Dabrafenib plus trametinib in patients with relapsed/refractory BRAF V600E mutation-positive hairy cell leukemia.

BRAF V600E is the key oncogenic driver mutation in hairy cell leukemia (HCL). We report the efficacy and safety of dabrafenib plus trametinib in patients with relapsed/refractory BRAF V600E mutation-positive HCL. This open-label, phase 2 study enrolled patients with BRAF V600E mutation-positive HCL refractory to first-line treatment with a purine analog or relapsed after ≥2 prior lines of treatment. Patients received dabrafenib 150 mg twice daily plus trametinib 2 mg once daily until disease progression, unacceptable toxicity, or death. The primary endpoint was investigator-assessed objective response rate (ORR) per criteria adapted from National Comprehensive Cancer Network-Consensus Resolution guidelines. Secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. Fifty-five patients with BRAF V600E mutation-positive HCL were enrolled. The investigator-assessed ORR was 89.0% (95% confidence interval, 77.8%-95.9%); 65.5% of patients had a complete response (without minimal residual disease [MRD]: 9.1% [negative immunohistochemistry of bone marrow {BM} biopsy], 12.7% [negative BM aspirate flow cytometry {FC}], 16.4% [negative immunohistochemistry and/or FC results]; with MRD, 49.1%), and 23.6% had a partial response. The 24-month DOR was 97.7% with 24-month PFS and OS rates of 94.4% and 94.5%, respectively. The most common treatment-related adverse events were pyrexia (58.2%), chills (47.3%), and hyperglycemia (40.0%). Dabrafenib plus trametinib demonstrated durable responses with a manageable safety profile consistent with previous observations in other indications and should be considered as a rituximab-free therapeutic option for patients with relapsed/refractory BRAF V600E mutation-positive HCL. This trial is registered at www.clinicaltrials.gov as #NCT02034110.

A phase 1 study of triple-targeted therapy with BRAF, MEK, and AKT inhibitors for patients with BRAF-mutated cancers.

BACKGROUND: Aberrant PI3K/AKT signaling in BRAF-mutant cancers contributes to resistance to BRAF inhibitors. The authors examined dual MAPK and PI3K pathway inhibition in patients who had BRAF-mutated solid tumors (ClinicalTrials.gov identifier NCT01902173). METHODS: Patients with BRAF V600E/V600K-mutant solid tumors received oral dabrafenib at 150 mg twice daily with dose escalation of oral uprosertib starting at 50 mg daily, or, in the triplet cohorts, with dose escalation of both oral trametinib starting at 1.5 mg daily and oral uprosertib starting at 25 mg daily. Dose-limiting toxicities (DLTs) were assessed within the first 56 days of treatment. Radiographic responses were assessed at 8-week intervals. RESULTS: Twenty-seven patients (22 evaluable) were enrolled in parallel doublet and triplet cohorts. No DLTs were observed in the doublet cohorts (N = 7). One patient had a DLT at the maximum administered dose of triplet therapy (dabrafenib 150 mg twice daily and trametinib 2 mg daily plus uprosertib 75 mg daily). Three patients in the doublet cohorts had partial responses (including one who had BRAF inhibitor-resistant melanoma). Two patients in the triplet cohorts had a partial response, and one patient had an unconfirmed partial response. Pharmacokinetic data suggested reduced dabrafenib and dabrafenib metabolite exposure in patients who were also exposed to both trametinib and uprosertib, but not in whose who were exposed to uprosertib without trametinib. CONCLUSIONS: Concomitant inhibition of both the MAPK and PI3K-AKT pathways for the treatment of BRAF-mutated cancers was well tolerated, leading to objective responses, but higher level drug-drug interactions affected exposure to dabrafenib and its metabolites.

Treatment of Uterine Fibroid Symptoms with Relugolix Combination Therapy.

