Brentuximab vedotin with dacarbazine or nivolumab as frontline cHL therapy for older patients ineligible for chemotherapy.

ABSTRACT: Older patients with advanced-stage classical Hodgkin lymphoma (cHL) have inferior outcomes compared with younger patients, potentially due to comorbidities and frailty. This noncomparative phase 2 study enrolled patients aged ≥60 years with cHL unfit for conventional chemotherapy to receive frontline brentuximab vedotin (BV; 1.8 mg/kg) with dacarbazine (DTIC; 375 mg/m2) (part B) or nivolumab (part D; 3 mg/kg). In parts B and D, 50% and 38% of patients, respectively, had ≥3 general comorbidities or ≥1 significant comorbidity. Of the 22 patients treated with BV-DTIC, 95% achieved objective response, and 64% achieved complete response (CR). With a median follow-up of 63.6 months, median duration of response (mDOR) was 46.0 months. Median progression-free survival (mPFS) was 47.2 months; median overall survival (mOS) was not reached. Of 21 patients treated with BV-nivolumab, 86% achieved objective response, and 67% achieved CR. With 51.6 months of median follow-up, mDOR, mPFS, and mOS were not reached. Ten patients (45%) with BV-DTIC and 16 patients (76%) with BV-nivolumab experienced grade ≥3 treatment-emergent adverse events; sensory peripheral neuropathy (PN; 27%) and neutropenia (9%) were most common with BV-DTIC, and increased lipase (24%), motor PN (19%), and sensory PN (19%) were most common with BV-nivolumab. Despite high median age, inclusion of patients aged ≤88 years, and frailty, these results demonstrate safety and promising durable efficacy of BV-DTIC and BV-nivolumab combinations as frontline treatment, suggesting potential alternatives for older patients with cHL unfit for initial conventional chemotherapy. This trial was registered at www.clinicaltrials.gov as #NCT01716806.

Assessing the efficacy and tolerability of PET-guided BrECADD versus eBEACOPP in advanced-stage, classical Hodgkin lymphoma (HD21): a randomised, multicentre, parallel, open-label, phase 3 trial.

BACKGROUND: Intensified systemic chemotherapy has the highest primary cure rate for advanced-stage, classical Hodgkin lymphoma but this comes with a cost of severe and potentially life long, persisting toxicities. With the new regimen of brentuximab vedotin, etoposide, cyclophosphamide, doxorubicin, dacarbazine, and dexamethasone (BrECADD), we aimed to improve the risk-to-benefit ratio of treatment of advanced-stage, classical Hodgkin lymphoma guided by PET after two cycles. METHODS: This randomised, multicentre, parallel, open-label, phase 3 trial was done in 233 trial sites across nine countries. Eligible patients were adults (aged ≤60 years) with newly diagnosed, advanced-stage, classical Hodgkin lymphoma (ie, Ann Arbor stage III/IV, stage II with B symptoms, and either one or both risk factors of large mediastinal mass and extranodal lesions). Patients were randomly assigned (1:1) to four or six cycles (21-day intervals) of escalated doses of etoposide (200 mg/m2 intravenously on days 1-3), doxorubicin (35 mg/m2 intravenously on day 1), and cyclophosphamide (1250 mg/m2 intravenously on day 1), and standard doses of bleomycin (10 mg/m2 intravenously on day 8), vincristine (1·4 mg/m2 intravenously on day 8), procarbazine (100 mg/m2 orally on days 1-7), and prednisone (40 mg/m2 orally on days 1-14; eBEACOPP) or BrECADD, guided by PET after two cycles. Patients and investigators were not masked to treatment assignment. Hierarchical coprimary objectives were to show (1) improved tolerability defined by treatment-related morbidity and (2) non-inferior efficacy defined by progression-free survival with an absolute non-inferiority margin of 6 percentage points of BrECADD compared with eBEACOPP. An additional test of superiority of progression-free survival was to be done if non-inferiority had been established. Analyses were done by intention to treat; the treatment-related morbidity assessment required documentation of at least one chemotherapy cycle. This trial was registered at ClinicalTrials.gov (NCT02661503). FINDINGS: Between July 22, 2016, and Aug 27, 2020, 1500 patients were enrolled, of whom 749 were randomly assigned to BrECADD and 751 to eBEACOPP. 1482 patients were included in the intention-to-treat analysis. The median age of patients was 31 years (IQR 24-42). 838 (56%) of 1482 patients were male and 644 (44%) were female. Most patients were White (1352 [91%] of 1482). Treatment-related morbidity was significantly lower with BrECADD (312 [42%] of 738 patients) than with eBEACOPP (430 [59%] of 732 patients; relative risk 0·72 [95% CI 0·65-0·80]; p<0·0001). At a median follow-up of 48 months, BrECADD improved progression-free survival with a hazard ratio of 0·66 (0·45-0·97; p=0·035); 4-year progression-free survival estimates were 94·3% (95% CI 92·6-96·1) for BrECADD and 90·9% (88·7-93·1) for eBEACOPP. 4-year overall survival rates were 98·6% (97·7-99·5) and 98·2% (97·2-99·3), respectively. INTERPRETATION: BrECADD guided by PET after two cycles is better tolerated and more effective than eBEACOPP in first-line treatment of adult patients with advanced-stage, classical Hodgkin lymphoma. FUNDING: Takeda Oncology.

