A phase Ib study evaluating the recommended phase II dose, safety, tolerability, and efficacy of mivavotinib in combination with nivolumab in advanced solid tumors

Mivavotinib (TAK-659/CB-659), a dual SYK/FLT3 inhibitor, reduced immunosuppressive immune cell populations and suppressed tumor growth in combination with anti-PD-1 therapy in cancer models. This dose-escalation/expansion study investigated the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of mivavotinib plus nivolumab in patients with advanced solid tumors. Patients received oral mivavotinib 60-100 mg once-daily plus intravenous nivolumab 3 mg/kg on days 1 and 15 in 28-day cycles until disease progression or unacceptable toxicity. The dose-escalation phase evaluated the recommended phase II dose (RP2D; primary endpoint). The expansion phase evaluated overall response rate (primary end point) at the RP2D in patients with triple-negative breast cancer (TNBC). During dose-escalation (n = 24), two dose-limiting toxicities (grade 4 lipase increased and grade 3 pyrexia) occurred in patients who received mivavotinib 80 mg and 100 mg, respectively. The determined RP2D was once-daily mivavotinib 80 mg plus nivolumab 3 mg/kg. The expansion phase was terminated at ~50% enrollment (n = 17) after failing to meet an ad hoc efficacy futility threshold. Among all 41 patients, common treatment-emergent adverse events (TEAEs) included dyspnea (48.8%), aspartate aminotransferase increased, and pyrexia (46.3% each). Common grade ≥3 TEAEs were hypophosphatemia and anemia (26.8% each). Mivavotinib plasma exposure was generally dose-proportional (60-100 mg). One patient had a partial response. Mivavotinib 80 mg plus nivolumab 3 mg/kg was well tolerated with no new safety signals beyond those of single-agent mivavotinib or nivolumab. Low response rates highlight the challenges of treating unresponsive tumor types, such as TNBC, with this combination and immunotherapies in general. TRIAL REGISTRATION ID: NCT02834247.

Conditional Dependency of LP-184 on Prostaglandin Reductase 1 is Synthetic Lethal in Pancreatic Cancers with DNA Damage Repair Deficiencies

The greater efficacy of DNA-damaging drugs for pancreatic adenocarcinoma (PDAC) relies on targeting cancer-specific vulnerabilities while sparing normal organs and tissues due to their inherent toxicities. We tested LP-184, a novel acylfulvene analog, for its activity in preclinical models of PDAC carrying mutations in the DNA damage repair (DDR) pathways. Cytotoxicity of LP-184 is solely dependent on prostaglandin reductase 1 (PTGR1), so that PTGR1 expression robustly correlates with LP-184 cytotoxicity in vitro and in vivo. Low-passage patient-derived PDAC xenografts with DDR deficiencies treated ex vivo are more sensitive to LP-184 compared with DDR-proficient tumors. Additional in vivo testing of PDAC xenografts for their sensitivity to LP-184 demonstrates marked tumor growth inhibition in models harboring pathogenic mutations in ATR, BRCA1, and BRCA2. Depletion of PTGR1, however, completely abrogates the antitumor effect of LP-184. Testing combinatorial strategies for LP-184 aimed at deregulation of nucleotide excision repair proteins ERCC3 and ERCC4 established synergy. Our results provide valuable biomarkers for clinical testing of LP-184 in a large subset of genetically defined characterized refractory carcinomas. High PTGR1 expression and deleterious DDR mutations are present in approximately one third of PDAC making these patients ideal candidates for clinical trials of LP-184.

Phase 1 study of the pan-RAF inhibitor tovorafenib in patients with advanced solid tumors followed by dose expansion in patients with metastatic melanoma

PURPOSE

Genomic alterations of BRAF and NRAS are oncogenic drivers in malignant melanoma and other solid tumors. Tovorafenib is an investigational, oral, selective, CNS-penetrant, small molecule, type II pan‑RAF inhibitor. This first-in-human phase 1 study explored the safety and antitumor activity of tovorafenib.

METHODS

This two-part study in adult patients with relapsed or refractory advanced solid tumors included a dose escalation phase and a dose expansion phase including molecularly defined cohorts of patients with melanoma. Primary objectives were to evaluate the safety of tovorafenib administered once every other day (Q2D) or once weekly (QW), and to determine the maximum-tolerated and recommended phase 2 dose (RP2D) on these schedules. Secondary objectives included evaluation of antitumor activity and tovorafenib pharmacokinetics.

RESULTS

Tovorafenib was administered to 149 patients (Q2D n = 110, QW n = 39). The RP2D of tovorafenib was defined as 200 mg Q2D or 600 mg QW. In the dose expansion phase, 58 (73%) of 80 patients in Q2D cohorts and 9 (47%) of 19 in the QW cohort had grade ≥ 3 adverse events. The most common of these overall were anemia (14 patients, 14%) and maculo-papular rash (8 patients, 8%). Responses were seen in 10 (15%) of 68 evaluable patients in the Q2D expansion phase, including in 8 of 16 (50%) patients with BRAF mutation-positive melanoma naïve to RAF and MEK inhibitors. In the QW dose expansion phase, there were no responses in 17 evaluable patients with NRAS mutation-positive melanoma naïve to RAF and MEK inhibitors; 9 patients (53%) had a best response of stable disease. QW dose administration was associated with minimal accumulation of tovorafenib in systemic circulation in the dose range of 400-800 mg.

CONCLUSIONS

The safety profile of both schedules was acceptable, with QW dosing at the RP2D of 600 mg QW preferred for future clinical studies. Antitumor activity of tovorafenib in BRAF-mutated melanoma was promising and justifies continued clinical development across multiple settings.

CLINICALTRIALS

GOV IDENTIFIER

NCT01425008.

SALVO: Single-Arm Trial of Ipilimumab and Nivolumab as Adjuvant Therapy for Resected Mucosal Melanoma

PURPOSE

Mucosal melanoma is a rare, aggressive form of melanoma with extremely high recurrence rates despite definitive surgical resection with curative intent. Currently there is no consensus on adjuvant therapy. Data on checkpoint inhibitors for adjuvant therapy are lacking.

PATIENTS AND METHODS

We performed a single-arm, multicenter clinical trial using "flip dose" ipilimumab (1 mg/kg q3w × 4 cycles), and nivolumab (3 mg/kg q3w × 4 cycles), then nivolumab 480 mg q4w × 11 cycles to complete a year of adjuvant therapy. Participants must have had R0/R1 resection ≤90 days before registration, no prior systemic therapy (adjuvant radiotherapy allowed), ECOG 0/1, and no uncontrolled autoimmune disease or other invasive cancer. Patients were recruited through the Midwest Melanoma Partnership/Hoosier Oncology Network.

RESULTS

From September 2017 to August 2021, 35 patients were enrolled. Of these, 29 (83%) had R0 resections, and 7 (20%) received adjuvant radiotherapy. Median age was 67 years, 21 (60.0%) female. Recurrence-free survival (RFS) rates at 1 and 2 years were 50% [95% confidence interval (CI), 31%-66%] and 37% (95% CI, 19%-55%), respectively. Overall survival rates at 1 and 2 years were 87% (95% CI, 68%-95%) and 68% (95% CI, 46%-83%), respectively. Median RFS was 10.3 months (95% CI, 5.7-25.8). Most common grade 3 toxicities were diarrhea (14%), hypertension (14%), and hyponatremia (11%), with no grade 4/5 toxicities.

CONCLUSIONS

Flip-dose ipilimumab and nivolumab after resection of mucosal melanoma is associated with outcomes improved over that of surgical resection alone. Long-term follow-up, subgroup analyses and correlative studies are ongoing.

A phase 1/2 study of REGN7075 (EGFRxCD28 costimulatory bispecific antibody) in combination with cemiplimab (anti–PD-1) in patients with advanced solid tumors: Trial-in-progress update

TPS277

Background: There is a need to develop novel immunotherapeutic approaches to enhance responses to immune checkpoint blockade. REGN7075 is a human costimulatory bispecific antibody designed to bridge epidermal growth factor receptor (EGFR)-expressing tumor cells with CD28-positive T cells to support further T-cell activation by endogenous tumor antigens. Methods: This is an open-label, Phase 1/2, first-in-human study evaluating the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of REGN7075 (EGFRxCD28) alone and in combination with cemiplimab (anti-programmed cell death [PD]-1) in patients with advanced solid tumors (NCT04626635). This study includes a dose-escalation (Bayesian optimal interval design; Part 1) and a dose-expansion phase (Part 2). Patients must have a protocol-defined advanced solid tumor, have an Eastern Cooperative Oncology Group performance status of 0 or 1, and be naive to anti–PD-1/anti–PD-ligand(L)1 therapy in the dose-expansion phase. In Part 1, heavily pre-treated patients with advanced solid tumors receive a lead-in of REGN7075 monotherapy every week for 3 weeks followed by combination therapy with cemiplimab 350 mg every 3 weeks. Planned dose levels (DLs) of REGN7075 are 0.03, 0.1, 0.3, 1, 3, 10, 30, 100, 300, and 900mg. Once the recommended Phase 2 dose is determined in Part 1, five tumor-specific expansion cohorts will be opened in Part 2: colorectal cancer (microsatellite stable [MSS-CRC]), non-small cell lung cancer (NSCLC, PD-L1 ≥50%), triple-negative breast cancer, cutaneous squamous cell carcinoma, and head and neck squamous cell carcinoma (PD-L1 combined positive score ≥1). Patients with MSS-CRC with RAS or BRAF wild type mutations must have received anti-EGFR therapy or anti-vascular endothelial growth factor (VEGF therapy). Primary endpoints are safety and tolerability of REGN7075 alone or in combination with cemiplimab for Part 1, and objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1 for Part 2. For Part 2, a secondary objective is to assess the effect of REGN7075 on patient-reported outcomes as measured by several validated instruments including the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), and EORTC QLQ-CR29 (CRC patients only). Approximately 400 patients will be enrolled in this phase 1/2 study, including ~80 patients in Part 1 and ~320 patients in Part 2 (including ~70 in the CRC cohort). As of September 13, 2022, 30 patients were treated in the dose-escalation phase, up to the 300 mg DL for REGN7075 in combination with cemiplimab. This study is ongoing and currently open to enrollment. Clinical trial information: NCT04626635 .

Pilot Study of ONCOS-102 and Pembrolizumab: Remodeling of the Tumor Microenvironment and Clinical Outcomes in Anti-PD-1-Resistant Advanced Melanoma

PURPOSE

Intratumoral oncolytic virotherapy may overcome anti-PD(L)-1 resistance by triggering pro-inflammatory remodeling of the tumor microenvironment. This pilot study investigated ONCOS-102 (oncolytic adenovirus expressing GM-CSF) plus anti-programmed cell death protein 1 (PD)-1 therapy in anti-PD-1-resistant melanoma.

PATIENTS AND METHODS

Patients with advanced melanoma progressing after prior PD-1 blockade received intratumoral ONCOS-102 either as priming with 3 doses (3 × 1011 viral particles) during Week 1 [Part 1 (sequential treatment)] or as 4-dose priming and 8 booster doses every 3 weeks [Part 2 (combination treatment)]. From Week 3, all patients received pembrolizumab every 3 weeks (≤8 doses). The primary endpoint was safety. Objective response rate (ORR), progression-free survival, and immunologic activation in repeat biopsies were also investigated.

RESULTS

In 21 patients (Part 1, n = 9; Part 2, n = 12) ONCOS-102 plus pembrolizumab was well tolerated: most adverse events (AE) were mild/moderate in severity. Pyrexia (43%), chills (43%), and nausea (28%) were the most common ONCOS-102-related AEs. There were no dose-limiting toxicities. ORR was 35% [response evaluation in solid tumors (RECIST) 1.1, irRECIST]. Reduction in size of ≥1 non-injected lesions observed in 53% patients indicated a systemic effect. In injected tumors, persistent immune-related gene expression and T-cell infiltration were associated with clinical benefit. Viral persistence and efficacy in injected and non-injected lesions without additional toxicity supported Part 2 dosing regimen in future studies.

CONCLUSIONS

ONCOS-102 plus pembrolizumab was well tolerated and led to objective responses in patients with anti-PD-1-resistant advanced melanoma. ONCOS-102 promoted T-cell infiltration, particularly cytotoxic CD8+ T cells, which persisted at Week 9, driving clinical benefit. Further investigation of ONCOS-102 plus PD-1 blockade is warranted. See related commentary by Levi and Boland, p. 3.

A Phase 1B open-label study of gedatolisib (PF-05212384) in combination with other anti-tumour agents for patients with advanced solid tumours and triple-negative breast cancer

BACKGROUND

This Phase 1b study (B2151002) evaluated the PI3K/mTOR inhibitor gedatolisib (PF-05212384) in combination with other anti-tumour agents in advanced solid tumours.

