Poor outcomes for trial-ineligible patients receiving polatuzumab for relapsed/refractory diffuse large B-cell lymphoma in routine care: An Australian Lymphoma and Related Diseases Registry project.

Polatuzumab vedotin (Pola) is an approved therapy in combination with rituximab and bendamustine for relapsed or refractory diffuse large B-cell lymphoma (RR-DLBCL) based on positive results of the landmark phase II randomised G029365 trial. However, trial results for many approved novel therapies in RR-DLBCL have not been replicated in routine care cohorts, as RR-DLBCL patient populations are heterogeneous and trial eligibility is increasingly restrictive. We evaluated outcomes from pola ± bendamustine and rituximab in patients with RR-DLBCL enrolled in a compassionate access program with no alternative treatment options identified via the Australasian Lymphoma and Related Diseases Registry according to their eligibility for the original phase II published study. Of 58 eligible patients, 74% met the criteria deeming them ineligible for the G029365 original study at the time of pola's commencement. Median progression-free survival and overall survival in our cohort were 2.3 and 3.5 months, respectively. In contrast to the landmark trial cohort, more of our patients ceased therapy prior to completion, the majority due to progressive disease and only 8/58 received any subsequent treatment. Dismal outcomes in this Australian real-world population demonstrate trial eligibility is challenging to meet, and newer treatments can be difficult to deliver in routine care. Clinically applicable results from therapeutic studies require trial cohorts to reflect representative clinical populations wherever possible, and more research is required to address the benefit of novel agents in the increasing majority who are ineligible for modern studies.

Impact and utility of follicular lymphoma GELF criteria in routine care: an Australasian Lymphoma Alliance study.

Follicular Lymphoma (FL) treatment initiation is largely determined by tumor burden and symptoms. In the pre-rituximab era, the Group d'Etude des Lymphomes Folliculaires (GELF) developed widely adopted criteria to identify high tumor burden FL patients to harmonize clinical trial populations. The utilization of GELF criteria (GELFc) in routine therapeutic decision-making is poorly described. This multicenter retrospective study evaluated patterns of GELFc at presentation and GELFc utilization in therapeutic decision-making in newly diagnosed, advanced stage rituximab-era FL. Associations between GELFc, treatment given, and patient survival were analyzed in 300 eligible cases identified between 2002-2019. 163 (54%) had ≥1 GELFc at diagnosis. The presence or cumulative number of GELFc did not predict PFS in patients undergoing watch-and-wait (WW) or those receiving systemic treatment. Of interest, in patients with ≥1 GELFc, 16/163 (10%) underwent initial watch-and-wait (comprising 22% of the watchand- wait cohort). In those receiving systemic therapy +/- radiotherapy, 74/215 (34%) met no GELFc. Our data suggest clinicians are using adjunctive measures to make decisions regarding treatment initiation in a significant proportion of patients. By restricting FL clinical trial eligibility only to those meeting GELFc, reported outcomes may not be applicable to a significant proportion of patients treated in routine care settings.

Utility of FDG-PET in predicting the histology of relapsed or refractory lymphoma.

ABSTRACT: 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is a valuable prognostic tool in modern lymphoma care. In this study, we explored the use of quantitative FDG-PET parameters in predicting the histology of suspected relapsed or refractory (R/R) lymphoma. We retrospectively analyzed 290 FDG-PET scans performed for suspected R/R lymphoma. FDG-PET parameters measured were maximum and mean standardized uptake value (SUVMax and SUVMean), total metabolic tumor volume, and total lesion glycolysis (TLG). Receiver operating characteristic curve analysis was used to obtain the optimal thresholds that best discriminate (1) benign vs R/R lymphoma, (2) indolent vs aggressive non-Hodgkin lymphoma (NHL), and (3) aggressive transformation of indolent NHL. We found that although all 4 FDG-PET parameters discriminated R/R lymphoma from benign histology, TLG was the best performing parameter (optimal cut-off ≥245, sensitivity 63%, specificity 86%, positive predictive value [PPV] 97%, negative predictive value [NPV] 30%, area under the curve [AUC] 0.798, and P < .001). SUVMax discriminated aggressive from indolent NHL with modest accuracy (optimal threshold ≥15, sensitivity 46%, specificity 79%, PPV 82%, NPV 38%, AUC 0.638, and P < .001). In patients with a prior diagnosis of indolent NHL, SUVMax was a modest predictor of transformation (optimal cut-off ≥12, sensitivity 71%, specificity 61%, PPV 50%, NPV 78%, AUC 0.676, and P .006). Additionally, SUVMax ≥25 and an increase in SUVMax (ΔSUVMax) from baseline ≥150% were highly specific (96% and 94%, respectively). These FDG-PET thresholds can aid in identification of suspected R/R lymphoma cases with higher likelihood of R/R disease and aggressive transformation of indolent NHL, guiding the necessity and urgency of biopsy.