Overall Survival with Brentuximab Vedotin in Stage III or IV Hodgkin's Lymphoma.

BACKGROUND: Five-year follow-up in a trial involving patients with previously untreated stage III or IV classic Hodgkin's lymphoma showed long-term progression-free survival benefits with first-line therapy with brentuximab vedotin, a CD30-directed antibody-drug conjugate, plus doxorubicin, vinblastine, and dacarbazine (A+AVD), as compared with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). A planned interim analysis indicated a potential benefit with regard to overall survival; data from a median of 6 years of follow-up are now available. METHODS: We randomly assigned patients in a 1:1 ratio to receive up to six cycles of A+AVD or ABVD. The primary end point, modified progression-free survival, has been reported previously. The key secondary end point was overall survival in the intention-to-treat population. Safety was also assessed. RESULTS: A total of 664 patients were assigned to receive A+AVD and 670 to receive ABVD. At a median follow-up of 73.0 months, 39 patients in the A+AVD group and 64 in the ABVD group had died (hazard ratio, 0.59; 95% confidence interval [CI], 0.40 to 0.88; P = 0.009). The 6-year overall survival estimates were 93.9% (95% CI, 91.6 to 95.5) in the A+AVD group and 89.4% (95% CI, 86.6 to 91.7) in the ABVD group. Progression-free survival was longer with A+AVD than with ABVD (hazard ratio for disease progression or death, 0.68; 95% CI, 0.53 to 0.86). Fewer patients in the A+AVD group than in the ABVD group received subsequent therapy, including transplantation, and fewer second cancers were reported with A+AVD (in 23 vs. 32 patients). Primary prophylaxis with granulocyte colony-stimulating factor was recommended after an increased incidence of febrile neutropenia was observed with A+AVD. More patients had peripheral neuropathy with A+AVD than with ABVD, but most patients in the two groups had resolution or amelioration of the event by the last follow-up. CONCLUSIONS: Patients who received A+AVD for the treatment of stage III or IV Hodgkin's lymphoma had a survival advantage over those who received ABVD. (Funded by Takeda Development Center Americas and Seagen; ECHELON-1 ClinicalTrials.gov number, NCT01712490; EudraCT number, 2011-005450-60.).

Interim PET-guided treatment for early-stage NLPHL: a subgroup analysis of the randomized GHSG HD16 and HD17 studies.

