LeBlanc, Michael

Abstract Although follicular lymphoma (FL) typically follows an indolent course, patients with FL who experience early events, such as transformation or progression, have increased risk of death related to lymphoma. The FL24Cx is an algorithm based on a 45-target gene expression profiling (GEP) assay, which was developed and trained using 265 formalin-fixed, paraffin-embedded tissue samples on a reliable platform to predict, at the time of diagnosis, whether a patient will experience an event within 24 months. The modeling also confirmed and relied upon previously reported synergy between immune response (IR) gene expression signatures IR1 and IR2. Once locked, the 5-factor logistic regression FL24Cx model was independently validated in a retrospectively assessed cohort of 232 patients from 2 immunochemotherapy-treated arms of SWOG Cancer Research Network S0016 phase 3 clinical trial, in which it assigned 169 patients to the low-risk group with 29 events before 24 months (17.2%) and 63 patients to the high-risk group with 24 events before 24 months (38.1%). The relative risk of an event within 24 months after registration among patients who were classified into the high-risk group relative to patients who were classified into the low-risk group was 2.2 (95% confidence interval, 1.41 to 3.51). An up-front GEP biomarker, such as the FL24Cx, rigorously validated in a clinical laboratory and with a clinically relevant turnaround time, could identify and steer enrollment of patients at high risk for early events in clinical trials, thus enabling timely interpretation of such trials and increasing the pace of innovation.

Background. FL is associated with a heterogeneous clinical course, and currently available prognostic indicators are unable to reliably separate patients who exhibit early therapy resistance (POD24, defined as progression within 24 months from diagnosis) from those who achieve “functional cure” following initial therapy. NGS methods developed in recent years enabled quantification of MRD. The ClonoSeq assay (Adaptive Biotechnology, Inc.) has been FDA-cleared to track MRD in several hematologic malignancies. Here we demonstrate that MRD analysis by ClonoSeq assay predicts outcomes in a prospective cohort of patients with advanced stage FL enrolled on SWOG S0016 clinical trial. Methods. SWOG S0016 was a phase III randomized study that compared the safety and efficacy of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) with CHOP-RIT (CHOP + I 133-tositumomab) in patients with FL. Between 2001 and 2008, 531 patients with previously untreated advanced-stage FL (bulky stage II, III-IV) of any pathologic grade were randomly assigned to receive 6 cycles of R-CHOP or CHOP-RIT. We used high-throughput sequencing (HTS) of the IGH and IGK/L loci (ClonoSeq assay) from tumor biopsy specimenstaken prior to treatment to define CDR3 rearrangements that tag the tumor. Subsequently, 1-year bone marrow specimens were screened for residual disease. The baseline dominant clone was defined as ≥10 estimated number of genomes (ENG) and comprised ≥5% of the library. MRD-positive state (MRDp) was defined as a minimum Hamming distance (HD) ≤6 in a patient's post-library (in any clone also detected in a pre-library) and conserved pre-existing SHM (if HD>0). Undetectable MRD (MRDu, at <10 -4) was defined as CRD3 HD>6 in a post-library with a depth >10,000 ENG. Five-year progression-free survival was the primary endpoint (PFS; defined as the time from registration to the first observation of progression or death due to any cause). Landmark analysis was defined at 1 year after registration and used for imputing the 5-year PFS and OS. Overall survival (OS) was defined as the time from registration to date of death due to any cause or last follow-up. PFS and OS estimates and 95% confidence interval were calculated using the Kaplan-Meier method and compared for MRDp and MRDu disease using two-sided log-rank test. HR and 95% CI were calculated using Cox regression model. Results. Tumor biopsy tissue was available for 189 patients. Of these, 24 patients were not evaluable (16 did not consent for banking, 6 were ineligible and 4 had an early event). In 36 patients, pre-libraries did not yield a trackable clone. In total, MRD status could not be ascertained in 47 patients due to absence of a clear trackable clone in either pre- or post-library, contributing to a 28.8% failure rate. Of 116 patients which yielded a trackable clone in both libraries, 83 were MRDu and 33 were MRDp. Baseline characteristics (age, sex, race, β2M, B symptoms, bulky disease, grade 3, stage, and FLIPI risk) were similar between MRDp and MRDu patients; however, MRDp patients were more likely to exhibit morphologic baseline bone marrow involvement by FL (82% vs. 55%, p=0.01). The estimated 5-year PFS was 72% in MRDu patients and 30% in MRD+ patients (Figure); 10-year PFS was 56% and 17%, correspondingly. Meanwhile, 5-year OS was not different (96% for MRDu, 81% for MRD+, p=0.91). Patients with MRDu had a significantly higher best overall response rate than MRDp patients (96% vs 79%, p=0.005), but complete response (CR) rates were similar (41% vs. 30.3%). Patients who received CHOP-RIT had better PFS regardless of MRD status (HR=0.48, p=0.01 for MRDu; HR=0.38, p=0.02 for MRDp), while OS was not statistically different. Five-year PFS was superior in patients who achieved MRDu (75% for CR and 70% for PR) compared with MRDp patients, regardless of response (34%). Patients who had MRDp status had a significantly increased risk of experiencing POD24 relative to MRDu patients (RR=6.5, 95% CI 3.0-14.0; p<0.0001). Conclusion. Here we for the first time demonstrate that MRDu status, as assessed by Clonoseq, predicts improved 5- and 10-year PFS in patients with FL initially treated with chemoimmunotherapy. MRD+ status in the bone marrow at a 1-year timepoint was associated with POD24. Despite a relatively high failure rate to detect trackable sequences using current technology (~29%), MRD assessment by NGS is a promising prognostic tool in FL. *co-senior authors

