Impact of individualized treatment on recovery from fatigue and return to work in survivors of advanced-stage Hodgkin's lymphoma: results from the randomized international GHSG HD18 trial

BACKGROUND

Persisting cancer-related fatigue impairs health-related quality of life (HRQoL) and social reintegration in patients with Hodgkin's lymphoma (HL). The GHSG HD18 trial established treatment de-escalation for advanced-stage HL guided by positron emission tomography after two cycles (PET-2) as new standard. Here, we investigate the impact of treatment de-escalation on long-term HRQoL, time to recovery from fatigue (TTR-F), and time to return to work (TTR-W).

PATIENTS AND METHODS

Patients received European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) and life situation questionnaires at baseline, interim, end of treatment, and yearly follow-up. TTR-F was defined as time from the end of chemotherapy until the first fatigue score <30. TTR-W was analyzed in previously working or studying patients and measured from the end of treatment until the first documented work or education. We compared duration of treatment on TTR-F and TTR-W using Cox proportional hazards regression adjusted for confounding variables.

RESULTS

HRQoL questionnaires at baseline were available in 1632 (83.9%) of all randomized patients. Overall, higher baseline fatigue and age were significantly associated with longer TTR-F and TTR-W and male sex with shorter TTR-W. Treatment reduction from eight to four chemotherapy cycles led to a significantly shorter TTR-F [hazard ratio (HR) 1.41, P = 0.008] and descriptively shorter TTR-W (HR 1.24, P = 0.084) in PET-2-negative patients. Reduction from six to four cycles led to non-significant but plausible intermediate accelerations. The addition of rituximab caused significantly slower TTR-F (HR 0.70, P = 0.0163) and TTR-W (HR 0.64, P = 0.0017) in PET-2-positive patients. HRQoL at baseline and age were the main determinants of 2-year HRQoL.

CONCLUSIONS

Individualized first-line treatment in patients with advanced-stage HL considerably shortens TTR-F and TTR-W in PET-2-negative patients. Our results support the use of response-adapted shortened treatment duration for patients with HL.

Quality Analysis of Radiation Therapy for Hodgkin Lymphoma in the HD 16/17 Trials: A Final Report By the Reference Radiation Oncology Panel of the German Hodgkin Study Group

PURPOSE/OBJECTIVE(S)

The HD 16 and 17 trials by the German Hodgkin Study Group (GHSG) have evaluated the use of consolidative radiotherapy (RT) in early-favorable and -unfavorable stage Hodgkin lymphoma (HL), respectively (1, 2). Quality of RT planning and execution is pivotal for treatment outcome in HL with protocol violations jeopardizing prognosis (3). Consequently, the present work aims at a decisive analysis of quality and dosimetry in the modern era.

MATERIALS/METHODS

Random samples of 100 involved-field RT (IFRT) plans in HD16 and 176 plans in HD17 (134 involved-node RT (INRT) and 42 IFRT) were selected for analysis. Evaluation was performed systematically by the reference radiation oncology panel using pre-chemotherapy imaging, recommendation by the reference radiation oncology and RT planning imaging and graded as "correct", "minor" or "major deviation", respectively. RT doses to the target volume and organs at risks (OAR) were analyzed using dose-volume histograms.

