Late Relapse Research Articles

Abstract 581: bbT369, a dual-targeted and CBLB gene-edited autologous CART product, demonstrates anti-lymphoma activity in preclinical mouse models

Abstract Anti-CD19 CAR T cell therapies have improved outcomes for non-Hodgkin lymphoma (NHL) patients. However, only 30-40% of patients treated with commercially available CART cell therapies obtain long term remission, highlighting the need for more efficacious and durable therapies. Emerging clinical data suggest several failure modes for CD19 CAR T cell therapies: including loss or downregulation of CD19 antigen, loss of co-stimulation pathways on tumor cells, exhaustion of CAR-T cells, and immunosuppressive microenvironments. To overcome these hurdles, we devised the next-generation autologous CAR-T cell therapy bbT369. bbT369 is dual targeted (CD79a/CD20) CAR T cell therapy that uses an OR gate design to limit antigen escape, has split 41BB and CD28 co-stimulatory domain architecture to augment T cell activation, and contains a knock-out of the CBLB gene to enhance potency and reduce T cell exhaustion. Here we report the first results with bbT369, demonstrating anti-lymphoma activity in in vitro assays and in vivo using xenograft mouse models. We demonstrate that CD79a and CD20 expression is B cell lineage restricted in normal human tissue and confirm that these proteins are co-expressed in diffuse large B cell samples. To target these antigens, we show a split dual-targeting CAR configuration is optimal for bbT369-directed tumor cell killing. Using an engineered megaTAL, we demonstrate high on-target activity of greater than 75% insertions and deletions (Indels) at the CBLB target site using clinical-scale manufacturing processes and low off-target activity (all off-targets less than 0.2%). In in vitro tumor co-culture assays, we show that inclusion of the CBLB gene edit in bbT369 increases Interleukin (IL)-2 production relative to an unedited anti-CD79a/CD20 CAR T cell control. Using various xenograft mouse models, we showed that bbT369 has similar or improved efficacy compared to anti-CD19 CAR drug product, including in low tumor-antigen models. In the Toledo subcutaneous xenograft model, bbT369 showed a 3-fold increase in T cell expansion compared with an unedited anti-CD79a/CD20 dual-targeting CAR T cell control. Furthermore, while a fraction of mice (3/5) receiving the unedited anti-CD79a/CD20 dual-targeting CAR T cells experienced late relapses (between 60-80 days following initial tumor clearance), all mice (n=5) receiving bbT369 were fully protected from late relapses (up to day 104 of follow-up). Collectively, the data support a first-in-human trial for bbT369 to evaluate initial safety and efficacy in NHL patients. Citation Format: Michael Certo, Christopher Baldeviano, Sharlene Adams, Martin Asimis, Alexander Astrakhan, Andy Chavkin, Maria L. Cabral, Jimmy Chu, Marie Debrue, Devina Desai, John Evans, Pinky Htun, Amanda Iniguez, Jordan Jarjour, Carl Johnson, Harini Kantamneni, Sema Kurtulus, Michael Magee, Unja Martin, Seamus McKenney, Sara Miller, Prashant Nambiar, Vinh Khang Nguyen, Mauris Nnamani, Jen Obrigewitch, Lisa Pechilis, Molly Perkins, Christopher Petersen, Jason Pinger, Cindy Rogers, Nick Rouillard, Kendal Sanson, Emily Thompson, Collin Walter, Roslyn Yi, Sarah Voytek, Philip Gregory. bbT369, a dual-targeted and CBLB gene-edited autologous CART product, demonstrates anti-lymphoma activity in preclinical mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 581.

Abstract 3575: Differential dynamics of response at single cell resolution between axi-cel and tisa-cel CAR-T therapy in refractory B-cell lymphomas