Immune priming with avelumab and rituximab prior to R-CHOP in diffuse large B-cell lymphoma: the phase II AvR-CHOP study.

Immune evasion, due to abnormal expression of programmed-death ligands 1 and 2 (PD-L1/PD-L2), predicts poor outcomes with chemoimmunotherapy in diffuse large B-cell lymphoma (DLBCL). Immune checkpoint inhibition (ICI) has limited efficacy at relapse but may sensitise relapsed lymphoma to subsequent chemotherapy. ICI delivery to immunologically intact patients may thus be the optimal use of this therapy. In the phase II AvR-CHOP study, 28 patients with treatment-naive stage II-IV DLBCL received sequential avelumab and rituximab priming ("AvRp;" avelumab 10 mg/kg and rituximab 375 mg/m2 2-weekly for 2 cycles), R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone for 6 cycles) and avelumab consolidation (10 mg/kg 2-weekly for 6 cycles). Grade 3/4 immune-related adverse events occurred in 11%, meeting the primary endpoint of a grade ≥3 irAE rate of <30%. R-CHOP delivery was not compromised but one patient ceased avelumab. Overall response rates (ORR) after AvRp and R-CHOP were 57% (18% CR) and 89% (all CR). High ORR to AvRp was observed in primary mediastinal B-cell lymphoma (67%; 4/6) and molecularly-defined EBV-positive DLBCL (100%; 3/3). Progression during AvRp was associated with chemorefractory disease. Two-year failure-free and overall survival were 82% and 89%. An immune priming strategy with AvRp, R-CHOP and avelumab consolidation shows acceptable toxicity with encouraging efficacy.

Australian experience with ibrutinib in patients with relapsed/refractory mantle cell lymphoma: a study from the Lymphoma and Related Diseases Registry.

Bruton's tyrosine kinase inhibitors (BTKi) have an established role in the management of patients with relapsed/refractory mantle cell lymphoma (MCL). However, scant data exist on outcomes of patients ineligible for clinical trials testing these therapies. We describe a contemporary cohort of relapsed/refractory MCL patients from the Australasian Lymphoma and Related Diseases Registry treated with ibrutinib December 2014 until July 2018, to determine the proportion potentially eligible for original trials, reasons for ineligibility and survival outcomes. Of 44 patients, 41% met one or more exclusion criteria from previous phase II/III MCL BTKi studies. Median progression-free and overall survival were 13.7 months (95% CI 6.2-28.1) and 15.6 months (95% CI 10.8-29.6) respectively and were shorter in patients excluded from clinical trials based on ECOG ≥2. Ibrutinib has demonstrable clinical effectiveness in a population enriched for unfit and trial-ineligible patients, and a need for more inclusive enrollment criteria in future BTKi studies is highlighted.

Concurrent ibrutinib plus venetoclax in relapsed/refractory mantle cell lymphoma: the safety run-in of the phase 3 SYMPATICO study.