METHODS

Patients with various malignancies were administered gedatolisib (90‒310 mg intravenously every week [QW]) plus docetaxel (arm A) or cisplatin (arm B) (each 75 mg/m2 intravenously Q3W) or dacomitinib (30 or 45 mg/day orally). The safety and tolerability of combination therapies were assessed during dose escalation; objective response (OR) and safety were assessed during dose expansion.

RESULTS

Of 110 patients enrolled, 107 received gedatolisib combination treatment. Seven of 70 (10.0%) evaluable patients had dose-limiting toxicities; the most common was grade 3 oral mucositis (n = 3). Based upon reprioritisation of the sponsor's portfolio, dose expansion focused on arm B, gedatolisib (180 mg QW) plus cisplatin in patients (N = 22) with triple-negative breast cancer (TNBC). OR (95% CI) was achieved in four of ten patients in first-line (overall response rate 40.0% [12.2-73.8%]) and four of 12 in second/third-line (33.3% [9.9-65.1%]) settings. One patient in each TNBC arm (10%, first-line; 8.3%, second/third-line) achieved a complete response.

CONCLUSIONS

Gedatolisib combination therapy showed an acceptable tolerability profile, with clinical activity at the recommended Phase 2 dose in patients with TNBC.

CLINICAL TRIAL

ClinicalTrial.gov: NCT01920061.

Autologous T cell therapy for MAGE-A4+ solid cancers in HLA-A*02+ patients: a phase 1 trial

Affinity-optimized T cell receptors can enhance the potency of adoptive T cell therapy. Afamitresgene autoleucel (afami-cel) is a human leukocyte antigen-restricted autologous T cell therapy targeting melanoma-associated antigen A4 (MAGE-A4), a cancer/testis antigen expressed at varying levels in multiple solid tumors. We conducted a multicenter, dose-escalation, phase 1 trial in patients with relapsed/refractory metastatic solid tumors expressing MAGE-A4, including synovial sarcoma (SS), ovarian cancer and head and neck cancer ( NCT03132922 ). The primary endpoint was safety, and the secondary efficacy endpoints included overall response rate (ORR) and duration of response. All patients (N = 38, nine tumor types) experienced Grade ≥3 hematologic toxicities; 55% of patients (90% Grade ≤2) experienced cytokine release syndrome. ORR (all partial response) was 24% (9/38), 7/16 (44%) for SS and 2/22 (9%) for all other cancers. Median duration of response was 25.6 weeks (95% confidence interval (CI): 12.286, not reached) and 28.1 weeks (95% CI: 12.286, not reached) overall and for SS, respectively. Exploratory analyses showed that afami-cel infiltrates tumors, has an interferon-γ-driven mechanism of action and triggers adaptive immune responses. In addition, afami-cel has an acceptable benefit-risk profile, with early and durable responses, especially in patients with metastatic SS. Although the small trial size limits conclusions that can be drawn, the results warrant further testing in larger studies.

Abstract CT249: First-in-human study of TAK-500, a novel STING agonist immune stimulating antibody conjugate (ISAC), alone and in combination with pembrolizumab in patients with select advanced solid tumors

Background: Although immune checkpoint inhibitors (CPIs) have revolutionized cancer treatment, resistance remains a challenge. Reduced interferon (IFN) signaling, immune escape and immunosuppressive tumor phenotypes have been proposed as resistance mechanisms, suggesting innate immune cell stimulation in the tumor microenvironment as a potential strategy to overcome resistance. Stimulator of Interferon Genes (STING) is a cytosolic protein critical for induction of type 1 IFN-dependent innate immunity. Cysteine-cysteine chemokine receptor type 2 (CCR2) is expressed by tumor-infiltrating myeloid cells, including tumor associated macrophages (TAM), and promotes immune escape by limiting CD8+ T-cell infiltration. TAK-500 is an ISAC that consists of three parts: a STING agonist payload based on TAK-676 (currently under phase 1 clinical evaluation [NCT04420884, NCT04879849]), the IgG1 anti-CCR2 antibody (previously evaluated in early phase studies), and a self-immolating maleimide-containing protease-cleavable peptide linker. By targeting STING to CCR2 expressing myeloid cells, TAK-500 has three possible mechanisms of action: activation of IFN response, reprogramming of suppressive intratumoral CCR2+ cells to an inflammatory phenotype, and blockade of suppressive TAM recruitment. TAK-500 thus has the potential to overcome resistance to CPIs in both CPI refractory and immunologically excluded or deserted tumors.

Methods: This phase 1a/1b open-label study (NCT05070247) will evaluate the safety, tolerability, antitumor activity, pharmacokinetics and pharmacodynamics of TAK-500 in patients aged ≥18 years with gastroesophageal adenocarcinoma, pancreatic adenocarcinoma, hepatocellular carcinoma, non-squamous non-small cell lung cancer, squamous cell carcinoma of the head and neck, mesothelioma or triple-negative breast cancer. Patients must have had progressive disease or intolerance to all standard therapy. In the initial dose escalation phase, patients will receive single-agent intravenous (IV) TAK-500 administered once every 3 weeks (Q3W) in 21-day cycles to determine the pharmacologically active dose (PAD) range. An additional escalation cohort will receive TAK-500 in combination with IV pembrolizumab 200 mg Q3W in 21-day cycles, with the initial TAK-500 dose level beginning 1-2 dose levels below the predicted single agent PAD range. Dose escalation in both single agent and combination cohorts will be guided by the Bayesian Optimal Interval design. A subsequent dose expansion phase will evaluate TAK-500 in combination with pembrolizumab. Planned enrollment for both escalation and expansion cohorts is ~106 patients.

Citation Format: Jennifer R. Diamond, Jason T. Henry, Gerald S. Falchook, Anthony J. Olszanski, Harshabad Singh, E. Jane Leonard, Richard C. Gregory, Vicky A. Appleman, John P. Gibbs, Carole E. Harbison, Cong Li, Jessica M. Sapiro, Tomoki Yoneyama, Alexander Parent, Vincent Chung. First-in-human study of TAK-500, a novel STING agonist immune stimulating antibody conjugate (ISAC), alone and in combination with pembrolizumab in patients with select advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT249.

Efficacy and safety of NT-I7, long-acting interleukin-7, plus pembrolizumab in patients with advanced solid tumors: Results from the phase 2a study

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Background: Checkpoint inhibitors (CPIs) are usually ineffective in patients (pts) with immune-cold microsatellite stable colorectal cancer (MSS-CRC) or pancreatic cancer (PDAC) and in those who progressed on previously treated with antibodies against PD1 or PD-L1. Here, we report the combination of NT-I7 plus pembrolizumab (pembro) on CPI-naïve MSS-CRC and PDAC cohorts, and patients (pts) with CPI-treated triple-negative breast cancer (TNBC), non-small cell lung cancer (NSCLC), and small cell lung cancer (SCLC) cohorts of this ongoing phase 2a trial. Methods: Pts with CPI-naïve relapsed/refractory (R/R) MSS-CRC and PDAC, and CPI-treated R/R TNBC, NSCLC, and SCLC, were enrolled. NT-I7 (efineptakin alfa) 1200 µg/kg intramuscularly every 6 weeks and 200 mg pembro intravenously every 3 weeks were administered until disease progression/unacceptable toxicity. The primary endpoint of the Phase 2a is the objective response rate (ORR), assessed by RECIST v1.1 and iRECIST. The secondary endpoints are duration of response (DoR), disease control rate, progression-free survival, and overall survival. Results: As of 14 Jan 2022, 92 pts with metastatic or locally advanced cancer who had received a median of 3 prior treatments were enrolled in the study; 32 in PDAC, 28 in MSS-CRC, 22 in NSCLC, 6 in TNBC, and 4 in SCLC. The median age was 62 years [29-81], ECOG PS 0 in 23 (25%), 1 in 68 (74%) and 2 in 1 (1%). Among 71 evaluable pts, the median follow up (months) was 7.7, 5.3, 5.0, 3.7, and 2.4 in TNBC, MSS-CRC, NSCLC, PDAC and SCLC, respectively. The ORR was 50% (1/2) in SCLC, 12% (3/25) in MSS CRC, 8% (2/26) in PDAC 6% (1/16) in NSCLC and 0% (0/2) in TNBC per iRECIST; and 50% (1/2) in SCLC, 4% (1/25) in MSS CRC, and 4% (1/26) in PDAC per RECIST 1.1. All 7 responders are ongoing. The two PDAC pts had DoR over 1.35 months (mos) and 6.64 mos with the best tumor reduction 100% and 72% respectively. The one SCLC pt had DoR over 1.5 mos with the tumor reduction 67%. The one NSCLC pt had DoR over 2.73 mos with the tumor reduction 60%, and the three MSS-CRC pts had DoR 6.34, 2.96, and 0.03 mos with the tumor reduction 60%, 56%, and 43% respectively. A sustained and significant (approximate 3X from baseline) increase of peripheral lymphocytes in all arms was observed as shown in our previous report. Among 92 treated pts, NT-I7-related adverse events (AEs) occurred in 67 (72.8%) pts, including 52 (56.5%) Grade (G)1-2, 13 (14.1%) G3, and 2 (2.2%) G4. There were no NT-I7 related G5 AEs. Additional updated efficacy, safety and biomarker data will be presented. Conclusions: The combination of NT-I7 and pembro demonstrated antitumor activity and manageable toxicity profile in heavily pretreated pts with CPI-naïve MSS-CRC and PDAC and CPI-treated TNBC, NSCLC, and SCLC, suggesting that the addition of NT-I7 to CPI can overcome the primary resistance to CPI in the former group and acquired resistance in the latter. Clinical trial information: NCT04332653.

Navtemadlin (KRT-232) activity after failure of anti-PD-1/L1 therapy in patients (pts) with TP53WT Merkel cell carcinoma (MCC)

9506

Background: MCC is a rare, aggressive, neuroendocrine skin cancer with a high risk of recurrence and metastases. A median survival of about 4 mo for pts with metastatic MCC who failed anti-PD-1/L1 therapy highlights an urgent need for novel therapies. In TP53WT MCC, oncoproteins from the Merkel cell polyomavirus (MCPyV) inhibit p53 tumor suppressor functions by activating murine double minute 2 (MDM2). Navtemadlin is a potent, selective, orally available MDM2 inhibitor that overcomes MDM2 dysregulation by restoring p53 activity and inducing apoptosis of TP53WT tumors. Methods: The dose-finding, phase 1b/2 KRT-232-103 study (NCT03787602) evaluated navtemadlin in adult TP53WT MCC pts who failed anti-PD-1/L1 therapy. Pts were randomly assigned to oral navtemadlin once daily in 21- or 28-day cycles: 240 mg 7 days (D) on/14D off or 5D on/23D off, 180 mg 5D on/23 D off or 7D on/21D off, or 120 mg 7D on/14D off, until disease progression or unacceptable toxicity. The primary endpoint was Recommended Phase 2 Dose (RP2D); objective response rate (ORR) was assessed per RECIST v1.1. Results: As of Nov 30, 2021, 31 pts were enrolled with median age 66 y (range, 25-82); 52% had visceral disease and 71% had received ≥2 lines of prior therapy. Baseline tumor profiling of available samples showed low tumor mutation burden, MCPyV-positivity, and nonamplified MDM2 gene in 100%, 92%, and 100% of pts, respectively. Treatment-emergent adverse events (TEAEs) were observed in 100% (68% grade 3/4) of pts. The most common Grade 3/4 TEAEs were hematologic: 32% anemia, 32% lymphopenia, and 19% thrombocytopenia. Navtemadlin doses ≤180 mg were well tolerated with fewer dose reductions and longer treatment durations; subsequently the 240 mg arms were closed to further enrollment. Evaluable pts receiving 180 mg 5D on/23D off showed a 25% confirmed ORR, a 38% unconfirmed + confirmed ORR, and a 63% disease control rate (Table); median duration of response was not reached (range, 6-16.2+ mo) and median time to treatment response was 4.1 mo (range, 1.2-7). Notably, one responder, following a prolonged partial response, achieved complete metabolic remission by PET/CT after 2 y on treatment. The 120 mg arm was closed due to a low response rate. The 180 mg dose has been selected for further evaluation. Conclusions: Navtemadlin is the first targeted agent to show promising single-agent activity in heavily pretreated MCC pts who failed anti-PD-1/L1 therapy. This study demonstrates that upregulation of the p53 pathway is a viable therapeutic strategy in MCC. Clinical trial information: NCT03787602. [Table: see text]

Safety of dual checkpoint-blockade with PSB205, an anti-PD-1/CTLA4 monoclonal antibody combination, manufactured and dispensed as a single product: A phase 1 study

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Background: PSB205 is a new biological agent consisting of two engineered monoclonal antibodies (anti-PD-1 IgG4 and anti-CTLA-4 IgG1) expressed in a fixed ratio (2:1) from a single cell-line, manufactured as one product and dispensed from a single vial. PSB205 was designed to optimally balance efficacy and safety through differential target coverage of PD-1 and CTLA-4: the anti-CTLA-4 antibody was engineered to have a shorter half-life to modulate exposure and lower risk of immune-related adverse events (irAEs). Methods: We report safety data from a first-in-human study, conducted in standard 3+3 Phase 1 dose escalation format, enrolling subjects with refractory solid tumors with mixed histologies, who had exhausted available standard treatments. Primary objectives were safety (including Dose Limiting Toxicities), tolerability and selection of a Phase 2 dose. Secondary objectives were PK and preliminary evaluation of effectiveness. Treatment was Q3 wks. Inclusive the 1st week following the 2nd infusion, the DLT-period was 28 days. Results:Nine US-centers enrolled 27 subjects, representing 19 tumor histologies, in 5 ascending dose cohorts ranging from 0.1 mg/kg to 5 mg/kg; an additional N = 49 pts were dosed in expansion cohorts at 5 mg/kg and 400 mg (fixed dose). Median number of prior systemic treatments for metastatic disease was 4. No DLT was observed at any of dose level evaluated. The most frequent Treatment-Related Adverse Events (TRAE) reported were diarrhea (9%), Infusion-Related Reaction (IRR) (5%) and fatigue (4%). Among the subset (N = 33) who completed at least 4 cycles of treatment, the most common TRAE were diarrhea (21%), IRR (12%), Fatigue (9%), and irAEs, specifically colitis, rash and arthralgia (6% each symptom). Most TRAEs were Grade 1 /2, with just 1 case each of diarrhea and colitis Graded as G 3/4. Tumor responses (all PRs) were observed at dose levels of 3 mg/kg and 5 mg/kg in 4 pts - 1 each with with RCC, SCLC, HNSCC and gastric cancer. Conclusions: PSB205 provides dual checkpoint blockade with a very tolerable side effect profile, with less AEs than typically noted in published studies of anti-PD1 and anti-CTLA-4 combination therapy. Further studies are ongoing to confirm this observation. Dose levels of 5 mg/kg and 400 mg fixed were selected for Phase 2, which has commenced enrollment. Clinical trial information: NCT03986606.