The optimal first-line treatment for nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) diagnosed in early stages is largely undefined. We, therefore, analyzed 100 NLPHL patients treated in the randomized HD16 (early-stage favorable; n = 85) and HD17 (early-stage unfavorable; n = 15) studies. These studies investigated the omission of consolidation radiotherapy (RT) in patients with a negative interim positron emission tomography (iPET) (ie, Deauville score <3) after chemotherapy (HD16: 2× doxorubicin, bleomycin, vinblastine, and dacarbazine [ABVD]; HD17: 2× escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone [BEACOPP] plus 2× ABVD). Patients with NLPHL treated in the HD16 and HD17 studies had 5-year progression-free survival (PFS) rates of 90.3% and 92.9%, respectively. Thus, the 5-year PFS did not differ significantly from that of patients with classical Hodgkin lymphoma treated within the same studies (HD16: P = .88; HD17: P = .50). Patients with early-stage favorable NLPHL who had a negative iPET after 2× ABVD and did not undergo consolidation RT tended to have a worse 5-year PFS than patients with a negative iPET who received consolidation RT (83% vs 100%; P = .05). There were 10 cases of NLPHL recurrence. However, no NLPHL patient died during follow-up. Hence, the 5-year overall survival rate was 100%. Taken together, contemporary Hodgkin lymphoma-directed treatment approaches result in excellent outcomes for patients with newly diagnosed early-stage NLPHL and, thus, represent valid treatment options. In early-stage favorable NLPHL, consolidation RT appears necessary after 2× ABVD to achieve the optimal disease control irrespective of the iPET result.

Managing common toxicities associated with checkpoint inhibitor and chemotherapy combinations for untreated classic Hodgkin lymphoma.

Combination checkpoint inhibitor (CPI) and chemotherapy is an effective and safe treatment strategy for patients with untreated classic Hodgkin lymphoma. Recent studies of programmed cell death protein 1 inhibitors combined with doxorubicin, vinblastine and dacarbazine have demonstrated high overall and complete response rates. This combination has a unique toxicity profile that should be managed appropriately so as not to compromise treatment efficacy. Common toxicities include rash, hepatoxicity, neutropenia and thyroid dysfunction. Here, we present four cases and the management strategies around such toxicities. In addition, we highlight key clinical decision-making around the administration of subsequent doses of CPI and chemotherapy.

Overall Survival Benefit with Tebentafusp in Metastatic Uveal Melanoma.

BACKGROUND: Uveal melanoma is a disease that is distinct from cutaneous melanoma, with a low tumor mutational burden and a 1-year overall survival of approximately 50% in patients with metastatic uveal melanoma. Data showing a proven overall survival benefit with a systemic treatment are lacking. Tebentafusp is a bispecific protein consisting of an affinity-enhanced T-cell receptor fused to an anti-CD3 effector that can redirect T cells to target glycoprotein 100-positive cells. METHODS: In this open-label, phase 3 trial, we randomly assigned previously untreated HLA-A*02:01-positive patients with metastatic uveal melanoma in a 2:1 ratio to receive tebentafusp (tebentafusp group) or the investigator's choice of therapy with single-agent pembrolizumab, ipilimumab, or dacarbazine (control group), stratified according to the lactate dehydrogenase level. The primary end point was overall survival. RESULTS: A total of 378 patients were randomly assigned to either the tebentafusp group (252 patients) or the control group (126 patients). Overall survival at 1 year was 73% in the tebentafusp group and 59% in the control group (hazard ratio for death, 0.51; 95% confidence interval [CI], 0.37 to 0.71; P<0.001) in the intention-to-treat population. Progression-free survival was also significantly higher in the tebentafusp group than in the control group (31% vs. 19% at 6 months; hazard ratio for disease progression or death, 0.73; 95% CI, 0.58 to 0.94; P = 0.01). The most common treatment-related adverse events in the tebentafusp group were cytokine-mediated events (due to T-cell activation) and skin-related events (due to glycoprotein 100-positive melanocytes), including rash (83%), pyrexia (76%), and pruritus (69%). These adverse events decreased in incidence and severity after the first three or four doses and infrequently led to discontinuation of the trial treatment (2%). No treatment-related deaths were reported. CONCLUSIONS: Treatment with tebentafusp resulted in longer overall survival than the control therapy among previously untreated patients with metastatic uveal melanoma. (Funded by Immunocore; ClinicalTrials.gov number, NCT03070392; EudraCT number, 2015-003153-18.).

Methionine restriction of glioma does not induce MGMT and greatly improves temozolomide efficacy in an orthotopic nude-mouse model: A potential curable approach to a clinically-incurable disease.