Abstract Chimeric Antigen Receptor (CAR)-T cell therapy has revolutionized the treatment of hematologic malignancies. Approximately half of patients with refractory large B-cell lymphomas achieve durable responses from CD19-targeting CAR-T treatment, across the commercially available CAR-T products with differing designs. Known failure mechanisms such as antigen loss account for only a fraction of cases without durable responses, and this knowledge gap has limited advances in CAR-T engineering and optimal targeting to patients. We hypothesized that characterization of the transcriptional programs and temporal evolution of CAR-T and host immune cell populations could provide novel insights into the basis of clinical response to CAR-T cell therapy for B cell lymphoma. We performed 10X single-cell RNA sequencing on serial samples collected from 32 individuals with high grade B cell lymphoma treated with the two first FDA-approved CD19 CAR-T products: axicabtagene ciloleucel (axi-cel, utilizing a CD28z costimulatory domain) and tisagenlecleucel (tisa-cel, with a 4-1BB domain). We analyzed 106 samples, including pre-infusion blood samples, infusion product, and post-infusion T cells sorted by flow cytometry into CAR+ and CAR- populations. Analyzing 602,577 single-cell transcriptomes, we discerned major differences in the dynamics of response of the two products. Tisa-cel responders showed dramatic expansion of CD8+ T cells at day 7 after infusion, which represented less than 10% of cells in the product. Conversely, CD8+ T cells in products of non-responders failed to expand to the same degree post-infusion and had a more effector- than memory-like T cell phenotype. In one tisa-cel–treated patient who had no CD8+ T cell expansion after initial infusion and relapsed at 6 months post-infusion, re-treatment with a second dose of the same product led to a durable response and was associated with greater CD8+ T cell expansion as well as a shift in CD4+ T phenotype from cytotoxic to helper. In contrast, axi-cel responders had pre-expanded effector populations distributed more heterogeneously among CD4+ and CD8+ T cells. Finally, we identified nominal elevations in CAR-T regulatory cells (CAR-Tregs) among both axi-cel and tisa-cel non-responders in our dataset, which we confirmed in an external dataset. These small increases in CAR-Tregs were sufficient to uniformly suppress conventional CAR-T cell expansion and drive late relapses in an in vivo mouse model of lymphoma after treatment with CARs with either CD28z or 4-1BB co-stimulatory domains. In summary, this represents the largest CAR-T scRNAseq cohort established thus far and provides important insights into (i) the temporal dynamics of a successful CAR-T response, (ii) the molecular phenotypes of CAR-T cells with different costimulatory domains, and (iii) the capacity for small increases in CAR-Tregs to drive relapse. Citation Format: Nicholas J. Haradhvala, Mark B. Leick, Katie Maurer, Satyen Gohil, Rebecca C. Larson, Estelle Yao, Matthew J. Frigault, Shuqiang Li, Kenneth J. Livak, Kahn Rhrissorrakrai, Filippo Utro, Chaya Levovitz, Raquel A. Jacobs, Kara Slowik, Brian P. Danysh, Laxmi Parida, Catherine J. Wu, Gad Getz, Marcela V. Maus. Differential dynamics of response at single cell resolution between axi-cel and tisa-cel CAR-T therapy in refractory B-cell lymphomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3575.

EPEN-02. Adaptive Convergence of Methylomes Reveals Epigenetic Drivers and Boosters of Repeated Relapses in Patient-matched Childhood Ependymomas and Identifies Targets for Anti-Recurrence Therapies

Ependymoma (EPN) is the third most common brain tumor in children and frequently recurs. Here, we report an integrated longitudinal analysis of epigenetic, genetic and tumorigenic changes in 30 patient-matched repeated relapses obtained from 10 pediatric patients to understand the mechanism of recurrences. Genome-wide DNA methylation analysis revealed stable molecular subtypes and convergent epigenetic reprogramming during serial relapses of the 5 RELA and 5 PFA EPNs that paralleled with elevated patient-derived orthotopic xenograft (PDOX) (13/27) formation in the late relapses. Differentially methylated CpGs (DMCs) preexisted in the primary tumors and persisted in the relapses (driver DMCs) were detected, ranging from 51 hypo-methylated in RELA to 148 hyper-methylated DMCs in PFA tumors; while newly acquired DMCs sustained in all the relapses but was absent in the primary tumors (booster DMCs) ranged from 38- 323 hyper-methylated DMCs in RELA and PFA EPNs, respectively. Integrated analysis of these DMC associated DNA methylation regions (DMRs) and RNAseq in both patient and PDOX tumors identified a small fraction of the differentially expressed genes (4.6±4.4% in RELA and 4.5±1.1% in PFA) as regulated by driver DMRs (e.g., up-regulated CACNA1H, SLC12A7, RARA in RELA and HSPB8, GMPR, ITGB4 in PFA) and booster DMRs (including the sole upregulated PLEKHG1 in RELA and NOTCH, EPHA2, SUFU, FOXJ1 in PFA tumors). Most these genes were novel to EPN relapses. Seven DMCs in RELA and 22 in PFA tumors were also identified as potential relapse predictors. Finally, integrating DNA methylation with histone modification identified LSD1 as a relapse driver gene. Combined treatment of a novel inhibitor SYC-836 with radiation significantly prolonged survival times in two PDOX models of recurrent PFA. This high-resolution epigenetic and genetic roadmap of EPN relapse and our 13 new PDOX models should significantly facilitate biological and preclinical studies of pediatric EPN recurrences.

Life expectancy and burden of late complications after reduced intensity conditioning allogeneic transplantation.