RESULTS

Median RT doses were 20 Gy (19.8 Gy-21.6 Gy) in HD16 and 30 Gy in HD17 (IFRT: 18-30.6 Gy, INRT: 14 Gy-40 Gy). Overall, 84.0%, 69.0%, and 76.1% of RT series in HD16, the IFRT-group of HD17 and the INRT-group of HD17, respectively, were planned correctly. The main reason for major deviation was an insufficient coverage of an involved region (11 %-14.3 %). There was no significant difference in quality between IFRT and INRT in HD17 (p = 0.418 for any deviations; p = 0.466 for major deviations). In comparison to previous GHSG studies in the respective stages, a significant increase in correct RT-series (p<0.001) and decrease in major deviations (p<0.001) occurred. However, doses to OAR varied individually with median values of 4.3 Gy (0.2 Gy-9.2 Gy), 4.7 Gy (0.2 Gy-15.2 Gy) and 3.8 Gy (0.0 Gy-16.0 Gy) for mean doses to the right lung, left lung and heart in HD16, respectively. Correspondingly, values were 9.8 Gy (0.3 Gy-20.0 Gy), 10.5 Gy (0.2 Gy-26.5 Gy) and 13.1 Gy (0.5 Gy-30.4 Gy) for mean doses to the right lung, left lung and heart in HD17, respectively. The size of the planning target volume decreased significantly with INRT compared to IFRT (median values: 1163.1 ml vs. 1464.3 ml; p = 0.043). However, only some OAR-parameters (V25 of the right and left lung, respectively, thyroid and spinal cord) showed significant differences between INRT and IFRT in HD17. The use of intensity-modulated techniques in HD 17 resulted in an increase in V5 and V10 of the lungs with a concomitant decrease in V20-V30.

CONCLUSION

Quality of RT in the planning and treatment of HL has improved significantly with the latest GHSG study generation. Future analyses will focus on a further individualization of treatment fields.

LITERATURE

[CAR T-cell therapy for malignant B-cell lymphoma : A new treatment paradigm]

Following the first demonstration of efficacy of anti-CD19-directed chimeric antigen receptor (CAR) T cells in a patient with relapsed chronic lymphocytic leukemia (CLL) in 2011, pivotal studies for this innovative therapy were initially conducted in multiple relapsed or refractory (r/r) childhood and young adult acute B‑cell leukemia and in aggressive adult B‑cell lymphoma. The studies demonstrated efficacy even in chemotherapy-refractory disease, resulting in the first approval of autologous and genetically engineered T cells for the treatment of r/r B‑cell acute lymphoblastic leukemia (B-ALL) in the US for the product tisagenlecleucel (Kymriah®, Novartis) back in 2018. Approval for the treatment of r/r aggressive B‑cell lymphoma followed shortly thereafter for tisagenlecleucel and axicabtagene ciloleucel (Yescarta, Kite/Gilead). This review focuses on the treatment of aggressive B‑cell lymphoma and other CD19 positive B‑cell lymphomas by summarizing the study results of clinically tested CAR T cells, discussing possible resistance mechanisms, and providing an outlook on ongoing studies with new target antigens for the treatment of B‑cell lymphomas.

Thrombosis as a treatment complication in Hodgkin lymphoma patients: a comprehensive analysis of three prospective randomized German Hodgkin Study Group (GHSG) trials

BACKGROUND

The prognosis of Hodgkin lymphoma (HL) is excellent rendering research into treatment complications highly important. An important complication of cancer and its treatment is thrombosis. Thrombotic events are regularly observed in HL patients but precise information on incidence and risk factors is lacking and the value of prophylactic anticoagulation unclear.

PATIENTS AND METHODS

Thus, we comprehensively studied thrombotic events in 5773 patients from the German Hodgkin Study Group (GHSG) HD13-15 trials in early-favorable, intermediate and advanced HL. We estimated the incidence of and identified risk factors for thrombotic events. Additionally, we provide detailed data on the time course and characteristics of thrombotic events.

RESULTS

A total of 193 thrombotic events occurred for an incidence of 3.3%. Out of these, 175 (90.7%) were venous thromboses, 3 (1.5%) newly emerging post-thrombotic syndromes and 15 (7.8%) arterial thromboses. There were 11 (0.7%) events in early-favorable, 27 (1.3%) in early-unfavorable and 155 (7.3%) in advanced patients, the latter incidence being significantly higher (P < 0.001). The most common locations were deep vein thrombosis of the arm (46.3%) and leg (24.6%). Most venous thrombotic events occurred during chemotherapy (78.9%). We observed 59 (30.6%) catheter-associated events and a descriptively increased risk of venous thrombotic events in patients with oral contraception use during treatment (6.8% versus 3.9%). In advanced HL, the incidence of venous thrombotic events was increased upon treatment with BEACOPP-14 (9.4%, P = 0.0079) compared with 5.1% with 6×BEACOPPesc and 5.7% with 8×BEACOPPesc. Among commonly applied risk factors, including the Khorana score, only age and smoking were prognostic.

