Background
Resistance to BRAF and MEK inhibitors in BRAF V600‐mutant melanoma is common. Multiple resistance mechanisms involve heat‐shock protein 90 (HSP90) clients, and a phase 1 study of ...vemurafenib with the HSP90 inhibitor XL888 in patients with advanced melanoma showed activity equivalent to that of BRAF and MEK inhibitors.
Methods
Vemurafenib (960 mg orally twice daily) and cobimetinib (60 mg orally once daily for 21 of 28 days) with escalating dose cohorts of XL888 (30, 45, 60, or 90 mg orally twice weekly) was investigated in a phase 1 trial of advanced melanoma, with a modified Ji dose‐escalation design.
Results
Twenty‐five patients were enrolled. After two dose‐limiting toxicities (DLTs) (rash and acute kidney injury) in the first cohort, lower doses of vemurafenib (720 mg) and cobimetinib (40 mg) were investigated with the same XL888 doses. Three DLTs (rash) were observed in 12 patients in the XL888 60‐mg cohort, and this was determined as the maximum tolerated dose. Objective responses were observed in 19 patients (76%), and the median progression‐free survival was 7.6 months, with a 5‐year progression‐free survival rate of 20%. The median overall survival was 41.7 months, with a 5‐year overall survival rate of 37%. Single‐cell RNA sequencing was performed on baseline and on‐treatment biopsies; treatment was associated with increased immune cell influx (CD4‐positive and CD8‐positive T cells) and decreased melanoma cells.
Conclusions
Combined vemurafenib and cobimetinib plus XL888 had significant toxicity, requiring frequent dose reductions, which may have contributed to the relatively low progression‐free survival despite a high tumor response rate. Given overlapping toxicities, caution must be used when combining HSP90 inhibitors with BRAF and MEK inhibitors.
Resistance to BRAF and MEK inhibitors in BRAF V600‐mutant melanoma is common, and many of the resistance mechanisms involve heat‐shock protein 90 client proteins. The combination of vemurafenib plus cobimetinib plus XL888 was evaluated in a phase 1 trial of patients with advanced melanoma and had significant toxicity, requiring frequent dose reductions, which may have contributed to the relatively low progression‐free survival despite a high tumor response rate.
Checkpoint molecules are cell surface receptors on immune cells that mitigate excessive immune responses, but they have increased expression levels in cancer to facilitate immune escape. Checkpoint ...blockade therapies (e.g., anti-PD-1, anti-CTLA-4, and anti-LAG-3 therapy, among others) have been developed for multiple cancers. Colitis associated with checkpoint blockade therapy has pathophysiological similarities to inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis. Current therapeutic guidelines for checkpoint blockade-induced colitis include corticosteroids and, if the patient is refractory to steroids, immunomodulating antibodies, such as anti-TNF and anti-integrin agents. Interestingly, immunomodulatory molecules, such as TNFα, are upregulated in both IBD and checkpoint-mediated colitis. The inflammatory colitis toxicity symptoms from checkpoint blockade are similar to clinical symptoms experienced by patients with IBD. The pathophysiologic, dietary, and genetic factors associated with IBD will be reviewed. We will then explain how the principles developed for the treatment of IBD can be applied to patients experiencing inflammatory bowel toxicity secondary to checkpoint blockade.
Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) for metastatic melanoma can be highly effective, but attrition due to progression before TIL administration (32% in prior ...institutional experience) remains a limitation. We hypothesized that combining ACT with cytotoxic T lymphocyte-associated antigen 4 blockade would decrease attrition and allow more patients to receive TIL.
Thirteen patients with metastatic melanoma were enrolled. Patients received four doses of ipilimumab (3 mg/kg) beginning 2 weeks prior to tumor resection for TIL generation, then 1 week after resection, and 2 and 5 weeks after preconditioning chemotherapy and TIL infusion followed by interleukin-2. The primary endpoint was safety and feasibility. Secondary endpoints included of clinical response at 12 weeks and at 1 year after TIL transfer, progression free survival (PFS), and overall survival (OS).
All patients received at least two doses of ipilimumab, and 12 of the 13 (92%) received TIL. A median of 6.5 × 10
(2.3 × 10
to 1.0 × 10
) TIL were infused. At 12 weeks following infusion, there were five patients who experienced objective response (38.5%), four of whom continued in objective response at 1 year and one of which became a complete response at 52 months. Median progression-free survival was 7.3 months (95% CI 6.1-29.9 months). Grade ≥ 3 immune-related adverse events included hypothyroidism (3), hepatitis (2), uveitis (1), and colitis (1).
Ipilimumab plus ACT for metastatic melanoma is feasible, well tolerated, and associated with a low rate of attrition due to progression during cell expansion. This combination approach serves as a model for future efforts to improve the efficacy of ACT.