Glioma is a highly recalcitrant disease with a 5-year survival of 6.8 %. Temozolomide (TMZ), first-line therapy for glioma, is more effective in O6-methylguanine-DNA methyltransferase (MGMT)-negative gliomas than in MGMT-positive gliomas as MGMT confers resistance to TMZ. Methionine restriction is effective for many cancers in mouse models including glioma. The concern is that methionine restriction could induce MGMT by decreasing DNA methylation and confer resistance to TMZ. In the present study, we investigated the efficacy of combining methionine restriction with TMZ for the treatment of MGMT-negative glioma, and whether methionine restriction induced MGMT. Human MGMT-negative U87 glioma cells were used to determine the efficacy of TMZ combined with methionine restriction. Recombinant methioninase (rMETase) inhibited U87 glioma growth without induction of MGMT in vitro. The combination of rMETase and TMZ inhibited U87 cell proliferation more than either agent alone in vitro. In the orthotopic nude-mouse model, the combination of TMZ and a methionine-deficient diet was much more effective than TMZ alone: two mice out of five were cured of glioma by the combination. No mice died during the treatment period. Methionine restriction enhanced the efficacy of TMZ in MGMT-negative glioma without inducing MGMT, demonstrating potential clinical promise for improved outcome of a currently incurable disease.

Early pseudoprogression and progression lesions in glioblastoma patients are both metabolically heterogeneous.

The standard treatment in glioblastoma includes maximal safe resection followed by concomitant radiotherapy plus chemotherapy and adjuvant temozolomide. The first follow-up study to evaluate treatment response is performed 1 month after concomitant treatment, when contrast-enhancing regions may appear that can correspond to true progression or pseudoprogression. We retrospectively evaluated 31 consecutive patients at the first follow-up after concomitant treatment to check whether the metabolic pattern assessed with multivoxel MRS was predictive of treatment response 2 months later. We extracted the underlying metabolic patterns of the contrast-enhancing regions with a blind-source separation method and mapped them over the reference images. Pattern heterogeneity was calculated using entropy, and association between patterns and outcomes was measured with Cramér's V. We identified three distinct metabolic patterns-proliferative, necrotic, and responsive, which were associated with status 2 months later. Individually, 70% of the patients showed metabolically heterogeneous patterns in the contrast-enhancing regions. Metabolic heterogeneity was not related to the regions' size and only stable patients were less heterogeneous than the rest. Contrast-enhancing regions are also metabolically heterogeneous 1 month after concomitant treatment. This could explain the reported difficulty in finding robust pseudoprogression biomarkers.

Clinical activity and safety of sintilimab, bevacizumab, and TMZ in patients with recurrent glioblastoma.

PURPOSE: There are limited and no standard therapies for recurrent glioblastoma. We herein report the antitumour activity and safety of sintilimab, bevacizumab and temozolomide (TMZ) in recurrent glioblastoma. METHODS: We retrospectively analysed eight patients with recurrent glioblastoma treated with sintilimab (200 mg) every three weeks + bevacizumab (10 mg/kg) every three weeks + TMZ (200 mg/m²orally) (5 days orally every 28 days for a total of four weeks). The primary objective was investigator-assessed median progression-free survival(mPFS). Secondary objectives were to assess the 6-month PFS, objective response rate (ORR) and duration of response (DOR) accroding to RANO criteria. RESULTS: The mPFS time for 8 patients was 3.340 months (95% CI: 2.217-4.463), The longest PFS was close to 9 months. Five patients were assessed to have achieved partial response (PR), with an overall remission rate of 62.5%, Four patients experienced a change in tumour volume at the best response time of greater than 60% shrinkage from baseline, and one patient remained progression free upon review, with a DOR of more than 6.57 months. The 6-month PFS was 25% (95% CI: 5.0-55.0%). Three patients had a treatment-related adverse events, though no grade 4 or 5 adverse events occurred. CONCLUSION: In this small retrospective study, the combination regimen of sintilimab, bevacizumab and TMZ showed promising antitumour activity in treatment of recurrent glioblastoma, with a good objective remission rate.

Efficacy of escalating therapy with brentuximab vedotin-AVD in advanced stage Hodgkin lymphoma patients with positive interim positron emission tomography after ABVD.

