PET-adapted therapy for advanced Hodgkin lymphoma - systematic review

Outcomes of Patients with Positive Interim Positron Emission Tomography (PET) Continuing ABVD in the Clinical Setting

Recent prospective clinical trial data suggest that patients with Hodgkin’s lymphoma who continue treatment with ABVD, despite failing to attain a complete metabolic response on interim PET (PET2+), may fare better than previously published. We describe the outcomes of PET2+ patients who continued ABVD and compare the performance of a quantitative measure based on the lesion-to-liver SUV ratio (LLS qPET2+) to that of the subjective Deauville criteria (dvPET2+). We analyzed all patients with newly diagnosed advanced-stage Hodgkin lymphoma treated with frontline ABVD at the Memorial Sloan Kettering Cancer Center between 2008 and 2017. Eligibility was set to correspond with the RATHL inclusion criteria. Images were reviewed by two nuclear medicine physicians and discordant cases were resolved with a third expert in consensus. qPET2+ was defined as LLS ≥ 1.3. We identified 227 patients of whom 25% (57) were qPET2+, but only 14% (31) were dvPET2+. Forty-eight patients (84%) continued ABVD with a 3-year PFS of 70% for qPET2+ and 64% for dvPET2+. In conclusion, interim PET interpretation in clinical practice may be associated with a higher rate of scans deemed positive. Irrespective of the criteria for PET2 positivity, a subset of patients may continue ABVD without a dismal outcome.

Radiotherapy for patients with stage IV classical Hodgkin lymphoma: a propensity-matched analysis of the surveillance, epidemiology, and end results database

Background The survival advantage of radiotherapy for patients with stage IV classic Hodgkin lymphoma (HL) has not been adequately evaluated. Methods We analyzed patients with stage IV HL enrolled from the Surveillance, Epidemiology, and End Results (SEER) registry from January 2000 to December 2012. Propensity score (PS) analysis with 1:2 matching was performed to ensure well-balanced characteristics of the comparison groups. Kaplan-Meier and Cox proportional hazardous model were used to evaluate the overall survival (OS), cancer-specific survival (CSS), the hazards ratio (HR) and corresponding 95% confidence intervals (95% CI). Results Overall, for all patients with stage IV HL, receiving radiotherapy was associated with both significantly improved OS and CSS. Radiotherapy to any lesions could independently improve the OS and CSS by 30% to 36% in the multivariate analyses before and after PS matching (PSM), with the best improvement of 33% to 40% observed for patients with nodular sclerosis (P < 0.05) among all HL pathological types. In particular, radiotherapy, most likely to the residual site, was more pronouncedly associated with the improvement in survival for patients with stage IV HL who were young (age<45, P < .05) or without B symptoms (P_Interaction for OS = 0.099, P_Interaction for CSS = 0.255). For those patients without B symptoms, after PSM, the OS was improved by 65% (P = .021). Conclusions The large SEER results support that radiotherapy is associated with better survival of patients with stage IV HL.

Efficacy and safety of front-line treatments for advanced Hodgkin lymphoma: a systematic literature review

OBJECTIVE

To assess evidence on the safety and efficacy of ABVD (doxorubicin [Adriamycin®], bleomycin, vinblastine, and dacarbazine), BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone), and A+AVD (brentuximab vedotin, with doxorubicin, vinblastine, and dacarbazine) for advanced-stage Hodgkin lymphoma (HL).

METHODS

A systematic literature review (SLR) was conducted on 29 July 2016 (updated 26 July 2018) to identify randomized controlled trials (RCTs) and non-RCTs assessing the treatment of newly-diagnosed advanced-stage HL with ABVD and BEACOPP (and their variants), and A+AVD.

RESULTS

The SLR identified 62 RCTs and 42 non-RCTs. Five-year overall survival rates for ABVD and BEACOPP were 60-97% and 84-99%, and 5-year progression-free survival rates were 58-81% and 83-96%, respectively. Both regimens were associated with tolerability issues and side effects. Discontinuation or dose reduction of bleomycin resulted in fewer adverse events, without significantly affecting efficacy. A head-to-head trial demonstrated improved efficacy for A+AVD vs ABVD, with an acceptable tolerability profile. No data from head-to-head trials comparing A+AVD with BEACOPP were available, and an indirect treatment comparison was not feasible.

CONCLUSION

New therapies, such as A+AVD, maintain the efficacy observed with current treatments, and may provide a more tolerable treatment option for patients with advanced-stage HL.