BACKGROUND: Uterine fibroids are a common cause of heavy menstrual bleeding and pain. Treatment with the combination of relugolix (an oral gonadotropin-releasing hormone-receptor antagonist), estradiol, and norethindrone acetate, administered once daily, may have efficacy in women with uterine fibroids and heavy bleeding while avoiding hypoestrogenic effects. METHODS: We conducted two replicate international, double-blind, 24-week, phase 3 trials involving women with fibroid-associated heavy menstrual bleeding. Participants were randomly assigned in a 1:1:1 ratio to receive once-daily placebo, relugolix combination therapy (40 mg of relugolix, 1 mg of estradiol, and 0.5 mg of norethindrone acetate), or delayed relugolix combination therapy (40 mg of relugolix monotherapy, followed by relugolix combination therapy, each for 12 weeks). The primary efficacy end point in each trial was the percentage of participants with a response (volume of menstrual blood loss <80 ml and a ≥50% reduction in volume from baseline) in the relugolix combination therapy group, as compared with the placebo group. Key secondary end points were amenorrhea, volume of menstrual blood loss, distress from bleeding and pelvic discomfort, anemia, pain, fibroid volume, and uterine volume. Safety and bone mineral density were assessed. RESULTS: A total of 388 women in trial L1 and 382 in trial L2 underwent randomization. A total of 73% of the participants in the relugolix combination therapy group in trial L1 and 71% of those in trial L2 had a response (primary end point), as compared with 19% and 15%, respectively, of those in the placebo groups (P<0.001 for both comparisons). Both relugolix combination therapy groups had significant improvements, as compared with the placebo groups, in six of seven key secondary end points, including measures of menstrual blood loss (including amenorrhea), pain, distress from bleeding and pelvic discomfort, anemia, and uterine volume, but not fibroid volume. The incidence of adverse events was similar with relugolix combination therapy and placebo. Bone mineral density was similar with relugolix combination therapy and placebo but decreased with relugolix monotherapy. CONCLUSIONS: Once-daily relugolix combination therapy resulted in a significant reduction in menstrual bleeding, as compared with placebo, and preserved bone mineral density in women with uterine fibroids. (Funded by Myovant Sciences; LIBERTY 1 [L1] and LIBERTY 2 [L2] ClinicalTrials.gov numbers, NCT03049735 and NCT03103087, respectively.).

Oral Relugolix for Androgen-Deprivation Therapy in Advanced Prostate Cancer.

BACKGROUND: Injectable luteinizing hormone-releasing hormone agonists (e.g., leuprolide) are the standard agents for achieving androgen deprivation for prostate cancer despite the initial testosterone surge and delay in therapeutic effect. The efficacy and safety of relugolix, an oral gonadotropin-releasing hormone antagonist, as compared with those of leuprolide are not known. METHODS: In this phase 3 trial, we randomly assigned patients with advanced prostate cancer, in a 2:1 ratio, to receive relugolix (120 mg orally once daily) or leuprolide (injections every 3 months) for 48 weeks. The primary end point was sustained testosterone suppression to castrate levels (<50 ng per deciliter) through 48 weeks. Secondary end points included noninferiority with respect to the primary end point, castrate levels of testosterone on day 4, and profound castrate levels (<20 ng per deciliter) on day 15. Testosterone recovery was evaluated in a subgroup of patients. RESULTS: A total of 622 patients received relugolix and 308 received leuprolide. Of men who received relugolix, 96.7% (95% confidence interval [CI], 94.9 to 97.9) maintained castration through 48 weeks, as compared with 88.8% (95% CI, 84.6 to 91.8) of men receiving leuprolide. The difference of 7.9 percentage points (95% CI, 4.1 to 11.8) showed noninferiority and superiority of relugolix (P<0.001 for superiority). All other key secondary end points showed superiority of relugolix over leuprolide (P<0.001). The percentage of patients with castrate levels of testosterone on day 4 was 56.0% with relugolix and 0% with leuprolide. In the subgroup of 184 patients followed for testosterone recovery, the mean testosterone levels 90 days after treatment discontinuation were 288.4 ng per deciliter in the relugolix group and 58.6 ng per deciliter in the leuprolide group. Among all the patients, the incidence of major adverse cardiovascular events was 2.9% in the relugolix group and 6.2% in the leuprolide group (hazard ratio, 0.46; 95% CI, 0.24 to 0.88). CONCLUSIONS: In this trial involving men with advanced prostate cancer, relugolix achieved rapid, sustained suppression of testosterone levels that was superior to that with leuprolide, with a 54% lower risk of major adverse cardiovascular events. (Funded by Myovant Sciences; HERO ClinicalTrials.gov number, NCT03085095.).

Thromboembolic toxicity observed with concurrent trametinib and lenalidomide therapy.