Patients with advanced-stage Hodgkin lymphoma treated with ABVD who have a positive interim FDG-PET (iPET) have a poor prognosis. Escalation to BEACOPP has been shown to improve progression-free survival (PFS). However, randomized trials are lacking to determine the best strategy for intensification. We report on A-AVD escalation treatment outcomes for 15 iPET-positive patients post-ABVD. Overall response and complete response rates were 80% and 60%, respectively. Four patients underwent salvage therapy followed by autologous stem cell transplantation. At a median 17-month follow-up, all patients are alive, 87% in complete remission, and 1-year PFS was 57.8%. For patients ineligible for BEACOPP due to age, comorbidities, or preference, A-AVD escalation may be a viable alternative.

Tislelizumab monotherapy in patients with previously untreated early-stage classical Hodgkin lymphoma: a real-world study.

The anti-PD-1 antibodies have been reported to show a striking effect in relapsed and refractory(R/R) classical Hodgkin lymphoma (cHL), however, there is still limited real-world data assessing the role of anti-PD-1 antibody monotherapy in early-stage cHL. In this retrospective analysis, we reported the effectiveness and safety of tislelizumab monotherapy in the first-line therapy of early-stage cHL. Twenty-three consecutive patients (10 males and 13 females) with previously untreated stage I A-II B cHL were included. At interim evaluation after 2 doses of tislelizumab monotherapy, 11 of 23 patients (47.8%) achieved complete response (CR). At the end of tislelizumab monotherapy (EOTM), objective response was observed in 22 of 23 patients (95.7%), with CR in 16 patients (69.6%). Among six patients with PR-EOTM, two patients underwent 4 cycles of ABVD chemotherapy and one patient underwent 4 cycles of tislelizumab plus AVD. One patient who developed progressive disease (PD) after 4 doses of tislelizumab subsequently underwent 4 cycles of ABVD chemotherapy. Except for four patients with CR-EOTM, consolidative radiotherapy was given to 19 patients. All patients obtained CR at the end of all treatments. With a median follow-up time of 21.3 months (range, 6.9-32.7 months), the estimated 2-year PFS rate and 2-year OS rate were 95.65% and 100%, respectively. Except for grade 3 lymphocyte count decreased, no other grade 3/4 TRAE was observed. In addition, no serious AE was reported. Our preliminary data observed that tislelizumab monotherapy was safe and highly effective in previously untreated early-stage cHL.

Impact of baseline and interim quantitative PET parameters on outcomes of classical Hodgkin Lymphoma.

Currently, analysis of interim PET (iPET) according to the Deauville score (DS) is the most important predictive factor in Hodgkin lymphoma (HL); however, there is room for improvement in its prognostic power. This study aimed to evaluate the prognostic value of quantitative PET analysis (maximum standard uptake value [SUVmax], total metabolic tumor volume [TMTV] and total lesion glicolysis [TLG]) at baseline (PET0) and iPET in a retrospective cohort of newly diagnosed classical HL. For positive iPET (+ iPET), the reduction of quantitative parameters in relation to PET0 (ΔSUVmax, ΔTMTV and ΔTLG) was calculated. Between 2011 and 2017, 234 patients treated with ABVD were analyzed. Median age was 30 years-old, 59% had advanced stage disease, 57% a bulky mass and 25% a + iPET (DS 4-5). At baseline, high TLG was associated with an increased cumulative incidence of failure (CIF) (p = 0.032) while neither SUVmax, TMTV or TLG were associated with overall survival (OS) or progression-free survival (PFS). In multivariate analysis, only iPET was associated with CIF (p < 0.001). Among ΔSUVmax, ΔTMTV and ΔTLG, only a ΔSUVmax ≥ 68.8 was significant for PFS (HR: 0.31, CI95%: 0.11-0.86, p = 0.024). A subset of patients with improved PFS amongst + iPET was identified by the quantitative (ΔSUVmax ≥ 68.8%) analysis. In this real-world Brazilian cohort, with prevalent high-risk patients, quantitative analysis of PET0 did not demonstrate to be prognostic, while a dynamic approach incorporating the ΔSUVmax to + iPET succeeded in refining a subset with better prognosis. These findings warrant validation in larger series and indicate that not all patients with + iPET might need treatment intensification.

Highly Soluble Dacarbazine Multicomponent Crystals Less Prone to Photodegradation.