Ibrutinib plus venetoclax, given with an ibrutinib lead-in, has shown encouraging clinical activity in early phase studies in mantle cell lymphoma (MCL). The ongoing phase 3 SYMPATICO study evaluates the safety and efficacy of concurrently administered, once-daily, all-oral ibrutinib plus venetoclax in patients with relapsed/refractory MCL. A safety run-in (SRI) cohort was conducted to inform whether an ibrutinib lead-in should be implemented for the randomized portion. Patients received concurrent ibrutinib 560 mg continuously plus venetoclax in a 5-week ramp-up to venetoclax 400 mg for up to 2 years. The primary endpoint was occurrence of tumor lysis syndrome (TLS) and dose-limiting toxicities (DLTs). The SRI cohort enrolled 21 patients; six and 15 were in low- or increased-risk categories for TLS, respectively. During the 5-week venetoclax ramp-up, three patients had DLTs, and one patient at increased risk for TLS had a laboratory TLS; no additional TLS events occurred during follow-up. With a median follow-up of 31 months, the overall response rate was 81% (17/21); 62% (13/21) of patients had a complete response. SRI data informed that the randomized portion should proceed with concurrent ibrutinib plus venetoclax, with no ibrutinib lead-in. Ibrutinib plus venetoclax demonstrated promising efficacy; no new safety signals were observed.Trial registration: ClinicalTrials.gov, NCT03112174. Registered 13 April 2017, https://clinicaltrials.gov/ct2/show/NCT03112174 .

Predicting primary treatment failure using interim FDG-PET scanning in diffuse large B-cell lymphoma.

Interim FDG-PET (iPET) in diffuse large B-cell lymphoma (DLBCL) is increasingly practised and used in clinical trials to adapt further therapy. However, the optimum timing and methodology of iPET remains controversial. We retrospectively analysed the iPET results and outcomes of 200 DLBCL patients where FDG-PET was routinely performed at baseline, after 2 cycles (iPET2) and at completion of chemoimmunotherapy. iPET was also performed after 4 cycles (iPET4) where at iPET2, Deauville score (DS) was ≥4. Scans were assessed by blinded expert lymphoma PET physicians for DS, maximum standard uptake value (SUVmax), total metabolic tumour volume (TMTV) and total lesion glycolysis (TLG). Treatment failure was defined as death, progression or refractory disease. 95.5% of patients received R-CHOP. No baseline PET parameter was predicted for EFS or OS independent of the NCCN-IPI. The multivariable analysis at iPET2 showed DS5 (19.5% of cases) predicted treatment failure (HR 6.29, 95% CI 3.01-13.17, P < .001), but DS4 was equivalent to DS1-3. At iPET4, ΔSUVmax < 66% predicted treatment failure (HR 5.49, 95% CI 3.03-9.99, P < .001). By multivariable analysis of all time points, high NCCN-IPI and DS5 at iPET2 were negative predictors of survival. These findings were independent of novel prognostic markers.

Evolution of eligibility criteria for diffuse large B-cell lymphoma randomised controlled trials over 30 years.

Eligibility criteria for randomised control trials (RCT) in diffuse large B-cell lymphoma (DLBCL) may be becoming increasingly strict. In this analysis, 42 first-line phase III RCTs enrolling DLBCL patients since 1990 were identified from PubMed and clinicaltrials.gov. Changes in 31 individual eligibility criteria were assessed using three pre-defined eras [(1) 1993-2005; (2) 2006-2013; and (3) 2014-2020]. The presence of 15/31 criteria increased significantly over time, and the total number of criteria per study also increased over time [median Era 1: 14·5, interquartile range (IQR) 12·6-16·4; Era 2: 21, 18·8-23·3; Era 3: 23, 21-25; P < 0·001]. When each trial's eligibility criteria were applied to 215 consecutive patients from an institutional database treated between 2010 and 2020, a median of 57% (IQR 47-70) of patients were hypothetically eligible for trial enrolment. The median percentage of patients eligible was 68% (56-91), 54% (37-81) and 47% (38-82) for Era 1, 2 and 3 respectively (P = 0·004). Phase III front-line DLBCL trial criteria have become increasingly restrictive over the last three decades, resulting in a diminishing proportion of trial-eligible patients, with less than 50% of our patients eligible for modern-era studies. This potentially impacts generalisability of recent trial results and will likely limit recruitment to ongoing studies.

Use of Ultrasonography Facilitates Noninvasive Evaluation of Lymphadenopathy in a Lymph Node Diagnostic Clinic.