Effect of intratumoral INT230-6 on tumor necrosis and promotion of a systemic immune response: Results from a multicenter phase 1/2 study of solid tumors with and without pembrolizumab (PEM) [Intensity IT-01; Merck KEYNOTE-A10]

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Background: INT230-6 is a new product with a unique dual anti-cancer mechanism. The drug is comprised of cisplatin (CIS) and vinblastine (VIN) co-formulated with an amphiphilic molecule that enables drug dispersion throughout a tumor and passive diffusion into cancer cells following intratumoral (IT) delivery. A neoadjuvant study in breast cancer confirms that a single injection can kill 95% of an injected tumor and recruit TILs. Methods: INT230-6 treatments are Q2W for up to 5 treatments followed by maintenance dosing every 9 weeks. Dose is set by the tumor’s longest diameter or volume. One arm received INT230-6 plus PEM 200mg IV Q3W. Biopsies from injected tumor are taken pretreatment and Day 28 for immunohistochemistry (IHC) analysis. Results: Sixty-two subjects received INT230-6 alone (median age 61, with 4 prior treatments), and 21 INT230-6 + PEM (median age 70, with 3 prior treatments). To these subjects over 575 image guided INT230-6 IT injections were given (320 to visceral tumors such as lung, liver, pancreas). Doses ranged from 0.14 to 175mL (87.5 mg of CIS, 17.5 mg VIN - higher than typical IV doses). Pharmacokinetic data shows > 95% of the INT230-6 active agents remain in the tumor. The most common ( > 25%) adverse events (AEs) related to INT230-6 were localized pain (58%), nausea (40%), and fatigue (29%). The most common AEs attributed to the PEM combination were nausea (62%), localized pain (57%), vomiting (57%), decreased appetite (43%), fatigue (43%) and constipation (29%). The incidence of grade 3 AEs for the INT230-6 arm was 11% and for the PEM combination was 14%. There were no related grade 4 or 5 AEs in the INT230-6 arm; and one grade 4 neutrophil count decrease was seen on the PEM combination. There were no dose limiting adverse events. No patient discontinued therapy due to toxicities related to either drug or injection procedure. The monotherapy arm enrolled patients from 17 tumor types; while the PEM combo recruited primarily pancreatic, CRC, triple negative breast, or bile duct cancer. IHC results confirm a marked reduction in proliferating tumor cells with influx of CD4 and CD8 T-cells. Seven of the INT230-6 monotherapy patients had non injected tumor shrinkage in 9 visceral/deep lesions. Estimated median overall survival (mOS) was over 1 year for both arms. Conclusions: In this clinical trial, deep and superficial tumor injections into patients with widely metastatic disease was feasible and well tolerated. Biopsies confirm the dual anti-cancer mechanism, and study patients live longer than would be expected for these refractory populations. INT230-6’s rapid tumor killing and immune activation properties may offer an alternative to control refractory patients (even those that are chemotherapy refractory) and the product is moving into randomized controlled registration trials. Clinical trial information: NCT03058289.

A phase 1b, multicenter, dose-escalation study of subasumstat (TAK-981) in combination with pembrolizumab in patients (pts) with advanced solid tumors

2506

Background: SUMOylation is a post-translational modification with a role in limiting type 1 interferon (IFN-1)-dependent immune responses. Subasumstat is a small-molecule inhibitor of SUMOylation with the potential to increase antitumor immunity and overcome tumor resistance to checkpoint inhibitors (CPI) by inducing IFN-1 signaling. Preclinical data suggest that subasumstat enhances antigen cross-presentation, promoting T cell dependent antitumor responses; subasumstat plus an anti-PD-1 CPI has shown synergistic tumor growth inhibition and activation of CD8+ T cells and natural killer cells in syngeneic mouse models. We report data from the dose escalation part of a phase 1b study of subasumstat with pembrolizumab in pts with relapsed/refractory, CPI-exposed, non-squamous non-small-cell lung cancer (NSCLC) or microsatellite-stable colorectal cancer (MSS-CRC). Methods: Pts received escalating doses (40, 60, 90, and 120 mg) of subasumstat IV in 3 dosing schedules: days 1 and 8 (QW), days 1, 4, 8, and 11 (BIW), or days 1, 8, and 15 (90 mg only) of 21-day cycles, plus pembrolizumab 200 mg IV on day 1 of each cycle for 2 years or until disease progression or unacceptable toxicity. Dose escalation was guided by Bayesian optimal interval design. Phase 1b primary objectives were safety, tolerability, and the recommended phase 2 dose of subasumstat with pembrolizumab. Results: As of October 13, 2021, 43 (35 MSS-CRC; 8 NSCLC) pts had received ≥1 dose of subasumstat (22 BIW [40–120 mg]; 15 QW [90 –120 mg]; 6 on days 1, 8, 15 [90 mg)]. Median number of treatment cycles was 3; 28 (65%) pts had discontinued treatment, 21 (49%) due to progressive disease. Median age was 58 years (range 34–77); 56% of pts were male. One pt had a dose-limiting toxicity of grade 3 angioedema at 120 mg BIW. The maximum tolerated dose was not identified. Treatment-emergent adverse events (TEAEs) occurred in 38 (88%) pts; subasumstat-related TEAEs occurred in 34 (79%) pts, and included chills in 20 (47%), pyrexia in 16 (37%), fatigue in 9 (21%), anemia in 6 (14%), and stomatitis in 5 pts (12%; 3 [50%] in the 120 mg BIW cohort). Grade ≥3 TEAEs occurred in 24 (56%) pts; subasumstat-related grade ≥3 TEAEs reported in 10 (23%) pts included anemia, pyrexia, and increased aspartate aminotransferase (2 [5%] pts each). Pharmacokinetic activity of subasumstat was linear and decreased in a tri-phasic manner. Subasumstat exerted pharmacodynamic activity including target engagement, SUMOylation inhibition and increased IFN-1 signaling. Partial responses were observed at ≥40 mg dose levels in pts with NSCLC and MSS-CRC. Conclusions: Subasumstat plus pembrolizumab showed a favorable safety profile and promising anti-tumor activity in pre-treated NSCLC and MSS-CRC pts. Updated data will be presented at the meeting. Subasumstat plus pembrolizumab is currently in phase 2 clinical development (NCT04381650). Clinical trial information: NCT04381650.

Phase 1a/1b study design of the novel STING agonist, immune-stimulating antibody-conjugate (ISAC) TAK-500, with or without pembrolizumab in patients with advanced solid tumors

TPS2690

Background: Tumor resistance to immune checkpoint inhibitors (CPIs), including pembrolizumab, is common. Suggested mechanisms of resistance include reduced interferon (IFN) signaling, immune escape, and immunosuppressive tumor phenotypes. Innate immune cell stimulation in the tumor microenvironment may be a potential pathway to overcome this resistance. Stimulator of interferon genes (STING) is a cytosolic protein critical for initiation of type-1 IFN-dependent innate immunity. TAK-500 is a novel ISAC comprising a STING agonist (based on TAK-676, which is currently in phase 1 clinical trials [NCT04420884, NCT04879849]), an IgG1 anti-cysteine-cysteine chemokine receptor 2 (CCR2) antibody, and a self-immolating maleimide-containing protease-cleavable peptide linker. CCR2-expressing myeloid cells, including tumor associated macrophages (TAMs), promote immune evasion in part by reducing infiltration of CD8+ T cells into the tumor microenvironment. As such, TAK-500 has the potential to mitigate CPI resistance in solid tumors via targeted STING activation of tumor-infiltrating CCR2-expressing myeloid cells, thus leading to stimulation of innate and adaptive immunity within the tumor microenvironment through three potential mechanisms of action: activation of IFN signaling, reprogramming of CCR2-expressing myeloid cells to an inflammatory phenotype, and blockade of suppressive TAM recruitment. Methods: Adult patients with a diagnosis of locally advanced or metastatic gastroesophageal adenocarcinoma, pancreatic adenocarcinoma, hepatocellular carcinoma, non-squamous non-small cell lung cancer, squamous cell carcinoma of the head and neck, mesothelioma or triple-negative breast cancer are eligible. All patients must have progressive disease while on, or be intolerant to, all current standard therapies. Approximately 106 patients in total will be enrolled to the dose escalation and expansion cohorts. In the dose escalation phase, intravenous (IV) TAK-500 will be administered over the range 8–480 µg/kg on day 1 of every 21-day cycle (Q3W) to establish the pharmacologically active dose (PAD) range. An additional escalation cohort of patients will receive TAK-500 + IV pembrolizumab 200 mg Q3W, starting at a dose of TAK-500 that is 1–2 dose levels below the lowest PAD range established in the single agent cohort. Dose escalation in both cohorts will be guided by Bayesian Optimal Interval design. In the dose expansion phase, only the combination of TAK-500 + pembrolizumab will be evaluated. Primary objectives of this study are safety and tolerability; secondary objectives include determination of the PAD range, the recommended phase 2 dose, pharmacokinetics, pharmacodynamics, and antitumor activity of TAK-500 as a single agent and in combination with pembrolizumab. Clinical trial information: NCT05070247.

SALVO: Single-arm trial of ipilimumab and nivolumab as adjuvant therapy for resected mucosal melanoma

9573

Background: Mucosal melanoma is a rare, highly aggressive form of melanoma with extremely high recurrence rates, despite definitive surgical resection. Median RFS has been reported to be 5.4m, with RFS rates at 1 and 2 years of 10%, and 0%, respectively (Lian B, Si L, Cui C, et al. Phase II Randomized Trial Comparing High-Dose IFN-α2b with Temozolomide Plus Cisplatin as Systemic Adjuvant Therapy for Resected Mucosal Melanoma. Clinical Cancer Research 2013, 19(16):4488-4498). Currently there is no consensus on recommendations for adjuvant therapy. Data on the use of immune checkpoint inhibitors (ICI) adjuvantly is lacking. Methods: We performed a single arm, multicenter clinical trial using “flip dose” ipilimumab (1mg/kg q3w x4 cycles),and nivolumab (3 mg.kg q3w x4 cycles), then Nivolumab 480 mg q4w x 11 cycles to complete a year of adjuvant therapy. The primary endpoint was recurrence-free survival (RFS), and the study had 85% power to detect an improvement in RFS between 5.5 and 9.5 months using a one-sided log rank test. Participants must have had R0/R1 resection <90 days prior to registration, and no prior systemic therapy (adjuvant radiation allowed), ECOG 0/1, no uncontrolled significant autoimmune disease or other invasive cancer. Patients were recruited through the Midwest Melanoma Partnership/Hoosier Oncology Network. Results: From 9/17 to 8/21, 44 patients were approached at 6 centers. Of these 9 were ineligible, and 35 were enrolled. Of these, 29 (83%) had R0 resections, and 7 (20%) had adjuvant radiation prior to enrollment. As of Dec 2021, 31 patients have completed the treatment phase. Of the 35 patients treated on study, 20 patients have recurred (7 local, 5 distant, 3 regional, 5 sites unconfirmed), 6 stopped therapy due to adverse effects, and 8 have died. The mean age of patients was 65.8 years and 21 (60.0%) were female. The primary site of disease was vulvovaginal N=12 (32.4%) patients, sinonasal N= 11 (29.7%), anorectal N= 9 (24.3%) and other site N= 5 (13.5%). Adjuvant radiation had been given in 7 pts. Driver mutations were rare, with only 3 (8.6%) patients having a KIT mutation, and one patient (2.9%) each having a NRAS or BRAF mutation. RFS rates at 1 and 2 years were 50% (95% CI 31-66%) and 37% (95% CI 19-55%), with OS rates at 1 and 2 years of 87% (95% CI 68-95%) and 68% (95% CI 46-83%). Median RFS was 10.3 m (95% CI5.7-25.8). Most common grade 3 adverse events were diarrhea (14%), hypertension (14%), hyponatremia (11%), with no grade 4/5 toxicities. Conclusions: Flip dose ipilimumab and nivolumab after resection is associated with outcomes improved over previously reported outcomes in the absence of therapy. Long term follow up is ongoing as are subgroup analyses and correlative studies. Clinical trial information: NCT03241186.