Dacarbazine (DTIC) is a widely prescribed oncolytic agent to treat advanced malignant melanomas. Nevertheless, the drug is known for exhibiting low and pH-dependent solubility, in addition to being photosensitive. These features imply the formation of the inactive photodegradation product 2-azahypoxanthine (2-AZA) during pharmaceutical manufacturing and even drug administration. We have focused on developing novel DTIC salt/cocrystal forms with enhanced solubility and dissolution behaviors to overcome or minimize this undesirable biopharmaceutical profile. By cocrystallization techniques, two salts, two cocrystals, and one salt-cocrystal have been successfully prepared through reactions with aliphatic carboxylic acids. A detailed structural study of these new multicomponent crystals was conducted using X-ray diffraction (SCXRD, PXRD), spectroscopic (FT-IR and 1H NMR), and thermal (TG and DSC) analyses. Most DTIC crystal forms reported display substantial enhancements in solubility (up to 19-fold), with faster intrinsic dissolution rates (from 1.3 to 22-fold), contributing positively to reducing the photodegradation of DTIC in solution. These findings reinforce the potential of these new solid forms to enhance the limited DTIC biopharmaceutical profile.

The role of adjuvant chemotherapy in patients with H3K27 altered diffuse midline gliomas: a multicentric retrospective study.

PURPOSE: Adult Diffuse midline glioma (DMG) is a very rare disease. DMGs are currently treated with radiotherapy and chemotherapy even if only a few retrospective studies assessed the impact on overall survival (OS) of these approaches. METHODS: We carried out an Italian multicentric retrospective study of adult patients with H3K27-altered DMG to assess the effective role of systemic therapy in the treatment landscape of this rare tumor type. RESULTS: We evaluated 49 patients from 6 Institutions. The median age was 37.3 years (range 20.1-68.3). Most patients received biopsy as primary approach (n = 30, 61.2%) and radiation therapy after surgery (n = 39, 79.6%). 25 (51.0%) of patients received concurrent chemotherapy and 26 (53.1%) patients received adjuvant temozolomide. In univariate analysis, concurrent chemotherapy did not result in OS improvement while adjuvant temozolomide was associated with longer OS (21.2 vs. 9.0 months, HR 0.14, 0.05-0.41, p < 0.001). Multivariate analysis confirmed the role of adjuvant chemotherapy (HR 0.1, 95%CI: 0.03-0.34, p = 0.003). In patients who progressed after radiation and/or chemotherapy the administration of a second-line systemic treatment had a significantly favorable impact on survival (8.0 vs. 3.2 months, HR 0.2, 95%CI 0.1-0.65, p = 0.004). CONCLUSION: In our series, adjuvant treatment after radiotherapy can be useful in improving OS of patients with H3K27-altered DMG. When feasible another systemic treatment after treatment progression could be proposed.

A combined analysis of two prospective randomised studies exploring the impact of extended post-radiation temozolomide on survival outcomes in newly diagnosed glioblastoma.

PURPOSE: The optimal duration of post-radiation temozolomide in newly diagnosed glioblastoma remains unclear, with no published phase III randomised trials. Standard-of-care stipulates 6 months. However, in routine care, it is often extended to 12 months, despite lacking robust supporting data. METHODS: GEINO14-01 (Spain) and EX-TEM (Australia) studies enrolled glioblastoma patients without progression at the end of 6 months post-radiation temozolomide. Participants were randomised 1:1 to six additional months of temozolomide or observation. Primary endpoint was 6-month progression free survival from date of randomisation (6mPFS). Secondary endpoints included overall survival (OS) and toxicity. 204 patients were required to detect an improvement in 6mPFS from 50 to 60% (80% power). Neither study recruited sufficient patients. We performed a combined analysis of individual patient data. RESULTS: 205 patients were recruited: 159 in GEINO14-01 (2014-2018) and 46 in EX-TEM (2019-2022). Median follow-up was 20.0 and 14.5 months. Baseline characteristics were balanced. There was no significant improvement in 6mPFS (57.2% vs 64.0%, OR0.75, p = 0.4), nor across any subgroups, including MGMT methylated; PFS (HR0.92, p = 0.59, median 7.8 vs 9.7 months); or OS (HR1.03, p = 0.87, median 20.1 vs 19.4 months). During treatment extension, 64% experienced any grade adverse event, mainly fatigue and gastrointestinal (both 54%). Only a minority required treatment changes: 4.5% dose delay, 7.5% dose reduction, 1.5% temozolomide discontinuation. CONCLUSION: For glioblastoma patients, extending post-radiation temozolomide from 6 to 12 months is well tolerated but does not improve 6mPFS. We could not identify any subset that benefitted from extended treatment. Six months should remain standard-of-care.

