Genetic Alteration of p18INK4C and its Expression in Peripheral Blood Mononuclear Cells Were Not Associated With Progression-free Survival of Multiple Myeloma Patients After Autologous Stem Cell Transplant.

BACKGROUND/AIM: The tumor suppressor CDKN2C (also designed as p18INK4C or p18) is deleted in approximately 7% to 40% of multiple myeloma (MM) patients, indicative of its potential association with myeloma pathogenesis. MATERIALS AND METHODS: A quantitative real-time PCR-based assay was developed to determine p18 deletion in DNA from peripheral blood mononuclear cells (PBMCs) in a cohort of 108 multiple myeloma patients after autologous stem cell transplant (ASCT). Additionally, the p18 mRNA expression level in PBMCs was quantitatively assessed using Taqman® gene expression assays. RESULTS: p18 was homozygously and hemizygously deleted in PBMCs from 3 (2.8%) and 5 (4.6%) patients, respectively. Neither the p18 deletion nor the p18 mRNA levels in PBMCs were associated with progression-free survival (PFS), 90-day response, and the occurrence of severe mucositis in these patients (all p-values >0.20). CONCLUSION: Neither p18 deletion nor p18 mRNA expression in PBMCs can be used as a prognostic biomarker in MM patients.

CDK4/6 and autophagy inhibitors synergize to suppress the growth of human head and neck squamous cell carcinomas.

Head and neck squamous cell carcinoma (HNSCC) accounts for over 10,000 deaths in the United States annually. Approximately 80% of HNSCC are human papillomavirus (HPV)-negative which have an overall poorer prognosis compared to the HPV-positive disease. Treatment options are mainly nontargeted chemotherapy, radiation, and surgery. The cyclin-d-CDK4/6-RB pathway, which regulates cell cycle progression, is often deregulated in HNSCC, making it an attractive therapeutic target. In the current study, we investigated the therapeutic effects of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors in preclinical models of HNSCCs. Our results show that the specific CDK4/6 inhibitor, abemaciclib, inhibited cell growth, and induced apoptosis in HNSCC cell lines. We also demonstrated that both the pro-survival autophagy pathway and the ERK pathway in HNSCC cells were activated with abemaciclib treatment through the generation of reactive oxygen species (ROS). Coinhibition of CDK4/6 and autophagy synergistically decreased cell viability, induced apoptosis, and inhibited tumor growth in both in vitro and in vivo preclinical HNSCC models. These results reveal a potential therapeutic strategy that supports the rationale for further clinical development of a combination of CDK4/6 and autophagy inhibitors in HNSCC.

PARP1 and POLD2 as prognostic biomarkers for multiple myeloma in autologous stem cell transplant.

Multiple Myeloma (MM) is an incurable plasma cell malignancy often treated by autologous stem cell transplant (ASCT). Clinical response to ASCT has been associated with DNA repair efficiency. Here we interrogated the role of the base excision DNA repair (BER) pathway in MM response to ASCT. Across 450 clinical samples and six disease stages, expression levels of genes in the BER pathway were found to be highly upregulated during the development of MM. In a separate cohort of 559 patients with MM treated with ASCT, expression of BER pathway members MPG and PARP3 was positively associated with overall survival (OS) while expression of PARP1, POLD1, and POLD2 was negatively associated with OS. In a validation cohort of 356 patients with MM treated with ASCT, PARP1 and POLD2 findings were replicated. In patients with MM who never received ASCT (n=319), PARP1 and POLD2 were not associated with OS, suggesting that the prognostic effect of these genes may be treatment-dependent. In preclinical models of MM, synergy was observed in anti-tumor activity when poly (ADPribose) polymerase (PARP) inhibitors (olaparib, talazoparib) were used in combination with melphalan. The negative prognosis associated with PARP1 and POLD2 expression along with the apparent melphalan-sensitizing effect of PARP inhibition may suggest this pathway as a potential biomarker in patients with MM in the setting of ASCT. Further understanding of the role of the BER pathway in MM is vital to improve therapeutic strategies related to ASCT.

Evaluating the Impacts of CYP3A4*1B and CYP3A5*3 Variations on Pharmacokinetic Behavior and Clinical Outcomes in Multiple Myeloma Patients With Autologous Stem Cell Transplant.

BACKGROUND/AIM: There exists considerably large interpatient variability in pharmacokinetic exposure of high dose melphalan in multiple myeloma patients with hematopoietic stem-cell transplantation. In this study, we aimed to evaluate the potential impacts of CYP3A4*1B (rs2940574) and CYP3A5*3 (rs776746) variations on pharmacokinetic properties of melphalan and clinical outcomes in multiple myeloma (MM) patients. PATIENTS AND METHODS: Genotypes of CYP3A4*1B (rs2940574) and CYP3A5*3 (rs776746) were determined by validated gene-specific real-time PCR (RT-PCR) assays using DNA samples from 108 MM patients; plasma concentrations of melphalan at different time points were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: CYP3A4*1B/*1B and CYP3A5*3/*3 carriers appeared to have a short median progression-free survival time and a higher maximum melphalan plasma concentration than non-carriers [792 vs. over 950 days, p=0.08; 9.91 (2.67, 34.03) vs. 8.66 (4.46, 17.61) mg/l, p=0.039]. CONCLUSION: CYP3A4*1B/*1B and CYP3A5*3/*3 variations might influence melphalan therapy in MM patients through yet-to-be-identified mechanisms.