The event-free survival of pediatric low-grade gliomas is poor, and patients often require multiple treatment strategies. While MEK and RAF inhibitors are efficacious in early-phase trials, not all patients respond, and many experience progression following completion of therapy. Evaluating combination therapies that may enhance efficacy or prolong disease stabilization is warranted. We report our institutional experience using concurrent trametinib and lenalidomide in the treatment of primary pediatric central and peripheral nervous system tumors. Two of four patients using this combination therapy experienced severe thromboembolic events, necessitating discontinuation of therapy. This combination requires further investigation, and we urge caution if used.

Effects of short-term treatment with vibegron for refractory nocturnal enuresis.

BACKGROUND: Long-term nocturnal enuresis treatment leads to stress and lowered self-esteem for children and their parents. This study evaluated the short-term effectiveness and safety of vibegron (50 mg) for children with refractory nocturnal enuresis. METHODS: A retrospective cohort study of children with therapy-resistant enuresis was conducted using data for July to December 2019. Enuresis frequency was recorded during 30 days before and after additional vibegron administration with prior treatment. We assessed the treatment effectiveness based on enuresis frequencies between before and after treatment with vibegron 50 mg. Statistical evaluation was performed using a paired t-test. RESULTS: Among 29 children receiving vibegron, 14 (48.3%) exhibited a partial or complete response to the drug. Enuresis frequencies (mean ± standard deviation [SD]) were, respectively, 15.8 ± 9.2 and 9.5 ± 9.6 before and after treatment with vibegron during the observed 30 days. A statistically significant reduction in enuresis frequency was found (p < 0.001). Moreover, maximum mean±SD morning urine of 200 ± 62.9 mL before treatment with vibegron changed to 232 ± 76.6 mL after treatment. A significant increase in voiding volume in the early morning was found (p < 0.05). No drug-related severe adverse event was found. CONCLUSION: Short-term treatment with vibegron is safe and effective for children with refractory enuresis.

Five-Year Outcomes with Dabrafenib plus Trametinib in Metastatic Melanoma.

BACKGROUND: Patients who have unresectable or metastatic melanoma with a BRAF V600E or V600K mutation have prolonged progression-free survival and overall survival when receiving treatment with BRAF inhibitors plus MEK inhibitors. However, long-term clinical outcomes in these patients remain undefined. To determine 5-year survival rates and clinical characteristics of the patients with durable benefit, we sought to review long-term data from randomized trials of combination therapy with BRAF and MEK inhibitors. METHODS: We analyzed pooled extended-survival data from two trials involving previously untreated patients who had received BRAF inhibitor dabrafenib (at a dose of 150 mg twice daily) plus MEK inhibitor trametinib (2 mg once daily) in the COMBI-d and COMBI-v trials. The median duration of follow-up was 22 months (range, 0 to 76). The primary end points in the COMBI-d and COMBI-v trials were progression-free survival and overall survival, respectively. RESULTS: A total of 563 patients were randomly assigned to receive dabrafenib plus trametinib (211 in the COMBI-d trial and 352 in the COMBI-v trial). The progression-free survival rates were 21% (95% confidence interval [CI], 17 to 24) at 4 years and 19% (95% CI, 15 to 22) at 5 years. The overall survival rates were 37% (95% CI, 33 to 42) at 4 years and 34% (95% CI, 30 to 38) at 5 years. In multivariate analysis, several baseline factors (e.g., performance status, age, sex, number of organ sites with metastasis, and lactate dehydrogenase level) were significantly associated with both progression-free survival and overall survival. A complete response occurred in 109 patients (19%) and was associated with an improved long-term outcome, with an overall survival rate of 71% (95% CI, 62 to 79) at 5 years. CONCLUSIONS: First-line treatment with dabrafenib plus trametinib led to long-term benefit in approximately one third of the patients who had unresectable or metastatic melanoma with a BRAF V600E or V600K mutation. (Funded by GlaxoSmithKline and Novartis; COMBI-d ClinicalTrials.gov number, NCT01584648; COMBI-v ClinicalTrials.gov number, NCT01597908.).

Targeting wild-type TP53 using AMG 232 in combination with MAPK inhibition in Metastatic Melanoma; a phase 1 study.