INT230-6 monotherapy and in combination with ipilimumab (IPI) across a broad spectrum of refractory soft tissue sarcomas (STS) [Intensity IT-01; BMS#CA184-592]

11515

Background: INT230-6 is a novel intratumoral (IT) agent with a dual anti-cancer mechanism (tumor cytoreduction while stimulating antigen presentation and recruitment of T-cells). The drug is comprised of cisplatin (CIS) and vinblastine (VIN) co-formulated with an amphiphilic molecule that enables drug dispersion throughout tumors and passive diffusion into cancer cells following IT delivery. In the neoadjuvant setting, a single injection can cause necrosis in > 95% of the tumor and recruit TILs. Combining with anti-CTLA-4 improved responses in preclinical models. Methods: INT230-6 dose is set by the tumor’s longest diameter and is proportional to the injected disease volume. INT230-6 is administered IT Q2W for 5 treatment sessions followed by maintenance every 9 weeks as monotherapy or with IPI 3mg/kg IV Q3W for 4 doses. Biopsies from injected tumors are obtained pretreatment and Day 28 for immunoprofiling. Results: 22 subjects with various advanced STS histologies with a median age of 64 and a median of 3 prior systemic therapies were enrolled (11 INT230-6 alone, 11 IPI combination). There were 178 image-guided IT INT230-6 injections (107 to deep tumors) at INT230-6 doses ranging from 5 to 242 mL (121mg CIS, 24.2mg VIN, doses which vastly exceed the usual IV doses of these drugs). PK analysis showed that > 95% of drug agents remain in the tumor. The most common (> 25%) all-grade related adverse events (AEs) in evaluable monotherapy subjects (n = 10) were pain (80%), decreased appetite (40%), nausea (40%), anemia (30%), fatigue (30%) and vomiting (30%). Tolerability was similar for the combination with IPI. Most events were low grade. The incidence of grade 3 AEs for the INT230-6 arm was 30% and for the IPI combination was 10%. There were no related grade 4 or 5 AEs in either cohort. RECIST metrics may not accurately reflect clinical benefit with this treatment given large volumes of INT230-6 is repeatedly injected into a tumor and local inflammation may occur. Paired biopsies showed reduction in proliferating tumor cells and an increase in T-cell infiltrates. The disease control rate at the first imaging timepoint for evaluable INT230-6 subjects (n = 9) was 56% and for evaluable IPI combination (n = 5) was 80%. Abscopal effects were seen in 2 monotherapy subjects, though most uninjected tumors were not tracked. The estimated 1-year overall survival was 88% for the IPI combo and 60% for the monotherapy cohort. Conclusions: IT INT230-6 is well tolerated as monotherapy and combined with IPI. STS, which is typically not sensitive to immunotherapy, may be amenable to INT230-6 or IPI combo to create antigens and promote a systemic immune response. Preliminary efficacy using INT230-6 alone is encouraging and will be evaluated in a global phase 3 trial. Further evaluation is needed to determine whether the addition of IPI may improve patient outcomes. Clinical trial information: NCT03058289.

DELTA-1: A global, multicenter, phase 2 study of ITIL-168, an unrestricted autologous tumor-infiltrating lymphocyte (TIL) cell therapy, in adult patients with advanced cutaneous melanoma

TPS9594

Background: Patients (pts) with advanced (unresectable or metastatic) cutaneous melanoma and persistent disease after checkpoint inhibitor therapy have poor outcomes and limited treatment options, highlighting a significant unmet medical need (Schadendorf D et al. Lancet. 2018;392:971-984). Investigational autologous TIL cell therapies have shown promise in this population, partly attributable to their intrinsic and patient-specific antitumor activity (Borch TH et al. J Immunother Cancer. 2020;8:e000668). Made from each patient’s digested and cryopreserved tumor, ITIL-168 is an autologous TIL cell therapy manufactured to offer an unrestricted T-cell receptor repertoire. A single-center, compassionate use clinical series demonstrated the feasibility and clinical utility of an earlier version of ITIL-168, with a high overall response rate among pts previously treated with PD-1 inhibitor (PD-1i) therapy (58%, n = 12; Pillai M et al. Ann Oncol. 2021;32[suppl 5]:S882). DELTA-1 (NCT05050006) is a global, multicenter phase 2 study to evaluate efficacy and safety of ITIL-168 in pts with cutaneous melanoma relapsed or refractory to a PD-1i, pts intolerant to a PD-1i, and pts whose current best response to a PD-1i is stable disease. Methods: Pts aged ≥18 years with histologically confirmed advanced cutaneous melanoma, ECOG performance status 0-1, and adequate organ function will be enrolled in 1 of 3 cohorts. Cohort 1 (n≈80) will include pts who relapsed after or were refractory to ≥1 prior line of systemic therapy, including a PD-1i and, if BRAF-mutated, a BRAFi ± MEKi. Cohorts 2 and 3 (n≈25 each) will include pts intolerant to PD-1i and those with stable disease after ≥4 doses of PD-1i, respectively. After tumor resection for TIL harvest, pts must have ≥1 remaining measurable lesion per RECIST 1.1. Pts with uveal, acral, or mucosal melanoma, prior allogeneic transplant or cell therapy, and with central nervous system (CNS) disorder or symptomatic and/or untreated CNS metastases are ineligible. Pts will receive 5 days of lymphodepleting chemotherapy (cyclophosphamide ×2 days overlapping with fludarabine ×5 days) followed by a single ITIL-168 infusion (≥5×109 cells) and supportive short-course, high-dose IL-2. The primary endpoint is objective response rate (ORR) per central review. Secondary endpoints include duration of response, progression-free survival, overall survival, disease control rate, TIL persistence, and safety. Hypothesis testing of ORR will be performed for cohort 1. The primary analysis will occur when all pts in the cohort 1 modified intent-to-treat population have been followed for ≥6 months after the first posttreatment disease assessment. DELTA-1 opened for enrollment in September 2021. Updated site information will be given at the time of presentation. Clinical trial information: NCT05050006.

Management of Immunotherapy-Related Toxicities, Version 1.2022, NCCN Clinical Practice Guidelines in Oncology

The aim of the NCCN Guidelines for Management of Immunotherapy-Related Toxicities is to provide guidance on the management of immune-related adverse events resulting from cancer immunotherapy. The NCCN Management of Immunotherapy-Related Toxicities Panel is an interdisciplinary group of representatives from NCCN Member Institutions, consisting of medical and hematologic oncologists with expertise across a wide range of disease sites, and experts from the areas of dermatology, gastroenterology, endocrinology, neurooncology, nephrology, cardio-oncology, ophthalmology, pulmonary medicine, and oncology nursing. The content featured in this issue is an excerpt of the recommendations for managing toxicities related to CAR T-cell therapies and a review of existing evidence. For the full version of the NCCN Guidelines, including recommendations for managing toxicities related to immune checkpoint inhibitors, visit NCCN.org.

Tumor mutational burden and somatic mutation status to predict disease recurrence in advanced melanoma

Tumor mutational burden (TMB) has recently been identified as a biomarker of response to immune checkpoint inhibitors in many cancers, including melanoma. Co-assessment of TMB with inflammatory markers and genetic mutations may better predict disease outcomes. The goal of this study was to evaluate the potential for TMB and somatic mutations in combination to predict the recurrence of disease in advanced melanoma. A retrospective review of 85 patients with stage III or IV melanoma whose tumors were analyzed by next-generation sequencing was conducted. Fisher's exact test was used to assess differences in TMB category by somatic mutation status as well as recurrence locations. Kaplan-Meier estimates and Cox-proportional regression model were used for survival analyses. The most frequently detected mutations were TERT (32.9%), CDKN2A (28.2%), KMT2 (25.9%), BRAF V600E (24.7%), and NRAS (24.7%). Patients with TMB-L + BRAFWT status were more likely to have a recurrence [hazard ratio (HR), 3.43; confidence interval (CI), 1.29-9.15; P = 0.01] compared to TMB-H + BRAF WT. Patients with TMB-L + NRASmut were more likely to have a recurrence (HR, 5.29; 95% CI, 1.44-19.45; P = 0.01) compared to TMB-H + NRAS WT. TMB-L tumors were associated with local (P = 0.029) and in-transit (P = 0.004) recurrences. Analysis of TMB alone may be insufficient in understanding the relationship between melanoma's molecular profile and the body's immune system. Classification into BRAFmut, NRASmut, and tumor mutational load groups may aid in identifying patients who are more likely to have disease recurrence in advanced melanoma.

Real-world frequency of BRAF testing and utilization of therapies in patients with advanced melanoma

Both BRAF/MEK targeted agents and immunotherapy are approved for the treatment of advanced melanoma. BRAF testing is recommended at the time of advanced melanoma diagnosis. In addition, little is known regarding the treatment trends for patients with BRAF mutated tumors. This investigation aims to assess the real-world prevalence of molecular testing and treatment trends for patients with BRAF mutated tumors. Using a de-identified database, patients of age ≥18 years with advanced melanoma from 2013 to 2018 were examined. Molecular testing performed within 3 months of advanced diagnosis was considered to have the test performed at the time of diagnosis. Test prevalence was calculated and compared in groups stratified by the patient, tumor and treatment factors. In total 4459 patients were included; 1936 (43.4%) stage III, 1191 (26.7%) stage IV and 1332 (29.9%) recurrent. Totally 50.4% of patients received systemic treatment; 76.4% stage IV, 71% recurrent patients and 26.7% stage III patients. However, 73.5% received first-line immunotherapy. In total 73.8% of patients had molecular testing, and 50.5% had tested at the time of advanced diagnosis. Of those tested 42% had a BRAF mutated tumor. In total 48% of these patients received first-line immunotherapy whereas 43% received a BRAF inhibitor, with increasing immunotherapy use seen over time. The majority of patients with advanced melanoma undergo molecular testing at the time of advanced diagnosis. Immunotherapy is the most commonly prescribed treatment regardless of BRAF mutational status. These results provide real-world data on the frequency of molecular testing and treatment trends for patients with advanced melanoma.

Abstract P5-16-13: Safety and efficacy of INT230-6, a potential first-in-class intratumoral therapy, in monotherapy and in combination with pembrolizumab: Results from the IT-01 study [KEYNOTE-A10] in subjects with locally advanced, unresectable and metastatic breast cancer

Background: INT230-6 is a novel formulation of cisplatin and vinblastine with an amphiphilic cell penetration enhancer that has been shown to enhance dispersion of the drug throughout tumors and allow diffusion into cells when given intratumorally. INT230-6 is being evaluated in monotherapy and in combination with immune checkpoint inhibitors (ICIs) in subjects with various advanced solid tumors, including advanced breast cancer. Methods: This phase 1/2 study evaluated INT230-6 in superficial and deep tumors with INT230-6 Q2W intratumoral injections for 5 doses alone or in combination with 200mg pembrolizumab IV Q3W for 2 years. Total INT230-6 injected in a subject ranged from 0.89 to 649 mL over 5 INT230-6 dosing sessions in each subject, except one subject who had only 2 dosing sessions. Subjects who had completed treatment in dose escalation cohorts were eligible for retreatment; and one subject was retreated with INT230-6 in multiple arms of the study. Advanced breast cancer subjects with an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or below who have failed one or more approved therapies, or have no alternate approved therapy, were enrolled. Subjects must have adequate organ function and measurable disease by RECIST 1.1 criteria including one target tumor for injection. Tumor response using RECIST 1.1 was evaluated at 12 weeks from the first INT230-6 dose and then every 8 weeks. Tumor biopsies were taken prior to INT230-6 dosing on day 0 and on day 28 post dose. Results: 7 advanced triple negative breast cancer subjects (4 monotherapy, 3 pembrolizumab combination) were evaluable as of June 1, 2021. The median age was 56 (range 46-82) years old, with a median of 8 (2, 17) prior systemic therapies for metastatic disease. The intratumoral INT230-6 dose was up to 164 mL (82 mg of CIS, 16.4mg VIN) to tumors in a single dosing session. With INT230-6, 133-200% more volume is injected into the tumor and pharmacokinetics (PK) analysis shows that 95% of INT230-6 active agents remain in the tumor. Accordingly, assessment of tumor response using RECIST principles may be challenging, and even stable disease may represent a large decrease in viable tumor cells as indicated by biopsy evaluations. The most common (&gt;20%) related treatment related adverse events (AE) were localized tumor related pain (71%), nausea (57%), anemia (29%), fatigue (29%), neck pain (29%), and vomiting (29%). AEs were mostly low grade and only one subject experienced grade 3 anemia (13%). There were no related grade 4 or 5 AEs or serious AEs. Disease control rate (DCR), defined as the percent of patients with a complete response, partial response, or stable disease at the first radiologic assessment, was 57%. Median overall survival was 12 months. Pre- and post- biopsy at 28 days after two INT230-6 doses (n= 3 evaluable, monotherapy, and combination with pembrolizumab) showed a 55% decrease in Ki67 and 69% reduction in viable cancer cells. In addition, multiplex immunofluorescence (n= 3 evaluable, combination with pembrolizumab) showed an influx of activated CD4 and CD8 T cells and in some cases a reduction in FoxP3 T-reg cells.. Conclusion: INT230-6 is a potential first-in-class intratumoral therapy for advanced breast cancer being developed in monotherapy and in combination with ICIs. There is a favorable safety profile in this population, similar to the broader metastatic solid tumor population presented elsewhere. There are early signs of cancer cell death in injected tumors and immune activation in heavily pre-treated patients. A Phase 2 expansion cohort of INT230-6 in combination with ICIs is ongoing. In addition, INT230-6 in being studied in a separate randomized Phase 2 neoadjuvant breast cancer study.