Reduced intensity conditionings (RIC) before after allogeneic hematopoietic stem cell transplantation (HSCT) allow older or unfit patients of being transplanted, but survival expectancy and burden of late complications are poorly described in this setting. All patients (N = 456) who were alive and relapse-free 2 years after HSCT following RIC were included. Cumulative incidences (CI), standardized incidence, or mortality, ratio (SIR or SMR), and competing risk models were used. The 10-year CIs of relapse and non-relapse mortality incidences were 13.9 and 13.4%, respectively. Seventy-eight patients died, late relapse being the most frequent cause of death leading to a SMR of 6.38 (95% CI, 5.1-8.0; p < 0.001). Among non-relapsing patients (n = 412), 30 died (SMR 4.38; 95% CI, 3.3-5.8: p < 0.001). A total of 37 patients developed 41 SM leading to a 10-year cumulative incidence of 12.9%, and a significant SIR relative to the general population (1.4). Finally, we found high CI of cardiovascular (CVC) and venous thromboembolic complications (VTE) (10-year CI; 15.1% and 11.7%, respectively). Older age was the only significant risk factor for CVC and VTE in multivariable analysis. In conclusion, with life expectancy rate of 70%, late survivors after RIC warrants long-term follow-up and active intervention on averting cardiovascular disease and screening cancers.

Outcomes of classic Hodgkin lymphoma, relapsed within one year of diagnosis, in the era of novel agents.

7515 Background: Primary refractory disease (PRD) and early relapse (ER) are predictors of poor prognosis in classic Hodgkin lymphoma (cHL). In this multicenter retrospective study, we describe outcomes of PRD and ER in pts with relapsed/refractory (R/R) cHL treated with salvage therapy (ST) and autologous stem cell transplant (ASCT). Methods: Of 14 sites, adult patients with R/R cHL who received ST and underwent ASCT were enrolled. PRD was defined as progression on frontline chemoimmunotherapy or within 6 months of diagnosis. ER was defined as relapse from 6 months-1 yr of diagnosis. Pts who relapsed &gt;1 yr of diagnosis were called late relapses (LR). Study objectives were Overall response rates (ORR), CR rates, PFS, and OS. Results: Of 986 total pts, 160 had PRD, 365 had ER and 461 had LR. Significantly higher number of pts with PRD, but not ER, had bulky disease (41% vs 27%, p&lt;0.01) and B symptoms (53% vs 38%, p&lt;0.001) than LR. Higher proportions of pts with PRD and ER required &gt;1 line of ST (44% vs 30% vs 23%, p&lt;0.001) before ASCT and received BV maintenance (25% vs 24% vs 16%, p&lt;0.05). When adjusted for B symptoms and Bulky disease, PRD and ER had significantly lower ORR (65% vs 76% vs 84%, p&lt;0.001) and CR (37% vs 46% vs 57%, p&lt;0.001) to first ST than LR. Pts with PRD and ER had significantly lower PFS (56.3%, 61.4%, vs 77.6%, p&lt;.0001) and OS (93% vs 89% vs 94%, p=0.01) than LR. In pts with ER, Brentuximab/bendamustine (BBV) and brentuximab vedotin/nivolumab (BV/nivo) had a trend towards higher ORR (92% vs 92% vs 75%) but significantly higher CR (79.2% vs 76% vs 42%, p&lt;0.01) than platinum based chemotherapy (PBC). In pts with PRD, BBV and BV/Nivo had a statistically insignificant trend towards higher ORR and CR than PBC. The table shows 2 yr PFS by type of ST in PRD, ER, LR. There was no difference in PFS by time to relapse in BV/nivo, CPI and miscellaneous agents. BV/Nivo had a significantly higher PFS than PBC in PRD (88% vs 48%, p&lt;0.05) and ER (95% vs 57%, p&lt;0.05). There was no difference in PFS of PBC and other ST in PRD, ER or LR. OS was not significantly associated with type of ST in either group. Conclusions: PRD and ER are associated with lower response to ST and survival after ASCT compared to late relapse. In pts with PRD and ER, BV/Nivo has high ORR and CR and leads to significantly higher PFS comparable to pts with late relapse and may be preferable ST regardless of time to relapse. [Table: see text]

Late relapses in testicular cancer: Results from a national cohort.

