Gastrointestinal Toxicity Research Articles

Non-Clinical Toxicology Evaluation of the Novel Non-ATP Competitive Oral PI3 Kinase Delta Inhibitor Roginolisib.

Roginolisib (IOA-244) is a novel, non-ATP competitive phosphoinositide-3-kinase (PI3K) delta inhibitor that regulates Akt/mTOR signaling. Roginolisib was administered once daily to rats and dogs in dose-range finding (DRF) and 4-week GLP toxicology studies. Free plasma levels of roginolisib exceeded the cellular target engagement IC90 for PI3Kδ for ≥12hours at doses of 5mg/kg, the IC90 for PI3Kβ for ≥2hours at doses ≥15mg/kg, and the IC50 for PI3Kα for ≥2hours at dose levels ≥45mg/kg. Toxicity in rats occurred at doses ≥100mg/kg. In dogs, we observed dose-dependent skin and gastrointestinal toxicity and doses ≥30mg/kg had a greater incidence of mortality. Lymphoid tissue toxicity occurred in both species. Toxicities in dogs observed at the ≥15mg/kg dose, affecting the digestive mucosa, liver, and skin, cleared after treatment cessation. Doses ≤75mg/kg were tolerated in rats and the no-observed-adverse-effect-level (NOAEL) in rats was 15mg/kg. Due to mainly epithelial lesions of the skin at 5mg/kg and necrotizing damage of the intestinal epithelia at ≥15mg/kg, no NOAEL was determined in dogs. However, the adverse effects observed in dogs at 5mg/kg were considered monitorable and reversible in patients with advanced malignancies. Furthermore, the PK profile subsequently proved to be a decisive factor for achieving selective PI3Kδ inhibition without the toxicities observed in dogs. As the result of the unique PK profile of roginolisib, patients were able to take daily roginolisib without dose modification and showed pharmacodynamic PI3Kδ inhibition over several months without gastrointestinal or dermatologic toxicities.

Long-term outcomes of whole-pelvis radiation therapy using volumetric modulated arc therapy for high-risk prostate cancer†.

This study investigated the outcomes of whole-pelvis radiation therapy (WPRT) using volumetric modulated arc therapy (VMAT) for high-risk prostate cancer. We retrospectively analysed 112 patients with high-risk prostate cancer who started WPRT at our hospital between August 2011 and August 2015. The prescribed dose was 78Gy in 39 fractions to the prostate and 46.8Gy in 26 fractions to the pelvic lymph node (LN) area. All patients received long-term androgen deprivation therapy. We evaluated late gastrointestinal (GI) and genitourinary (GU) toxicities using the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up period for censored cases was 97 (interquartile range [IQR] = 85-108) months. The median age was 72 (IQR = 67-75) years. The high-risk and very-high-risk groups included 41 (36.6%) and 71 patients (63.4%), respectively. The median risk of LN invasion calculated by the Roach formula was 36.9 (IQR = 26.6-56.3) %. The 8-year overall survival, biochemical failure-free survival, disease-free survival and distant metastasis-free survival rates were 88.4, 91.9, 83.8 and 98.0%, respectively. Only one patient experienced common iliac LN recurrence, which was outside the pelvic irradiation area. All patients with recurrent disease were categorized into the very-high-risk group. The 8-year cumulative rates of ≥Grade 2 late GI and GU toxicities were 12.8 and 11.8%, respectively. No patients experienced Grade 4 or higher toxicities. WPRT using VMAT for high-risk prostate cancer was well tolerated and effective.

Perillaldehyde Mitigates Ionizing Radiation-Induced Intestinal Injury by Inhibiting Ferroptosis via the Nrf2 Signaling Pathway.