BACKGROUND: Targeting the MDM2-p53 interaction using AMG 232 is synergistic with MAPK inhibitors (MAPKi) in preclinical melanoma models. We postulated that AMG 232 plus MAPKi is safe and more effective than MAPKi alone in TP53-wild type, MAPKi-naïve metastatic melanoma. METHODS: Patients were treated with increasing (120 mg, 180 mg, 240 mg) oral doses of AMG 232 (seven-days-on, 15-days-off, 21-day cycle) plus dabrafenib (D) and trametinib (T) (Arm 1, BRAFV600-mutant) or T alone (Arm 2, BRAFV600-wild type). Patients were treated for seven days with AMG 232 alone before adding T±D. Safety and efficacy were assessed using CTCAE v4.0 and RECIST v1.1 criteria, respectively. Pharmacokinetic (PK) analysis was performed at baseline and steady-state levels for AMG 232. RESULTS: 31 patients were enrolled. Ten and 21 patients were enrolled in Arm 1 and Arm 2, respectively. The most common AMG 232-related adverse events (AEs) were nausea (87%), diarrhea (77%), and fatigue (74%). Seven patients (23%) were withdrawn from the study due to AMG 232-related AEs. Three dose-limiting AEs occurred (Arm 1, 180 mg, nausea; Arm 2, 240 mg, grade 3 pulmonary embolism; Arm 2, 180 mg, grade 4 thrombocytopenia). AMG 232 PK exposures were not altered when AMG 232 was combined with T±D. Objective responses were seen in 8/10 (Arm 1) and 3/20 (Arm 2) evaluable patients. The median progression-free survival for Arm 1 and Arm 2 was 19.0 months-not reached and 2.8 months, respectively. CONCLUSION: The maximum tolerated dose of AMG 232 for both arms was 120 mg. AMG 232 plus T±D exhibited a favorable PK profile. Although objective responses occurred in both arms, adding AMG 232 to T±D did not confer additional clinical benefit.

Interstitial lung disease associated with combination therapy of dabrafenib and trametinib in metastatic BRAFV600E-mutated poorly differentiated thyroid cancer: A case report and review of the literature.

BACKGROUND: Thyroid cancer is the most common malignancy of the endocrine system, accounting for ~ 5% of all thyroid nodules and 1% of all systemic malignancies. BRAF mutations, primarily p.V600E hot spot mutations, are found in 60 - 70% of papillary thyroid cancer cases (PTC) and in 33 - 40% of fatal anaplastic thyroid cancers (ATC), also called poorly differentiated thyroid cancer. Dabrafenib was approved by the United States Food and Drug Administration (FDA) in 2018 to be applied in combination with trametinib for unresectable advanced or metastatic anaplastic thyroid cancer harboring the BRAFV600E mutation. Unfortunately, there are few reports on the pathophysiology, molecular mechanism, and risk factors of interstitial lung disease induced by combined BRAF- and MEK-targeted therapy. CASE PRESENTATION: We treated a 73-year-old man with metastatic BRAFV600E-mutated poorly differentiated thyroid cancer using the combination of dabrafenib and trametinib. Although a significant morphologic tumor response was observed in our patient using combined BRAF- and MEK-targeted therapy, he presented with non-febrile respiratory failure, and his chest computed tomography (CT) revealed bilateral reticulation and pleural effusion. Withdrawal from dabrafenib-trametinib and administration of methylprednisolone rapidly improved his respiratory status and imaging features. CONCLUSION: The mechanisms of lung disease after the combined treatment with dabrafenib and trametinib are unclear. We hypothesized that dual-targeted therapy with a BRAF inhibitor, dabrafenib, and a MEK inhibitor, trametinib, might prevent the regeneration and proliferation of fibrotic epithelium in lung disease by blocking downstream proliferative signals.

Once-Daily Vibegron 75 mg for Overactive Bladder: Long-Term Safety and Efficacy from a Double-Blind Extension Study of the International Phase 3 Trial (EMPOWUR).