5008 Background: Late relapses (LR; relapse occurring after disease-free interval of two years) in testicular cancer are relatively uncommon. The limited data published is hampered by selection bias and incomplete data regarding follow-up. We aimed to investigate the frequency of LR and of very late relapses (VLR; relapse occurring after disease-free interval of five years), and the survival of patients with VLR in a cohort treated after 1995, compared to a cohort before 1995. Finally, we aimed to describe the number of missed relapses beyond a 5-year follow-up scheme. Methods: A total of 5712 patients, 2978 seminoma and 2734 nonseminoma, were diagnosed with testicular cancer in Norway, with 2207 patients diagnosed 1980-1995 and 5712 patients diagnosed 1995-2009. Data are complete, due to identification by the Cancer Registry of Norway and Norwegian Cause of Death Registry. Details regarding diagnosis, stage, treatment, and follow-up were obtained from medical records. Relapse rates have been estimated using Kaplan-Meyer. Results: A total of 472 patients experienced relapse, 186 seminoma and 286 nonseminoma. Of these 109 were LR (51 seminomas, 58 nonseminomas), 50 VLR (22 seminomas, 28 nonseminomas with 17 relapses (4 seminomas, 13 nonseminomas) beyond ten years. The median time to LR was 4.7 years (range 2.0-21.6). In clinical stage I patients, there were 306 relapses (7.9%); with overall 1.9% LR, 1.0% VLR, and 0.5% relapse beyond ten years. Patients followed with surveillance had a higher rate of LR compared to patients receiving adjuvant therapy (4.0% vs 1.0%). Three patients with LR died of testicular cancer, all three had a VLR and initial nonseminoma. In patients with metastatic disease, 166 patients experienced relapse (10.5%); with overall 3.6% LR 1.6% VLR, and 0,8% relapse beyond ten years. In nonseminoma diagnosed after 1995, the rate of VLR was 0.8% compared to 2.3% in the earlier cohort. Eight patients with VLR died of testicular cancer, all with initial nonseminoma, and seven of these were diagnosed in the earlier cohort. Outside a five-year follow-up scheme, 50 patients would be diagnosed with a VLR. Prolonging follow-up to ten years would potentially identify only 33 of these relapses. Conclusions: In this first population-based series investigating late relapses of testicular cancer with complete data regarding treatment and follow-up, we find a low rate of VLR in patients treated according to modern guidelines. We believe centralization of treatment, adherence to guidelines, prospective registration of patients, and subsequent reporting of results are key to these improved results. Patients with CS I followed by surveillance will have higher rate of VLR compared to patients receiving adjuvant treatment, resulting in a higher VLR rate in the modern cohort, without affecting survival. In metastatic disease, the VLR rate was drastically reduced in the modern cohort, with a subsequent improved survival.

Daratumumab (DARA) in combination with bortezomib plus dexamethasone (D-Vd) or lenalidomide plus dexamethasone (D-Rd) in relapsed or refractory multiple myeloma (RRMM): Subgroup analysis of the phase 3 CASTOR and POLLUX studies in patients (pts) with early or late relapse after initial therapy.

8052 Background: High-risk multiple myeloma (MM) is often defined based on cytogenetic abnormalities (ie, t[4;14], t[14;16], and/or del17p); however, pts who relapse early (12-18 months) after initial therapy are considered a functional high-risk group that is also associated with poor prognosis. DARA, a human IgGκ monoclonal antibody targeting CD38, is approved in combination with standard-of-care regimens for MM. In the phase 3 CASTOR and POLLUX studies, D-Vd and D-Rd significantly improved progression-free survival (PFS), regardless of cytogenetic risk, and achieved higher rates of complete response or better (≥CR) and minimal residual disease (MRD)–negativity vs Vd or Rd alone in pts with RRMM. Post hoc analyses of CASTOR and POLLUX evaluated D-Vd vs Vd and D-Rd vs Rd in pt subgroups with 1 prior line of therapy based on timing of relapse (early or late) after initiation of the first line of therapy. Methods: In CASTOR and POLLUX, pts with RRMM and ≥1 prior line of therapy were randomized to D-Vd/Vd or D-Rd/Rd, respectively. The primary endpoint was PFS. In this analysis, the early relapse subgroup included pts with 1 prior line of therapy who relapsed &lt;18 months after initiating their first line of therapy; pts with 1 prior line of therapy who relapsed ≥18 months after initiating their first line of therapy were included in the late relapse subgroup. Results: 49 and 186 pts from CASTOR and 99 and 196 pts from POLLUX were included in the early relapse and late relapse subgroups, respectively. Median follow-up was 72.6 months (CASTOR) and 79.7 months (POLLUX). PFS consistently favored the DARA-containing regimens across subgroups (Table). In CASTOR, ≥CR rates were higher with D-Vd vs Vd in the early relapse (21% vs 17%; P = 0.7360) and late relapse (51% vs 14%; P &lt;0.0001) subgroups. In POLLUX, ≥CR rates were higher with D-Rd vs Rd in the early relapse (53% vs 12%; P &lt;0.0001) and late relapse (62% vs 38%; P = 0.0012) subgroups. MRD-negativity rates (10–5) were higher with D-Vd/D-Rd vs Vd/Rd regardless of relapse timing (CASTOR: early, 13% vs 0%; P = 0.1476; late, 23% vs 3%; P &lt;0.0001; POLLUX: early, 30% vs 4%; P = 0.0006; late, 34% vs 14%; P = 0.0009). Conclusions: These post hoc analyses of CASTOR and POLLUX showed PFS and depth of response benefits of DARA-containing regimens in patients with 1 prior line of therapy, regardless of relapse timing (early or late). Our results support the use of D-Vd and D-Rd in RRMM, including in pts who are considered functional high risk. Clinical trial information: NCT02136134 and NCT02076009. [Table: see text]

Three-year follow-up of outcomes with KTE-X19 in patients with relapsed/refractory mantle cell lymphoma in ZUMA-2.