Gastrointestinal toxicity is one of the major side effects of abdominopelvic tumor radiotherapy. Studies have shown that perillaldehyde (PAH) has antioxidant, antiinflammatory, antimicrobial activity, and antitumor effects. This study aims to determine whether PAH has radioprotective effects on radiation-induced intestinal injury and explore the underlying mechanisms. C57BL/6J mice are gavaged with PAH for 7 days, then exposed to a single dose of 13 Gy X-ray total abdominal irradiation (TAI). PAH treatment prolongs the survival time, promotes the survival of crypt cells, attenuates radiation-induced DNA damage, and mitigates intestinal barrier damage in the irradiated mice. PAH also shows radioprotective effects in intestinal crypt organoids and human intestinal epithelial cells (HIEC-6). PAH-mediated radioprotection is associated with the upregulation of nuclear factor erythroid-2 related factor 2 (Nrf2), activation of the antioxidant pathway, and inhibition of ferroptosis. Notably, treatment with the Nrf2 inhibitor ML385 abolishes the protective effects of PAH, indicating that Nrf2 activation is essential for PAH activity. PAH inhibits ionizing radiation (IR)-induced ferroptosis and attenuates intestinal injury after irradiation by activating Nrf2 signaling. Therefore, PAH is a promising therapeutic strategy for IR-induced intestinal injury.

Osimertinib early dose reduction as a risk to brain metastasis control in EGFR-mutant non-small cell lung cancer.

The epidermal growth factor receptor (EGFR) mutation is a risk factor associated with brain metastases (BMs) in patients with non-small cell lung cancer (NSCLC). This study aimed to evaluate the impact of osimertinib early dose reduction on BM worsening. We retrospectively analyzed EGFR-mutant NSCLC patients treated with osimertinib as first-line treatment between August 2018 and October 2021. To evaluate the impact of osimertinib early dose reduction, we performed a landmark analysis of patients who achieved disease control at 4 months. Patients were divided into two groups according to whether the osimertinib dose was reduced or not, within 4 months after the start of treatment. We evaluated the time to BMs onset or progression, progression-free survival, and overall survival. In total, 62 NSCLC patients with EGFR mutations were analyzed. Thirteen patients experienced early dose reduction of osimertinib treatment. Seven patients received osimertinib 40 mg daily, and six received 80 mg every other day. The most common reason for dose reduction was gastrointestinal toxicity (n = 4), followed by skin rashes (n = 3). The time to BMs onset or progression was significantly shorter in patients who experienced early dose reduction than in those who continued regular treatment (Hazard ratio 4.47, 95% confidence interval, 1.52-13.11). The 1-year cumulative incidence of BM onset or progression was 23.1% in the reduced-dose group and 5.0% in the standard dose group. The risk of worsening BMs with early dose reduction of osimertinib treatment was higher in patients who had BMs before treatment and in younger patients. Early dose reduction of osimertinib was a risk factor for the worsening of BMs. A higher risk was associated with younger patients and those presenting BMs before treatment.

Late Effects of Pelvic Radiation Therapy in the Female Patient: A Comprehensive Review

Abstract Radiation therapy (RT) is a valuable treatment option for gynecologic cancers, but it is also associated with acute and chronic toxicity that can greatly impact a patient’s quality of life. The severity and incidence of these side effects depend on various factors, such as the site, volume of tissue within the radiation field, treatment schedule, total dose, dose per fraction, and type of RT. Gastrointestinal (GI) toxicity is the most common side effect of pelvic radiation and late toxicity can include strictures, lower GI bleeding, and fibrosis. Genitourinary complications may include hemorrhagic cystitis, urethral and ureteral strictures, urge incontinence, fistulas, vaginal stenosis, premature ovarian insufficiency, and secondary malignancies. Outside the visceral tissues, insufficiency fractures, bone marrow suppression, and skin changes are also sporadically seen. Overall, advances in RT techniques and the understanding of patient-related factors influencing toxicity have led to improvements in treatment outcomes and reduced rates of late side effects. Understanding the late side effects associated with pelvic RT is critical for developing strategies to both minimize the risk of long-term complications and improve the quality of life of patients. This review aims to summarize the late side effects associated with RT in the pelvis and the respective interventions that may help treat toxicities.