PURPOSE: The long-term safety, tolerability and efficacy of vibegron in adults with overactive bladder were evaluated in the 40-week phase 3 EMPOWUR extension study. MATERIALS AND METHODS: Patients who completed 12 weeks of once-daily vibegron 75 mg or tolterodine 4 mg extended release in EMPOWUR continued double-blind treatment; patients who completed 12 weeks of placebo were randomly assigned 1:1 to receive double-blind vibegron or tolterodine. The primary outcome was safety, measured by incidence of adverse events. Secondary outcomes included change from baseline at week 52 in average daily number of micturitions and urgency episodes (all patients), and urge and total urinary incontinence episodes (patients with overactive bladder wet) based on 7-day diary data. RESULTS: Of 506 patients randomized 505 received ≥1 dose of medication, and 430 (85%) completed the study. A total of 12 patients (2.4%) discontinued owing to adverse events. The most common adverse events with vibegron/tolterodine (>5% in either group) were hypertension (8.8%/8.6%), urinary tract infection (6.6%/7.3%), headache (5.5%/3.9%), nasopharyngitis (4.8%/5.2%) and dry mouth (1.8%/5.2%). Improvements in efficacy end points were maintained for patients receiving vibegron for 52 weeks; least squares mean change from baseline to week 52 in micturitions was ‒2.4 for vibegron vs ‒2.0 for tolterodine; in urge urinary incontinence episodes ‒2.2 vs ‒1.7 (p <0.05); in urgency episodes ‒3.4 vs ‒3.2; and in total incontinence episodes ‒2.5 vs ‒1.9 (p <0.05). Among patients with overactive bladder wet 61.0% receiving vibegron experienced ≥75% reduction in urge urinary incontinence episodes after 52 weeks of treatment vs 54.4% with tolterodine, while 40.8% vs 34.2% experienced a 100% reduction. CONCLUSIONS: Vibegron demonstrated favorable long-term safety, tolerability and efficacy in patients with overactive bladder, consistent with results of the 12-week study.

Gastrointestinal perforation following dabrafenib and trametinib administration in non-small cell lung carcinoma with BRAF V600E mutation: a case report and literature review.

Gastrointestinal perforation related to mitogen-activated protein kinase kinase (MEK) inhibitors has been reported previously; however, there has been no case report of such a condition in patients with non-small cell lung cancer (NSCLC). Herein, we report a case of small intestinal perforation secondary to dabrafenib and trametinib administration, but not related to tumor regression. A 62-year-old man with non-small cell lung cancer harboring BRAF V600E mutation was treated with dabrafenib and trametinib. Four months after the initiation of treatment, a small intestinal perforation was diagnosed. Dabrafenib and trametinib rechallenge was performed after gastrointestinal perforation. The patient responded well to therapy and did not experience recurrence of gastrointestinal perforation. To the best of our knowledge, this is the first report of gastrointestinal perforation in a patient with NSCLC treated with a MEK inhibitor. The mechanism and risk factors of trametinib-induced perforation are currently unknown. Physicians should be aware of such severe gastrointestinal side effects of trametinib.

PAN-selective inhibition of cAMP-phosphodiesterase 4 (PDE4) induces gastroparesis in mice.

Inhibitors of cAMP-phosphodiesterase 4 (PDE4) exert a number of promising therapeutic benefits, but adverse effects, in particular emesis and nausea, have curbed their clinical utility. Here, we show that PAN-selective inhibition of PDE4, but not inhibition of PDE3, causes a time- and dose-dependent accumulation of chow in the stomachs of mice fed ad libitum without changing the animals' food intake or the weight of their intestines, suggesting that PDE4 inhibition impairs gastric emptying. Indeed, PDE4 inhibition induced gastric retention in an acute model of gastric motility that traces the passage of a food bolus through the stomach over a 30 minutes time period. In humans, abnormal gastric retention of food is known as gastroparesis, a syndrome predominated by nausea (>90% of cases) and vomiting (>80% of cases). We thus explored the abnormal gastric retention induced by PDE4 inhibition in mice under the premise that it may represent a useful correlate of emesis and nausea. Delayed gastric emptying was produced by structurally distinct PAN-PDE4 inhibitors including Rolipram, Piclamilast, Roflumilast, and RS25344, suggesting that it is a class effect. PDE4 inhibitors induced gastric retention at similar or below doses commonly used to induce therapeutic benefits (e.g., 0.04 mg/kg Rolipram), thus mirroring the narrow therapeutic window of PDE4 inhibitors in humans. YM976, a PAN-PDE4 inhibitor that does not efficiently cross the blood-brain barrier, induced gastroparesis only at significantly higher doses (≥1 mg/kg). This suggests that PDE4 inhibition may act in part through effects on the autonomic nervous system regulation of gastric emptying and that PDE4 inhibitors that are not brain-penetrant may have an improved safety profile. The PDE4 family comprises four subtypes, PDE4A, B, C, and D. Selective ablation of any of these subtypes in mice did not induce gastroparesis per se, nor did it protect from PAN-PDE4 inhibitor-induced gastroparesis, indicating that gastric retention may result from the concurrent inhibition of multiple PDE4s. Thus, potentially, any of the four PDE4 subtypes may be targeted individually for therapeutic benefits without inducing nausea or emesis. Acute gastric retention induced by PDE4 inhibition is alleviated by treatment with the widely used prokinetic Metoclopramide, suggesting a potential of this drug to alleviate the side effects of PDE4 inhibitors. Finally, given that the cause of gastroparesis remains largely idiopathic, our findings open the possibility that a physiologic or pathophysiologic downregulation of PDE4 activity/expression may be causative in a subset of patients.