CYP3A5 influences oral tacrolimus pharmacokinetics and timing of acute kidney injury following allogeneic hematopoietic stem cell transplantation.

Introduction: Polymorphisms in genes responsible for the metabolism and transport of tacrolimus have been demonstrated to influence clinical outcomes for patients following allogeneic hematologic stem cell transplant (allo-HSCT). However, the clinical impact of germline polymorphisms specifically for oral formulations of tacrolimus is not fully described. Methods: To investigate the clinical impact of genetic polymorphisms in CYP3A4, CYP3A5, and ABCB1 on oral tacrolimus pharmacokinetics and clinical outcomes, we prospectively enrolled 103 adult patients receiving oral tacrolimus for the prevention of graft-versus-host disease (GVHD) following allo-HSCT. Patients were followed in the inpatient and outpatient phase of care for the first 100 days of tacrolimus therapy. Patients were genotyped for CYP3A5 *3 (rs776746), CYP3A4 *1B (rs2740574), ABCB1 exon 12 (rs1128503), ABCB1 exon 21 (rs2032582), ABCB1 exon 26 (rs1045642). Results: Expression of CYP3A5 *1 was highly correlated with tacrolimus pharmacokinetics in the inpatient phase of care (p < 0.001) and throughout the entirety of the study period (p < 0.001). Additionally, Expression of CYP3A5 *1 was associated with decreased risk of developing AKI as an inpatient (p = 0.06). Variants in ABCB1 were not associated with tacrolimus pharmacokinetics in this study. We were unable to discern an independent effect of CYP3A4 *1B or *22 in this population. Conclusion: Expression of CYP3A5 *1 is highly influential on the pharmacokinetics and clinical outcomes for patients receiving oral tacrolimus as GVHD prophylaxis following allo-HSCT.

Dabrafenib Versus Dabrafenib + Trametinib in BRAF-Mutated Radioactive Iodine Refractory Differentiated Thyroid Cancer: Results of a Randomized, Phase 2, Open-Label Multicenter Trial.

Background: Oncogenic BRAF mutations are commonly found in advanced differentiated thyroid cancer (DTC), and reports have shown efficacy of BRAF inhibitors in these tumors. We investigated the difference in response between dabrafenib monotherapy and dabrafenib + trametinib therapy in patients with BRAF-mutated radioactive iodine refractory DTC. Methods: In this open-label randomized phase 2 multicenter trial, patients aged ≥18 years with BRAF-mutated radioactive iodine refractory DTC with progressive disease by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 within 13 months before enrollment were eligible. Patients were randomly assigned to receive dabrafenib alone or dabrafenib + trametinib. The primary endpoint was objective response rate by modified RECIST (minor response of -20% to -29%, partial and complete response) within the first 24 weeks of therapy. Trial Registration Number: NCT01723202. Results: A total of 53 patients were enrolled. The objective response rate (modified RECIST) was 42% (11/26 [95% confidence interval {CI} 23-63%]) with dabrafenib versus 48% (13/27 [CI 29-68%]) with dabrafenib + trametinib (p = 0.67). Objective response rate (RECIST 1.1) was 35% (9/26 [CI 17-56%]) with dabrafenib and 30% (8/27 [CI 14-51%]) with dabrafenib + trametinib. Most common treatment-related adverse events included skin and subcutaneous tissue disorders (17/26, 65%), fever (13/26, 50%), hyperglycemia (12/26, 46%) with dabrafenib alone and fever (16/27, 59%), nausea, chills, fatigue (14/27, 52% each) with dabrafenib + trametinib. There were no treatment-related deaths. Conclusions: Combination dabrafenib + trametinib was not superior in efficacy compared to dabrafenib monotherapy in patients with BRAF-mutated radioiodine refractory progressive DTC.

Factors Predicting Participation in the Prospective Genomic Sequencing Study, Total Cancer Care (TCC), in Kentucky.

PURPOSE: Large-scale genomic sequencing studies are driving oncology drug development. However, rural populations, like those residing in Appalachian Kentucky, are underrepresented in these efforts. In this study, we determined the frequency of participation, reasons for nonparticipation, and factors predicting the decision to participate in the Total Cancer Care (TCC) prospective genomic cohort study. METHODS: A total of 1,188 patients were invited to enroll in the TCC prospective cohort from December 2018 to May 2019. Declining patients were queried for their rationale for nonparticipation and their patient data were obtained from the Kentucky Cancer Registry (KCR). Logistic regression was used to assess the association between characteristics and study participation. The association of study participation with survival was modeled with Cox proportional-hazards regression. RESULTS: 90.9% (1,081) patients consented to participate. In multivariate analysis, factors significantly associated with participation were age, gender, treatment status, and race. Though overall more women participated in the study, men were more likely to participate than women when invited (OR 1.57). Younger, Caucasian individuals who had received chemotherapy, but not surgery, were also more likely to participate. Patients in the Kentucky Appalachian cohort were primarily rural, had less educational attainment, and lower socioeconomic status. Kentucky Appalachian patients were no less likely to enroll in TCC than non-Appalachian patients. Consented individuals had higher overall survival compared to those who declined. CONCLUSION: Though minorities, those with low socioeconomic status, and rural populations are underrepresented in genomic studies, they were no less likely to participate when given the opportunity, and participation was associated with better clinical outcomes.