BACKGROUND: Prompt and accurate diagnosis of lymphadenopathy is important, yet there is wide variability in clinical approach and referral patterns, leading to unnecessary investigations and delays in diagnosis. To address this, a lymph node diagnostic clinic (LNDC) was established at our tertiary referral center. PATIENTS AND METHODS: We retrospectively analyzed data from 320 consecutive patients referred to the LNDC from March 2008 to March 2020, to describe their management and outcomes. RESULTS: The most common diagnoses were reactive (57%) and malignant lymphadenopathy (28%). In those with reactive lymphadenopathy, 33% did not undergo further investigations, 37% underwent imaging only, and 29% underwent biopsy. For malignant lymphadenopathy, diagnosis was made at a median (interquartile range) of 9 (6-16) days from first LNDC review, with the decision to biopsy made at the first LNDC review in 95% of cases. Clinical features significantly associated with malignancy included age > 45, B symptoms, history of malignancy, and lymphadenopathy that was ≥ 2 cm, in multiple regions, bilateral, multiple nodes, or supraclavicular. At least 3 of these features were present in 88% of patients with malignant lymphadenopathy. Ultrasound had a sensitivity of 98% and negative predictive value of 97% for detecting malignant lymphadenopathy. CONCLUSION: A dedicated LNDC in a tertiary referral center facilitates rapid assessment and diagnosis of lymphadenopathy through a risk-stratified model of management. Ultrasonography, as well as the presence of defined clinical risk factors, were most useful to differentiate benign from malignant lymphadenopathy.

Dual Antiangiogenesis Agents Bevacizumab Plus Trebananib, without Chemotherapy, in First-line Treatment of Metastatic Colorectal Cancer: Results of a Phase II Study.

PURPOSE: To assess the efficacy and safety of dual antiangiogenesis agents, bevacizumab plus trebananib, without chemotherapy, in first-line treatment of metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: This open-label phase II study enrolled patients with unresectable mCRC with no prior systemic treatment. All patients received bevacizumab 7.5 mg/kg 3-weekly and trebananib 15 mg/kg weekly. The primary endpoint was disease control [stable disease, partial response (PR), or complete response (CR)] at 6 months (DC6m). Secondary endpoints included toxicity, overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Exploratory biomarkers in plasma angiogenesis-related proteins, tumor gene expression, and plasma antibodies to tumor antigens were examined. RESULTS: Forty-five patients were enrolled from four Australian sites. DC6m was 63% [95% confidence interval (CI), 47-77]. ORR was 17% (95% CI, 7-32), comprising of seven PRs. Median duration of response was 20 months (range, 10-48 months). Median PFS was 8.4 months and median OS 31.4 months. Grade 1-2 peripheral edema and joint-related symptoms were common. Overall incidence of grade 3-4 adverse events (AE) of any type was 33% (n = 15). Expected AEs of bevacizumab treatment did not appear to be increased by the addition of trebananib. CONCLUSIONS: In a first-line mCRC population, the dual antiangiogenic combination, bevacizumab plus trebananib, without chemotherapy, was efficacious with durable responses. The toxicity profile of the combination was manageable and did not exceed that expected with bevacizumab +/- chemotherapy. Exploratory biomarker results raise the hypothesis that the antiangiogenic combination may enable the antitumor immune response in immunotolerant colorectal cancer.

Single-agent activity of phosphatidylinositol 3-kinase inhibition with copanlisib in patients with molecularly defined relapsed or refractory diffuse large B-cell lymphoma.

Patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) have adverse outcomes. We evaluated the efficacy and safety of the phosphatidylinositol 3-kinase inhibitor copanlisib in patients with relapsed/refractory DLBCL and assessed the relationship between efficacy and DLBCL cell of origin (COO; activated B-cell like [ABC] and germinal center B-cell like [GCB]) and other biomarkers. The primary endpoint was objective response rate (ORR) in DLBCL COO subgroups (ABC, GCB, and unclassifiable) and by CD79B mutational status (NCT02391116). Sixty-seven patients received copanlisib (ABC DLBCL, n = 19; GCB DLBCL, n = 30; unclassifiable, n = 3; missing, n = 15). The ORR was 19.4%; 31.6% and 13.3% in ABC and GCB DLBCL patients, respectively. ORR was 22.2%/20.0% for patients with/without CD79B mutations (wild type, n = 45; mutant, n = 9; missing, n = 13). Overall median progression-free survival and duration of response were 1.8 and 4.3 months, respectively. Adverse events included hypertension (40.3%), diarrhea (37.3%), and hyperglycemia (32.8%). Aberrations were detected in 338 genes, including BCL2 (53.7%) and MLL2 (53.7%). A 16-gene signature separating responders from nonresponders was identified. Copanlisib treatment demonstrated a manageable safety profile in patients with relapsed/refractory DLBCL and a numerically higher response rate in ABC vs. GCB DLBCL patients.