The clinical success of immune-checkpoint inhibitors (ICI) in both resected and metastatic melanoma has confirmed the validity of therapeutic strategies that boost the immune system to counteract ...cancer. However, half of patients with metastatic disease treated with even the most aggressive regimen do not derive durable clinical benefit. Thus, there is a critical need for predictive biomarkers that can identify individuals who are unlikely to benefit with high accuracy so that these patients may be spared the toxicity of treatment without the likely benefit of response. Ideally, such an assay would have a fast turnaround time and minimal invasiveness. Here, we utilize a novel platform that combines mass spectrometry with an artificial intelligence-based data processing engine to interrogate the blood glycoproteome in melanoma patients before receiving ICI therapy. We identify 143 biomarkers that demonstrate a difference in expression between the patients who died within six months of starting ICI treatment and those who remained progression-free for three years. We then develop a glycoproteomic classifier that predicts benefit of immunotherapy (HR=2.7; p=0.026) and achieves a significant separation of patients in an independent cohort (HR=5.6; p=0.027). To understand how circulating glycoproteins may affect efficacy of treatment, we analyze the differences in glycosylation structure and discover a fucosylation signature in patients with shorter overall survival (OS). We then develop a fucosylation-based model that effectively stratifies patients (HR=3.5; p=0.0066). Together, our data demonstrate the utility of plasma glycoproteomics for biomarker discovery and prediction of ICI benefit in patients with metastatic melanoma and suggest that protein fucosylation may be a determinant of anti-tumor immunity.
CD200 is a cell surface glycoprotein that functions through engaging CD200R on cells of the myeloid lineage and inhibits their functions. Expression of CD200 was implicated in a variety of human ...cancer cells, including melanoma cells; however, its roles in tumor growth and immunity are not clearly understood. In this study, we used CD200R-deficient mice and the B16 tumor model to evaluate this issue. We found that CD200R-deficient mice exhibited accelerated growth of CD200(+), but not CD200(-), B16 tumors. Strikingly, CD200R-deficient mice receiving CD200(+) B16 cells i.v. exhibited massive tumor growth in multiple organs, including liver, lung, kidney, and peritoneal cavity, whereas the growth of the same tumors in wild-type mice was limited. CD200(+) tumors grown in CD200R-deficient mice contained higher numbers of CD11b(+)Ly6C(+) myeloid cells, exhibited increased expression of VEGF and HIF1α genes with increased angiogenesis, and showed significantly reduced infiltration of CD4(+) and CD8(+) T cells, presumably as the result of reduced expression of T cell chemokines, such as CXCL9 and CXCL16. The liver from CD200R-deficient mice, under metastatic growth of CD200(+) tumors, contained significantly increased numbers of CD11b(+)Gr1(-) myeloid cells and Foxp3(+) regulatory T cells and reduced numbers of NK cells. Liver T cells also had a reduced capacity to produce IFN-γ or TNF-α. Taken together, we revealed a critical role for CD200R signaling in limiting the growth and metastasis of CD200(+) tumors. Thus, targeting CD200R signaling may potentially interfere with the metastatic growth of CD200(+) tumors, like melanoma.
Anti-PD1 therapy demonstrated impressive, prolonged responses in advanced cutaneous squamous cell carcinoma (CSCC). Therapy for ICI-refractory/ineligible disease remains unclear. We performed a ...retrospective analysis in locally-advanced/metastatic CSCC using cetuximab across three cohorts: immediately after ICI failure (A), not immediately following ICI failure (B), or without prior ICI (C). The primary endpoint was the overall response rate (ORR). Secondary endpoints included disease-control rate (DCR), progression-free survival (PFS), overall survival (OS), time-to-response (TTR) and toxicity. Twenty-three patients were included. In cohort A (n = 11), the ORR was 64% and DCR was 91%, with six ongoing responses at data cutoff. In cohort B (n = 2), all patients had progression as the best response. At a median follow-up of 21 months for A and B, TTR and PFS were 2.0 and 17.3 months, respectively. The median OS was not reached. In cohort C (n = 10), the ORR and DCR were 80%, including five ongoing responses at the data cutoff. At a median follow-up of 22.4 months, the TTR, PFS and OS were 2.5, 7.3 and 23.1 months, respectively. Cetuximab was well tolerated in all cohorts. In summary, cetuximab is effective in patients with failure/contraindications to ICI. Cetuximab immediately after ICI failure yielded particularly fast, durable responses. If confirmed, this could be the preferred therapy following ICI failure.
The B-Raf proto-oncogene serine/threonine kinase (BRAF) gene is the most frequently mutated gene in malignant melanoma (MM) and papillary thyroid cancer (PTC) and is causally involved in malignant ...cell transformation. Mutated BRAF is associated with an aggressive disease phenotype, thus making it a top candidate for targeted treatment strategies in MM and PTC. We show that BRAF mutations in both MM and PTC drive increased expression of oncomiR-3151, which is coactivated by the SP1/NF-κB complex. Knockdown of microRNA-3151 (miR-3151) with short hairpin RNAs reduces cell proliferation and increases apoptosis of MM and PTC cells. Using a targeted RNA sequencing approach, we mechanistically determined that miR-3151 directly targets TP53 and other members of the TP53 pathway. Reducing miR-3151's abundance increases TP53's mRNA and protein expression and favors its nuclear localization. Consequently, knockdown of miR-3151 also leads to caspase-3-dependent apoptosis. Simultaneous inhibition of aberrantly activated BRAF and knockdown of miR-3151 potentiates the effects of sole BRAF inhibition with the BRAF inhibitor vemurafenib and may provide a novel targeted therapeutic approach in BRAF-mutated MM and PTC patients. In conclusion, we identify miR-3151 as a previously unidentified player in MM and PTC pathogenesis, which is driven by BRAF-dependent and BRAF-independent mechanisms. Characterization of TP53 as a downstream effector of miR-3151 provides evidence for a causal link between BRAF mutations and TP53 inactivation.
