SUMMARY Telomerase is present in human cancer cells but absent in most somatic tissues. The mRNA of human telomerase (hTERT) is alternatively spliced into mostly non-functional products. We sought to understand splicing so we could decrease functional splice isoforms to reduce telomerase activity to complement direct enzyme inhibition. Unexpectedly, minigenes containing hTERT exons 5–10 flanked by 150–300bp intronic sequences did not produce alternative splicing. A 1.1kb region of 38bp repeats ~2kb from the exon 6/intron junction restored exclusion of exons 7/8. An element within intron 8, also >1kb from intron/exon junctions, modulated this effect. Transducing an oligonucleotide complementary to this second element increased non-functional hTERT mRNA from endogenous telomerase. These results demonstrate the potential of manipulating hTERT splicing for both chemotherapy and regenerative medicine, and provide the first specific sequences deep within introns that regulate alternative splicing in mammalian cells by mechanisms other than introducing cryptic splice sites.

IMPORTANCETotal neoadjuvant therapy (TNT) is often used to downstage locally advanced rectal cancer (LARC) and decrease locoregional relapse; however, more than one-third of patients develop recurrent metastatic disease. As such, novel combinations are needed.OBJECTIVE To assess whether the addition of pembrolizumab during and after neoadjuvant chemoradiotherapy can lead to an improvement in the neoadjuvant rectal (NAR) score compared with treatment with FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) and chemoradiotherapy alone. DESIGN, SETTING, AND PARTICIPANTSIn this open-label, phase 2, randomized clinical trial (NRG-GI002), patients in academic and private practice settings were enrolled. Patients with stage II/III LARC with distal location (cT3-4 Յ 5 cm from anal verge, any N), with bulky disease (any cT4 or tumor within 3 mm of mesorectal fascia), at high risk for metastatic disease (cN2), and/or who were not candidates for sphincter-sparing surgery (SSS) were stratified based on clinical tumor and nodal stages. Trial accrual opened on August 1, 2018, and ended on May 31, 2019. This intent-to-treat analysis is based on data as of August 2020.INTERVENTIONS Patients were randomized (1:1) to neoadjuvant FOLFOX for 4 months and then underwent chemoradiotherapy (capecitabine with 50.4 Gy) with or without intravenous pembrolizumab administered at a dosage of 200 mg every 3 weeks for up to 6 doses before surgery. MAIN OUTCOMES AND MEASURESThe primary end point was the NAR score. Secondary end points included pathologic complete response (pCR) rate, SSS, disease-free survival, and overall survival. This report focuses on end points available after definitive surgery (NAR score, pCR, SSS, clinical complete response rate, margin involvement, and safety).RESULTS A total of 185 patients (126 [68.1%] male; mean [SD] age, 55.7 [11.1] years) were randomized to the control arm (CA) (n = 95) or the pembrolizumab arm (PA) (n = 90). Of these patients, 137 were evaluable for NAR score (68 CA patients and 69 PA patients). The mean (SD) NAR score was 11.53 (12.43) for the PA patients (95% CI, 8.54-14.51) vs 14.08 (13.82) for the CA patients (95% CI, 10.74-17.43) (P = .26). The pCR rate was 31.9% in the PA vs 29.4% in the CA (P = .75). The clinical complete response rate was 13.9% in the PA vs 13.6% in the CA (P = .95). The percentage of patients who underwent SSS was 59.4% in the PA vs 71.0% in the CA (P = .15). Grade 3 to 4 adverse events were slightly increased in the PA (48.2%) vs the CA (37.3%) during chemoradiotherapy. Two deaths occurred during FOLFOX: sepsis (CA) and pneumonia (PA). No differences in radiotherapy fractions, FOLFOX, or capecitabine doses were found.CONCLUSIONS AND RELEVANCE Pembrolizumab added to chemoradiotherapy as part of total neoadjuvant therapy was suggested to be safe; however, the NAR score difference does not support further study.

Dabrafenib was developed as a highly specific reversible inhibitor of V600-mutant BRAF kinase, an oncogenic mutation driving proliferation in many different types of aggressive tumors. Metastatic melanoma has a high prevalence of V600-mutant BRAF, and clinical trials showed that dabrafenib improved response rates and median progression-free survival in patients with V600E BRAF mutations, including those with brain metastasis. Preliminary results suggest that dabrafenib may also have some role in non-melanoma V600-mutant solid tumors; however, more studies are needed. With a well-tolerated toxicity profile and few drug interactions, dabrafenib is effective as a monotherapy; however, resistance eventually develops in most patients after persistent exposure to the drug. Current research focuses on combination strategies with dabrafenib to not only improve response rates but also overcome resistance.

Objective:To describe risk factors for mortality in HIV-associated Kaposi's sarcoma in an urban population in Dallas, Texas.Design:Retrospective electronic medical record review of patients with HIV-associated Kaposi's sarcoma.Methods:Electronic medical records were reviewed from 1 January 2009 to 31 December 2018 for patients with a diagnosis of HIV and Kaposi's sarcoma by ICD-9 or ICD-10 codes. Demographics, HIV history, Kaposi's sarcoma history, treatment, and mortality data were collected. Mortality data was supplemented by an inquiry from the National Death Index (NDI). Survival analyses were performed using Cox proportional hazards analysis to determine independent predictors of mortality.Results:Black patients had higher mortality than white or Hispanic patients (hazard ratio 2.07, 95% confidence interval 1.12–3.82), even after adjusting for covariates. This mortality difference correlates with higher rates of advanced Kaposi's sarcoma disease and KS-IRIS in black patients compared with other groups and is not explained by differences in CD4+ cell count, HIV viral load, engagement in care, or ART adherence at the time of cancer diagnosis.Conclusion:Despite nationwide trends showing decreased incidence and decreased mortality in Kaposi's sarcoma in the ART era, a high number of Kaposi's sarcoma cases and disparities in Kaposi's sarcoma outcomes persist in certain populations in the United States.