ-30 and EuroQol EQ-5D-5L instruments administered at baseline, wk 3, and wk 6; then Q6W through y 1; then Q9W until treatment end/discontinuation; and at the 30-day safety follow-up. HRQoL was analyzed in pts who received ≥1 pembro dose and completed baseline and ≥1 postbaseline HRQoL assessments. Mean change from baseline in EORTC QLQ-C30 global health status (GHS)/quality of life (QoL), physical functioning (PF), and EQ-5D-5L visual analog scale (VAS) scores were evaluated at wk 12 to ensure adequate completion rate and through last pt visit at wk 75 for EORTC QLQ-C30 GHS/QoL and PF scores. HRQoL was categorized as improved or deteriorated based on ≥10-point change in EORTC QLQ-C30 scores (considered clinically meaningful). Results: The HRQoL analysis population for LA had 47 pts for EORTC QLQ-C30 and EQ-5D-5L; the R/M cohort had 99 pts for EORTC QLQ-C30 and 100 for EQ-5D-5L. At wk 12, compliance rates were >75% for LA and >80% for R/M cohorts for EORTC QLQ-C30 and EQ-5D-5L. Mean change from baseline to wk 12 was minimal for EORTC QLQ-C30 GHS/QoL, PF, and EQ-5D-5L VAS scores for both cohorts (Table). Mean change from baseline in EORTC QLQ-C30 GHS/QoL and PF scores remained stable over 48 wk in the LA cohort (75-wk data unavailable) and over 75 wk in the R/M cohort. Most pts had improved or stable EORTC QLQ-C30 GHS/QoL and PF scores relative to baseline during follow-up. Conclusions: HRQoL was generally maintained with pembro in LA and R/M cSCC cohorts and was not negatively impacted by tumor progression or AEs. Clinical trial information: NCT03284424. [Table: see text]

Abstract CT034: Phase I study of WNT974 + spartalizumab in patients (pts) with advanced solid tumors

Background: WNT974, a Porcupine inhibitor, has shown evidence of Wnt pathway inhibition in clinical trials. Dysregulated Wnt signaling has been linked to immunotherapy resistance, suggesting WNT974 may act synergistically with checkpoint inhibitors. Spartalizumab is an αPD-1 mAb with demonstrated clinical activity in solid tumors. Methods: In this Phase I, open-label trial (NCT01351103) adult pts received WNT974 ± spartalizumab; here we report on the dose escalation of the combination. Eligible pts had melanoma (including uveal), lung SCC, HNSCC, esophageal SCC, cervical SCC, or TNBC. Pts with melanoma, lung SCC, or HNSCC must have had a best response of progressive disease (primary refractory) to prior αPD-1 therapy; other pts were naïve or primary refractory to prior αPD-1. WNT974 was dosed orally QD in 28-day cycles (2.5-10 mg, Days 1-8 or 1-15 of Cycles 1 or 1-4); spartalizumab was dosed IV at 400 mg Q4W. Objectives were to determine the maximum tolerated dose (MTD)/recommended dose for expansion (RDE), safety, pharmacokinetics (PK), pharmacodynamics, and activity of WNT974 + spartalizumab. Pre- and on-treatment pt samples were collected: skin samples for RT-PCR analysis of AXIN2, a marker of Wnt pathway activity; tumor samples for RNAseq of AXIN2 and immune cell markers. Results: As of Sept 2, 2019, 27 pts were enrolled: 24 discontinued (18 due to disease progression; 67%), 3 were ongoing. Most common tumor types were non-uveal melanoma (n=8), TNBC (n=7), and uveal melanoma (n=5); 63% had received prior αPD-1. PK parameters for WNT974 + spartalizumab were consistent with prior single agent data. Dose-limiting toxicities were reported in 2 pts: Grade (G) 2 spinal compression fracture that occurred in the setting of trauma and G3 arthralgia. 78% of pts experienced a treatment-related AE, the most common being hypothyroidism (19%); 4 pts (15%) had 7 suspected-related G3/4 AEs (arthralgia, atrial fibrillation, diabetes mellitus, diabetic ketoacidosis, hyperglycemia, hyponatremia, and maculopapular rash). One pt (4%) with TNBC had a partial response, 11 pts (41%) had stable disease (SD), 13 pts (48%) had progressive disease; response was unknown in 2 pts. SD was reported in 9/17 pts (53%) who were primary refractory to prior αPD-1; 4 remained on study &gt;24 wks. All pts with uveal melanoma (n=5) had SD. Evidence of Porcupine inhibition, assessed by skin AXIN2 suppression, was detected at all dose levels studied. Pts with the largest reductions in tumor size had on-treatment increases in immune marker mRNA in tumor samples, including a pt with αPD-1 primary refractory melanoma with high baseline AXIN2 expression and 42% reduction in the sum of target lesion diameters; this pt remained on study at 48 wks at the cutoff date. Conclusions: WNT974 + spartalizumab was well tolerated; MTD/RDE have not been determined. Preliminary data suggest blocking Wnt signaling may enable response to checkpoint inhibition in some pts.