Circadian regulation of MGMT expression and promoter methylation underlies daily rhythms in TMZ sensitivity in glioblastoma.

BACKGROUND: Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite extensive research and clinical trials, median survival post-treatment remains at 15 months. Thus, all opportunities to optimize current treatments and improve patient outcomes should be considered. A recent retrospective clinical study found that taking TMZ in the morning compared to the evening was associated with a 6-month increase in median survival in patients with MGMT-methylated GBM. Here, we hypothesized that TMZ efficacy depends on time-of-day and O6-Methylguanine-DNA Methyltransferase (MGMT) activity in murine and human models of GBM. METHODS AND RESULTS: In vitro recordings using real-time bioluminescence reporters revealed that GBM cells have intrinsic circadian rhythms in the expression of the core circadian clock genes Bmal1 and Per2, as well as in the DNA repair enzyme, MGMT. Independent measures of MGMT transcript levels and promoter methylation also showed daily rhythms intrinsic to GBM cells. These cells were more susceptible to TMZ when delivered at the daily peak of Bmal1 transcription. We found that in vivo morning administration of TMZ also decreased tumor size and increased body weight compared to evening drug delivery in mice bearing GBM xenografts. Finally, inhibition of MGMT activity with O6-Benzylguanine abrogated the daily rhythm in sensitivity to TMZ in vitro by increasing sensitivity at both the peak and trough of Bmal1 expression. CONCLUSION: We conclude that chemotherapy with TMZ can be dramatically enhanced by delivering at the daily maximum of tumor Bmal1 expression and minimum of MGMT activity and that scoring MGMT methylation status requires controlling for time of day of biopsy.

dCas9/CRISPR-based methylation of O-6-methylguanine-DNA methyltransferase enhances chemosensitivity to temozolomide in malignant glioma.

BACKGROUND: Malignant glioma carries a poor prognosis despite current therapeutic modalities. Standard of care therapy consists of surgical resection, fractionated radiotherapy concurrently administered with temozolomide (TMZ), a DNA-alkylating chemotherapeutic agent, followed by adjuvant TMZ. O-6-methylguanine-DNA methyltransferase (MGMT), a DNA repair enzyme, removes alkylated lesions from tumor DNA, thereby promoting chemoresistance. MGMT promoter methylation status predicts responsiveness to TMZ; patients harboring unmethylated MGMT (~60% of glioblastoma) have a poorer prognosis with limited treatment benefits from TMZ. METHODS: Via lentiviral-mediated delivery into LN18 glioma cells, we employed deactivated Cas9-CRISPR technology to target the MGMT promoter and enhancer regions for methylation, as mediated by the catalytic domain of the methylation enzyme DNMT3A. Methylation patterns were examined at a clonal level in regions containing Differentially Methylation Regions (DMR1, DMR2) and the Methylation Specific PCR (MSP) region used for clinical assessment of MGMT methylation status. Correlative studies of genomic and transcriptomic effects of dCas9/CRISPR-based methylation were performed via Illumina 850K methylation array platform and bulk RNA-Seq analysis. RESULTS: We used the dCas9/DNMT3A catalytic domain to achieve targeted MGMT methylation at specific CpG clusters in the vicinity of promoter, enhancer, DMRs and MSP regions. Consequently, we observed MGMT downregulation and enhanced glioma chemosensitivity in survival assays in vitro, with minimal off-target effects. CONCLUSION: dCas9/CRISPR is a viable method of epigenetic editing, using the DNMT3A catalytic domain. This study provides initial proof-of-principle for CRISPR technology applications in malignant glioma, laying groundwork for subsequent translational studies, with implications for future epigenetic editing-based clinical applications.

Overcoming chemotherapy resistance in low-grade gliomas: A computational approach.