7518 Background: Brexucabtagene autoleucel (KTE-X19) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for the treatment of patients (pts) with relapsed/refractory (R/R) mantle cell lymphoma (MCL). In ZUMA-2, a 93% objective response rate (ORR; 67% complete response [CR] rate) was reported with KTE-X19 in pts with R/R MCL (median follow-up: 12.3 mo; 60 efficacy-evaluable pts; Wang et al. N Engl J Med. 2020). Here, we present updated outcomes with 2 years of additional follow-up. Methods: Adult pts (≥18 years) with R/R MCL underwent leukapheresis and conditioning chemotherapy followed by a single infusion of KTE-X19. Minimal residual disease (MRD) was an exploratory endpoint (sensitivity 10-5) evaluated in peripheral blood using next-generation sequencing. Updated results are reported for all 68 treated pts. Results: After 35.6 mo median follow-up, the ORR (CR + partial response) was 91% (95% CI, 81.8-96.7), with a 68% CR rate (95% CI, 55.2-78.5). The median duration of response (DOR) was 28.2 mo (95% CI, 13.5-47.1), with 25 of 68 treated pts (37%) still in ongoing response (all CR) at data cutoff. Late relapse &gt; 24 mo post-infusion was infrequent (n = 3). The medians for progression-free survival (PFS) and overall survival (OS) were 25.8 mo (95% CI, 9.6-47.6) and 46.6 mo (95% CI, 24.9-not estimable), respectively. MRD was analyzed in 29 pts total; 24 of 29 were MRD-negative at mo 1, and 15 of 19 with available data were MRD-negative at mo 6. At data cutoff, the medians for DOR, PFS, and OS in the 15 MRD-negative pts were all not reached, vs 6.1, 7.1, and 27.0 mo, in the 4 MRD-positive pts, respectively. MRD-negative status at mo 1, 3, and 6 was associated with durable response, with 55%, 71%, and 69% of MRD-negative pts at those timepoints remaining in ongoing CR at data cutoff. Circulating tumor DNA analysis of MRD at mo 3 and 6 was predictive of relapse (AUC 0.80 and 0.75, respectively). No new safety signals were observed. Only 3% of treatment-emergent adverse events (AEs) of interest occurred since the primary report. The most frequent Grade ≥3 AE was neutropenia (1 [1%] Grade 3; 7 [10%] Grade 4). Two pts had KTE-X19-related Grade 3 serious infections: pneumonia and upper respiratory tract infection (n = 1); influenza (n = 1). There were no new cytokine release syndrome AEs and 1 new serious neurologic AE of Grade 3 encephalopathy (13.0 mo post-infusion) that was considered not related to study treatment. Three new Grade 5 AEs occurred, none of which were considered related to study treatment: Salmonella bacteremia (24.9 mo post-infusion), myelodysplastic syndrome (25.2 mo post-infusion), and acute myeloid leukemia (37.5 mo post-infusion). Conclusions: These data represent the longest follow-up of CAR T-cell therapy in pts with MCL to date and suggest that KTE-X19 induces durable long-term responses with manageable safety and low late relapse potential in R/R MCL. Clinical trial information: NCT02601313.

Racial, ethnic, and socioeconomic survival disparities among children with high-risk neuroblastoma treated on upfront Children’s Oncology Group clinical trials.

10005 Background: Racial and socioeconomic disparities have not been comprehensively investigated in high-risk neuroblastoma (HR NBL). Prior Children’s Oncology Group (COG) investigations have demonstrated population-based disparities in late relapse rates among Black children, and trial-based disparities in relapse and survival among children living in poverty receiving post-consolidation immunotherapy. It is unknown whether these disparities persist in upfront trials for newly diagnosed patients. We leveraged COG data to investigate race, ethnicity, and socioeconomic disparities in a cohort of children with HR NBL treated on upfront clinical trials from 2007-2016. Methods: Retrospective cohort study of children enrolled on upfront COG HR NBL trials ANBL0532, ANBL09P1, and ANBL12P1. Race and ethnicity were the primary exposures categorized as: Black Non-Hispanic (BNH); Hispanic; Other Non-Hispanic (ONH); or White Non-Hispanic (WNH). Poverty was the secondary exposure, defined as household (public insurance only vs others), area (census-defined high-poverty ZIP code with &gt;20% of population living below 100% Federal Poverty Level (FPL) vs &lt;20% below 100% FPL), and rural (Census-defined rurality measures linked to ZIP code). Overall (OS) and event-free (EFS) survival from time of trial enrollment were plotted by Kaplan-Meier methods; associations with race/ethnicity and poverty were evaluated by log-rank tests. Results: Among 696 children, 16% were BNH, 11% Hispanic, 4% ONH, and 69% WNH. One-third (33%) of children were household poverty-exposed, 26% area poverty-exposed, and 15% rural-exposed. Tumor stage and biology did not differ by race/ethnicity or poverty measures. Five-year OS differed significantly by race/ethnicity (47% Hispanic vs. 50% ONH vs. 61% WNH vs. 62% BNH; p=0.047). Five-year OS was inferior among children exposed to household-poverty (53% vs. 63%; p=0.036) and neighborhood-poverty (54% vs. 62%; p=0.050) compared to unexposed children. There was no difference in OS by rurality. Similar directionality in 5-year EFS outcomes by race/ethnicity and poverty were observed without statistical significance. Conclusions: Race/ethnicity and poverty-exposure are associated with inferior OS outcomes among children with HR NBL despite uniform planned treatment on upfront COG trials. Investigation of mechanisms driving these disparities, including disparate early phase trial enrollment are ongoing to inform targeted health equity interventions to improve outcomes.