Abstract Basket, umbrella, and platform trial designs (master protocols) have emerged over the last decade to study precision medicine approaches in oncology. First-generation trials like NCI-MATCH (Molecular Analysis for Therapy Choice) have proven the principle that studying targeted therapies on a large scale is feasible both from the laboratory and clinical perspectives. However, single-agent targeted therapies have shown limited ability to control metastatic disease, despite careful matching of drug to target. As such, newer approaches employing combinations of targeted therapy, or targeted therapy with standard therapies, need to be considered. The NCI has recently embarked on three second-generation precision medicine trials to address this need: ComboMATCH, iMATCH, and myeloMATCH. The design of these trials and necessary infrastructure are discussed in the following perspective.

Abstract Although TP53 is commonly mutated in transformed follicular lymphoma, mutations are reported in <5% of pretreatment follicular lymphoma (FL) specimens. We assayed archival follicular B-cell non-Hodgkin lymphoma specimens from a completed clinical trial, Southwest Oncology Group S0016, a phase 3 randomized intergroup trial of CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone) chemotherapy plus R-CHOP (rituximab-CHOP) compared with CHOP chemotherapy plus 131-iodine tositumomab (radioimmunotherapy [RIT]-CHOP). Subclonal TP53 mutations (median allele frequency 0.02) were found in 25% of diagnostic FL specimens and in 27% of a separate validation cohort. In the R-CHOP arm, pathogenic TP53 mutations were not associated with progression-free survival (PFS) (10-year PFS 43% vs 44%). In contrast, among patients with no detectable pathogenic TP53 mutation, RIT-CHOP was associated with a longer PFS than with R-CHOP (10-year PFS 67% vs 44%; hazard ratio = 0.49; P = .008). No relationship was detected between PFS and the extent of activation-induced cytidine deaminase (AICDA)–mediated heterogeneity. In summary, subclonal TP53 mutations are common in FL and are a distinct phenomenon from AICDA-mediated genetic heterogeneity. The absence of a detectable subclonal mutation in TP53 defined a population that particularly benefited from RIT.

