Outcome and feasibility of radiotherapy bridging in large B-cell lymphoma patients receiving CD19 CAR T in the UK

Radiotherapy (RT) has potential synergistic effects with chimeric antigen receptor (CAR) T but is not widely used as bridging therapy due to logistical challenges and lack of standardised protocols. We analysed RT bridging in a multicentre national cohort of large B-cell lymphoma patients approved for 3L axicabtagene ciloleucel or tisagenlecleucel across 12 UK centres. Of 763 approved patients, 722 were leukapheresed, 717 had data available on bridging therapy. 169/717 (24%) received RT bridging, 129 as single modality and 40 as combined modality treatment (CMT). Of 169 patients, 65.7% had advanced stage, 36.9% bulky disease, 86.5% elevated LDH, 41.7% international prognostic index (IPI) ≥3 and 15.2% double/triple hit at the time of approval. Use of RT bridging varied from 11% to 32% between centres and increased over time. Vein-to-vein time and infusion rate did not differ between bridging modalities. RT-bridged patients had favourable outcomes with 1-year progression-free survival (PFS) of 56% for single modality and 47% for CMT (1-year PFS 43% for systemic bridging). This is the largest cohort of LBCL patients receiving RT bridging prior to CAR T reported to date. Our results show that RT bridging can be safely and effectively used even in advanced stage and high-risk disease, with low dropout rates and excellent outcomes.

The ECHELON-2 Trial: 5-year results of a randomized, phase 3 study of brentuximab vedotin with chemotherapy for CD30-positive peripheral T-cell lymphoma

Background:

For patients with peripheral T-cell lymphoma (PTCL), outcomes using frontline treatment with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like therapy are typically poor. The ECHELON-2 study demonstrated that brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) exhibited statistically superior progression-free survival (PFS) per independent central review and improvements in overall survival versus CHOP for the frontline treatment of patients with systemic anaplastic large cell lymphoma or other CD30-positive PTCL.

Patients and methods:

ECHELON-2 is a double-blind, double-dummy, randomized, placebo-controlled, active-comparator phase III study. We present an exploratory update of the ECHELON-2 study, including an analysis of 5-year PFS per investigator in the intent-to-treat analysis group.

Results:

A total of 452 patients were randomized (1 : 1) to six or eight cycles of A+CHP (N = 226) or CHOP (N = 226). At median follow-up of 47.6 months, 5-year PFS rates were 51.4% [95% confidence interval (CI): 42.8% to 59.4%] with A+CHP versus 43.0% (95% CI: 35.8% to 50.0%) with CHOP (hazard ratio = 0.70; 95% CI: 0.53–0.91), and 5-year overall survival (OS) rates were 70.1% (95% CI: 63.3% to 75.9%) with A+CHP versus 61.0% (95% CI: 54.0% to 67.3%) with CHOP (hazard ratio = 0.72; 95% CI: 0.53–0.99). Both PFS and OS were generally consistent across key subgroups. Peripheral neuropathy was resolved or improved in 72% (84/117) of patients in the A+CHP arm and 78% (97/124) in the CHOP arm. Among patients who relapsed and subsequently received brentuximab vedotin, the objective response rate was 59% with brentuximab vedotin retreatment after A+CHP and 50% with subsequent brentuximab vedotin after CHOP.

Conclusions:

In this 5-year update of ECHELON-2, frontline treatment of patients with PTCL with A+CHP continues to provide clinically meaningful improvement in PFS and OS versus CHOP, with a manageable safety profile, including continued resolution or improvement of peripheral neuropathy.

Efficacy and Toxicity of Alternative Radiation Treatment Schemes for Patients With Hematologic Malignancies: A Collaborative ILROG COVID Era Report

Purpose/Objective(s)

The COVID19 pandemic required radiation oncologists (ROs) to consider shorter treatment courses to minimize patient and staff exposure and conserve healthcare resources. Hematologic ROs adopted hypofractionated radiation therapy (hRT) regimens according to guidelines published by the International Lymphoma Radiation Oncology Group (ILROG). We report for the first time the preliminary efficacy and toxicity of these novel hypofractionated regimens in the treatment of hematologic malignancies.