PP05 Presentation Time: 8:56 AM: Gastrointestinal and Genitourinary Toxicity Following High Dose Rate Vaginal Cuff Brachytherapy with 21 Gray in 3 Fractions for Endometrial Cancer

PP05 Presentation Time: 8:56 AM: Gastrointestinal and Genitourinary Toxicity Following High Dose Rate Vaginal Cuff Brachytherapy with 21 Gray in 3 Fractions for Endometrial Cancer

Effect of hydrocortisone ultrasonic phonophoresis in the treatment of knee osteoarthritis

Background: Knee Osteoarthritis (KOA) is a frequent type of degenerative joint disease, which results in a gradual loss of function, discomfort, and stiffness. KOA can be effectively treated with oral drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs may raise the dangers of renal, gastrointestinal, and other systemic toxicities. Compared with oral NSAIDs, topical gels are an alternative therapeutic option with fewer side effects, with less therapeutic efficacy. Studies on ultrasound (US) as a therapeutic method go back a long time in KOA. US not only relieves symptoms but may also provide potential cartilage repair effects, and regulates inflammatory responses. Widely used as a physical enhancer of drug absorption is ultrasonic phonophoresis. By making the skin more permeable to topical pharmaceuticals, it improves the absorption of drugs used topically. (2) Material and method: A monocentric study was conducted in the Center of Physical Therapy and Rehabilitation - "Dunărea de Jos" University of Galați on 20 patients, diagnosed with bilateral and unilateral moderate KOA. The experimental group (EG) included 10 patients who received 10 sessions of PT (Physical Therapy), transcutaneous electrical nerve stimulation (TENS), and Ultrasound (US) phonophoresis therapy with hydrocortisone 10mg/g. The control group (CG) included 10 patients who received 10 sessions of TENS and US with neutral gel. (3) Results: All patients were clinically assessed with The "timed up and go test" (TUG), pain scale (VAS), and WOMAC. The t-test was used to calculate the statistical differences between the means of the EG and CG. (4) Conclusion: Hydrocortisone therapy combined with PT had a beneficial effect on pain and functional mobility in patients with KOA form EG. Furthermore, significantly greater improvement was observed among the intervention group with hydrocortisone.

Late Effects of Pelvic Radiation Therapy in the Female Patient: A Comprehensive Review

Abstract Radiation therapy (RT) is a valuable treatment option for gynecologic cancers, but it is also associated with acute and chronic toxicity that can greatly impact a patient’s quality of life. The severity and incidence of these side effects depend on various factors, such as the site, volume of tissue within the radiation field, treatment schedule, total dose, dose per fraction, and type of RT. Gastrointestinal (GI) toxicity is the most common side effect of pelvic radiation and late toxicity can include strictures, lower GI bleeding, and fibrosis. Genitourinary complications may include hemorrhagic cystitis, urethral and ureteral strictures, urge incontinence, fistulas, vaginal stenosis, premature ovarian insufficiency, and secondary malignancies. Outside the visceral tissues, insufficiency fractures, bone marrow suppression, and skin changes are also sporadically seen. Overall, advances in RT techniques and the understanding of patient-related factors influencing toxicity have led to improvements in treatment outcomes and reduced rates of late side effects. Understanding the late side effects associated with pelvic RT is critical for developing strategies to both minimize the risk of long-term complications and improve the quality of life of patients. This review aims to summarize the late side effects associated with RT in the pelvis and the respective interventions that may help treat toxicities.

PO70: Combining External Beam Radiation, Brachytherapy, and Rectal Hydrogel Spacer for Prostate Cancer: A Study of Gastrointestinal Toxicity and Implant Quality

PO70: Combining External Beam Radiation, Brachytherapy, and Rectal Hydrogel Spacer for Prostate Cancer: A Study of Gastrointestinal Toxicity and Implant Quality

Molecular Docking Analysis of Novel Thiourea Derivatives of Naproxen with Potential Antitumor Activity