OReO/ENGOT Ov-38 trial: Impact of maintenance olaparib rechallenge according to ovarian cancer patient prognosis—An exploratory joint analysis of the BRCA and non-BRCA cohorts.

5558 Background: In the Phase IIIb OReO/ENGOT Ov-38 trial (NCT03106987), maintenance olaparib (O) rechallenge significantly improved progression-free survival (PFS) vs placebo in patients (pts) with platinum-sensitive relapsed ovarian cancer (PSROC) regardless of their BRCA status (Pujade-Lauraine, ESMO 2021). The impact of prognostic factors on this PFS benefit were unknown. Methods: Pts had PSROC, one prior line of PARP inhibitor (PARPi) maintenance and were in response to platinum-based chemotherapy (Cx). Pts were enrolled into two cohorts – BRCA mutated (BRCAm) and non-BRCAm – and randomized to receive maintenance O (300 mg bid) or placebo. Primary endpoint was PFS. Post-hoc individual patient data meta-analysis was used to combine both cohorts using fixed and random effect models, interaction, and stratified tests in the Cox model. Stepwise Cox multivariate model for PFS and logistic regression models were used for late relapse, defined as disease progression occurring &gt;24 weeks after randomization. Randomization stratification criteria and cohort effect were included in all models. Results: This study included 220 pts from the BRCAm (n=112) and non-BRCAm (n=108) cohorts recruited between October 3, 2017 and February 10, 2021. No heterogeneity was detected between cohorts: Cochran’s Q test P=0.53 (fixed and random); interaction test P=0.63. The O effect was consistent, and no significant interactions were observed between subgroups. In the multivariate PFS analyses, the main independent factors for prognosis were CA-125 level, visceral disease (liver, lung, pleura, brain), and treatment arm. These factors were independent predictive factors for late relapse among the 181 evaluable pts with the opportunity of at least 6 months of follow-up (Table). Conclusions: In the OReO/ENGOT Ov-38 trial, CA-125 level and presence of visceral disease at baseline were the best predictors of patient outcome. Maintenance olaparib rechallenge was effective overall regardless of prognostic subgroup. Clinical trial information: NCT03106987. [Table: see text]

Minimally invasive video-assisted parathyroidectomy (MIVAP) versus conventional parathyroidectomy for renal hyperparathyroidism: a retrospective multicenter study

To compare minimally invasive video-assisted parathyroidectomy (MIVAP) versus conventional surgery for renal hyperparathyroidism (rHPT). Between 2006 and 2020, 53 patients underwent MIVAP and 182 underwent conventional parathyroidectomy for rHPT at the Kliniken Essen-Mitte and Knappschaftskrankenhaus Bochum, respectively. Two propensity score-matched groups were retrospectively analyzed: the MIVAP group (VG; n = 53) and the conventional group (CG; n = 53). To assess long-term results, the patients were questioned prospectively (VG; n = 17, and CG; n = 26). The VG had a smaller incision (2.8 vs. 4.8 cm), shorter operation duration (81.0 vs. 13.9 min), and shorter duration of stay (2.4 vs. 5.7 days) (p < 0.0001) but a smaller drop in parathyroid hormone (PTH) postoperatively (81.3 vs. 85.5%. p = 0.022) than the CG. The conversion rate was 9.4% (n = 5). The VG had better Patient Scar Assessment Scale (PSAS) scores (10.8 vs. 11.7 p = 0.001) but worse SF-12 health survey scores (38.7 vs. 45.8 for physical health and 46.7 vs. 53.4 for mental health) (p < 0.0001). The PTH level at follow-up was higher in the VG (162.7 vs. 59.1 ng/l, p < 0.0001). There were no differences in morbidity, number of removed parathyroid glands, disease persistence, late rHPT relapse and need for repeat surgery between groups. MIVAP was superior to conventional parathyroidectomy regarding aesthetic outcomes and cost effectiveness. Conventional surgery showed better control of PTH levels and health scores on follow-up than MIVAP, without any impact on rHPT relapse and need for repeat surgery.Trail registration number and date of registration: DRKS00022545 on 14.12.2020.Graphical abstract

Application of Non-Blood-Derived Fluid Biopsy in Monitoring Minimal Residual Diseases of Lung Cancer.