Citation Format: Philippe Bedard, Lillian L Siu, Jacob Thomas, Diana Hanna, Anthony J Olszanski, Nilofer Azad, Giles Whalen, Matthew Ingham, Syed Mahmood, Lewis H Bender, Ian B Walters, Anthony El-Khoueiry. Safety and efficacy of INT230-6, a potential first-in-class intratumoral therapy, in monotherapy and in combination with pembrolizumab: Results from the IT-01 study [KEYNOTE-A10] in subjects with locally advanced, unresectable and metastatic breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-16-13.

Phase I trial of ATM inhibitor M3541 in combination with palliative radiotherapy in patients with solid tumors

BACKGROUND

Ataxia telangiectasia mutated (ATM) kinase orchestrates DNA double strand break (DSB) repair; ATM inhibitors may therefore enhance the therapeutic effect of DSB-inducing treatments such as radiotherapy (RT). M3541 is an orally administered selective inhibitor of ATM.

METHODS

This phase I dose-escalation study evaluated the maximum-tolerated dose (MTD), recommended phase II dose(s) (RP2D), safety, pharmacokinetics (PK) and antitumor activity of M3541 in combination with fractionated palliative RT in patients with solid tumors. Fifteen patients received palliative RT (30 Gy in 10 fractions) and escalating doses of M3541 (50-300 mg administered on RT fraction days) guided by a Bayesian 2-parameter logistic regression model with overdose control.

RESULTS

Doses of M3541 up to 300 mg/fraction day were well tolerated. One patient (200 mg group) experienced two dose-limiting toxicities (urinary tract infection, febrile neutropenia) that resolved with antibiotics. All patients reported ≥ 1 treatment-emergent adverse event (TEAE) but none led to treatment discontinuation. No grade ≥ 4 TEAEs were reported and there was no indication of a dose effect for any TEAE. Three patients (20.0%; 95% confidence interval 4.3-48.1) had confirmed complete or partial response. M3541 total plasma levels did not increase with dose following single or repeated dosing. No relationship was observed between dose and changes in the ratio of phosphorylated to total ATM or in immune cell counts.

CONCLUSIONS

The MTD and RP2D could not be established as the study closed early due to the absence of a dose-response relationship and non-optimal PK profile. No further clinical development of M3541 was pursued. (Trial registration number ClinicalTrials.gov NCT03225105. Registration date July 21, 2017).

Adverse Events Reported by Patients With Cancer After Administration of a 2-Dose mRNA COVID-19 Vaccine

BACKGROUND

Most safety and efficacy trials of the SARS-CoV-2 vaccines excluded patients with cancer, yet these patients are more likely than healthy individuals to contract SARS-CoV-2 and more likely to become seriously ill after infection. Our objective was to record short-term adverse reactions to the COVID-19 vaccine in patients with cancer, to compare the magnitude and duration of these reactions with those of patients without cancer, and to determine whether adverse reactions are related to active cancer therapy.

PATIENTS AND METHODS

A prospective, single-institution observational study was performed at an NCI-designated Comprehensive Cancer Center. All study participants received 2 doses of the Pfizer BNT162b2 vaccine separated by approximately 3 weeks. A report of adverse reactions to dose 1 of the vaccine was completed upon return to the clinic for dose 2. Participants completed an identical survey either online or by telephone 2 weeks after the second vaccine dose.

RESULTS

The cohort of 1,753 patients included 67.5% who had a history of cancer and 12.0% who were receiving active cancer treatment. Local pain at the injection site was the most frequently reported symptom for all respondents and did not distinguish patients with cancer from those without cancer after either dose 1 (39.3% vs 43.9%; P=.07) or dose 2 (42.5% vs 40.3%; P=.45). Among patients with cancer, those receiving active treatment were less likely to report pain at the injection site after dose 1 compared with those not receiving active treatment (30.0% vs 41.4%; P=.002). The onset and duration of adverse events was otherwise unrelated to active cancer treatment.

CONCLUSIONS

When patients with cancer were compared with those without cancer, few differences in reported adverse events were noted. Active cancer treatment had little impact on adverse event profiles.

Feasibility and safety of targeting mitochondria for cancer therapy – preclinical characterization of gamitrinib, a first-in-class, mitochondriaL-targeted small molecule Hsp90 inhibitor

Mitochondria are key tumor drivers, but their suitability as a therapeutic target is unknown. Here, we report on the preclinical characterization of Gamitrinib (GA mitochondrial matrix inhibitor), a first-in-class anticancer agent that couples the Heat Shock Protein-90 (Hsp90) inhibitor 17-allylamino-geldanamycin (17-AAG) to the mitochondrial-targeting moiety, triphenylphosphonium. Formulated as a stable (≥24 weeks at −20°C) injectable suspension produced by microfluidization (<200 nm particle size), Gamitrinib (>99.5% purity) is heavily bound to plasma proteins (>99%), has intrinsic clearance from liver microsomes of 3.30 mL/min/g and minimally penetrates a Caco-2 intestinal monolayer. Compared to 17-AAG, Gamitrinib has slower clearance (85.6 ± 5.8 mL/min/kg), longer t_1/2 (12.2 ± 1.55 h), mean AUC_0-t of 783.1 ± 71.3 h∙ng/mL, and unique metabolism without generation of 17-AG. Concentrations of Gamitrinib that trigger tumor cell killing (IC₅₀ ~1-4 µM) do not affect cytochrome P450 isoforms CYP1A2, CYP2A6, CYP2B6, CYP2C8 or ion channel conductance (Nav1.5, Kv4.3/KChIP2, Cav1.2, Kv1.5, KCNQ1/mink, HCN4, Kir2). Twice weekly IV administration of Gamitrinib to Sprague-Dawley rats or beagle dogs for up to 36 d is feasible. At dose levels of up to 5 (rats)- and 12 (dogs)-fold higher than therapeutically effective doses in mice (10 mg/kg), Gamitrinib treatment is unremarkable in dogs with no alterations in clinical-chemistry parameters, heart function, or tissue histology, and causes occasional inflammation at the infusion site and mild elevation of serum urea nitrogen in rats (≥10 mg/kg/dose). Therefore, targeting mitochondria for cancer therapy is feasible and well tolerated. A publicly funded, first-in-human phase I clinical trial of Gamitrinib in patients with advanced cancer is ongoing (ClinicalTrials.gov NCT04827810)

Mogamulizumab in Combination with Nivolumab in a Phase I/II Study of Patients with Locally Advanced or Metastatic Solid Tumors

PURPOSE

The aim of the study was to determine safety, antitumor activity, and pharmacodynamic profile of mogamulizumab, an anti-CCR4 monoclonal antibody targeting effector regulatory T cells (Treg) in combination with the checkpoint inhibitor nivolumab in patients with locally advanced or metastatic solid tumors.

PATIENTS AND METHODS

This was a multicenter, dose-finding (phase I), and dose expansion (phase II) study (NCT02705105) in patients with locally advanced or metastatic solid tumors. There were no dose-limiting toxicities in phase I with mogamulizumab 1 mg/kg every week for cycle 1 followed by 1 mg/kg every 2 weeks plus nivolumab 240 mg every 2 weeks intravenously, and cohort expansion occurred at this dose level.

RESULTS

All 114 patients treated with mogamulizumab 1 mg/kg plus nivolumab 240 mg in phases I (n = 4) and II (n = 110) were assessed for safety and efficacy. Mogamulizumab plus nivolumab showed acceptable safety and tolerability. Objective response rate was 10.5% [95% confidence interval (CI), 5.6-17.7; 3 complete and 9 partial responses]. Disease control rate was 36.8%. Median duration of response was 14.4 months. Median progression-free survival was 2.6 (95% CI, 2.3-3.1) months, and median overall survival was 9.5 (95% CI, 5.9-13.5) months.

CONCLUSIONS

Combination of mogamulizumab with nivolumab for treatment of patients with locally advanced or metastatic solid tumors did not result in enhanced efficacy. Tolerability of mogamulizumab 1 mg/kg plus nivolumab 240 mg was acceptable.

Phase I clinical trial evaluating the safety and efficacy of ADP-A2M10 SPEAR T cells in patients with MAGE-A10+ advanced non-small cell lung cancer

Background

ADP-A2M10 specific peptide enhanced affinity receptor (SPEAR) T cells (ADP-A2M10) are genetically engineered autologous T cells that express a high-affinity melanoma-associated antigen A10 (MAGE-A10)-specific T-cell receptor (TCR) targeting MAGE-A10⁺ tumors in the context of human leukocyte antigen (HLA)-A*02. ADP-0022-003 was a phase I dose-escalation trial that aimed to evaluate the safety and antitumor activity of ADP-A2M10 in non-small cell lung cancer (NSCLC) (NCT02592577).

Methods

Eligible patients were HLA-A*02 positive with advanced NSCLC expressing MAGE-A10. Patients underwent apheresis; T cells were isolated, transduced with a lentiviral vector containing the TCR targeting MAGE-A10, and expanded. Patients underwent lymphodepletion with varying doses/schedules of fludarabine and cyclophosphamide prior to receiving ADP-A2M10. ADP-A2M10 were administered at 0.08–0.12×10⁹ (dose group 1), 0.5–1.2×10⁹ (dose group 2), and 1.2–15×10⁹ (dose group 3/expansion) transduced cells.

Results

Eleven patients (male, n=6; female, n=5) with NSCLC (adenocarcinoma, n=8; squamous cell carcinoma, n=3) were treated. Five, three, and three patients received cells in dose group 1, dose group 2, and dose group 3/expansion, respectively. The most frequently reported grade ≥3 adverse events were lymphopenia (n=11), leukopenia (n=10), neutropenia (n=8), anemia (n=6), thrombocytopenia (n=5), and hyponatremia (n=5). Three patients presented with cytokine release syndrome (grades 1, 2, and 4, respectively). One patient received the highest dose of lymphodepletion (fludarabine 30 mg/m² on days –5 to –2 and cyclophosphamide 1800 mg/m² on days −5 to −4) prior to a second infusion of ADP-A2M10 and had a partial response, subsequently complicated by aplastic anemia and death. Responses included: partial response (after second infusion; one patient), stable disease (four patients), clinical or radiographic progressive disease (five patients), and not evaluable (one patient). ADP-A2M10 were detectable in peripheral blood and in tumor tissue. Peak persistence was higher in patients who received higher doses of ADP-A2M10.

Conclusions

ADP-A2M10 demonstrated an acceptable safety profile and no evidence of toxicity related to off-target binding or alloreactivity. There was persistence of ADP-A2M10 in peripheral blood as well as ADP-A2M10 trafficking into the tumor. Given the discovery that MAGE-A10 and MAGE-A4 expression frequently overlap, this clinical program closed as trials with SPEAR T cells targeting MAGE-A4 are ongoing.