Abstract Naproxen, as a propionic acid derivative, causes serious gastrointestinal side effects due to the presence of free carboxylic group. In that sense, masking of carboxylic group with other pharmacophores may be a promising strategy to decrease gastrointestinal toxicity. Thiourea derivatives have been intensively investigated as potential antitumor drugs, whereby their activity is based on potential inhibition of protein kinases, topoisomerases, carbonic anhydrase and sirtuins. In addition, it was shown that inhibition of certain protein kinases might reverse resistance to chemotherapeutic drugs by enhancing the cell death in the presence of low concentrations of drug. Twenty new thiourea derivatives of naproxen were designed and their binding to four selected protein kinases involved in tumor multidrug resistance (AKT2, mTOR, EGFR and VEGFR1) was estimated using two molecular docking programs (AutoDock Vina and OEDocking). According to OEDocking, the highest potential to inhibit AKT2 and mTor has derivative 1, while derivative 20 demonstrates the highest potential towards EGFR and VEGFR1. According to AutoDock Vina, the highest potential for inhibition of EGFR, AKT2 and VEGFR1 have derivatives 16 and 17. Therefore, derivatives 1, 16, 17 and 20 are potentially the most potent protein kinase inhibitors that could be further synthesized and tested for anticancer activity.

Safety and efficacy of neoadjuvant chemoradiotherapy with moderately hypofractionated intensity-modulated radiotherapy for resectable pancreatic cancer: A prospective, open-label, phase II study.

Resectable pancreatic cancer (RPC) is potentially resectable on admission, and the impact of neoadjuvant therapy on these tumors is controversial. Moreover, the safety and efficacy of neoadjuvant chemoradiotherapy with moderately hypofractionated intensity-modulated radiation therapy (NACIMRT) for RPC have not been studied. Here, we conducted a phase II study to evaluate the safety and efficacy of hypofractionated NACIMRT for RPC. A total of 54 RPC patients were enrolled and treated according to the study protocol. We used moderately hypofractionated (45 Gy in 15 fractions) IMRT with gemcitabine to shorten the duration of radiotherapy and reduce gastrointestinal toxicity. The primary endpoint was overall survival (OS), and we subsequently analyzed the microscopically margin-negative resection (R0) rate, disease-free survival (DFS), and histologic effects and safety of NACIMRT. Median OS for the cohort was 40.0 months. Forty-two patients (77.8%) underwent pancreatectomy after NACIMRT. Median DFS was 20.3 months. The R0 resection rate was 95.2% (40/42) per protocol and 85.2% (46/54) for the cohort. There were no intervention-related deaths during the study period. Local treatment response, as assessed by the CAP classification, showed no residual tumor in 4.8% of patients. Overall, 23.9% of patients experienced CTCAE grade 3 or 4 during NACIMRT. Adjuvant therapy was initiated in 88% of patients undergoing resection. Postoperative complications grade ≥3b on the Clavien-Dindo scale occurred in 4.8% of patients. CA19-9 level at enrollment was an independent prognostic factor for OS and DFS. This is the first prospective study of hypofractionated IMRT as neoadjuvant therapy for RPC. Hypofractionated NACIMRT for RPC could be safely introduced with a high induction rate of adjuvant chemotherapy, with an overall survival of 40.0 months.

Impact of reduced margin pelvic radiotherapy on gastrointestinal toxicity and outcome in gynecological cancer

PurposeTo investigate the effect of reduced margin pelvic radiotherapy on gastrointestinal toxicity and outcomes in gynecological cancer. Materials and methodsThis retrospective study analyzed data of 590 patients who underwent hysterectomy and adjuvant pelvic radiotherapy between 2010 and 2020 at two tertiary centers. The pelvic nodal region was delineated based on a reduced margin definition or the Radiation Therapy Oncology Group (RTOG) guidelines. All patients were treated with intensity-modulated radiotherapy with imaging guidance. Gastrointestinal toxicity was assessed using the Common Terminology Criteria for Adverse Events (CTCAE) and the Patient-Reported Outcome version (PRO-CTCAE). ResultsOverall, 352 (59.7%) and 238 (40.3%) patients underwent RTOG and reduced margin pelvic radiotherapy, respectively. Median follow-up was 6.4 years (IQR: 3.7–9.6). Reduced margin pelvic radiotherapy significantly lowered the radiation dose to the small bowel. For CTCAE grade ≥ 2 or 3, acute gastrointestinal toxicity was lower in the reduced margin group than in the RTOG group (16.4% vs. 33.5%, p < 0.001; 2.9% vs. 8.5%, p < 0.001). The reduced margin group reported less severe acute gastrointestinal toxicity (PRO-CTCAE score ≥ 3) than the RTOG group (12.5% vs. 28.7%, p < 0.001). Late grade 3 gastrointestinal toxicity was lower in the reduced margin group than in the RTOG group (0.8% vs. 4.8%, p = 0.006). The 5-year pelvic recurrence-free survival and disease-free survival in the RTOG and reduced margin pelvic radiotherapy groups were 97.4% and 97.9% (p = 0.55) and 80.7% and 83.5% (p = 0.18), respectively. ConclusionReduced margin pelvic radiotherapy decreased acute and late gastrointestinal toxicity and achieved favorable outcomes.