Dabrafenib and trametinib induced pancreatitis: a case report and review of the literature.

Approximately 50% of melanomas are characterized by BRAF mutation (V600E in 90% of cases), that predicts more aggressive behaviour. This mutation is the target of dabrafenib, an anti-BRAF tyrosine-kinase inhibitor (TKI), that together with trametinib, anti-MEK TKI, is approved for first-line treatment of metastatic melanoma due to significant benefit in overall and progression-free survival. Most common treatment-related adverse events are pyrexia, chills, fatigue, rash, nausea, vomiting, and diarrhoea. This case report aims to present another less common adverse event of combined anti-BRAF and anti-MEK treatment. Our patient, after 4 months on target-therapy, experienced sudden deep abdominal pain. At the initial work-out at the emergency department, increase in serum lipase was detected and radiological findings were consistent with acute pancreatitis. Admitted to the hospital, other causes were ruled out and target-therapy was discontinued with symptoms improvement. Radiological and clinical follow-up was performed and a diagnosis of drug-induced pancreatitis was made. After few days of medical support with analgesia and antibiotic, the patient felt better and was discharged; target-therapy was permanently interrupted. Searching the literature, not so many cases of iatrogenic pancreatitis are described with this TKI combination, therefore, we have reported it as a rare but life-threatening adverse event that should be investigated whenever conceivable.

Relugolix, an oral gonadotropin-releasing hormone antagonist for the treatment of prostate cancer.

Androgen deprivation therapy using gonadotropin-releasing hormone (GnRH) analogues is standard treatment for intermediate and advanced prostate cancer. GnRH agonist therapy results in an initial testosterone flare, and increased metabolic and cardiovascular risks. The GnRH antagonist relugolix is able to reduce serum testosterone levels in men with prostate cancer without inducing testosterone flare. In the HERO Phase III trial, relugolix was superior to leuprolide acetate at rapidly reducing testosterone and continuously suppressing testosterone, with faster post-treatment recovery of testosterone levels. Relugolix was associated with a 54% lower incidence of major adverse cardiovascular events than leuprolide acetate. As the first oral GnRH antagonist approved for the treatment of advanced prostate cancer, relugolix offers a new treatment option.

Lay abstract The male sex hormone testosterone promotes the growth of prostate cancer cells. Some drug treatments for prostate cancer, such as gonadotropin-releasing hormone (GnRH) receptor agonists and antagonists, work to reduce the production of testosterone. However, GnRH receptor agonists like leuprolide acetate can increase testosterone levels at first, before reducing it, and this temporary increase can cause side effects, such as bone pain. Drugs of this type have also been linked to a higher risk of heart attacks, strokes, and death. Relugolix works a different way; it is a GnRH receptor antagonist that reduces testosterone without an initial increase. A clinical study showed that relugolix reduced testosterone levels more quickly than leuprolide acetate, a commonly used injectable drug for the treatment of prostate cancer. After stopping treatment, levels of testosterone in the blood returned to normal faster in men who received relugolix than in men who received leuprolide acetate. Men who received relugolix had a lower incidence of heart attacks, strokes, and death compared with men who received leuprolide acetate. The US FDA approved relugolix as the first oral, once-daily GnRH receptor antagonist for the treatment of advanced prostate cancer, offering men a new treatment option.

Trametinib-associated Hyponatremia in a Child With Low-grade Glioma is Not Seen Following Treatment With Alternative MEK Inhibitor.