Materials/Methods

We conducted a multicenter, multinational retrospective study under the direction of the ILROG. All patients receiving hRT according to ILROG guidelines from 1/1/2020 to 8/31/2020 were included. Patient and treatment details were abstracted from separate institutional databases. Toxicity was graded using CTCAE v5.0.

Results

Ninety-three patients from 4 institutions treated with 114 RT courses were included. Patient and treatment details are displayed in Table 1. Median follow up for the cohort was 179 days, and 77 patients (82%) were alive at last follow up. Maximal toxicity experienced by patients included Grade 1 (n = 16), Grade 2 (n = 1) and Grade 3 (n = 1) toxicities. Of 80 sites with response assessment within the RT field, 69% of patients achieved a complete response (n = 55), 20% partial response (n = 16), 9% stable disease (n = 7), and 2% progressive disease (n = 2). No COVID19 infections during or after RT have been documented in this patient cohort.

Conclusion

HRT according to ILROG guidelines resulted in low rates of acute toxicity and reasonable short-term treatment efficacy. Longer follow up and comparison with control groups is needed to draw more definitive conclusions and will be presented at the Annual Meeting.

Radiotherapy and anti-PD-1/PD-L1 combinations in lung cancer: building better translational research platforms

Despite the unheralded success of immune checkpoint blockade in delivering durable responses for some patients with non-small-cell lung cancer (NSCLC), the majority of patients do not respond. PD-L1 tumour expression and pre-existing tumour T-cell infiltration have been correlated with improved clinical outcomes to anti-PD-1/anti-PD-L1. However, patients with tumours that are negative for PD-L1 expression can also respond to treatment. Strategies to combine other treatment modalities like radiotherapy (RT) with immune checkpoint inhibitors are being investigated as means of improving the response rates to PD-1/PD-L1 antibody blockade. RT induces immunogenic changes in cancer cells, can adaptively upregulate tumour cell PD-L1 expression and can improve the efficacy of anti-PD-1/anti-PD-L1 therapy. How we design future clinical trials in NSCLC also depends on practical considerations of delivering these treatment combinations, such as RT dose, fractionation and field volume, as well as scheduling with immune checkpoint blockade. Here, we review reasons for resistance to anti-PD-1/anti-PD-L1 and how RT may be utilised in combination with these drugs to enhance their effect by building better translational research platforms.

Immune Checkpoint Inhibitors in Lung Cancer - An Unheralded Opportunity?

Lung cancer remains the leading cause of cancer-related death worldwide, with non-small cell lung cancer accounting for 85% of the disease. Over 70% of patients present with locally advanced, non-resectable or metastatic disease and despite improvements in chemoradiotherapy regimens and the development of molecularly targeted agents, 5 year survival rates remain poor, with acquired resistance to novel targeted therapies becoming a growing concern. Currently there remains an unmet need in effectively treating and inducing durable responses in advanced disease. Targeting the immune system has, however, recently given hope of improving therapeutic outcomes for these patients. The notion that the immune system is capable of recognising and eliminating cancer cells is now a widely accepted phenomenon and growing evidence suggests lung cancer is an attractive target for such intervention. Recent success targeting the programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) axis of immune checkpoint inhibition suggests a major immunotherapeutic advance in treating lung cancer and unheralded opportunity for such approaches to further improve outcome for patients. Currently there is considerable interest in combining anti-PD-1 or PD-L1 monoclonal antibodies with established standard of care therapies such as radiotherapy. Radiotherapy is known to be immunostimulatory and efforts are underway to combine and augment the efficacy of the immune checkpoint inhibitors further. This review outlines the interaction between lung cancer and the immune system, summarises current evidence supporting the use of monoclonal antibodies targeting the PD-1 axis in lung cancer and explores the potential of combining radiotherapy with immunotherapy to augment anti-tumour immune responses.

Radiotherapy and Immunotherapy Combinations in Non-small Cell Lung Cancer: A Promising Future?