Mitigative and anti-inflammatory effects of Trichostatin A against radiation-induced gastrointestinal toxicity and gut microbiota alteration in mice

Purpose Radiation-induced gastrointestinal injury (RIGI) is a serious side effect of abdominal and pelvic radiotherapy, which often limits the treatment of gastrointestinal and gynaecological cancers. RIGI is also observed during accidental radiological or nuclear scenarios with no approved agents available till date to prevent or mitigate RIGI in humans. Trichostatin A (TSA), an epigenetic modulator, has been currently in clinical trials for cancer treatment and is also well known for its antibiotic and antifungal properties. Methods In this study, partial body (abdominal) irradiation mice model was used to investigate the mitigative effect of TSA against gastrointestinal toxicity caused by gamma radiation. Mice were checked for alterations in mean body weight, diarrheal incidence, disease activity index and survival against 15 Gy radiation. Structural abnormalities in intestine and changes in microbiota composition were studied by histopathology and 16S rRNA sequencing of fecal samples respectively. Immunoblotting and biochemical assays were performed to check protein nitrosylation, expression of inflammatory mediators, infiltration of inflammatory cells and changes in pro-inflammatory cytokine. Results TSA administration to C57Bl/6 mice improved radiation induced mean body weight loss, maintained better health score, reduced disease activity index and promoted survival. The 16S rRNA sequencing of fecal DNA demonstrated that TSA influenced the fecal microbiota dynamics with significant alterations in the Firmicutes/Bacteriodetes ratio. TSA effectively mitigated intestinal injury, down-regulated NF-κB, Cox-2, iNOS expression, inhibited PGE2 and protein nitrosylation levels in irradiated intestine. The upregulation of NLRP3-inflammasome complex and infiltrations of inflammatory cells in the inflamed intestine were also prevented by TSA. Subsequently, the myeloperoxidase activity in intestine alongwith serum IL-18 levels was found reduced. Conclusion These findings provide evidence that TSA inhibits inflammatory mediators, alleviates gut dysbiosis, and promotes structural restoration of the irradiated intestine. TSA, therefore, can be considered as a potential agent for mitigation of RIGI in humans.

Carbon-ion radiotherapy (CIRT) as treatment of pancreatic cancer at HIT: initial radiation plan analysis of the prospective phase II PACK-study

PurposeTo analyze the dose objectives and constraints applied at the prospective phase II PACK-study at Heidelberg ion therapy center (HIT) for different radiobiological models. MethodsTreatment plans of 14 patients from the PACK-study were analyzed and recomputed in terms of physical, biological dose and dose-averaged linear energy transfer (LETd). Both LEM-I (local effect model 1) and the adapted NIRS-MKM (microdosimetric kinetic model), were used for relative biological effectiveness (RBE)-weighted dose calculations (DBio|HIT and DBio|NIRS). A new constraint to the gastrointestinal (GI) tract was derived from the National Institute of Radiological Science (NIRS) clinical experience and considered for plan reoptimization (DBio|NIRS-const_48Gy and DBio|NIRS-const_50.4Gy). The Lyman-Kutcher-Burman (LKB) model of Normal Tissue Complication Probability (NTCP) for GI toxicity endpoints was computed. Furthermore, the computed LETd distribution was evaluated and correlated with Local Control (LC). ResultsOnly two patients showed a LETd98% in the GTV greater than 44 keV/μm. A HIT-dose constraint to the GI of D2cm3=48.6GyRBEHIT was derived from the NIRS experience, in alternative to the standard at HIT Dmax = 45.6 GyRBEHIT. In comparison with the original DBio|HIT,DBio|NIRS-const_48GyandDBio|NIRS-const_50.4Gy resulted in an increase in the ITV’s D98% of 8.7% and 11.3%. The NTCP calculation resulted in a probability for gastrointestinal bleeding of 4.5%, 12.3% and 13.0%, for DBio|NIRS, DBio|NIRS-const_48Gy and DBio|NIRS-const_50.4Gy, respectively. ConclusionThe results indicate that the current standards applied at HIT for CIRT closely align with the Japanese experience. However, to enhance tumor coverage, a more relaxed constraint on the GI tract may be considered. As the PACK-trial progresses, further analyses of various clinical endpoints are anticipated.