PURPOSE In the United States, the National Cancer Institute National Cancer Clinical Trials Network (NCTN) groups have conducted publicly funded oncology research for 50 years. The combined impact of all adult network group trials has never been systematically examined. METHODS We identified randomized, phase III trials from the adult NCTN groups, reported from 1980 onward, with statistically significant findings for ≥ 1 clinical, time-dependent outcomes. In the subset of trials in which the experimental arm improved overall survival, gains in population life-years were estimated by deriving trial-specific hazard functions and hazard ratios to estimate the experimental treatment benefit and then mapping this trial-level benefit onto the US cancer population using registry and life-table data. Scientific impact was based on citation data from Google Scholar. Federal investment costs per life-year gained were estimated. The results were derived through December 31, 2020. RESULTS One hundred sixty-two trials comprised of 108,334 patients were analyzed, representing 29.8% (162/544) of trials conducted. The most common cancers included breast (34), gynecologic (28), and lung (14). The trials were cited 165,336 times (mean, 62.2 citations/trial/year); 87.7% of trials were cited in cancer care guidelines in favor of the recommended treatment. These studies were estimated to have generated 14.2 million (95% CI, 11.5 to 16.5 million) additional life-years to patients with cancer, with projected gains of 24.1 million (95% CI, 19.7 to 28.2 million) life-years by 2030. The federal investment cost per life-year gained through 2020 was $326 in US dollars. CONCLUSION NCTN randomized trials have been widely cited and are routinely included in clinical guidelines. Moreover, their conduct has predicted substantial improvements in overall survival in the United States for patients with oncologic disease, suggesting they have contributed meaningfully to this nation's health. These findings demonstrate the critical role of government-sponsored research in extending the lives of patients with cancer.

PURPOSE Bone marrow biopsies (BMB) are performed before/after therapy to confirm complete response (CR) in patients with lymphoma on clinical trials. We sought to establish whether BMB add value in assessing response or predict progression-free survival (PFS) or overall survival (OS) outcomes in follicular lymphoma (FL) subjects in a large, multicenter, multitrial cohort. METHODS Data were pooled from seven trials of 580 subjects with previously untreated FL through Alliance for Clinical Trials in Oncology (Alliance) and SWOG Cancer Research Network (SWOG) completing enrollment from 2008 to 2016. RESULTS Only 5/580 (0.9%) had positive baseline BMB, CR on imaging, and subsequent positive BMB ( P < .0001). Therefore, BMB were irrelevant to response in 99% of subjects. A sensitivity analysis of 385 FL subjects treated on an Eastern Cooperative Oncology Group study was included. In the Eastern Cooperative Oncology Group cohort, 5/385 (1.3%) had BMB that affected response assessment. Since some subjects do not undergo confirmatory BMB, we performed a landmark survival analysis from first radiologic CR with data from 580 subjects from Alliance and SWOG. Of subjects with CR on imaging (n = 187), PFS and OS were not significantly different among those with negative BMB to confirm CR (n = 47) versus those without repeat BMB (n = 140; PFS: adjusted hazard ratio, 1.10, 95% CI, 0.62 to 1.94, log-rank P = .686; OS: hazard ratio, 0.59, 95% CI, 0.23 to 1.53, log-rank P = .276). CONCLUSION We conclude that BMB add little value to response assessment in subjects with FL treated on clinical trials and we recommend eliminating BMB from clinical trial requirements. BMB should also be removed from diagnostic guidelines for FL except in scenarios in which it may change management including confirmation of limited stage and assessment of cytopenias. This would reduce cost, patient discomfort, resource utilization, and potentially remove a barrier to trial enrollment.