The goal of re-programming the host immune system to target malignancy with durable anti-tumour clinical responses has been speculated for decades. In the last decade such speculation has been transformed into reality with unprecedented and durable responses to immune checkpoint inhibitors seen in solid tumours. This mini-review considers the mechanism of action of immune modulating agents and the potential for combination with radiotherapy in the treatment of non-small cell lung cancer.

Phase II study of gemcitabine and bexarotene (GEMBEX) in the treatment of cutaneous T-cell lymphoma

BACKGROUND

Both gemcitabine and bexarotene are established single agents for the treatment of cutaneous T-cell lymphoma (CTCL). We investigated the feasibility and efficacy of combining these drugs in a single-arm phase II study.

METHODS

Cutaneous T-cell lymphoma patients who had failed standard skin-directed therapy and at least one prior systemic therapy were given four cycles of gemcitabine and concurrent bexarotene for 12 weeks. Responders were continued on bexarotene maintenance until disease progression or unacceptable toxicity.

RESULTS

The median age was 65 years, stage IB (n=5), stage IIA (n=2), stage IIB (n=8), stage III (n=8) and stage IVA (n=12), 17 patients were erythrodermic, 17 patients were B1, and 10 patients were both erythrodermic and B1. Thirty (86%) patients completed four cycles of gemcitabine. In all, 80.0% of patients demonstrated a reduction in modified Severity-Weighted Assessment Tool (mSWAT) score although the objective disease response rate at 12 weeks was 31% (partial response (PR) 31%) and at 24 weeks 14% (PR 14%, stable disease (SD) 23%, progressive disease (PD) 54%, not evaluable 9%). Median progression-free survival was 5.3 months and median overall survival was 21.2 months.

CONCLUSION

The overall response rate of the combination did not reach the specified target to proceed further and is lower than that previously reported for gemcitabine as a single agent.

Breast cancer risk following Hodgkin lymphoma radiotherapy in relation to menstrual and reproductive factors

BACKGROUND

Women treated with supradiaphragmatic radiotherapy (sRT) for Hodgkin lymphoma (HL) at young ages have a substantially increased breast cancer risk. Little is known about how menarcheal and reproductive factors modify this risk.

METHODS

We examined the effects of menarcheal age, pregnancy, and menopausal age on breast cancer risk following sRT in case-control data from questionnaires completed by 2497 women from a cohort of 5002 treated with sRT for HL at ages <36 during 1956-2003.

RESULTS

Two-hundred and sixty women had been diagnosed with breast cancer. Breast cancer risk was significantly increased in patients treated within 6 months of menarche (odds ratio (OR) 5.52, 95% confidence interval (CI) (1.97-15.46)), and increased significantly with proximity of sRT to menarche (Ptrend<0.001). It was greatest when sRT was close to a late menarche, but based on small numbers and needing reexamination elsewhere. Risk was not significantly affected by full-term pregnancies before or after treatment. Risk was significantly reduced by early menopause (OR 0.55, 95% CI (0.35-0.85)), and increased with number of premenopausal years after treatment (Ptrend=0.003).

CONCLUSION

In summary, this paper shows for the first time that sRT close to menarche substantially increases breast cancer risk. Careful consideration should be given to follow-up of these women, and to measures that might reduce their future breast cancer risk.

U.K. consensus statement on safe clinical prescribing of bexarotene for patients with cutaneous T-cell lymphoma

BACKGROUND

Bexarotene is a synthetic retinoid from the subclass of retinoids called rexinoids which selectively activate retinoid X receptors. It has activity in cutaneous T-cell lymphoma (CTCL) and has been approved by the European Medicines Agency since 1999 for treatment of the skin manifestations of advanced-stage (IIB-IVB) CTCL in adult patients refractory to at least one systemic treatment. In vivo bexarotene produces primary hypothyroidism which may be managed with thyroxine replacement. It also affects lipid metabolism, typically resulting in raised triglycerides, which requires prophylactic lipid-modification therapy. Effects on neutrophils, glucose and liver function may also occur. These side-effects are dose dependent and may be controlled with corrective therapy or dose adjustments.