Random Forest Modeling of Acute Toxicity in Anal Cancer: Effects of Peritoneal Cavity Contouring Approaches on Model Performance

Our purpose was to analyze the effect on gastrointestinal (GI) toxicity models when their dose-volume metrics predictors are derived from segmentations of the peritoneal cavity after different contouring approaches. A random forest machine learning approach was used to predict acute grade ≥3 GI toxicity from dose-volume metrics and clinicopathologic factors for 246 patients (toxicity incidence=9.5%) treated with definitive chemoradiation for squamous cell carcinoma of the anus. Three types of random forest models were constructed based on different bowel bag segmentation approaches: (1) physician-delineated after Radiation Therapy Oncology Group (RTOG) guidelines, (2) autosegmented by a deep learning model (nnU-Net) following RTOG guidelines, and (3) autosegmented but spanning the entire bowel space. Each model type was evaluated using repeated cross-validation (100 iterations; 50%/50% training/test split). The performance of the models was assessed using area under the precision-recall curve (AUPRC) and the receiver operating characteristic curve (AUROCC), as well as optimal F1 score. When following RTOG guidelines, the models based on the nnU-Net auto segmentations (mean values: AUROCC, 0.71 ± 0.07; AUPRC, 0.42 ± 0.09; F1 score, 0.46 ± 0.08) significantly outperformed (P < .001) those based on the physician-delineated contours (mean values: AUROCC, 0.67 ± 0.07; AUPRC, 0.34 ± 0.08; F1 score, 0.36 ± 0.07). When spanning the entire bowel space, the performance of the autosegmentation models improved considerably (mean values: AUROCC, 0.87 ± 0.05; AUPRC, 0.70 ± 0.09; F1 score, 0.68 ± 0.09). Random forest models were superior at predicting acute grade ≥3 GI toxicity when based on RTOG-defined bowel bag autosegmentations rather than physician-delineated contours. Models based on autosegmentations spanning the entire bowel space show further considerable improvement in model performance. The results of this study should be further validated using an external data set.

Randomized phase II trial of MRI-guided salvage radiotherapy for prostate cancer in 4 weeks versus 2 weeks (SHORTER)