Citation Format: Filip Janku, Filip de Vos, Maria de Miguel, Patrick Forde, Antoni Ribas, Misako Nagasaka, Guillem Argiles, Ana Maria Arance, Aitano Calvo, Marios Giannakis, Maritza Melendez, Jiachang Gong, Sebastian Szpakowski, Rebecca Kan, Susan E. Moody, Maja De Jonge. Phase I study of WNT974 + spartalizumab in patients (pts) with advanced solid tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT034.

Open-label, multicenter safety study of vemurafenib in patients with BRAFV600 mutation–positive metastatic melanoma

9046

Background: Vemurafenib (VEM), a BRAF kinase inhibitor, has demonstrated high response rates and improved progression-free and overall survival in pts with BRAFV600mutation–positive metastatic melanoma (mM). We present interim results from predefined subgroups from a large multicenter, open-label safety study of VEM in pts with mM (NCT01307397). Methods: Pts with BRAFV600mutation–positive histologically confirmed mM received VEM (960 mg BID) as first-line therapy or subsequent to previous therapies. Assessments for safety and efficacy were made every 28 days. Results: As of Feb 29, 2012, 2,265 pts have received VEM. Pts had a median age of 54.0 (13-95) yrs and median time since diagnosis of mM of 6.2 (0-351.9) mos. 59% had received prior systemic therapy. Median time of exposure to VEM as of the cut-off date was 3 (0.03-11.24) mos for the overall population and majority of subgroups, and approximately 2.5 mos for pts with ECOG ≥2 and age ≥75 yrs. 1537 (68%) pts were still receiving VEM at the cut-off date. 728 (32%) pts discontinued, most frequently because of PD (538/728 pts; 74%). Adverse events (AEs) were reported for 87% of all patients, with arthralgia (32%) and rash (26%) the most frequent. The incidences of AEs in the subgroups are summarized (Table). Although efficacy analyses are limited by the short duration of follow-up, six-month OS rate was 76% (95% CI 72-79%) and median PFS was 4.1 mos (95% CI 3.9-4.5 mos). Postbaseline tumor assessments were available for 63% and 30% of pts at wk 8 and 16, respectively. At wk 8 CR: 2%, PR: 57%, SD: 30%, PD: 6%. At wk 16 CR: 3%, PR: 46%, SD: 31%, PD: 15%. Conclusions: Although the overall safety profile of VEM in this study was consistent with previous clinical data, interim analyses of subgroups suggest that very elderly pts may be at higher risk of G3 AEs. Clinical trial information: NCT01307397. [Table: see text]

Spanish Melanoma Multidisciplinary Group (GEM): Long-term survivors treated with ipilimumab (IPI) in the expanded access programme (EAP)

e20007

Background: Advances in metastatic melanoma treatment have demonstrated improvement in survival. After 5 year follow-up of clinical trials with IPI, LTS have been reported. Current follow-up of patients treated within IPI EAP in Spain is 2 years. Methods: we performed a retrospective subgroup analysis of 138 treated patients (pts) within the IPI not randomized EAP (48% of the total EAP population). LTS were defined as pts with ≥ 12 months overall survival (OS). Pts were treated with IPI at 3 mg/kg q 3 w x 4. Data was registered using a socio-demographic and therapeutic questionnaire, collecting overall response (RR), survival (OS) and toxicity (T). Results: In our analysis of138 treated pts 39 were LTS (28.2%), 14 pts were alive at 12 months (M), 12 pts between 13-19 m and 7 pts 20-24m, for all this patients the follow up continues. Median age was: 56.5 (30-81). Gender: Male 48.7%. Stage: IVa 25.6%, IVb 17.9%, IVc 56.8%. Primary tumor site: skin 56.4%; accral 12.8%; mucosal 10.3%; ocular 10.3%; rest unknown. Metastases (mts): soft tissue 38.5%, lung 33.3%, visceral 28.2%. Median number of prior treatments: 1 (1-5), 20.5% received more than one chemotherapy (chx) line. 92.3% of total pts population have completed the induction schema (4 IPI doses). Response assessment: CR 15.4%; PR 38.5%; SD 33.3%; P 12.8%. Mean duration of response: 10.6m. Mean survival: 16.6m. 56.4% received thx after IPI, in those pts 41% received chx; 17.9% radiotherapy; 12.9% B-RAF inhibitor. 18 pts (46.2%) presented T: 12.8% Grades (G) 3-4 were reported; 23.1% G2; 7.7% G1. The most frequent T was cutaneous (17.9%). When compared with the overall EAP pts population LTS have less visceral disease, lower median LDH, more objective responses and completion of the four induction ipilimumab doses. Conclusions: Ipilimumabin the Spanish EAP experience in pretreated patients has shown to improve long term survival similar to that seen in studies in patients with advanced melanoma. Further research and analysis are needed to identify the patient population most likely to achieve a long term survival benefit with ipilimumab treatment.