OBJECTIVES

  To produce a U.K. statement outlining a bexarotene dosing schedule and monitoring protocol to enable bexarotene prescribers to deliver bexarotene safely for optimal effect.

METHODS

 Leaders from U.K. supraregional centres produced this consensus statement after a series of meetings and a review of the literature.

RESULTS

 The statement outlines a bexarotene dosing schedule and monitoring protocol. This gives instructions on monitoring and treating thyroid, lipid, liver, blood count, creatine kinase, glucose and amylase abnormalities. The statement also includes algorithms for a bexarotene protocol and lipid management, which may be used in the clinical setting.

CONCLUSION

 Clinical prescribing of bexarotene for patients with CTCL requires careful monitoring to allow safe administration of bexarotene at the optimal dose.

Comparisons of dosimetric approaches for fractionated radioimmunotherapy of non-Hodgkin lymphoma

AIM

The aim of this study was to compare different dosimetric approaches on therapy naïve patients enrolled in a multicentre fractionated radioimmunotherapy trial, to determine which methodological approach correlates with bone marrow toxicity.

METHODS

Twenty-height non-Hodgkin lymphoma patients were treated with one or two fractions of 90Y-Ibritumomab-Tiuxetan (11.1 MBq/kg) 8 to 12 weeks apart in four different institutions. Quantitative imaging with 111In-Ibritumomab-Tiuxetan (185 MBq) was performed at 0, 1, 4 and 7 days after infusion, starting two weeks before the therapeutic administration. A whole-body (WB) CT scan was also acquired prior to the 111In-Ibritumomab injection, for attenuation correction purposes and was segmented to derive patient-specific organ masses. All dosimetry processing was centralized in a single institution. The first method (M_2D) was based on geometric mean WB scans, corrected for attenuation, scatter and organs superposition. The second method (M_2.5D) was based on the computed assisted matrix inversion approach and used segmented CT scans. The third method (M_3D) used iterative reconstruction of tomographic scans, corrected for attenuation, scatter and collimator response. Absorbed doses were estimated for lungs, liver, kidneys and spleen using MIRD S values adjusted for organ masses. Bone marrow (BM) absorbed doses were evaluated according to imaging methods (3) and compared to blood-based approaches.

RESULTS

For some patients, organ masses such as liver or spleen significantly differed from male/female reference masses, whereas lungs and kidneys masses were relatively constant. Except for lungs, absorbed doses estimated by M_2D were higher than those from M_2.5D and these, in turn, were higher that those calculated from M_3D (Wilcoxon P<8.6e-4). Median organ absorbed dose estimates were equivalent for both fractions except for the spleen. In fact, spleen absorbed doses for the second fraction were lower than those for the first fraction, regardless of the approach. Possible explanations are that patient spleen masses were kept constant for analysis of both fractions and/or that spleen uptake was lowered after the first fraction. Estimation of BM absorbed doses from blood sampling was unable to predict platelet toxicity, but image-based methods performed better. Additionally, for most organs, the absorbed dose delivered by the first fraction could predict that delivered by the second fraction.

CONCLUSION

These results confirm that different acquisition/processing protocols will lead to statistically different absorbed doses. Additionally, image-based dosimetric approaches are needed in order to correlate absorbed dose to bone marrow toxicity.

A retrospective analysis of selective internal radiation therapy (SIRT) with yttrium-90 microspheres in patients with unresectable hepatic malignancies

AIM

To evaluate the efficacy and safety of selective internal radiation therapy (SIRT).

MATERIALS AND METHODS

A retrospective analysis was undertaken of all patients who underwent SIRT at a single institution. Diagnostic and therapeutic angiograms, computed tomography (CT) images, positron-emission tomography (PET) images, and planar isotope images were analysed. The response to SIRT was analysed using radiological data and tumour markers. Overall survival, complications, and side effects of SIRT were also analysed.