A phase 1 study of LY3076226, a fibroblast growth factor receptor 3 (FGFR3) antibody-drug conjugate, in patients with advanced or metastatic cancer

Background We report a Phase 1 study of LY3076226, an antibody-drug conjugate composed of human IgG1 monoclonal antibody against the human FGFR3 attached with a cleavable linker to the maytansine derivative DM4 in patients with advanced or metastatic cancer. Methods This study was comprised of two parts: (A) dose escalation in patients with advanced or metastatic cancer and (B) dose expansion in patients with urothelial carcinoma with locally determined FGFR3 alterations. The dose range of LY3076226 tested was 0.2-5.0 mg/kg as an intravenous infusion on Day 1 of each 21-day cycle. The primary objective was to determine a recommended phase 2 dose (RP2D). Results Twenty-five patients were enrolled (Part A: 22, Part B: 3) and received ≥ 1 dose of LY3076226. No dose-limiting toxicities were reported. LY3076226 was generally well tolerated; most of the toxicities were Grade 1 or 2. Two patients experienced treatment-related Grade 3 toxicity (embolism and decreased platelet count). Four patients experienced serious adverse events (not treatment-related), all in Part A. Dose-proportional exposure was observed, with an estimated half-life of 2-7 days. No responses were seen with LY3076226 treatment. Stable disease persisting for > 6 months was observed in 1 patient receiving 3.2 mg/kg of LY3076226. Conclusion The study demonstrates acceptable safety and tolerability of LY3076226 up to the 5.0 mg/kg dose. Recruitment was stopped due to pipeline prioritization. Dose escalation of LY3076226 beyond 5.0 mg/kg in patients with advanced tumors may be possible. The trial was registered on August 19, 2015 under identifier NCT02529553 with ClinicalTrials.gov.

Abstract CT227: A phase 1 multiple ascending dose study to investigate the safety, pharmacokinetics, pharmacodynamics and preliminary efficacy of KD033 in subjects with metastatic or locally advanced solid tumors

Background: IL-2 and IL-15 signal through the shared IL-2/15 βγ receptor, but unlike IL-2, IL-15 does not expand regulatory T cells (Tregs). In addition, unlike IL-2, IL-15 does not mediate activation-induced cell death and is expected to have an improved therapeutic index compared to IL-2. KD033 is a fusion antibody molecule generated by combining a fully human, high affinity anti-human Programmed Death Ligand 1 (PD-L1) IgG1 antibody with the human IL-15 receptor alpha (IL15Rα) sushi domain and human IL-15 (IL-15). KD033 (or its mouse cross reactive surrogate molecule, srKD033) has been extensively characterized in multiple in vitro and in vivo nonclinical studies to understand the pharmacology, pharmacokinetic (PK) and toxicology properties. The fusion of anti-PD-L1 antibody to IL-15 significantly increases the maximal-tolerated dose (MTD) of srKD033 in mice compared to free-IL-15. The increased safety and efficacy of PD-L1-targeted IL-15 observed in pre-clinical studies warranted evaluation of KD033 in humans. Methods: This is a phase 1, open-label, multiple ascending dose, multi-center clinical trial being conducted in patients with metastatic or locally advanced solid tumors (NCT04242147). The primary objective is to determine the safety and tolerability and the MTD of KD033. KD033 is administered as an IV infusion over 30 minutes every 14 days (i.e., a cycle equals 2 weeks). The starting dose of KD033 is 3 µg/kg, with step-up dosing to 12.5 µg/kg in the first cohort of 3 subjects. After the first cohort, the dose escalation will use a standard 3+3 design with planned doses from 25 µg/kg to 600 µg/kg. The dose escalation phase will be followed by one expansion cohort, which will enroll patients who received PD-1/PD-L1 inhibitor but have either progressed or are refractory to therapy. Secondary objectives include characterization of PK and immunogenicity, evaluation of immune correlates that will potentially differentiate the impact of KD033 versus monotherapy as well as investigate IL-15 biology and determine best overall response and duration of response. (NCT04242147)

Citation Format: Jason J. Luke, Anthony J. Olszanski, Igor Puzanov, Dan Lu, Adrian Hackett, Stella Martomo, Jeegar Patel, Olivier Schueller, Alessandro Mora, Miranda L. Schlitt, Linghui Li. A phase 1 multiple ascending dose study to investigate the safety, pharmacokinetics, pharmacodynamics and preliminary efficacy of KD033 in subjects with metastatic or locally advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT227.

Abstract CT032: CMP-001 demonstrates improved response in noninflamed anti-PD-1 refractory melanoma and response is associated with serum CXCL10

Background

In the treatment-naive setting, PD-1 blockade is associated with greater response in T cell-inflamed vs non-T cell-inflamed tumors. CMP-001 is a CpG-A oligonucleotide TLR9 agonist in a virus-like particle that is hypothesized to activate tumor-associated plasmacytoid dendritic cells (pDCs) to secrete type I interferons. Through this activity, CMP-001 may convert the tumor microenvironment to a Th1-like chemokine milieu (eg, increased CXCL10) and induce an antitumor CD8+ T-cell response. We have recently reported that intratumoral injection of CMP-001 + IV pembrolizumab (pembro) had an acceptable safety profile and can reverse PD-1 blockade resistance in patients (pts) with melanoma (Milhem et al, SITC 2019). Regression was observed in injected and uninjected lesions. Herein we report pharmacodynamic and translational data.

Methods

This 2-part, open-label, multicenter, phase 1b study (NCT02680184) enrolled pts with metastatic/unresectable melanoma and stable disease (SD) or progressive disease (PD) on/after anti−PD-1 therapy. In part 1 (3+3 dose-escalation and dose-expansion), pts received CMP-001 + pembro. In part 2, pts received CMP-001 monotherapy. Determination of safety and clinical activity were the study's main objectives. Prespecified pharmacodynamic and translational studies evaluated serum chemokines and evaluated tumor biopsies using RNA and/or whole exome sequencing and immunohistochemistry for PD-L1 (reported as H-score), CD8, and CD303 (pDC marker).

Results

As of September 30, 2020, 159 pts (part 1) and 40 pts (part 2) have been treated. A greater median fold increase of serum CXCL10 (a marker of innate immunity, n=40) was observed in responders (R) to CMP-001 + pembro (18.8x) vs nonresponders (NR) after treatment (9.9x in SD; 6.15x in PD; differences were not statistically significant). Preliminary analyses showed that interferon gene expression distinguished R vs NR. Tumor biopsy analyses (part 1, n=139; part 2, n=34) showed that pts with high PD-L1, high CD8+ T cells, or inflamed transcriptional signatures at baseline were less likely to respond to CMP-001 + pembro vs pts without inflammation markers at baseline. Baseline mean PD-L1 expression (H-score) was 8.1 in R (n=10) vs 21.8 in NR (n=49). Posttreatment biopsies generally showed increased PD-L1, CD8+ T cells, and inflamed transcriptional signatures in R vs NR. Neither tumor mutational burden nor baseline pDC density distinguished R vs NR.

Conclusions

In pts with anti-PD-1 refractory melanoma, intratumoral CMP-001 ± pembro appears to disproportionately induce antitumor responses in noninflamed tumors. Clinical response to CMP-001 ± pembro was associated with induction of markers of both innate and adaptive antitumor immunity.

Citation Format: Jason John Luke, Riyue Bao, John M. Kirkwood, Yousef Zakharia, Diwakar Davar, Elizabeth Buchbinder, Theresa Medina, Adil Daud, Antoni Ribas, Jiaxin Niu, Geoffrey Gibney, Kim Margolin, Anthony J. Olszanski, Inderjit Mehmi, Takami Sato, Montaser Shaheen, Aaron Morris, Dmitri Bobilev, Katie Campbell, George Weiner, James E. Wooldridge, Arthur M. Krieg, Mohammed Milhem. CMP-001 demonstrates improved response in noninflamed anti-PD-1 refractory melanoma and response is associated with serum CXCL10 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT032.

NCCN Guidelines Insights: Management of Immunotherapy-Related Toxicities, Version 1.2020

The NCCN Guidelines for Management of Immunotherapy-Related Toxicities provide interdisciplinary guidance on the management of immune-related adverse events (irAEs) resulting from cancer immunotherapy. These NCCN Guidelines Insights describe symptoms that may be caused by an irAE and should trigger further investigation, and summarize the NCCN Management of Immunotherapy-Related Toxicities Panel discussions for the 2020 update to the guidelines regarding immune checkpoint inhibitor-related diarrhea/colitis and cardiovascular irAEs.

Phase I dose escalation of KD033, a PDL1-IL15 bispecific molecule, in advanced solid tumors

2568

Background: IL-2 and IL-15 signal through the shared IL-2/15 βγ receptor, but unlike IL-2, IL-15 does not expand regulatory T cells (Tregs), does not mediate activation-induced cell death and may have an improved therapeutic index. KD033 is a fusion antibody combining a fully human, high affinity anti-human Programmed Death Ligand 1 (PD-L1) IgG1 antibody with the human IL-15 receptor alpha (IL15Rα) sushi domain and human IL-15 (IL-15). KD033 (or its mouse cross reactive surrogate molecule, srKD033) has been extensively characterized in multiple in vitro and in vivo nonclinical studies. The fusion of anti-PD-L1 antibody to IL-15 significantly increases the maximal-tolerated dose (MTD) of srKD033 in mice compared to free IL-15. In addition, srKD033 has exhibited increased efficacy in rejecting tumors in mice as compared to the combination of its individual components, anti-PD-L1 antibody and IL-15. Methods: This is a phase 1, open-label, multiple ascending dose, multi-center clinical trial being conducted in patients with metastatic or locally advanced solid tumors (NCT04242147). The primary objective is to determine the safety and tolerability and the MTD of KD033. Secondary objectives include characterization of PK and immunogenicity, evaluation of CD8 T and NK cell activation and assessment of best overall response and duration of response. KD033 is administered by IV infusion over 30 minutes every 14 days. Accelerated intra-patient dose escalation across the initial three dose levels, followed by 3+3 escalation thereafter, is investigating dose ranges from 3 µg/kg to 600 µg/kg. Efficacy evaluation is planned in an expansion cohort of patients with PD-1/L1 refractory tumors. Results: A total of 7 patients have received treatment. Three patients were dosed in Cohort 1 and four patients were dosed in Cohort 2. Through two dose escalation cohorts (3 µg/kg – 25 µg/kg), no dose-limiting toxicities have been reported. Grade 1-2 treatment-related toxicities, when observed, resolved within 24 hours with supportive management. 6 patients are evaluable for treatment response with one patient (adenoid cystic carcinoma) in the first cohort having stable disease for more than 6 months. Conclusions: KD033 has been well tolerated early in dose escalation with on-mechanism pharmacodynamics consistent with IL-15 agonism. Clinical trial information: NCT04242147.

Phase 1/2 study of the novel SUMOylation inhibitor TAK-981 in adult patients (pts) with advanced or metastatic solid tumors or relapsed/refractory (RR) hematologic malignancies

TPS2667

Background: SUMOylation, a posttranslational modification analogous to ubiquitination, attaches a small, ubiquitin-like modifier (SUMO) to target proteins. SUMOylation plays a central role in regulating type I interferon (IFN-I)-dependent innate response and functions to constrain the innate immune response, which can impair tumor immune surveillance. TAK-981 is a first-in-class, small-molecule inhibitor of SUMO-activating enzyme subunit 2 (SAE2). Inhibition of SAE2 by TAK-981 disrupts SUMOylation, thereby allowing innate immune system activation. In ex vivo assays, TAK-981 increased phagocytic activity of monocyte-derived macrophages, increased natural killer cell cytotoxicity, and induced markers of dendritic cell activation and maturation via IFN-I signaling. In syngeneic mouse models, TAK-981 resulted in antitumor activity, including complete remissions, and a sustained, protective antitumor immune response. Methods: This first-in-human study of single-agent TAK-981 comprises two parts. Phase 1 primary objectives are to determine safety and tolerability, and to select a recommended phase 2 dose (RP2D); secondary objectives are to assess preliminary antitumor activity, characterize pharmacokinetics (PK), and explore pharmacodynamic (PD) biomarkers. This phase will enroll ̃70 pts with untreatable locally advanced or metastatic solid tumors or RR lymphoma. The phase 2 primary objective is to evaluate preliminary efficacy at the RP2D in ̃132 pts with non-squamous non-small cell lung cancer, cervical cancer, microsatellite-stable colorectal cancer, or CD20+ RR diffuse large B-cell lymphoma or follicular lymphoma. Pts receive TAK-981 via a 1-hour intravenous infusion on days 1, 4, 8, and 11 in 21-day cycles until unacceptable toxicity, pt withdrawal, or death. Dose escalation is proceeding from 3 mg, guided by an adaptive 3+3 design combined with Bayesian logistic regression modelling with overdose control, plus consideration of other safety, clinical, PK, and PD data. The RP2D will be based on the maximum tolerated dose (MTD) or on a biologically effective dose (BED) that is ≤MTD. The BED is defined as a dose at which there is evidence of drug-target engagement and inhibition of SUMOylation, plus: induction of cytokines/chemokines and/or IFN-I signature in tumor or blood; evidence of increased T cell infiltration in tumor; or antitumor activity. PK/PD modeling in the BED range is ongoing and will be used in RP2D determination. Clinical trial information: NCT03648372.