Lung cancer is one of the most fatal malignant tumors in the world. Overcoming this disease is difficult due to its late diagnosis and relapse after treatment. Minimal residual disease (MRD) is described as the presence of free circulating tumor cells or other tumor cell derivatives in the biological fluid of patients without any clinical symptoms of cancer and negative imaging examination after the treatment of primary tumors. It has been widely discussed in the medical community as a bridge to solid tumor recurrence. Radiology, serology (carcinoembryonic antigen), and other clinical diagnosis and treatment methods widely used to monitor the progression of disease recurrence have obvious time-limited and -specific defects. Furthermore, as most samples of traditional liquid biopsies come from patients’ blood (including plasma and serum), the low concentration of tumor markers in blood samples limits the ability of these liquid biopsies in the early detection of cancer recurrence. The use of non-blood-derived fluid biopsy in monitoring the status of MRD and further improving the postoperative individualized treatment of patients with lung cancer is gradually ushering in the dawn of hope. This paper reviews the progress of several non-blood-derived fluid samples (urine, saliva, sputum, and pleural effusion) in detecting MRD in lung cancer as well as selecting the accurate treatment for it.

Abstract PR001: Deciphering clonal evolution under chemotherapy in high-risk neuroblastoma using patient derived models

Abstract Neuroblastoma is a pediatric tumor originating from the developing sympathetic nervous system, most often arising in the adrenal medulla in children below 5 years of age. After diagnosis, children with high-risk neuroblastoma are treated with COJEC, which is an aggressive chemotherapeutic treatment protocol encompassing five different chemotherapeutic agents. This is followed by surgical resection of the remaining tumor tissue. The aim of this project was to decipher how the subclonal landscape in the tumor changes during treatment with COJEC. To do this, three different patient derived xenograft (PDX) models were used by implanting dissociated tumor organoids subcutaneously in nude and NSG mice. The mice were subsequently randomized into either obtaining a mock treatment with saline solution (n=16), or treatment with the COJEC protocol (n=18). In PDX1 (3 controls, 4 treated) and in PDX2 (3 controls, 3 treated), progression or moderate response during treatment was seen respectively. In PDX3 (10 controls, 9 treated who went through surgical removal of remaining tumor tissue, 5 treated mice that didn’t undergo tumor resection) late relapses were seen in two of the mice who underwent surgery as well as two mice who did not. In the control group all tumors progressed. SNP-array analysis and RNA-sequencing was conducted on the parental sample as well as the tumors after treatment and relapses, in addition to single cell whole genome sequencing (scWGS) on a subset of samples. Array analysis was followed by computation of the proportion of cells in each sample harboring each genetic alteration, allowing phylogenetic reconstruction with DEVOLUTION. This revealed extensive convergent evolution of specific chromosomal regions across the PDX models. In PDX3 PTPRD deletions (also seen in PDX1) were found in all cells across samples before treatment. Deletions of the second PTPRD allele were detected in a total of six unique ways. Four of these were only seen in the relapses, while the remaining two were found after surgical resection. Other genes affected by convergent deletions were e.g., MACROD2 and LSAMP that were convergent in all three PDX models. High RNA expression of the genes encompassed by the affected chromosomal regions correlated with good treatment response both in the PDX models and patients, but not the copy number. Surprisingly, no significant increase in the number of genetic alterations was found after compared to before treatment. Phylogenetic reconstruction was conducted on scWGS-data for PDX1 and 3. PDX1 displayed a vast genetic diversity across tumors. In PDX3 parallel evolution of unique 1pq+ and 17q+ alterations and genetic bottlenecks with a selective sweep of 1pq/17q++ were seen in several tumors. In conclusion, both COJEC treatment and surgical resection induced bottlenecks and selective sweeps in the subclonal landscape and extensive convergent evolution was seen across tumors. Combined with the expression results, it supports the relevance of these specific genes in the evolution of neuroblastoma under treatment pressure. Citation Format: Natalie Andersson, Adriana Mañas Nuñez, Kristina Aaltonen, Karin Hansson, Alexandra Seger, Katarzyna Radke, Javanshir Esfandyari, Daniel Bexell, David Gisselsson. Deciphering clonal evolution under chemotherapy in high-risk neuroblastoma using patient derived models [abstract]. In: Proceedings of the AACR Special Conference on the Evolutionary Dynamics in Carcinogenesis and Response to Therapy; 2022 Mar 14-17. Philadelphia (PA): AACR; Cancer Res 2022;82(10 Suppl):Abstract nr PR001.