Molecularly targeted therapy with MEK inhibitors has been increasingly incorporated into the treatment of pediatric low-grade gliomas, but this promising therapy is associated with distinctive and specific toxicities. Understanding life-threatening MEK inhibitor toxicities and their management is critical to MEK inhibitor safety, especially among young children. This report describes severe hyponatremia associated with trametinib in an infant with progressive low-grade glioma without underlying endocrine dysfunction, which recurred despite significant dose reduction. Therapy with an alternative MEK inhibitor, binimetinib, provided excellent tumor response without hyponatremia, suggesting that some toxicities may be avoided by changing MEK inhibitor agents within the same class.

Dabrafenib plus trametinib in patients with BRAFV600E-mutated biliary tract cancer (ROAR): a phase 2, open-label, single-arm, multicentre basket trial.

BACKGROUND: Effective treatments for patients with cholangiocarcinoma after progression on gemcitabine-based chemotherapy are urgently needed. Mutations in the BRAF gene have been found in 5% of biliary tract tumours. The combination of dabrafenib and trametinib has shown activity in several BRAFV600E-mutated cancers. We aimed to assess the activity and safety of dabrafenib and trametinib combination therapy in patients with BRAFV600E-mutated biliary tract cancer. METHODS: This study is part of an ongoing, phase 2, open-label, single-arm, multicentre, Rare Oncology Agnostic Research (ROAR) basket trial in patients with BRAFV600E-mutated rare cancers. Patients were eligible for the biliary tract cancer cohort if they were aged 18 years or older, had BRAFV600E-mutated, unresectable, metastatic, locally advanced, or recurrent biliary tract cancer, an Eastern Cooperative Oncology Group performance status of 0-2, and had received previous systemic treatment. All patients were treated with oral dabrafenib 150 mg twice daily and oral trametinib 2 mg once daily until disease progression or intolerance of treatment. The primary endpoint was the overall response rate, which was determined by Response Evaluation Criteria in Solid Tumors version 1.1 in the intention-to-treat evaluable population, which comprised all enrolled patients regardless of receiving treatment who were evaluable (ie, had progression, began a new anticancer treatment, withdrew consent, died, had stable disease for 6 weeks or longer, or had two or more post-baseline assessments). The ROAR trial is registered with ClinicalTrials.gov, NCT02034110. These results are based on an interim analysis; the study is active but not recruiting. FINDINGS: Between March 12, 2014, and July 18, 2018, 43 patients with BRAFV600E-mutated biliary tract cancer were enrolled to the study and were evaluable. Median follow-up was 10 months (IQR 6-15). An investigator-assessed overall response was achieved by 22 (51%, 95% CI 36-67) of 43 patients. An independent reviewer-assessed overall response was achieved by 20 (47%, 95% CI 31-62) of 43 patients. The most common grade 3 or worse adverse event was increased γ-glutamyltransferase in five (12%) patients. 17 (40%) patients had serious adverse events and nine (21%) had treatment-related serious adverse events, the most frequent of which was pyrexia (eight [19%]). No treatment-related deaths were reported. INTERPRETATION: Dabrafenib plus trametinib combination treatment showed promising activity in patients with BRAFV600E-mutated biliary tract cancer, with a manageable safety profile. Routine testing for BRAFV600E mutations should be considered in patients with biliary tract cancer. FUNDING: GlaxoSmithKline and Novartis.

A case of malignant hyperlactaemic acidosis appearing upon treatment with the mono-carboxylase transporter 1 inhibitor AZD3965.

A 47-year-old man with metastatic melanoma presented with refractory hyperlactaemic acidosis following the first dose of the mono-carboxylase transporter 1 inhibitor AZD3965 within a "first time in man" clinical trial. The mechanism of the agent and the temporal relationship suggested that this event was potentially drug related and recruitment was suspended. However, urinary metabolomics showed extensive abnormalities even prior to drug administration, leading to investigations for an underlying metabolic disorder. The lack of clinical symptoms from the elevated lactate and low blood glucose suggested a diagnosis of "hyper-Warburgism", where the high tumour burden was associated with extensive glucose uptake and lactate efflux from malignant cells, and the subsequent impact on blood biochemistry. This was supported by an FDG-PET scan showing extensive glucose uptake in numerous metastases and lack of uptake in the brain. A review of the literature showed 16 case reports of "hyper-Warburgism" in non-haematological malignancies, none of them with melanoma, with most associated with a poor outcome. The patient was treated symptomatically, but died 2 months later. The development of AZD3965 continues with the exclusion of patients with elevated plasma lactate at screening added to the protocol as a safety measure.Trial identification number ClinicalTrials.Gov. NCT01791595.