CONCLUSIONS

The incidence of thrombotic events in advanced stage HL is comparable to other high-risk cancer patients, especially if treated with dose-dense regimens. Additional risk factors are higher age and smoking. Selected HL patients could benefit from prophylactic anticoagulation, however, further interventional studies are needed before general recommendations can be made.

Value of bone marrow biopsy in Hodgkin lymphoma patients staged by FDG PET: results from the German Hodgkin Study Group trials HD16, HD17, and HD18

Background

Bone marrow (BM) involvement defines advanced-stage Hodgkin lymphoma and thus has impact on the assignment to treatment. Our aim was to evaluate whether the established BM biopsy may be omitted in patients if 18F-fluorodeoxyglucose positron emission tomography (PET) scanning is carried out during staging.

Patients and methods

Our analysis set consisted of 832 Hodgkin lymphoma patients from the German Hodgkin Study Group trials HD16, HD17, and HD18 who underwent both PET scanning and BM biopsy before treatment. All PET studies were centrally reviewed and BM was categorized as showing focal involvement or not.

Results

Taking BM biopsy as reference standard, baseline PET showed a negative predictive value of 99.9% [95% confidence interval (CI) 99.2% to 100%] with true-negative results in 702 of 703 cases. The sensitivity of PET for detecting BM involvement was 95.0% (95% CI 75.1% to 99.9%) as it could identify 19 out of 20 patients with positive BM biopsy. Moreover, PET found 110 additional subjects with focal BM lesions who would have been considered negative by biopsy.

Conclusions

When compared with BM biopsy, PET was able to detect focal BM lesions in a large number of additional patients. This indicates that conventional BM biopsy may substantially underestimate the actual incidence of BM involvement. Given the high negative predictive value, baseline PET scanning can safely be used to exclude BM involvement in Hodgkin lymphoma. BM biopsy should be considered only in such patients in whom PET-detected lesions lead to a change of treatment protocol.

Registered trials

The trials included in this analysis were registered at ClinicalTrials.gov: HD16-NCT00736320, HD17-NCT01356680, and HD18-NCT00515554.

FDG-PET in Hodgkin lymphoma

The high negative predictive value of FDG-PET in therapy control of Hodgkin lymphoma is proven by the data acquired up to now. Thus, the analysis of the HD15 trial has shown that consolidation radiotherapy might be omitted in PET negative patients after effective chemotherapy. Further response adapted therapy guided by PET seems to be a promising approach in reducing the toxicity for patients undergoing chemotherapy. The criteria used for the PET interpretation have been standardized by the German study groups for Hodgkin lymphoma patients and will be reevaluated in the current studies.

Concordance in the interpretation of PET after chemotherapy in advanced stage Hodgkin lymphoma

The aim was to analyze the degree of agreement between the central review panel and the local PET interpretation within the HD15 trial and its impact on subsequent treatment and progression free survival.

PATIENTS, METHODS

The analysis set consisted of 739 patients with residues ≥ 2.5 cm after 6 or 8 cycles of BEACOPPesc from the HD15 trial performed by the German Hodgkin Study Group. The recommendation for or against further radiotherapy was based on the central [(18)F]FDG-PET interpretation. Central PET interpretation was compared to the local PET interpretation and concordance was measured using Cohen's Kappa coefficient. Prognostic impact of the analysis of concordance between local and central PET interpretations was evaluated using progression free survival (PFS); groups were compared with the log rank test.

RESULTS

The central panel rated 548 of 739 patients (74%) as PET negative. Of these, 513 were also rated as PET negative in the local PET interpretation. PET positivity was seen by central reviewers in the remaining 191 patients (26%), in concordance with local reviewers in 155 cases. Even though substantial agreement was found (Cohen's Kappa 0.81), the interpretation of the central PET review panel led to a different therapeutic recommendation in 71/739 (10%) patients. PFS was equally high in groups in which the therapeutic regime had been changed on the basis of the central panel decision.