BackgroundUltra-hypofractionated image-guided stereotactic body radiotherapy (SBRT) is increasingly used for definitive treatment of localized prostate cancer. Magnetic resonance imaging-guided radiotherapy (MRgRT) facilitates improved visualization, real-time tracking of targets and/or organs-at-risk (OAR), and capacity for adaptive planning which may translate to improved targeting and reduced toxicity to surrounding tissues. Given promising results from NRG-GU003 comparing conventional and moderate hypofractionation in the post-operative setting, there is growing interest in exploring ultra-hypofractionated post-operative regimens. It remains unclear whether this can be done safely and whether MRgRT may help mitigate potential toxicity. SHORTER (NCT04422132) is a phase II randomized trial prospectively evaluating whether salvage MRgRT delivered in 5 fractions versus 20 fractions is non-inferior with respect to gastrointestinal (GI) and genitourinary (GU) toxicities at 2-years post-treatment.MethodsA total of 136 patients will be randomized in a 1:1 ratio to salvage MRgRT in 5 fractions or 20 fractions using permuted block randomization. Patients will be stratified according to baseline Expanded Prostate Cancer Index Composite (EPIC) bowel and urinary domain scores as well as nodal treatment and androgen deprivation therapy (ADT). Patients undergoing 5 fractions will receive a total of 32.5 Gy over 2 weeks and patients undergoing 20 fractions will receive a total of 55 Gy over 4 weeks, with or without nodal coverage (25.5 Gy over 2 weeks and 42 Gy over 4 weeks) and ADT as per the investigator’s discretion. The co-primary endpoints are change scores in the bowel and the urinary domains of the EPIC. The change scores will reflect the 2-year score minus the pre-treatment (baseline) score. The secondary endpoints include safety endpoints, including change in GI and GU symptoms at 3, 6, 12 and 60 months from completion of treatment, and efficacy endpoints, including time to progression, prostate cancer specific survival and overall survival.DiscussionThe SHORTER trial is the first randomized phase II trial comparing toxicity of ultra-hypofractionated and hypofractionated MRgRT in the salvage setting. The primary hypothesis is that salvage MRgRT delivered in 5 fractions will not significantly increase GI and GU toxicities when compared to salvage MRgRT delivered in 20 fractions.Trial registrationClinicalTrials.gov Identifier: NCT04422132. Date of registration: June 9, 2020.

Liquid biopsy: an innovative and reliable method for detecting not only somatic, but also germline mutations in patients with colorectal and non-small cell lung carcinoma

Liquid biopsy is a non-invasive method of detecting cancer-related mutations from circulating cell-free DNA (cfDNA) and has emerged as a promising alternative to traditional tissue biopsies. However, its utility has so far been limited to the detection of somatic mutations in cancer cells. Our study examined germline mutations that are associated with pharmacogenetics in 19 patients diagnosed with colorectal cancer and 12 patients with non-small cell lung carcinoma, utilizing the highly advanced and non-invasive technique of liquid biopsy, followed by subsequent next-generation sequencing for comprehensive analysis. Despite the relatively modest sample size of patients under consideration, our results indicated a noteworthy correlation between the presence of adverse effects and the identified germline mutations. We have identified the following mutations with significant implications for pharmacogenetics: MTHFR c.1286A > C, MTHFR c.665C > T, DPYD c.2194G > A, DPYD c.85C > T, XPC c.2815C > A, UMPS c.638G > C, SLC22A2 c.808T > G, EGFR c.1562G > A, ABCB1 2677 T > G, GSTP1 c.313A > G, ERCC2 c.2251A > C, and SLC19A1 c.80A > G. In addition, we observed various adverse drug reactions in our patient cohort, encompassing myelosuppression, hepatotoxicity, neurotoxicity and gastrointestinal toxicity. Liquid biopsy has the potential to revolutionize cancer diagnosis and treatment by detecting both somatic and germline mutations. The preliminary results of studies on germline mutations are promising, but further research is needed to address the remaining challenges and to establish the utility of liquid biopsy as a reliable diagnostic tool for germline mutations.

Low dose venetoclax plus itraconazole outpatient induction in newly diagnosed acute myeloid leukemia: A phase 2 study

Data concerning venetoclax and azacitidine (Ven/Aza) as first-line therapy for newly diagnosed acute myeloid leukemia (ND-AML) in candidates for intensive chemotherapy are limited, and outpatient induction regimens in ND-AML have been poorly explored. The enzyme CYP3A4 metabolizes Venetoclax. Conversely, itraconazole is a strong CYP3A4 inhibitor; thus, it produces a 75 % reduction in the dose and cost of venetoclax. This phase 2 trial assessed the feasibility, safety, and efficacy of outpatient induction with venetoclax 100 mg daily from days 1–21, itraconazole 100 mg twice daily from days 1–21, and azacytidine 100 mg subcutaneously, once daily from days 1–7. Fifteen adults with ND-AML were enrolled. The median age was 53 (range 25–73) and twelve (80 %) were considered candidates for intensive chemotherapy. Nine (60 %) subjects started treatment as outpatients,. The first treatment cycle completion in the outpatient setting was achieved in 77.7 %. Early 14-day, 30-day, and 60-day mortality rates were 6.7 %, 13.3 %, and 13.3 %, respectively. Composite CR/CRi after the first and second treatment cycles were 53.9 % and 85.7 %, respectively. Common adverse events included hematological and gastrointestinal toxicities. Outpatient induction with low-dose venetoclax plus itraconazole is feasible, safe, and has acceptable preliminary efficacy in ND-AML patients. This trial was registered in www.clinicaltrials.gov as #NCT05048615.