Although Ipilimumab (anti-CTLA-4) is FDA-approved for stage III/IV melanoma adjuvant treatment, it is not used clinically in first-line therapy, given the superior relapse-free survival ...(RFS)/toxicity benefits of anti-PD-1 therapy. However, it is important to understand anti-CTLA-4's mechanistic contribution to combination anti-PD-1/CTLA-4 therapy and investigate anti-CTLA-4 therapy for BRAF-wild type melanoma cases reresected after previous adjuvant anti-PD-1 therapy. Our group published that nitric oxide (NO) increased within the immune effector cells among patients with longer RFS after adjuvant ipilimumab, whereas NO increased within the immune suppressor cells among patients with shorter RFS. Herein, we measured the post-translational modifications of STAT1 (nitration-nSTAT1 and phosphorylation-pSTAT1) that are important for regulating its activity via flow cytometry and mass spectrometry approaches. PBMCs were analyzed from 35 patients undergoing adjuvant ipilimumab treatment. Shorter RFS was associated with higher pSTAT1 levels before (
= 0.007) and after (
= 0.036) ipilimumab. Ipilimumab-treated patients with high nSTAT1 levels before and after therapy in PBMCs experienced decreased RFS, but the change in nSTAT1 levels before and after ipilimumab therapy was associated with longer RFS (
= 0.01). The measurement of post-translational modifications in STAT1 may distinguish patients with prolonged RFS from ipilimumab and provide mechanistic insight into responses to ipilimumab combination regimens.
Background: Hepatocellular carcinoma (HCC) is on the rise worldwide. HCC responds poorly to chemotherapy. Lapatinib is an inhibitor of
epidermal growth factor receptor and HER2/NEU both implicated in ...hepatocarcinogenesis. This trial was designed to determine
the safety and efficacy of lapatinib in HCC.
Methods: A Fleming phase II design with a single stage of 25 patients with a 90% power to exclude a true response rate of <10% and
detect a true response rate of â¥30% was used. The dose of lapatinib was 1,500 mg/day administered orally in 28-day cycles.
Tumor and blood specimens were analyzed for expression of HER2/NEU/CEP17 and status of downstream signal pathway proteins.
Results: Twenty-six patients with HCC enrolled on this study. Nineteen percent had one prior therapy. Most common toxicities were
diarrhea (73%), nausea (54%), and rash (42%). No objective responses were observed. Ten (40%) patients had stable disease
as their best response including six (23%) with stable disease lasting >120 days. Median progression-free survival was 1.9
months and median overall survival was 12.6 months. Patients who developed a rash had a borderline statistically significant
longer survival. Tissue and blood specimens were available on >90% of patients. No somatic mutations in EGFR (exons 18-21) were found. In contrast to our previous findings, we did not find evidence of HER2/NEU somatic mutations. PTEN, P-AKT, and P70S6K expression did not correlate with survival.
Conclusions: Lapatinib is well-tolerated but seems to benefit only a subgroup of patients for whom predictive molecular or clinical characteristics
are not yet fully defined. (Clin Cancer Res 2009;15(18):5895â901)
Phenotyping of immune cell subsets in clinical trials is limited to well-defined phenotypes, due to technological limitations of reporting flow cytometry multi-dimensional phenotyping data. We ...developed a multi-dimensional phenotyping analysis tool and applied it to detect nitric oxide (NO) levels in peripheral blood immune cells before and after adjuvant ipilimumab co-administration with a peptide vaccine in melanoma patients. We analyzed inhibitory and stimulatory markers for immune cell phenotypes that were felt to be important in the NO analysis. The pipeline allows visualization of immune cell phenotypes without knowledge of clustering techniques and to categorize cells by association with relapse-free survival (RFS). Using this analysis, we uncovered the potential for a dichotomous role of NO as a pro- and anti-melanoma factor. NO was found in subsets of immune-suppressor cells associated with shorter-term (≤ 1 year) RFS, whereas NO was also present in immune-stimulatory effector cells obtained from patients with significant longer-term (> 1 year) RFS. These studies provide insights into the cell-specific immunomodulatory role of NO. The methods presented herein can be applied to monitor the pro- and anti-tumor effects of a variety of immune-based therapeutics in cancer patients.
NCT00084656 (https://clinicaltrials.gov/ct2/show/NCT00084656).
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