CONCLUSION

High concordance is found between local and central reviewers with regard to PET interpretation in residual tissue after intense chemotherapy. The existence of the central PET review panel allows the identification of additional patients as PET negative so that radiotherapy can be safely omitted (35 of 548 patients = 4.7%).

Impact of risk factors on outcomes in early-stage Hodgkin's lymphoma: an analysis of international staging definitions

BACKGROUND

In early-stage Hodgkin's lymphoma (HL), treatment according to the early favorable or unfavorable subgroup is guided by staging definitions, which differ between various study groups worldwide. We analyzed risk factors used in different international staging systems and their impact on the outcome of early-stage HL patients.

PATIENTS AND METHODS

In 1173 early-stage HL patients treated homogenously within the German Hodgkin Study Group (GHSG) trials HD10 and HD11, the impact of three staging systems developed and used by the GHSG, the European Organization for Research and Treatment of Cancer (EORTC), and the National Comprehensive Cancer Network (NCCN) in discriminating risk groups for progression-free survival (PFS) and overall survival (OS) was assessed and the relevance of their single risk factors was investigated.

RESULTS

All the three staging systems defined an unfavorable risk group out of early-stage patients of comparable size (56%, 55%, and 57%), having a significantly poorer PFS and OS as compared with the corresponding favorable group; 5-year differences between early favorable and early unfavorable in terms of PFS were 9.4% (HR 2.61, 95% CI 1.74-3.91), 6.7% (HR 2.10, 95% CI 1.41-3.13), and 8.6% (HR 2.14, 95% CI 1.45-3.16) with the GHSG, EORTC, and NCCN definition, respectively. Sensitivity was high for all systems (84%, 79%, and 83%); however, there was a low specificity with high rates of false-positive results (1-specificity 54%, 53%, and 55%, respectively). Models of high sensitivity included risk factors associated with large tumor burden and high tumor activity. Most risk factors for tumor-specific end points were also predictive of OS.

CONCLUSIONS

Differentiating between a favorable and an unfavorable risk group has significant impact on PFS and OS in early-stage HL patients in the modern treatment era. Risk-adapted treatment strategies using new risk factors with higher specificity are needed.

An individual patient-data comparison of combined modality therapy and ABVD alone for patients with limited-stage Hodgkin lymphoma

BACKGROUND

Treatment options for patients with nonbulky stage IA-IIA Hodgkin lymphoma include combined modality therapy (CMT) using doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) plus involved-field radiation therapy (IFRT), and chemotherapy with ABVD alone. There are no mature randomized data comparing ABVD with CMT using modern radiation techniques.

PATIENTS AND METHODS

Using German Hodgkin Study Group HD10/HD11 and NCIC Clinical Trials Group HD.6 databases, we identified 588 patients who met mutually inclusive eligibility criteria from the preferred arms of HD10 or 11 (n = 406) and HD.6 (n = 182). We evaluated time to progression (TTP), progression-free (PFS) and overall survival, including in three predefined exploratory subset analyses.

RESULTS

With median follow-up of 91 (HD10/11) and 134 (HD.6) months, respective 8-year outcomes were for TTP, 93% versus 87% [hazard ratio (HR) 0.44, 95% confidence interval (CI) 0.24-0.78]; for PFS, 89% versus 86% (HR 0.71, 95% CI 0.42-1.18) and for overall survival, 95% versus 95% (HR 1.09, 95% CI 0.49-2.40). In the exploratory subset analysis including HD10 eligible patients who achieved complete response (CR) or unconfirmed complete response (CRu) after two cycles of ABVD, 8-year PFS was 87% (HD10) versus 95% (HD.6) (HR 2.8; 95% CI 0.64-12.5) and overall survival 96% versus 100%. In contrast, among those without CR/CRu after two cycles of ABVD, 8-year PFS was 88% versus 74% (HR 0.35; 95% CI 0.16-0.79) and overall survival 95% versus 91%, respectively (HR 0.42; 95% CI 0.12-1.44).