Dosimetric correlates of toxicities and quality of life following two-fraction stereotactic ablative radiotherapy (SABR) for prostate cancer

PurposeThere is no evidence-based data to guide dose constraints in two-fraction prostate stereotactic ablative radiotherapy (SABR). Using individual patient-data from two prospective trials, we aimed to correlate dosimetric parameters with toxicities and quality of life (QoL) outcomes. Materials and methodsWe included 60 patients who had two-fraction prostate SABR in the 2STAR (NCT02031328) and 2SMART (NCT03588819) trials. The prescribed dose was 26 Gy to the prostate+/–32 Gy boost to the dominant intraprostatic lesions. Toxicities and QoL data were prospectively collected using CTCAEv4 and EPIC-26 questionnaire. The outcomes evaluated were acute and late grade ≥ 2 toxicities, and late minimal clinical important changes (MCIC) in QoL domains. Dosimetric parameters for bladder, urethra, rectum, and penile bulb were evaluated. ResultsThe median follow-up was 56 months (range: 39–78 months). The cumulative incidence of grade ≥ 2 genitourinary (GU), gastrointestinal (GI), and sexual toxicities were 62%, 3%, and 17% respectively in the acute setting (<3 months), and 57%, 15%, and 52% respectively in late setting (>6 months). There were 36%, 28%, and 29% patients who had late MCIC in urinary, bowel and sexual QoL outcomes respectively. Bladder 0.5 cc was significant predictor for late grade ≥ 2 GU toxicities, with optimal cut-off of 25.5 Gy. Penile bulb D5cc was associated of late grade ≥ 2 sexual toxicities (no optimal cut-off was identified). No dosimetric parameters were identified to be associated with other outcomes. ConclusionUsing real-life patient data from prospective trials with medium-term follow-up, we identified additional dose constraints that may mitigate the risk of late treatment-related toxicities for two-fraction prostate SABR.

Step-in dosing of bosutinib in pts with chronic phase chronic myeloid leukemia (CML) after second-generation tyrosine kinase inhibitor (TKI) therapy: results of the Bosutinib Dose Optimization (BODO) Study

The approved dose of bosutinib in chronic phase CML is 400 mg QD in first-line and 500 mg QD in later-line treatment. However, given that gastrointestinal (GI) toxicity typically occurs early after treatment initiation, physicians often tend to start therapy with lower doses although this has never been tested systematically in prospective trials in the Western world. The Bosutinib Dose Optimization (BODO) Study, a multicenter phase II study, investigated the tolerability and efficacy of a step-in dosing concept of bosutinib (starting at 300 mg QD) in chronic phase CML patients in 2nd or 3rd line who were intolerant and/or refractory to previous TKI treatment. Of 57 patients included until premature closure of the study due to slow recruitment, 34 (60%) reached the targeted dose level of 500 mg QD following the 2-weekly step-in dosing regimen. While the dosing-in concept failed to reduce GI toxicity (grade II–IV, primary study endpoint) to < 40% (overall rate of 60%; 95% CI: 45–74%), bosutinib treatment (mean dosage: 403 mg/day) showed remarkable efficacy with a cumulative major molecular remission (MMR) rate of 79% (95% CI: 66 to 88%) at month 24. Of thirty patients refractory to previous therapy and not in MMR at baseline, 19 (64%) achieved an MMR during treatment. GI toxicity did not significantly impact on patient-reported outcomes (PRO) and led to treatment discontinuation in only one patient. Overall, the results of our trial support the efficacy and safety of bosutinib after failure of second-generation TKI pre-treatment. Trial registration: NCT02577926.