Adjuvant Dabrafenib plus Trametinib in Stage III BRAF-Mutated Melanoma.

BACKGROUND: Combination therapy with the BRAF inhibitor dabrafenib plus the MEK inhibitor trametinib improved survival in patients with advanced melanoma with BRAF V600 mutations. We sought to determine whether adjuvant dabrafenib plus trametinib would improve outcomes in patients with resected, stage III melanoma with BRAF V600 mutations. METHODS: In this double-blind, placebo-controlled, phase 3 trial, we randomly assigned 870 patients with completely resected, stage III melanoma with BRAF V600E or V600K mutations to receive oral dabrafenib at a dose of 150 mg twice daily plus trametinib at a dose of 2 mg once daily (combination therapy, 438 patients) or two matched placebo tablets (432 patients) for 12 months. The primary end point was relapse-free survival. Secondary end points included overall survival, distant metastasis-free survival, freedom from relapse, and safety. RESULTS: At a median follow-up of 2.8 years, the estimated 3-year rate of relapse-free survival was 58% in the combination-therapy group and 39% in the placebo group (hazard ratio for relapse or death, 0.47; 95% confidence interval [CI], 0.39 to 0.58; P<0.001). The 3-year overall survival rate was 86% in the combination-therapy group and 77% in the placebo group (hazard ratio for death, 0.57; 95% CI, 0.42 to 0.79; P=0.0006), but this level of improvement did not cross the prespecified interim analysis boundary of P=0.000019. Rates of distant metastasis-free survival and freedom from relapse were also higher in the combination-therapy group than in the placebo group. The safety profile of dabrafenib plus trametinib was consistent with that observed with the combination in patients with metastatic melanoma. CONCLUSIONS: Adjuvant use of combination therapy with dabrafenib plus trametinib resulted in a significantly lower risk of recurrence in patients with stage III melanoma with BRAF V600E or V600K mutations than the adjuvant use of placebo and was not associated with new toxic effects. (Funded by GlaxoSmithKline and Novartis; COMBI-AD ClinicalTrials.gov, NCT01682083 ; EudraCT number, 2012-001266-15 .).

Granulomatosis with polyangiitis in a patient treated with dabrafenib and trametinib for BRAF V600E positive lung adenocarcinoma.

BACKGROUND: Dabrafenib and trametinib combination therapy is approved for the treatment of patients with BRAF V600E positive tumors including melanoma and lung cancer. The effect of BRAF and MEK inhibitors on the immune system is not fully understood although a number of case reports indicate autoimmune side effects related to the use of these drugs. Here, we discuss a case of a patient diagnosed with granulomatosis with polyangiitis (GPA) shortly after starting treatment with dabrafenib and trametinib for BRAF V600E positive metastatic lung adenocarcinoma. CASE PRESENTATION: A 57 years old female patient was diagnosed with recurrent lung adenocarcinoma following initial lobectomy for early stage disease. A BRAF V600E mutation was identified at the time of recurrence and she received combination dabrafenib and trametinib therapy. Shortly after commencement of treatment, she developed persistent fevers necessitating withholding both drugs. Pyrexia continued and was followed by left vision loss and acute kidney injury. Further rheumatological workup led to the unifying diagnosis of GPA. The patient was then treated with rituximab for GPA to the present date while all antineoplastic drugs were held. Lung cancer oligoprogression was addressed with radiation therapy and has not required further systemic treatment whereas GPA has been controlled to-date with rituximab. CONCLUSIONS: This case report raises awareness among clinicians treating patients with lung cancer for the possibility of triggering a flare of autoimmune diseases like GPA in patients with BRAF V600E positive lung cancer receiving treatment with BRAF directed therapy.

Neuropsychological impact of trametinib in pediatric low-grade glioma: A case series.

Clinical trials of MEK inhibitors are underway in pediatric low-grade glioma (PLGG) with BRAF oncogene mutations and recurrent/refractory disease. Cognitive and behavioral impacts of MEK inhibitors, such as trametinib, are unknown as these outcomes have not yet been studied. This case series compared cognition and behavior in eight PLGG cases prior to and while on treatment with trametinib compared to four PLGG controls. Intelligence in the trametinib cases was mainly unchanged while on treatment, with mild decline in one of seven cases with complete data. Parent-reported depression symptoms increased in five of eight trametinib cases relative to one of four controls.