CONCLUSIONS

In patients with nonbulky stage IA-IIA Hodgkin lymphoma, CMT provides better disease control than ABVD alone, especially among those not achieving complete response after two cycles of ABVD. Within the follow-up duration evaluated, overall survivals were similar. Longer follow-up is required to understand the implications of radiation and chemotherapy-related late effects.

CLINICAL TRIALS

The trials included in this analysis were registered at ClinicalTrials.gov: HD10 - NCT00265018, HD11 - NCT00264953, HD.6 - NCT00002561.

Sexual quality of life in Hodgkin Lymphoma: a longitudinal analysis by the German Hodgkin Study Group

Background:

Health-related quality of life (HRQoL) comprises different domains of physical, mental, and social well-being. In this analysis, we focus on sexual quality of life in Hodgkin Lymphoma (HL) patients.

Methods:

Four-thousand one-hundred and sixty patients enroled in the HD10–HD12 trials underwent HRQoL assessment. Instruments included the Quality of Life Questionnaire for survivors (QLQ-S), combining the European Organisation for Research and Treatment of Cancer QLQ-C30, Multidimensional fatigue (FA) inventory (MFI-20) and an additional sexual functioning (SX) scale. We describe SX up to 27 months after therapy and analyse relationship to stage, age, gender, FA, social functioning, and therapy. Statistical methods range from descriptive statistics to a classification of SX courses, and a longitudinal structural equations model with full information maximum likelihood estimation of missing data. In the analysis, a score below 50 was used to describe severe sexual dysfunction.

Results:

Three-thousand two-hundred and eight patients provided data on SX. Patients in advanced stages reported lower SX than patients in early stages both, before and after the treatment. During follow-up, an improvement of SX compared with baseline was detected, except for those ⩾50 years. Patients in early stages reached normal SX, whereas advanced-stage patients remained below the reference value for healthy controls. Sexual functioning during follow-up was significantly and strongly related to previous SX, other HRQoL measures, age, and stage, and to lesser degree with gender and chemotherapy.

Conclusion:

Overall, HL patients have a decreased sexual quality of life at baseline, which improves after therapy and normalises in early-stage patients. Importantly, long-term SX is more closely related to patient characteristics and SX at baseline than to the intensity of treatment.

Comparing long-term toxicity and efficacy of combined modality treatment including extended- or involved-field radiotherapy in early-stage Hodgkin's lymphoma

BACKGROUND

To evaluate long-term toxicity and efficacy of a combined modality strategy including extended-field radiotherapy (EF-RT) or involved-field radiotherapy (IF-RT), the German Hodgkin Study Group carried out a follow-up analysis in patients with early unfavorable Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

One thousand two hundred and four patients were randomized to four cycles of chemotherapy followed by either 30 Gy EF- or 30 Gy IF-RT (HD8 trial); 532 patients in each treatment arm were eligible.

RESULTS

At 10 years, no arm differences were revealed with respect to freedom from treatment failure (FFTF) (79.8% versus 79.7%), progression-free survival (79.8% versus 80.0%), and overall survival (86.4% versus 87.3%). Non-inferiority of IF-RT was demonstrated for the primary end point FFTF (95% confidence interval for hazard ratio 0.72-1.25). Elderly patients had a poorer outcome when treated with EF-RT. So far, 15.0% of patients in arm A and 12.2% in arm B died, mostly due to secondary malignancies (5.3% versus 3.4%) or HL (3.2% versus 3.4%). After EF-RT, there were more secondary malignancies overall (58 versus 45), especially acute myeloid leukemias (11 versus 4).

CONCLUSION

Radiotherapy intensity reduction to IF-RT does not result in poorer long-term outcome but is associated with less acute toxicity and might be associated with less secondary malignancies.