Phase II double-blind, randomized study of selumetinib (SEL) plus dacarbazine (DTIC) versus placebo (PBO) plus DTIC as first-line treatment for advanced BRAF-mutant cutaneous or unknown primary melanoma

9004

Background: BRAF mutations play an oncogenic role in melanomas. Selumetinib (AZD6244, ARRY-142886) inhibits MEK1/2 downstream of B-Raf and may have an additive effect to chemotherapy. We prospectively evaluated SEL + DTIC vs PBO + DTIC in patients with stage III-IV BRAF mutation-positive advanced cutaneous or unknown primary melanoma (NCT00936221). Methods: Eligible patients (pts) received iv DTIC 1000 mg/m2, and po SEL 75 mg or matched PBO bd as first-line treatment. The primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety and tolerability. Results: A total of 385 pts were screened across 44 centers; 91 patients were randomized (SEL + DTIC, 45; PBO + DTIC, 46). One pt from each group did not receive the randomized treatment. Baseline characteristics were balanced between the two groups, with the exception of histology, gender and previous medications. At data cut-off, 66 deaths had occurred (73% maturity) and median follow-up was 12.3 mo. OS was longer for SEL + DTIC vs PBO + DTIC (median 13.9 vs 10.5 mo), but this did not meet statistical significance (HR 0.93; 80% CI 0.67, 1.28; 1-sided p=0.3873). PFS was significantly improved for SEL + DTIC vs PBO + DTIC, median 5.6 vs 3.0 mo (HR 0.63; 80% CI 0.47, 0.84; 1-sided p=0.021). ORR was 40% with SEL + DTIC vs 26% with PBO + DTIC. Most frequent adverse events (AEs) observed with SEL + DTIC were: nausea (64%), dermatitis acneiform (52%), diarrhea (48%), vomiting (48%), and peripheral edema (43%). AEs that led to hospitalization were higher for SEL + DTIC vs PBO + DTIC (36 vs 13%), and were mostly infections and gastrointestinal disorders. The incidence of grade ≥3 AEs (68 vs 42%), serious AEs (50 vs 18%) and discontinuation of the randomized treatment due to AEs were higher for SEL + DTIC vs PBO + DTIC (16 vs 4%). Conclusions: Clinical activity was observed in patients with BRAF mutation-positive melanoma treated with SEL + DTIC, reflected by a nonsignificant improvement in OS and a significant benefit in PFS. Tolerability of this combination was generally consistent with the monotherapy safety profiles. Clinical trial information: NCT00936221.

Spanish experience with the ipilimumab Expanded Access Program

e19023

Background: Second line ipilimumab has proven efficacy in clinical trial but few is known outside this setting. Methods: We have retrospectively reviewed experience with the Expanded Access Program for Ipilimumab in Spain. We have collected data on demographics, response survival and toxicity. Ipilimumab was administered at a 3 mg/kg dose for four induction courses. Results: We have retrieved 99 expanded access ipilimumab applications that represent 40% of all possible applications. Five patients are not evaluable because they never received ipilimumab 4 due to progression and 1 declined consent. Median age is 58.5 years (30-81) and 54.3% of the patients are males. 59.6% have 3 or more metastatic locations, 50% have liver metastases, 16% have CNS metastasis and 74.6% have elevated LDH. ECOG performance status was 0 to 1 in 91.9%. Previous adyuvant treatment was received by 43.6% of the patients and consisted in high dose interferon in 85.4%. All except one patient have received previous first line chemotherapy and 34.2% have received 2 or more chemotherapy lines. Medium time from the start of metastatic disease to the start of ipilimumab was 11.2 months. 58.5% of the patients completed 4 doses of ipilimumab main reason for not completion was death or progression in 84.6% and toxicity in 5.1%. 8 patients are not evaluable for response, 5 have just completed the treatment and 3 are still on treatment. Responses are 1 (1.1%) CR, 6 (6.4%) PR, 6 (6.4%) PR with previous progression or new lesions, 13 (13.8%) SD, and 60 (63.8%) progressive disease. Reinduction treatment was offered to 5 patients 2 PR patients achieved a new PR, one PR patients a SD and 2 SD patients progressed after reinduction. Kaplan and Meier median survival is 150 days (95% CI 110,5-189.4). One year survival is 32.4% and 18 months survival 21.6%. Toxicity has been mild, skin, 20.2% grade I and 5.3% grade II, liver 7.4% grade I, 2.1% grade II, 3.2 grade III, and diarrhea 19.1% gI, 3.2% grade II and 1.1% grade IV. Only 7 patients experienced toxicity grade III to IV. Conclusions: Ipilimumab efficacy when it is used outside clinical trial is similar to the reported. There is room for improvement in patient selection as 40% of them did not completed treatment. Toxicity of the 3 mg/kg schedule is mild.