Patient selection and tolerability of high-dose methotrexate as central nervous system prophylaxis in diffuse large B-cell lymphoma.

INTRODUCTION: Central nervous system (CNS) relapse in diffuse large B-cell lymphoma (DLBCL) is usually fatal. Risk stratification of patients has historically been poorly defined, and CNS prophylaxis with high-dose methotrexate (HDMTX) can be associated with multiple toxicities. The CNS International Prognostic Index (IPI) defines three patient risk groups for CNS disease. The aims of this study were to evaluate the toxicity of HDMTX and describe outcomes in HDMTX and non-HDMTX patients according to the CNS-IPI. METHODS: 205 patients diagnosed with DLBCL between 2004 and 2014, initially treated with RCHOP-like chemotherapy and considered for HDMTX CNS prophylaxis were identified by pharmacy records at two teaching hospitals. Patient records were retrospectively reviewed for HDMTX toxicity, CNS-IPI calculation and CNS relapse. RESULTS: 28 patients with DLBCL were selected for two doses of HDMTX. Two of 28 patients received only one dose, and three had their second dose reduced due to renal impairment. 28% of patients experienced nephrotoxicity. 24 HDMTX and 122 non-HDMTX patients were evaluable for the CNS-IPI. No significant difference in the CNS-IPI distribution between the two groups was identified (p = 0.695). Five patients had CNS relapse, two who received HDMTX and three who did not. No significant difference in CNS relapse rate was identified between 24 HDMTX patients propensity-matched to 24 non-HDMTX patients. CONCLUSIONS: HDMTX was well-tolerated by patients. Application of the CNS-IPI identifies a different population of candidates for CNS prophylaxis compared to traditional criteria.

Comprehensive geriatric assessment is useful in an elderly Australian population with diffuse large B-cell lymphoma receiving rituximab-chemotherapy combinations.

Elderly patients may be heterogeneous in their abilities to tolerate immunochemotherapy-associated toxicities. We describe the morbidity of rituximab-chemotherapy combinations among 205 newly-diagnosed diffuse large B-cell lymphoma (DLBCL) patients aged ≥60 years from 3 tertiary hospitals between 2009 and 2016, and explore the utility of retrospectively-assigned baseline Comprehensive Geriatric Assessment (CGA) in predicting these toxicities. Seventy-three percent (146/201) experienced grade ≥3 toxicities, 81% (163/201) needed admission, 52% (107/205) had ≥2 unplanned admissions, 82/201 (41%) required dose reductions (DR) subsequent to Cycle 1, 39/166 (23%) had chemotherapy delays and 26/198 (13%) ceased therapy early. CGA was associated with pre-emptive baseline DR and perhaps because of this, did not predict grade ≥3 toxicities, ≥2 unplanned admissions or subsequent DR. Three-year overall survival (OS) of CGA-fit, CGA-unfit and CGA-frail patients was 82%, 60% and 53%, respectively. Three-year progression-free survival (PFS) of CGA-fit, CGA-unfit and CGA-frail patients was 66%, 58% and 46%, respectively. OS of CGA-fit patients was not statistically different from CGA-unfit patients, but was superior to CGA-frail patients (hazard ratio 2·892, 95% confidence interval 1·275-6·559, P = 0·011). PFS differences were not statistically significant. Baseline DR and early therapy cessation were associated with inferior OS and PFS independent of CGA. Prospective studies are needed to confirm if CGA-adapted treatment strategies minimize morbidity and improves survival.