RESULTS

The initial 12 patients were included on an intention-to-treat basis, between 21/09/2005 and 07/05/2008. All patients had advanced disease and multiple prior courses of chemotherapy. One patient did not receive yttrium-90 due to complex vascular anatomy; the remaining 11 patients underwent 13 SIRT treatment episodes following work-up angiography. A response was seen using PET in 80% of patients. Using CT, the response of the tumour to therapy in the treated hepatic segments demonstrated a 20% partial response, stable disease in 50%, and progressive disease in 30%. Estimated median survival was 229 days, with 64% of patients still alive at the time of writing. No major complications were observed, although 82% of patients experienced side-effects following SIRT, mainly nausea, vomiting, and abdominal pain.

CONCLUSIONS

There have been no complications in the 12 SIRT patients. Tumour response was seen in four out of five patients who underwent PET. Objective CT response rates were mixed and are perhaps partially explained by advanced disease and limitations of using measurements to assess response. This complex and potentially hazardous service has been successfully and safely established.

Anti-Yo antibody-positive cerebellar degeneration associated with endometrial carcinoma: case report and review of the literature

Paraneoplastic cerebellar degeneration (PCD) is a rare, severely debilitating disease, often with a rapid onset and progression, which predate the diagnosis of malignancy. Despite characteristic features, diagnosis is commonly difficult and successful therapy, which relies on early instigation of treatment, is rare. Here we present a patient in whom anti-Yo antibody-positive PCD was associated with endometrial carcinoma and an extensive review of the literature outlining the clinical features, pathogenesis and treatment of PCD.

A new in vivo and in vitro B cell lymphoma model, pi-BCL1

We report a new variant of the BCL1 syngeneic mouse B-cell lymphoma model, which we have called pi-BCL1. pi-BCL1 can be established as a syngeneic tumor in BALB/c mice. Tumors can be removed, prepared and easily grown in liquid culture and subsequently transferred back successfully as syngeneic tumors. As a syngeneic tumor pi-BCL1 behave more like a lymphoma with solid tumor masses, than a chronic lymphocytic leukaemia of the original BCL1 model. The immunophenotype and the growth characteristics of the pi-BCL1 and BCL1 tumors appear very similar. Cytologically, pi-BCL1 appears to be a transformation from a small lymphocytic lymphoma to a more diffuse large cell centroblast-like higher-grade lymphoma. We are not aware of any previous reports of such transformation events in a syngeneic animal model of B cell lymphoma. We believe pi-BCL1 provides a useful new tool for the study of B cell lymphoma in vitro and in vivo and enables reduced numbers of tumor passage in mice.

Radioimmunotherapy in the pi-BCL1 B cell lymphoma model: efficacy depends on more than targeted irradiation alone

We report the in vivo radioimmunotherapy (RIT) of a new variant of the BCL1 syngeneic mouse B-cell lymphoma model, pi-BCL1, using a panel of monoclonal antibodies (MoAb) reactive with B cell-associated antigens (CD19, CD22, CD40, MHC II, and idiotype). MoAb were radiolabeled with 131I or used in conjunction with external beam irradiation. When administered early in disease (day 4) 131I-anti-MHC II MoAb produced long term disease free survivors as a result of targeted irradiation alone; the equivalent unlabelled MoAb was non-therapeutic. In contrast, 131I-anti-CD40, and 131I-anti-Idiotype (Id) MoAb administered at day 4 despite targeting irradiation and having intrinsic therapeutic activity as unconjugated antibodies, protected mice for approximately 30 days. The 131I-anti-CD19 and anti-CD22 were therapeutically inactive. Treating later in the disease (day 14, after tumor inoculation) permitted study of the efficacy in the presence of an increased tumor load. An increased tumor burden brought about an expected reduction in therapeutic activity with 131I-anti-MHC II, but surprisingly, 131I anti-CD40 and 131I-anti-Id were able to produce prolonged disease free survival in most mice. This unexpected potency of 131I-anti-CD40 and 131I-anti-Id late in disease appeared to result from the direct cytotoxic action induced by these MoAb. Mechanisms by which these two MoAb operate, in producing long-term disease free survival in animals with advanced disease appear different. Our therapeutic results have important implications for the selection of reagents for RIT and demonstrate that successful treatment with such agents may involve more than simple targeting of irradiation.