Low-grade gliomas are primary brain tumors that arise from glial cells and are usually treated with temozolomide (TMZ) as a chemotherapeutic option. They are often incurable, but patients have a prolonged survival. One of the shortcomings of the treatment is that patients eventually develop drug resistance. Recent findings show that persisters, cells that enter a dormancy state to resist treatment, play an important role in the development of resistance to TMZ. In this study we constructed a mathematical model of low-grade glioma response to TMZ incorporating a persister population. The model was able to describe the volumetric longitudinal dynamics, observed in routine FLAIR 3D sequences, of low-grade glioma patients acquiring TMZ resistance. We used the model to explore different TMZ administration protocols, first on virtual clones of real patients and afterwards on virtual patients preserving the relationships between parameters of real patients. In silico clinical trials showed that resistance development was deferred by protocols in which individual doses are administered after rest periods, rather than the 28-days cycle standard protocol. This led to median survival gains in virtual patients of more than 15 months when using resting periods between two and three weeks and agreed with recent experimental observations in animal models. Additionally, we tested adaptive variations of these new protocols, what showed a potential reduction in toxicity, but no survival gain. Our computational results highlight the need of further clinical trials that could obtain better results from treatment with TMZ in low grade gliomas.

Mitochondrial response of glioma cells to temozolomide.

Metabolic adaptations are central for carcinogenesis and response to therapy, but little is known about the contribution of mitochondrial dynamics to the response of glioma cells to the standard treatment with temozolomide (TMZ). Glioma cells responded to TMZ with mitochondrial mass increased and the production of round structures of dysfunctional mitochondria. At single-cell level, asymmetric mitosis contributed to the heterogeneity of mitochondrial levels. It affected the fitness of cells in control and treated condition, indicating that the mitochondrial levels are relevant for glioma cell fitness in the presence of TMZ.

Long-term clinical outcomes of combined modality therapy for advanced-stage Hodgkin lymphoma in the PET era: A retrospective study.

BACKGROUND OBJECTIVES: The role of consolidation radiation therapy (CRT) after complete metabolic response to chemotherapy in advanced-stage (stage III and IV) Hodgkin lymphoma (HL) is controversial. This study was undertaken to assess the clinical outcomes in terms of event free survival, local failure free survival and overall survival in individuals with advanced HL treated with chemotherapy and CRT. METHODS: A retrospective review was conducted to study the long-term clinical outcomes in individuals diagnosed with HL and treated with chemotherapy and CRT from 2012 to 2016 at a tertiary cancer care hospital in India. RESULTS: Data from 203 study participants with advanced-stage HL were analyzed. Positron emission tomography-computed tomography (PET-CT) was done at baseline and after 2 cycles for response assessment. The median age at presentation was 32 yr [interquartile range (IQR): 26-46]. Early metabolic response (after 2 cycles) and delayed metabolic response (after 4 or 6 cycles) were observed in 74.4 and 25.6 per cent of individuals, respectively. With a median follow up of 52 months (IQR: 40-67), the five-year event-free survival (EFS), local failure-free survival (LFFS) and overall survival (OS) were 83.2, 95.1 and 94.6 per cent, respectively. On univariate analysis, extranodal disease was associated with inferior EFS (P=0.043). Haemoglobin <10.5 g/dl (P=0.002) and Hasenclever index >3 (P=0.00047) were associated with poorer OS. Relapses were observed in 28/203 (13.8%) study participants with predominance at central nodal stations. The median time to relapse was 19.4 months (IQR: 13-33). Local relapse alone (at the irradiated site) was observed in 5/28 study participants, systemic (distant) relapse in 14/28 individuals, while both systemic and local relapse was observed in 9/28 participants. Extranodal disease (P=0.05), bulky disease (P=0.005) and haemoglobin concentration ≤10.5 g/dl (P=0.036) were significant predictors for disease relapse. INTERPRETATION CONCLUSIONS: Individuals with advanced-stage HL treated with anthracycline-based chemotherapy (anthracycline-based chemotherapy with doxorubicin, bleomycin, vinblastine and dacarbazine regimen) and CRT had excellent long-term outcomes. As isolated infield failures are uncommon, selective consolidation with conformal RT to high-risk sites improves final disease outcomes.