Prognostication of diffuse large B-cell lymphoma in the molecular era: moving beyond the IPI.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with variable outcomes. Despite the majority of patients being cured with combination chemoimmunotherapy, up to 30% eventually succumb to the disease. Until recently, baseline prognostic assessment has centred on the International Prognostic Index (IPI), although this index is yet to impact strongly on treatment choice. Molecular features such as cell of origin, MYC and BCL-2 genetic alterations and protein overexpression were identified over a decade ago, yet their prognostic value is still not fully elucidated. Adding complexity are the plethora of new clinical, biological and molecular prognostic markers described in the recent literature, most of which lack independent validation, likely act as surrogate markers for those already in common use and have yet to substantially impact on therapeutic decision making. This review comprehensively assesses the value of individual prognostic markers in the clinical setting and their potential to predict response to novel agents, and ways to optimise their use in future research.

Novel Indications for Bruton's Tyrosine Kinase Inhibitors, beyond Hematological Malignancies.

Bruton's tyrosine kinase (BTK) is a critical terminal enzyme in the B-cell antigen receptor (BCR) pathway. BTK activation has been implicated in the pathogenesis of certain B-cell malignancies. Targeting this pathway has emerged as a novel target in B-cell malignancies, of which ibrutinib is the first-in-class agent. A few other BTK inhibitors (BTKi) are also under development (e.g., acalabrutinib). While the predominant action of BTKi is the blockade of B-cell receptor pathway within malignant B-cells, increasing the knowledge of off-target effects as well as a potential role for B-cells in proliferation of solid malignancies is expanding the indication of BTKi into non-hematological malignancies. In addition to the expansion of the role of BTKi monotherapy, combination therapy strategies utilizing ibrutinib with established regimens and combination with modern immunotherapy compounds are being explored.

A Randomized Controlled Trial of a Nurse-Led Supportive Care Package (SurvivorCare) for Survivors of Colorectal Cancer.

INTRODUCTION: Colorectal cancer (CRC) and its treatments can cause distressing sequelae. We conducted a multicenter randomized controlled trial aiming to improve psychological distress, supportive care needs (SCNs), and quality of life (QOL) of patients with CRC. The intervention, called SurvivorCare (SC), comprised educational materials, needs assessment, survivorship care plan, end-of-treatment session, and three follow-up telephone calls. METHODS: At the end of treatment for stage I-III CRC, eligible patients were randomized 1:1 to usual care (UC) or to UC plus SC. Distress (Brief Symptom Inventory 18), SCNs (Cancer Survivors' Unmet Needs measure), and QOL (European Organization for Research and Treatment of Cancer [EORTC] QOL questionnaires C30 and EORTC CRC module CR29) were assessed at baseline and at 2 and 6 months (follow-up 1 [FU1] and FU2, respectively). The primary hypothesis was that SC would have a beneficial effect on distress at FU1. The secondary hypotheses were that SC would have a beneficial effect on (a) SCN and QOL at FU1 and on (b) distress, SCNs, and QOL at FU2. A total of 15 items assessed experience of care. RESULTS: Of 221 patients randomly assigned, 4 were ineligible for the study and 1 was lost to FU, leaving 110 in the UC group and 106 in the SC group. Patients' characteristics included the following: median age, 64 years; men, 52%; colon cancer, 56%; rectal cancer, 35%; overlapping sites of disease, 10%; stage I disease, 7%; stage II, 22%; stage III, 71%. Baseline distress and QOL scores were similar to population norms. Between-group differences in distress at FU1 (primary outcome) and at FU2, and SCNs and QOL at FU1 and FU2 were small and nonsignificant. Patients in the SC group were more satisfied with survivorship care than those in the UC group (significant differences on 10 of 15 items). CONCLUSION: The addition of SC to UC did not have a beneficial effect on distress, SCNs, or QOL outcomes, but patients in the SC group were more satisfied with care. IMPLICATIONS FOR PRACTICE: Some survivors of colorectal cancer report distressing effects after completing treatment. Strategies to identify and respond to survivors' issues are needed. In a randomized controlled trial, the addition of a nurse-led supportive care package (SurvivorCare) to usual post-treatment care did not impact survivors' distress, quality of life, or unmet needs. However, patients receiving the SurvivorCare intervention were more satisfied with survivorship care. Factors for consideration in the design of subsequent studies are discussed.