Fertility and gonadal function in female survivors after treatment of early unfavorable Hodgkin lymphoma (HL) within the German Hodgkin Study Group HD14 trial

BACKGROUND

In the HD14 trial, 2×BEACOPPescalated+2×ABVD (2+2) has improved the primary outcome. Compared with 4×ABVD, this benefit might be compromised by more infertility in women. Therefore, we analyzed gonadal function and fertility.

PATIENTS AND METHODS

Women≤45 years in ongoing remission at least 1 year after therapy were included. Hormone parameters, menopausal symptoms, measures to preserve fertility, menstrual cycle, pregnancies, and offspring were evaluated.

RESULTS

Three hundred and thirty one of 579 women addressed participated (57.2%) and 263 per-protocol treated patients qualified (A=ABVD: 137, B=2+2: 126, mean time after therapy 42 and 43 months, respectively). Regular menstrual cycle after treatment (A: 87%, B: 83%) and time to recovery (≤12 months) were not different. Follicle-stimulating hormone and anti-Muellerian hormone were significantly better in arm A. However, pregnancies after therapy favored arm B (A: 15%, B: 26%, P=0.043) and motherhood rates were equivalent to the German normal population. Multivariate analysis revealed prophylactic use of gonadotropin-releasing hormone (GnRH) analogues as highly significant prognostic factor for preservation of fertility (odds ratio=12.87, P=0.001). Severe menopausal symptoms were frequent in women≥30 years (A: 21%, B: 25%).

CONCLUSIONS

Hormonal levels after 2+2 indicate a reduced ovarian reserve. However, 2+2 in combination with GnRH analogues does not compromise fertility within the evaluated observation time.

No protection of the ovarian follicle pool with the use of GnRH-analogues or oral contraceptives in young women treated with escalated BEACOPP for advanced-stage Hodgkin lymphoma. Final results of a phase II trial from the German Hodgkin Study Group

BACKGROUND

The reduction of treatment-related toxic effects is the main goal in the current trials of the German Hodgkin Study Group (GHSG). In this regard, the protection of the ovarian reserve in young women is very important. Therefore, the GHSG investigated the use of gonadotropin-releasing hormone-analogues (GnRH-a) and oral contraceptives (OC) in young women with advanced-stage Hodgkin lymphoma (HL).

PATIENTS AND METHODS

Women (18-40 years) were randomly assigned either to receive daily OC or monthly GnRH-a during escalated combination therapy with bleomycin, etoposide, adriamycin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPPesc). Hormonal levels were determined at baseline, during therapy, and at follow-up.

RESULTS

The study was closed prematurely after an interim analysis of 12 patients in arm A (OC) and 11 in arm B (GnRH-a), 9 and 10 are assessable for the primary end point. Women's median age was 25 years in both arms. The anti-Mullerian hormone level after at least 12 months was reduced in all patients. For the entire study cohort, the respective ovarian follicle preservation rate was 0% (95% confidence interval 0% to 12%).

CONCLUSION

We observed no protection of the ovarian reserve with hormonal co-treatment during BEACOPPesc. This result supports efforts of ongoing trials to reduce chemotherapy intensity and toxicity. Alternative strategies for the protection of fertility must be offered to young female HL patients before the start of BEACOPPesc therapy.

[Secondary malignancies after successful primary treatment of malignant Hodgkin's lymphoma]

Malignant Hodgkin's lymphoma (HL) has become a curable disease through the increasing intensity of the treatment strategies applied. These regimens are aggressive, including radiotherapy and chemotherapy leading to the possibility of secondary malignancies. The German Hodgkin Lymphoma Study Group considered three cohorts including 5,411 patients with all stages of HL. In 127 patients a secondary solid tumor was diagnosed (cumulative risk 2%, median follow-up 72 months), with bronchial carcinomas (23.6%) and colorectal adenocarcinomas (20.5%) being the most frequent neoplasms. Secondary acute myeloid leukemia was found in 36 patients, another ten developed myeloid dysplasia (cumulative risk 1%, median follow-up 55 months). A total of 52 patients revealed a non-Hodgkin's lymphoma (NHL; cumulative risk 0.9%, median follow-up 46 months). The overall incidence of secondary malignancies was 3.9% in patients who had been treated successfully for their HL with radio- and/or chemotherapy.A secondary NHL can be particularly difficult to be distinguished from the preceding HL. Therefore, in case of a suspected relapse, a complete histopathological work-up must be performed.