A Single Nucleotide Polymorphism (SNP) in the SLC22A3 Transporter Gene Is Associated With the Severity of Oral Mucositis in Multiple Myeloma Patients Receiving Autologous Stem Cell Transplant Followed by Melphalan Therapy.

BACKGROUND: It has been reported that expression of OCT3 enhanced the sensitivity to melphalan in cells, indicative of potential roles of OCT3 in melphalan transport. Herein we investigated the association of select single nucleotide polymorphisms in SLC22A3 (gene encoding OCT3) with clinical outcomes in multiple myeloma (MM) patients with hematopoietic autologous stem cell transplants followed by high-dose melphalan therapy. MATERIALS AND METHODS: Melphlan concentrations in blood samples from 108 MM patients were measured using liquid chromatography-tandem mass spectrometry (LC-MS/ΜS); genotypes of rs2048327, rs1810126, and rs3088442 in these patients were determined using quatitive RT-PCR assays. RESULTS: Rs3088442 A variant-carriers had a significantly increased risk of severe oral mucositis in comparison with homozygous rs3088442 G-carriers with adjusted odds ratio of 4.00 (95% CI=1.25-14.7; p=0.027). Rs3088442 A carriers tended to have lower creatinine clearance (p=0.10) and higher maximum plasma concentration of melphalan (p=0.07). CONCLUSION: OCT3 might be involved in melphalan transport in MM patients.

Brigatinib causes tumor shrinkage in both NF2-deficient meningioma and schwannoma through inhibition of multiple tyrosine kinases but not ALK.

Neurofibromatosis Type 2 (NF2) is an autosomal dominant genetic syndrome caused by mutations in the NF2 tumor suppressor gene resulting in multiple schwannomas and meningiomas. There are no FDA approved therapies for these tumors and their relentless progression results in high rates of morbidity and mortality. Through a combination of high throughput screens, preclinical in vivo modeling, and evaluation of the kinome en masse, we identified actionable drug targets and efficacious experimental therapeutics for the treatment of NF2 related schwannomas and meningiomas. These efforts identified brigatinib (ALUNBRIG®), an FDA-approved inhibitor of multiple tyrosine kinases including ALK, to be a potent inhibitor of tumor growth in established NF2 deficient xenograft meningiomas and a genetically engineered murine model of spontaneous NF2 schwannomas. Surprisingly, neither meningioma nor schwannoma cells express ALK. Instead, we demonstrate that brigatinib inhibited multiple tyrosine kinases, including EphA2, Fer and focal adhesion kinase 1 (FAK1). These data demonstrate the power of the de novo unbiased approach for drug discovery and represents a major step forward in the advancement of therapeutics for the treatment of NF2 related malignancies.

Phase I evaluation of lenvatinib and weekly paclitaxel in patients with recurrent endometrial, ovarian, fallopian tube, or primary peritoneal Cancer.

OBJECTIVES: To estimate the maximally tolerated dose (MTD) and describe toxicities associated with lenvatinib and weekly paclitaxel in patients with recurrent endometrial and platinum resistant epithelial ovarian cancer. METHODS: Using a 3 + 3 design patients were given weekly paclitaxel 80 mg/m2 IV day 1, 8, 15 and oral levantinib daily on a 28-day cycle. Lenvatinib dose levels were 8 mg, 12 mg, 16 mg, 20 mg. Toxicities were recorded using CTCAE v4.03 and response was determined with imaging after cycle 2, then every 3rd cycle, using RECIST 1.1 criteria. RESULTS: 26 patients were enrolled; 19 with ovarian cancer (14 high grade serous, 1 low grade serous, 2 clear cell, 1 endometrioid, and 1 carcinosarcoma), and 7 with endometrial cancer (3 serous, and 4 endometrioid). The MTD was established at lenvatinib 16 mg and weekly paclitaxel 80 mg/m2. Toxicities (all grades) occurring in ≥25% of patients included anemia, neutropenia, lymphopenia, mucositis, nausea, diarrhea, anorexia, hypertension, fatigue, proteinuria, epistaxis, hoarseness. Twenty-three patients were evaluable for response and PFS; 15 (65%) had a partial response, 7 (30%) stable, 1 (4%) progressive disease with an objective response rate of 65%; 71% in ovarian and 50% in endometrial cancer. Median progression free survival (PFS) is 12.4 months; 14.0 months in endometrial cancer, 7.2 months in ovarian cancer; 54% had a PFS > 6 months. The median duration of response for PR patients (n = 15) was 10.9 months. CONCLUSIONS: The regimen was tolerable with manageable side effects. Encouraging activity was observed in endometrial and ovarian cancer, and warrants further development.