A phase 1/2 study of intratumoral INT230-6 alone (IT-01) or in combination with pembrolizumab [KEYNOTE-A10] in adult subjects with locally advanced, unresectable and metastatic solid tumors refractory to therapy

2592

Background: Study IT-01 (KEYNOTE-A10) evaluates INT230-6, a novel formulation of cisplatin (CIS) and vinblastine (VIN) with an amphiphilic cell penetration enhancer designed for intratumoral (IT) administration, alone or in combination with pembrolizumab (PEM), an antibody to PD-1. INT230-6 dosing is set by a tumor’s volume. In preclinical studies, INT230-6 increases drug dispersion throughout the tumor, allows drug diffusion into cancer cells and recruits dendritic, CD4 and CD8 T cells. The addition of PEM has been shown to improve these responses in models. Phase 1 data indicated INT230-6 alone induced tumor regression in both injected and non-injected lesions. Considering the large volume of drug injected and retained in the tumor, coupled with immune infiltration on biopsies, RECIST response methodology may not capture the benefit of INT230-6 treatment. Methods: IT-01 is an open-label phase 1/2 study, currently enrolling adult subjects with solid tumors in phase 2. INT230-6 was administered IT Q2W for 5 doses alone or with PEM 200mg Q3W. The study seeks to assess the safety and efficacy of IT INT230-6 alone and in combination with PEM. Results: 67 subjects have been enrolled (58 mono and 12 INT230-6 + PEM (3 started in mono, then received combo)) having a median of 3 prior therapies (0, 10). Median age was 60 (42, 85). 20+ cancer types were accrued; breast cancer and sarcoma were the most frequent. Over 500 image guided INT230-6 IT injections were given (253 to deep tumors) at doses of 0.3 to 172mL (86 mg CIS, 17.2 mg VIN) in a single session, which are higher amounts than typical IV doses. PK shows that 95% of INT230-6 active agents remain in the tumor. The most common (> 20%) related TEAEs for INT230-6 alone were localized pain (57%), nausea (36%), fatigue (29%) and vomiting (24%); with grade 3 TEAEs (> 1) of localized pain (5%) and anemia (3%). The safety in the combination was similar. There were no related grade 4 or 5 TEAEs. In evaluable monotherapy subjects (n = 43), the disease control rate (DCR) was 65% vs. 100% in PEM subjects (n = 5). Given the range of dose and entering tumor burden, an exploratory analysis of dose relative to tumor burden (TB) showed that subjects receiving a dose of INT230-6 < 50% of their reported TB (n = 30) had a mOS of 3.5 months. While in subjects receiving a dose of INT230-6 to ≥50% of TB (n = 37), mOS has not yet been reached after a median follow up of 9.5 months (HR: 0.26 (0.13,0.51)). Conclusions: INT230-6 is well tolerated when administered IT as monotherapy and combined with PEM. Given the challenge in assessing overall response rate following IT delivery, an exploratory analysis suggests prolonged survival for subjects receiving an INT230-6 dose ≥50% of their tumor burden compares favorably to the < 50% group and to literature accounting for prognostic factors (ECOG, LDH, # of metastatic sites). Clinical trial information: 03058289.

A phase 1 dose-escalation study of intravenously (IV) administered TAK-676, a novel STING agonist, alone and in combination with pembrolizumab in patients (pts) with advanced or metastatic solid tumors

TPS2670

Background: Immuno-oncology therapies, including immune checkpoint inhibitors (CPIs), are revolutionizing cancer treatment. However, primary and secondary resistance to CPIs remains a significant challenge. CPI resistance has been associated with reduced interferon (IFN) signaling, altered antigen presentation, and an immunosuppressive tumor phenotype. Stimulating innate immune cells to develop a proinflammatory tumor environment that activates IFN signaling and downstream adaptive antitumor immune mechanisms is predicted to overcome such resistance. Stimulator of Interferon Genes (STING) is a key mediator of type 1 IFN-dependent innate immune modulation. Most STING agonists evaluated clinically have required intratumoral administration, which has significant logistical challenges and excludes many pts whose tumors are not accessible for injection. TAK-676 is a novel STING agonist under clinical investigation as an IV administered systemic therapy in pts with solid tumors. Methods: The primary objective of this study is to determine the safety and tolerability of TAK-676 alone and in combination with pembrolizumab. Secondary objectives are to: determine the pharmacologically active dose and recommended phase 2 dose; characterize TAK-676 pharmacokinetics; assess preliminary antitumor activity; and assess STING agonism gene signature induction. An exploratory objective is to assess immune cell activation and clinical response. The study comprises a single-pt safety lead-in with single-agent (SA) TAK-676 0.1 mg IV, followed by dose escalation using Bayesian Logistic Regression Model design. Dose escalation will start in the combination arm when ≥2 dose levels in the SA arm have been evaluated and considered safe. In both arms, pts will receive TAK-676 on days 1, 8, and 15 in 21-day cycles for up to 1 year. In the combination arm, pts will also receive pembrolizumab 200 mg IV on day 1 of each cycle. Adult pts with histologically confirmed advanced or metastatic solid tumors who have no standard therapeutic options or are intolerant to them, with an Eastern Cooperative Oncology Group (ECOG) performance status 0–1, and ≥1 Response Evaluation Criteria in Solid Tumors (RECIST) v.1.1- evaluable lesion are eligible; pts with tumors that have relapsed, are refractory or naïve to anti-programmed death 1 (PD-1) or anti-programmed death ligand 1 (PD-L1) therapy are eligible for the combination arm. Planned enrollment is ̃76 pts; recruitment is ongoing. Clinical trial information: NCT04420884.

Early results of intratumoral INT230-6 alone or in combination with ipilimumab in subjects with advanced sarcomas

11557

Background: Patients have limited treatment options following initial chemotherapy failure. INT230-6, a novel formulation of cisplatin (CIS) and vinblastine (VIN) with an amphiphilic cell penetration enhancer, is designed for intratumoral (IT) administration. Study IT-01 (BMS # CA184-592, NCT 03058289) evaluates INT230-6 alone or in combination with ipilimumab (IPI), an antibody to CTLA-4. INT230-6 dosing is set by a % of the volume of the tumor to be injected. The product has been shown to disperse throughout an injected tumor and diffuse into cancer cells. Cell death leads to recruitment of dendritic and T cells, the effect of which may be augmented by CTLA-4 inhibition as evidenced by increased efficacy of the combination in preclinical models. Historically, checkpoint inhibitors have limited activity in sarcoma. Considering the large volume of drug injected and retained in the tumor, coupled with immune infiltration on biopsies, RECIST response methodology may not capture the benefits of INT230-6 treatment. Methods: IT-01 is an open-label phase 1/2 study that is enrolling adult subjects with locally advanced, unresectable or metastatic sarcoma. INT230-6 was administered IT Q2W for 5 doses alone or with IPI 3mg/kg IV Q3W for 4 doses. The study objectives are to assess the safety and efficacy of IT INT230-6 alone and in combination with IPI. Results: 16 heterogenous sarcoma subjects (13 monotherapy, 3 IPI combination) having a median of 3 prior therapies (0, 8) were enrolled to date. The INT230-6 dose was up to 145 mL (72.5 mg of CIS, 14.5 mg VIN) in a single session (an amount of each agent in excess of standard IV doses). The most common ( > 20%) related TEAEs in sarcoma subjects (n = 16) were localized pain (63%), fatigue (38%), decreased appetite (31%), nausea (31%), and vomiting (25%) most of which were low grade; with only grade 3 TEAE above 5% being anemia (13%). There were no related grade 4 or 5 TEAEs. In 11 evaluable monotherapy subjects, the disease control rate (DCR = CR+PD+SD) was 82%. Basket studies of sarcomas, including chordoma, with Royal Marsden Hospital index (RMHI) scores of 2 or higher report median overall survival (mOS) of 4 months. In this study 75% of monotherapy subjects had a RMHI score of 2 and preliminary estimates of mOS was 21.3 (4.67, NA) months. Pilot immunohistochemistry analysis of 5 paired (pre- and 28 days post-dose) biopsy samples showed substantial tumor necrosis, reduction of viable cancer, a decreased cancer proliferation as measured by Ki67, and increased TILs. Conclusions: Preliminary data shows that INT230-6 administered intratumorally alone or in combination with ipilimumab is well-tolerated in this small, heterogenous sarcoma population. The preclinical cancer cell death and immune infiltration mechanism of action appears to translate to sarcoma subjects. There are early signs of efficacy, DCR and potentially OS, that need to be confirmed in randomized studies. Clinical trial information: 03058289.

Selection of the recommended phase 2 dose (RP2D) for subcutaneous nemvaleukin alfa: ARTISTRY-2

2552

Background: Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel engineered cytokine that selectively binds the intermediate-affinity interleukin-2 receptor to preferentially activate CD8+ T and natural killer (NK) cells with minimal expansion of regulatory T cells (Tregs),designed for use as a cancer immunotherapy. ARTISTRY-2 (NCT03861793) is an ongoing phase 1/2 study evaluating the safety, efficacy, and pharmacokinetic and pharmacodynamic (PD) responses of subcutaneous (SC) nemvaleukin in combination with pembrolizumab in patients (pts) with advanced solid tumors. Methods: In phase 1, cohort-specific doses of SC nemvaleukin are administered on an every-7-day (q7d) or every-21-day (q21d) schedule during a 6-week monotherapy lead-in period, followed by combination with pembrolizumab 200 mg q21d. We present safety, PD effects, and preliminary clinical activity outcomes as of 12/02/2020. Results: 57 pts received nemvaleukin doses ranging from 0.3 mg to 6 mg q7d or 1 mg to 10 mg q21d. The most frequent tumor types (> 5 pts) were colorectal, pancreatic, ovarian, and lung; median number of prior therapies was 4. Treatment-related adverse events (TRAEs) in > 30% pts overall were pyrexia (43.9%), chills (38.6%), injection site erythema (33.3%), injection site reaction (33.3%), and fatigue (31.6%). 3 mg q7d (n = 7) had no drug-related dose reductions, discontinuations, or deaths during the monotherapy or combination periods. 6 mg was declared the maximum tolerated dose (MTD) for q7d dosing as 2 of 8 pts experienced dose-limiting toxicities (DLTs). For 6 mg q21d (n = 7), no drug-related dose reductions, discontinuations, or deaths have occurred during the monotherapy period; combination period data are not mature. 10 mg was declared the MTD for q21d dosing as 1 of 9 pts experienced DLTs and 3 had TRAEs leading to dose reductions. Systemic exposure to nemvaleukin increased with increasing dose. Increases in NK cells and CD8+ T cells of approximately 16-fold and 3-fold, respectively, at 3 mg q7d, and approximately 8-fold and 3-fold, respectively, at 6 mg q21d were observed, with minimal change in Tregs. 46 pts had at least 1 on-treatment scan as of the data cutoff date, and 30 (65%) had stable disease (SD) on the first scan. Of the 30 pts with ≥2 scans, 13 (43%) had 2+ consecutive scans of SD. 16 of 57 pts remain on therapy. Antitumor activity data for more recent cohorts are still maturing. Based on the totality of the safety, PD effects, and antitumor activity data, 3 mg q7d was selected as the RP2D for SC nemvaleukin. Conclusions: SC nemvaleukin 3 mg q7d was generally well tolerated as monotherapy and in combination with pembrolizumab, and demonstrated robust PD effects on NK cells and CD8+ T cells with minimal expansion of Tregs. These PD effects are similar to or greater than those observed with intravenous nemvaleukin. Thus, 3 mg q7d was selected as RP2D; phase 2 expansion cohorts for combination with pembrolizumab are enrolling. Clinical trial information: NCT03861793.

NCCN Guidelines® Insights: Melanoma: Cutaneous, Version 2.2021

Over the past few years, the NCCN Guidelines for Melanoma: Cutaneous have been expanded to include pathways for treatment of microscopic satellitosis (added in v2.2020), and the following Principles sections: Molecular Testing (added in v2.2019), Systemic Therapy Considerations (added in v2.2020), and Brain Metastases Management (added in v3.2020). The v1.2021 update included additional modifications of these sections and notable revisions to Principles of: Pathology, Surgical Margins for Wide Excision of Primary Melanoma, Sentinel Lymph Node Biopsy, Completion/Therapeutic Lymph Node Dissection, and Radiation Therapy. These NCCN Guidelines Insights discuss the important changes to pathology and surgery recommendations, as well as additions to systemic therapy options for patients with advanced disease.