Immunotherapy of Hodgkin's lymphoma

Many new treatment approaches have given promising results in experimental Hodgkin's lymphoma (HL) models. Early clinical trials evaluating antibody based compounds as immunotoxins (ITs), radioimmunotherapy (RIT), bispecific molecules (BSMs), and recently monoclonal antibodies (MAbs), have demonstrated some clinical efficacy in patients with advanced refractory or relapsed HL. In addition, cellular immunotherapy is evolving. Although it seems unlikely to cure chemotherapy resistant patients with larger tumor masses by either of these approaches alone, the combination with conventional chemotherapy might help to overcome resistance of Hodgkin-/ReedSternberg (H-RS) cells. Another rationale for the development of these immunotherapies is to eliminate residual disease and thereby to prevent relapses from the disease. Currently, several clinical studies are running. A murine MAb (Ki-4) based 131 Iodine conjugate has shown efficacy in refractory HL patients in a phase II study, but less toxic constructs using alternate MAbs or isotopes should be developed. A humanized as well as a fully human anti-CD30 MAb are being tested in clinical phase I/II studies. These MAbs could engage the human immune system against the H-RS cells. In addition, these MAbs could be then combined with conventional chemotherapy in order to improve the treatment of HL.

Clinical evaluation of ricin A-chain immunotoxins in patients with Hodgkin's lymphoma

BACKGROUND

Immunotoxins (ITs) consist of cell binding ligands coupled to toxins or their subunits. Hodgkin's lymphoma (HL) is an excellent target for ITs since lymphocyte activation markers such as CD25 and CD30 are expressed in large numbers. The ITs RFT5.dgA (anti CD25) and Ki-4.dgA (anti CD30) were constructed by linking the monoclonal antibodies RFT5 and Ki-4 to deglycosylated ricin A-chain (dgA). Both ITs showed potent specific activity against HL cells in vitro and in vivo in animal models, and were subsequently evaluated in phase I/II clinical trials in humans.

PATIENTS AND METHODS

In two separate trials, the ITs were administered i.v. four times every other day over 4 h. The objectives of the phase I trials included the determination of the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics, antitumor activity and immune response against the IT.

RESULTS

Twenty-seven patients with refractory HL were included in the phase I/II study of RFT5.dgA and 17 patients were included in the phase I study of Ki-4.dgA. The MTD of RFT5.dgA was 15 mg/m(2), whereas that of Ki-4.dgA was 5 mg/m(2). DLTs were related to vascular leak syndrome, consisting of edema, tachycardia, dyspnea, weakness and myalgia. Measurement of serum levels of RFT5.dgA demonstrated a C(max) of 0.2-9.7 micro g/ml with a half-life (t()) varying from 4 to 10.5 h. Peak serum concentration of Ki-4.dgA ranged from 0.23 to 1.7 micro g/ml. In both trials approximately 60% of patients developed human anti-mouse and/or anti-dgA antibodies. Seventeen of 18 patients treated at the MTD of RFT5.dgA were evaluable for clinical response. Responses included two partial remissions (PR), one minor response (MR) and five stable diseases (SD). Fifteen of 17 patients treated with Ki-4.dgA were evaluable for clinical response. Responses included one PR, one MR and two SD.

CONCLUSIONS

RFT5.dgA and Ki-4.dgA showed moderate efficacy in heavily pretreated refractory patients with HL. Ki-4.dgA was less well tolerated than RFT5.dgA. This might be due, at least in part, to the formation of Ki-4.dgA/sCD30 complexes.