PURPOSEDiffuse large B-cell lymphoma (DLBCL) presents as a limited-stage disease in 25% to 30% of patients, with better overall survival (OS) than that for advanced-stage disease but with continuous relapse regardless of treatment approach. The preferred treatment is abbreviated rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and radiation therapy. On the basis of promising results of positron emission tomography (PET)–directed treatment approaches, we designed a National Clinical Trials Network (NCTN) study to improve outcomes and decrease toxicity.METHODSPatients with nonbulky (< 10 cm) stage I/II untreated DLBCL received 3 cycles of standard R-CHOP therapy and underwent a centrally reviewed interim PET/computed tomography scan (iPET). Those with a negative iPET proceeded with 1 additional cycle of R-CHOP, whereas those with a positive iPET received involved field radiation therapy followed by ibritumomab tiuxetan radioimmunotherapy.RESULTSOf 158 patients enrolled, 132 were eligible and 128 underwent iPET, which was positive in 14 (11%) of the patients. With a median follow-up of 4.92 years (range, 1.1-7.7 years), only 6 patients progressed and 3 died as a result of lymphoma. Eleven patients died as a result of nonlymphoma causes at a median age of 80 years. The 5-year progression-free survival estimate was 87% (95% CI, 79% to 92%) and the OS estimate was 89% (95% CI, 82% to 94%), with iPET-positive and iPET-negative patients having similar outcomes.CONCLUSIONTo our knowledge, S1001 is the largest prospective study in the United States of limited-stage DLBCL in the rituximab era, with the best NCTN results in this disease subset. With PET-directed therapy, 89% of the patients with a negative iPET received R-CHOP × 4, and only 11% had a positive iPET and required radiation, with both groups having excellent outcomes. The trial establishes R-CHOP × 4 alone as the new standard approach to limited-stage disease for the absolute majority of patients.

8038 Background: Bone marrow biopsies (BMB) are performed pre/post therapy to confirm complete response (CR) in patients (pts) with lymphoma on clinical trials. We evaluated 2 prior data sets and concluded that BMB impact response assessment in a minority of pts with follicular lymphoma (FL) (Rutherford BJH 2017; Rutherford ASH abstract 1605, 2018). We sought to establish if BMB add value in assessing response or identify distinct progression free (PFS) or overall survival (OS) outcomes in a large, multicenter, multi-trial cohort. Methods: Data were pooled from 7 trials of 580 pts with untreated FL conducted through the Alliance for Clinical Trials in Oncology and SWOG from 2002-2016. The proportion of pts with positive (+) baseline BMB, CR on imaging after treatment, and (+) repeat BMB was calculated using total pts enrolled as the denominator. We tested against the null hypothesis that the proportion was = 10%, the threshold below which BMB would be considered irrelevant for response assessment, versus (vs) the alternative hypothesis that this proportion was < 10%, using 1-sided exact binomial test. Response criteria were CT-based. Imaging was not used to assess BM involvement. Because confirmatory BMB were not completed in all indicated pts, landmark survival analyses compared PFS/OS of pts with CR on imaging and negative (-) BMB vs pts with CR on imaging without repeat BMB. Pts with CR on imaging were categorized as having (-) repeat BMB or no repeat BMB within 60 days of first CR on imaging. PFS and OS were calculated from time of first CR and estimated using Kaplan-Meier and Cox models adjusting for age, sex, stage, Follicular Lymphoma International Prognostic Index (FLIPI) score, and treatment type (targeted vs chemotherapy plus targeted therapy), and stratified by treatment arm. Results: Median age was 55 with 51% male, 96% stage III-IV, and 88% grade I-II. FLIPI scores were 113 low, 265 intermediate, and 199 high risk. 67% received chemotherapy-based regimens. Baseline BMB was (+) in 321 (55%). Only 5/580 (0.8%) had (+) baseline BMB, CR on imaging, and subsequent (+) BMB (p < 0.0001). Of pts with CR on imaging, PFS and OS were not different among pts with (-) BMB vs pts without repeat BMB (PFS: HR = 1.08, 95%CI 0.61-1.93, p = 0.783; OS: HR = 0.52, 95%CI 0.20-1.40, p = 0.199). Conclusions: BMB requirements may discourage pt participation in trials and add pain, expense and time without providing necessary information. We recommend eliminating BMB for response assessment from FL clinical trials. Clinical trial information: NCT00553501, NCT01145495, NCT01190449, NCT01286272, NCT01829568, NCT00822120, and NCT00770224 .