Addressing Recent Failures in Immuno-Oncology Trials to Guide Novel Immunotherapeutic Treatment Strategies

The incorporation of checkpoint inhibitors into the treatment armamentarium of oncologic therapeutics has revolutionized the course of disease in many cancers. This has spurred the evaluation of other novel immunotherapy agents in clinical trials with varying levels of success. This review explores possible explanations for differences in efficacy in clinical outcomes among currently US FDA-approved immunotherapy agents, lessons learned from clinical trial failures of investigational immunotherapies, and methods to improve success in the future. An inherent challenge of early phase immunotherapy trials is identifying the maximum tolerated dose and improving understanding of the pharmacokinetics/pharmacodynamics of immunotherapies as they exert their effects indirectly via T cells rather than directly via dose-dependent cytotoxic activity. The wide heterogeneity of the immune system among patients and within an individual patient over time largely affects the results of optimal dose- and toxicity-finding studies as well as the effectiveness of immunotherapy. Therefore, optimization of phase I/II study design is crucial for clinical trial success. These differences may also help elucidate the lack of immunotherapy benefit in certain disease subtypes despite the presence of specific biomarkers. Broader investigation of the tumor microenvironment and its dynamic nature can help in the identification of alternative pathways for targeted therapies, mechanisms of immunotherapy resistance, and more correlative biomarkers. Finally, manipulation of the tumor microenvironment via a single agonist or antagonist may be inadequate, so combination therapies and sequencing of agents must be further assessed while balancing cumulative toxicity risk.

Metastatic Melanoma With Leptomeningeal Disease

Leptomeningeal disease in patients with melanoma historically portends a grim prognosis, with median survival measured in weeks to months. The advent of effective immunotherapy and targeted agents may modify the outcome of such patients. This case report describes a 43-year-old patient diagnosed with stage IIIa BRAF-positive cutaneous melanoma in 2012 who subsequently developed leptomeningeal involvement as her sole site of melanotic metastasis. She received multiple systemic therapies and radiotherapy and survived 2.5 years after her diagnosis with central nervous system involvement. This case report highlights the importance of a multidisciplinary team and the advent of effective agents, which offers the potential for significantly improved outcomes for patients with metastatic melanoma involving the central nervous system.

NCCN Guidelines Insights: Uveal Melanoma, Version 1.2019

The NCCN Guidelines for Uveal Melanoma include recommendations for staging, treatment, and follow-up of patients diagnosed with uveal melanoma of the choroid or ciliary body. In addition, because distinguishing between uveal melanoma and benign uveal nevi is in some cases difficult, these guidelines also contain recommendations for workup of patients with suspicious pigmented uveal lesions, to clarify the tests needed to distinguish between those who should have further workup and treatment for uveal melanoma versus those with uncertain diagnosis and low risk who should to be followed and later reevaluated. These NCCN Guidelines Insights describe recommendations for treatment of newly diagnosed nonmetastatic uveal melanoma in patients who have already undergone a complete workup.

OX40 Agonist BMS-986178 Alone or in Combination With Nivolumab and/or Ipilimumab in Patients With Advanced Solid Tumors

PURPOSE

This phase I/IIa study (NCT02737475) evaluated the safety and activity of BMS-986178, a fully human OX40 agonist IgG1 mAb, ± nivolumab and/or ipilimumab in patients with advanced solid tumors.

PATIENTS AND METHODS

Patients (with non-small cell lung, renal cell, bladder, other advanced cancers) received BMS-986178 (20-320 mg) ± nivolumab (240-480 mg) and/or ipilimumab (1-3 mg/kg). The primary endpoint was safety. Additional endpoints included immunogenicity, pharmacodynamics, pharmacokinetics, and antitumor activity per RECIST version 1.1.

RESULTS

Twenty patients received BMS-986178 monotherapy, and 145 received combination therapy in various regimens (including two patients receiving nivolumab monotherapy). With a follow-up of 1.1 to 103.6 weeks, the most common (≥5%) treatment-related adverse events (TRAEs) included fatigue, pruritus, rash, pyrexia, diarrhea, and infusion-related reactions. Overall, grade 3-4 TRAEs occurred in one of 20 patients (5%) receiving BMS-986178 monotherapy, six of 79 (8%) receiving BMS-986178 plus nivolumab, zero of two receiving nivolumab monotherapy, six of 41 (15%) receiving BMS-986178 plus ipilimumab, and three of 23 (13%) receiving BMS-986178 plus nivolumab plus ipilimumab. No deaths occurred. No dose-limiting toxicities were observed with monotherapy, and the MTD was not reached in either the monotherapy or the combination escalation cohorts. No objective responses were seen with BMS-986178 alone; objective response rates ranged from 0% to 13% across combination therapy cohorts.

CONCLUSIONS

In this study, BMS-986178 ± nivolumab and/or ipilimumab appeared to have a manageable safety profile, but no clear efficacy signal was observed above that expected for nivolumab and/or ipilimumab.

Safety and efficacy of AMG 820, an anti-colony-stimulating factor 1 receptor antibody, in combination with pembrolizumab in adults with advanced solid tumors

Background

To determine the safety and efficacy of the anti-colony-stimulating factor 1 receptor (anti-CSF1R) monoclonal antibody AMG 820 in combination with pembrolizumab in patients with select solid tumors.

Patients and methods

Patients had advanced, refractory mismatch repair-proficient colorectal cancer, pancreatic cancer, or non-small cell lung cancer (NSCLC) with low (<50%) programmed cell death-ligand 1 (PD-L1) expression and were naïve to anti-programmed cell death-1 (PD-1)/PD-L1 or had relapsed/refractory NSCLC after anti-PD-1/PD-L1 treatment with low or high (≥50%) PD-L1 expression; all were anti-CSF1/CSF1R naïve. Patients received 1100 mg or 1400 mg AMG 820 plus 200 mg pembrolizumab intravenously every 3 weeks. The primary endpoints were incidence of dose-limiting toxicities (DLTs) and adverse events (AEs) and objective response rate per immune-related Response Evaluation Criteria in Solid Tumours at the recommended combination dose.

Results

Overall, 116 patients received ≥1 dose of AMG 820 plus pembrolizumab (18 at 1400 mg AMG 820; 98 at 1100 mg AMG 820). Most patients (64%) were male; the median age was 64 (range 30–86) years. Seven patients had DLTs (1 at 1400 mg AMG 820; 6 at 1100 mg AMG 820). Almost all patients (99.1%) had AEs, 87.9% with grade ≥3 AEs. The most common AEs were increased aspartate aminotransferase (59.5%), fatigue (48.3%), periorbital/face edema (48.3%), and rash/maculopapular rash (37.1%). The best response was immune-related partial response in 3 patients (3%; duration of response 9.2, 10.0, 12.5 months) and immune-related stable disease in 39 patients (34%). None of the completed phase II cohorts met the predefined threshold for efficacy. Post-treatment there was accumulation of serum colony-stimulating factor 1 (CSF1) and interleukin-34, reduction in CSF1-dependent CD16-expressing monocytes, and increased PD-L1 expression and CD4 and CD8 cell numbers in tumor biopsies.

Conclusions

The recommended combination dose of 1100 mg AMG 820 plus 200 mg pembrolizumab had an acceptable safety profile. Although pharmacodynamic effects were observed, antitumor activity was insufficient for further evaluation of this combination in selected patient populations.

Trial registration number

NCT02713529

The effect of sonidegib (LDE225) on the pharmacokinetics of bupropion and warfarin in patients with advanced solid tumours

AIMS

We evaluated the potential effect of sonidegib at an oral dose of 800 mg once daily (QD) on the pharmacokinetics (PK) of the probe drugs warfarin (CYP2C9) and bupropion (CYP2B6).

METHODS

This was a multicentre, open-label study to evaluate the effect of sonidegib on the PK of the probe drugs warfarin and bupropion in patients with advanced solid tumours. Cohort 1 patients received a single warfarin 15-mg dose on Day 1 of the run-in period and on Cycle 2 Day 22 (C2D22) of sonidegib administration. Cohort 2 patients received a single bupropion 75-mg dose on Day 1 of run-in period and on C2D22 of sonidegib administration. Sonidegib 800 mg QD oral dosing began on Cycle 1 Day 1 of a 28-day cycle after the run-in period in both cohorts.

RESULTS

The geometric means ratios [90% confidence interval] for (S)-warfarin with and without sonidegib were: area under the concentration-time curve from time 0 to infinity (AUC_inf ) 1.15 [1.07, 1.24] and maximum plasma concentration (C_max ) 0.88 [0.81, 0.97]; and for (R)-warfarin were: AUC_inf 1.10 [0.98, 1.24] and C_max 0.93 [0.87, 1.0]. The geometric means ratios [90% confidence interval] of bupropion with and without sonidegib were: AUC_inf 1.10 [0.99, 1.23] and C_max 1.16 [0.95, 1.42]. Sonidegib 800 mg had a safety profile that was similar to that of lower dose sonidegib 200 mg and was unaffected by single doses of the probe drugs.

CONCLUSIONS

Sonidegib dosed orally at 800 mg QD (higher than the Food and Drug Administration-approved dose) did not impact the PK or pharmacodynamics of warfarin (CYP2C9 probe substrate) or the PK of bupropion (CYP2B6 probe substrate).

Molecular profiling of melanoma brain metastases compared to primary cutaneous melanoma and to extracranial metastases

BACKGROUND

Brain metastases are a significant cause of mortality and morbidity for patients with melanoma. We hypothesize that the development of brain metastases may be explained by molecular heterogeneity between primary cutaneous melanoma (PCM) or extracranial (ECM) and brain (MBM) melanoma metastases.

MATERIALS AND METHODS

We compared next-generation sequencing, tumor mutational burden (TMB), and immunohistochemical staining for PD-L1 expression, among 132 MBM, 745 PCM, and 1190 ECM.

RESULTS

The most common genetic alterations among MBM included: BRAF (52.4%), NRAS (26.6%), CDKN2A (23.3%), NF1 (18.9%), TP53 (18%), ARID2 (13.8%), SETD2 (11.9%), and PBRM1 (7.5%). Four genes were found with higher frequency among MBM compared to PCM or ECM: BRAF (52.4% v 40.4% v 40.9%), SETD2 (11.9% v 1.9% v 3.9%), PBRM1 (7.5% v 1.6% v 2.6%), and DICER1 (4.4% v 0.6% v 0.4%). MBM showed higher TMB (p = .04) and higher PD-L1 expression (p = .002), compared to PCM. PD-L1 expression was slightly higher among MBM compared to ECM (p = .042), but there was no difference between TMB (p = .21).

CONCLUSIONS

Our findings suggest a unique molecular profile for MBM, including higher rates of BRAF mutations, higher TMB and higher PD-L1 expression, and also implicate chromatin remodeling in the pathogenesis of MBM.

Molecular profiling of melanoma brain metastases compared to primary cutaneous melanoma and to extracranial metastases

BACKGROUND

Brain metastases are a significant cause of mortality and morbidity for patients with melanoma. We hypothesize that the development of brain metastases may be explained by molecular heterogeneity between primary cutaneous melanoma (PCM) or extracranial (ECM) and brain (MBM) melanoma metastases.

MATERIALS AND METHODS

We compared next-generation sequencing, tumor mutational burden (TMB), and immunohistochemical staining for PD-L1 expression, among 132 MBM, 745 PCM, and 1190 ECM.

RESULTS

The most common genetic alterations among MBM included: BRAF (52.4%), NRAS (26.6%), CDKN2A (23.3%), NF1 (18.9%), TP53 (18%), ARID2 (13.8%), SETD2 (11.9%), and PBRM1 (7.5%). Four genes were found with higher frequency among MBM compared to PCM or ECM: BRAF (52.4% v 40.4% v 40.9%), SETD2 (11.9% v 1.9% v 3.9%), PBRM1 (7.5% v 1.6% v 2.6%), and DICER1 (4.4% v 0.6% v 0.4%). MBM showed higher TMB (p = .04) and higher PD-L1 expression (p = .002), compared to PCM. PD-L1 expression was slightly higher among MBM compared to ECM (p = .042), but there was no difference between TMB (p = .21).

CONCLUSIONS

Our findings suggest a unique molecular profile for MBM, including higher rates of BRAF mutations, higher TMB and higher PD-L1 expression, and also implicate chromatin remodeling in the pathogenesis of MBM.

Primary tumor characteristics and next-generation sequencing mutations as biomarkers for melanoma immunotherapy response

INTRODUCTION

Considerable advances in melanoma have been realized through immunotherapy. The principal aim was to determine whether primary tumor characteristics or next-generation sequencing (NGS) could serve as markers of immunotherapy response.

METHODS AND RESULTS

The study cohort consisted of 67 patients who received immunotherapy for recurrent or metastatic melanoma and for whom primary tumor biopsies and pathology reports were available. A subset of 59 patient tumors were profiled using an NGS panel of 50 cancer-related genes. Objective response rate to immunotherapy was assessed using RECIST v1.1 criteria. Progression-free survival (PFS) and overall survival (OS) were used as endpoints. Lymphovascular invasion (LVI) strongly correlated with an increased proportion of immunotherapy responders (p = .002). PFS interval (p = .003) and OS (p = .036) were significantly higher in patients with LVI. NRAS mutation was more strongly correlated with an increased proportion of immunotherapy responders (p =.050). PFS was significantly higher in patients with NRAS mutation (p = .042); no difference in OS (p = .111).

DISCUSSION

This analysis demonstrates an association between lymphovascular invasion and immunotherapy response. Additionally, NGS mutation analysis demonstrated a potential association between NRAS mutations and immunotherapy response.