[Hodgkin's lymphoma in nuclear medicine: diagnostic and therapeutic aspects]

Today, diagnostic and therapeutic strategies of Hodgkin lymphoma (HL) with positron emission tomography and radioimmunotherapy include state-of-the-art nuclear medicine which require the cooperation between oncology and nuclear medicine. The benefit of FDG-PET in HL patients with residual tumor masses consists of its high negative predictive value in the therapy control of the disease. The concept of waitful watching in patients with PET-negative residual masses after BEACOPP-chemotherapy will be evaluated in a large multicenter trial of the GHSG (German Hodgkin Study Group). Radioimmunotherapy has been performed in patients with CD20-positive Non-Hodgkin lymphoma for 10 years with promising results. HL is also an excellent target for immunotherapy due to the expression of antigens such as CD25 and CD30. Thus, a new radioimmunoconstruct consisting of the murine anti-CD30 antibody Ki-4 labeled with iodine-131 was developed for patients with relapsed or refractory HL.

Hodgkin’s lymphoma in nuclear medicine: diagnostic and therapeutic aspects

Today, diagnostic and therapeutic strategies of Hodgkin lymphoma (HL) with positrone emission tomography and radioiummunotherapy include state-of-the-art nuclear medicine which require the cooperation between oncology and nuclear medicine. The benefit of FDG-PET in HL patients with residual tumor masses consists of its high negative predictive value in the therapy control of the disease. The concept of waitful watching in patients with PET-negative residual masses after BEACOPPchemotherapy will be evaluated in a large multicenter trial of the GHSG (German Hodgkin Study Group). Radioimmunotherapy has been performed in patients with CD20-positive Non-Hodgkin lymphoma for 10 years with promising results. HL is also an excellent target for immunotherapy due to the expression of antigens such as CD25 and CD30. Thus, a new radio-immunoconstruct consisting of the murine anti-CD30 antibody Ki-4 labeled with iodine-131 was developed for patients with relapsed or refractory HL.

Current strategies of antibody-based treatment in Hodgkin's disease

Many new approaches involving antibody-based agents have given promising results in experimental Hodgkin's disease (HD) models. Clinical trials with monoclonal antibodies, immunotoxins, bispecific constructs and radioimmunoconjugates have demonstrated some clinical efficacy in patients with advanced refractory HD. Although it seems unlikely that resistant patients with larger tumor masses will be cured by either of these approaches, it might be feasible to treat bulky disease by conventional therapy and then administer biological agents to kill residual Hodgkin and Reed-Sternberg cells. Future phase III trials will have to prove a possible superior effect of this combined immunochemotherapy. Currently, the evaluation of the most promising approaches continues.

Quantitative molecular monitoring of residual tumor cells in chronic lymphocytic leukemia

New therapeutic approaches for the treatment of B-cell chronic lymphocytic leukemia (B-CLL) can induce remarkable responses. Molecular remissions have been observed occasionally after high-dose chemotherapy. Thus, new improved techniques to monitor residual tumor cells on a molecular basis in CLL are warranted. For this purpose, a real-time quantitative allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) for patients with B-CLL was designed. In the present study, the PCR assay was standardized with identical cycling parameters as well as primer, probe, and MgCl(2) concentration for each patient. Ten patients were monitored with DNA samples obtained at 52 time points (median: 5.2 per patient). The median follow-up per patient was 11.4 months. Nine of ten patients had PCR-detectable residual tumor cells in the peripheral blood after therapy. One patient became PCR negative with a combination of fludarabine and rituximab after the end of treatment. The MRD levels in patients with detectable disease ranged from 0.002% to 10.1% after therapy. We conclude that real-time quantitative ASO-PCR can be utilized for quantitative molecular monitoring of minimal residual disease (MRD) in B-CLL patients in complete remission (CR), that new effective treatment approaches such as combined chemo/immunotherapy can render CLL patients PCR negative, and that different MRD levels in PCR-positive patients were observed warranting further investigation into possible correlation with clinical outcome.