Functional imaging using radiomic features in assessment of lymphoma

Lymphomas are typically large, well-defined, and relatively homogeneous tumors, and therefore represent ideal targets for the use of radiomics. Of the available functional imaging tests, [18F]FDG-PET for body lymphoma and diffusion-weighted MRI (DWI) for central nervous system (CNS) lymphoma are of particular interest. The current literature suggests that two main applications for radiomics in lymphoma show promise: differentiation of lymphomas from other tumors, and lymphoma treatment response and outcome prognostication. In particular, encouraging results reported in the limited number of presently available studies that utilize functional imaging suggest that (1) MRI-based radiomics enables differentiation of CNS lymphoma from glioblastoma, and (2) baseline [18F]FDG-PET radiomics could be useful for survival prognostication, adding to or even replacing commonly used metrics such as standardized uptake values and metabolic tumor volume. However, due to differences in biological and clinical characteristics of different lymphoma subtypes and an increasing number of treatment options, more data are required to support these findings. Furthermore, a consensus on several critical steps in the radiomics workflow -most importantly, image reconstruction and post processing, lesion segmentation, and choice of classification algorithm- is desirable to ensure comparability of results between research institutions.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages). Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12). Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies. Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study. Overall survival Twelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Four studies were assessed as low risk, and eight studies as high risk of bias for the domain other prognostic factors (covariates). Nine studies were assessed as low risk, and three studies as high risk of bias for the domain 'statistical analysis and reporting'. We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result. Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence). Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as low risk, and ten studies as high risk of bias for the domain other prognostic factors (covariates). Eight studies were assessed as high risk, thirteen as low risk of bias for statistical analysis and reporting. We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result. Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence). PET-associated adverse events No study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages).Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12).Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies.Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study.Overall survivalTwelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Nine studies were assessed as high risk, and three studies as moderate risk of bias for the domain study confounding. Eight studies were assessed as low risk, and four studies as high risk of bias for the domain statistical analysis and reporting.We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result.Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence).Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as high risk, nine studies as moderate risk and one study as low risk of bias for study confounding. Eight studies were assessed as high risk, three as moderate risk and nine as low risk of bias for statistical analysis and reporting.We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result.Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence).PET-associated adverse eventsNo study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

FDA's and EMA's approval of brentuximab vedotin for advanced Hodgkin lymphoma: Another player in the town?

ECHELON-1 study is a randomized open-labeled controlled trial investigating whether addition of brentuximab vedotin to chemotherapy offers benefit over the standard chemotherapy regimen in advanced Hodgkin lymphoma. After a median follow-up of 24.6 months, it has met its primary endpoint the reduction of modified progression-free survival being 23 percent. However, the beneficial effects have not been seen across all subgroups leading to further questions. The main aim of this review is to tackle these questions to provide the reader with in-depth insight of pros and cons of this novel, promising but ultimately controversial regimen.

Cost-Effectiveness Analysis of Brentuximab Vedotin With Chemotherapy in Newly Diagnosed Stage III and IV Hodgkin Lymphoma

PURPOSE

In a recent randomized, open-label trial (ECHELON-1), brentuximab vedotin (BV) combined with doxorubicin, vinblastine, and dacarbazine (AVD+BV) decreased the risk of progression in adults diagnosed with stage III or IV Hodgkin lymphoma (HL) compared with standard bleomycin-containing chemotherapy (doxorubicin, bleomycin, vinblastine, and dacarbazine [ABVD]). However, the cost effectiveness of incorporating BV (US$6,970 per 50-mg vial) into the first-line setting is unknown.

PATIENTS AND METHODS

We constructed a Markov decision-analytic model to measure the costs and clinical outcomes for AVD+BV compared with ABVD as first-line therapy in a cohort of patients with stage III or IV HL. Transition probabilities were estimated from ECHELON-1 by fitting parametric survival distributions. Lifetime direct health care costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated for AVD+BV compared with ABVD from a US payer perspective. Our model was also used to estimate BV price reductions that would achieve more favorable cost effectiveness under indication-specific pricing.

RESULTS

AVD+BV was associated with an improvement of 0.56 QALYs compared with treatment with standard ABVD. However, incorporating BV into first-line therapy led to significantly higher lifetime health care costs ($361,137 v $184,291), causing the ICER for AVD+BV to be $317,254 per QALY. If indication-specific pricing were implemented, acquisition costs for BV used in the first-line setting would need to be reduced by 56% to 73% for ICERs of $150,000 to $100,000 per QALY, respectively.

CONCLUSION

Substituting BV for bleomycin during first-line therapy for stage III or IV HL is unlikely to be cost effective under current drug pricing. Should indication-specific pricing be implemented, significant price reductions for BV used in the first-line setting would be needed to reduce ICERs to more widely acceptable values.