Phase I Imaging and Pharmacodynamic Trial of CS-1008 in Patients With Metastatic Colorectal Cancer.

PURPOSE: CS-1008 (tigatuzumab) is a humanized, monoclonal immunoglobulin G1 (IgG1) agonistic antibody to human death receptor 5. The purpose of this study was to investigate the impact of CS-1008 dose on the biodistribution, quantitative tumor uptake, and antitumor response in patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: Patients with mCRC who had received at least one course of chemotherapy were assigned to one of five dosage cohorts and infused with a weekly dose of CS-1008. Day 1 and day 36 doses were trace-labeled with indium-111 ((111)In), followed by whole-body planar and regional single-photon emission computed tomography (SPECT) imaging at several time points over the course of 10 days. RESULTS: Nineteen patients were enrolled. (111)In-CS-1008 uptake in tumor was observed in only 12 patients (63%). (111)In-CS-1008 uptake and pharmacokinetics were not affected by dose or repeated drug administration. (111)In-CS-1008 biodistribution showed gradual blood-pool clearance and no abnormal uptake in normal tissue. No anti-CS-1008 antibody development was detected. One patient achieved partial response (3.7 months duration), eight patients had stable disease, and 10 patients had progressive disease. Clinical benefit rate (stable disease + partial response) in patients with (111)In-CS-1008 uptake in tumor was 58% versus 28% in patients with no uptake. An analysis of individual lesions showed that lesions with antibody uptake were one third as likely to progress as those without antibody uptake (P = .07). Death-receptor-5 expression in archived tumor samples did not correlate with (111)In-CS-1008 uptake (P = .5) or tumor response (P = .6). CONCLUSION: Death-receptor-5 imaging with (111)In-CS-1008 reveals interpatient and intrapatient heterogeneity of uptake in tumor, is not dose dependent, and is predictive of clinical benefit in the treatment of patients who have mCRC.

Quantitative intratumoural microdistribution and kinetics of (131)I-huA33 antibody in patients with colorectal carcinoma.

BACKGROUND: The ability of recombinant antibodies to adequately penetrate into tumours is a key factor in achieving therapeutic effect; however, the behaviour of antibodies at a cellular level in tumours is poorly understood. The purpose of this study was to investigate those factors that influence the macroscopic and microscopic intratumoural distribution of an IgG1-humanized antibody, huA33, in colorectal tumours. METHODS: Twelve patients were infused with radiolabelled huA33 at 7 days prior to elective surgery for colorectal carcinoma. Macroscopic huA33 uptake was determined by both gamma well counter and autoradiography measurements of the resected tumour specimens. Microscopic uptake was then quantitated at a cellular level and compared to vascular penetrance. The impact of variation in tumour antigen (GPA33) expression, tumour size, specimen type (primary vs metastatic), presence of macroscopic necrosis, and tumour vasculature on huA33 uptake were examined. RESULTS: The I-huA33 uptake in whole tumour sections was (mean ± SD) 5.13 ± 2.71 × 10(-3)% injected dose per gram (ID/g). GPA33 was expressed in all viable tumour cells, and huA33 uptake was excellent regardless of tumour size and specimen type. In tumours with macroscopically evident central necrosis (n = 5), huA33 uptake in tumour necrotic centres was lower than in viable peripheries (0.606 ± 0.493 vs 2.98 ± 2.17 × 10(-3)%ID, p = 0.06). However, when corrected for low cell viability in necrotic centres, uptake of huA33 at the cellular level was highly comparable to that in the more viable tumour periphery (7.10 ± 5.10 × 10(-9) vs 3.82 ± 3.67 × 10(-9)%ID/cell, p = 0.4). In the five patients who exhibited macroscopic necrosis in their tumours, huA33 showed excellent tissue penetration, with a maximum penetration distance of 26 µm in peripheral tumour regions and 118 µm in central regions. No correlation was observed between (131)I-huA33 uptake in tumour on a cellular basis and tumour vascularity. CONCLUSIONS: In patients with colorectal carcinoma, monoclonal antibody huA33 effectively targets viable tumour cells in all cellular milieus examined, including effective penetration into necrotic tumour centres, a novel and therapeutically important finding.