Abstract B023: An integrated approach to understanding the evolutionary dynamics of childhood acute lymphoblastic leukemia from diagnosis to relapse

Abstract Up to 20% of children with acute lymphoblastic leukemia (cALL) will relapse after initially responding to treatment. Dissecting the evolutionary population dynamics leading to relapse would help explain treatment failure from a mechanistic standpoint, aiding the design of more effective therapies. Comparisons of genetic heterogeneity at diagnosis and relapse have shown that relapse is often dominated by either a specific diagnostic subclone or its evolutionary progeny, leading to the idea that selection during treatment of cALL primarily operates at the genotype level. However, due to the technical difficulties associated with analyzing the rare cells that survive treatment in patients - definitive support for this idea is thus far missing. To overcome this challenge, we have previously developed a xenograft model of cALL induction chemotherapy treatment. Combining this with single-cell resolution analysis, we showed that, despite a massive reduction in leukemic burden, the first 28 days of chemotherapy have little impact on the genetic heterogeneity of cALL. This finding was inconsistent with the idea of selection acting at the level of genotypes. Instead, treatment induced a bottleneck at the level of cell state, determining the survival of a transcriptionally homogeneous population broadly characterized by reduced biosynthetic activity and cell dormancy. However, cALL treatment lasts several years and cannot be entirely modelled in vivo. Hence to assess whether genetic selection could act on a larger timescale or whether the clonal dominance frequently observed at relapse results from stochastic sweeps, we have implemented a data-driven mathematical model using the Hybrid Automata Library (HAL) to simulate longer treatment courses. The model allows for explicit spatial and temporal tracking of the evolutionary trajectories of individual cALL cells from diagnosis to relapse. Surprisingly we found that preserved genetic heterogeneity post-induction treatment and clonal dominance at relapse are features of virtually all relapsed leukemias; regardless of whether subclones with equal or varied fitness populate the diagnostic disease. This finding highlights the misinterpretation risks associated with limited disease snapshot analysis. Crucially, although genetically driven leukemias and leukemias in which all subclones have a similar probability of entering dormancy had similar endpoints, their temporal evolutionary dynamics largely differed. In the latter, reproducibly fewer cells survived induction chemotherapy, and relapse occurred on longer timelines, predominantly post-treatment. This observation provides the first empirical evidence of the notion that early and late relapse in cALLs may result from distinct selection mechanisms. Our preliminary data further suggest that even when high-fitness subclones are present, specifically targeting them is, in many cases, unlikely to improve overall outcome. Alternative dose fractionation protocols leveraging the epigenetically homogenous nature of residual cells may hold a better promise. Citation Format: Virginia A. Turati, Javier Herrero Sanchez, Jeffrey West, Mark Robertson-Tessi, Tariq Enver, Andriy Marusyk, Alexander R. A. Anderson. An integrated approach to understanding the evolutionary dynamics of childhood acute lymphoblastic leukemia from diagnosis to relapse [abstract]. In: Proceedings of the AACR Special Conference on the Evolutionary Dynamics in Carcinogenesis and Response to Therapy; 2022 Mar 14-17. Philadelphia (PA): AACR; Cancer Res 2022;82(10 Suppl):Abstract nr B023.

Adult-type non-rhabdomyosarcoma soft tissue sarcomas in pediatric age: Salvage rates and prognostic factors after relapse

PurposeThough the prognosis for patients with pediatric non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) is generally good, the chances of being cured after relapse are limited. This report describes a series of relapsing NRSTS patients treated at a referral center for pediatric sarcoma, investigating the pattern of relapse, salvage rates, and factors correlating with the final outcome. MethodsThe analysis concerned 103 patients <21 years old with relapsing adult-type NRSTS treated from 1985 to 2020. For risk-adapted stratification purposes, the patient outcome was examined using univariable and multivariable analyses based on patients’ clinical features at first diagnosis, first-line treatments, clinical findings at first relapse, and second-line treatments. ResultsThe first relapse occurred within 2–102 months (median 14 months) after patients' first diagnosis and was local in 47%, metastatic in 34%, and both in 19%. Treatment at relapse included chemotherapy in 72 patients, radiotherapy in 38, and surgery in 55. The median overall survival (OS) was 20 months. Post-relapse OS was 56.1%, 25.8%, and 19.1% at 1, 5, and 10 years, respectively. Cox's multivariable regression analysis showed that OS was significantly better for patients with local and late relapses (occurring more than 12 months after their first diagnosis) and for those achieving secondary remission. ConclusionThe outcome of patients with recurrent NRSTS is poor. The above-mentioned variables (type and time of relapse and achievement of secondary remission) were combined in a risk-adapted model to develop a tool for estimating the chance of salvage and deciding the best second-line treatment approach.

Long-term efficacy, safety and neurotolerability of MATRix regimen followed by autologous transplant in primary CNS lymphoma: 7-year results of the IELSG32 randomized trial.

219 HIV-negative adults ≤70 years with primary CNS lymphoma (PCNSL) were enrolled in the randomized IELSG32 trial. Enrolled patients were randomly assigned to receive methotrexate-cytarabine (arm A), or methotrexate-cytarabine-rituximab (B), or methotrexate-cytarabine-thiotepa-rituximab (MATRix; arm C). A second randomization allocated patients with responsive/stable disease to whole-brain irradiation (WBRT) or carmustine-thiotepa-conditioned autologous transplantation (ASCT). First results, after a median follow-up of 30 months, showed that MATRix significantly improves outcome, with both WBRT and ASCT being similarly effective. However, sound assessment of overall survival (OS), efficacy of salvage therapy, late complications, secondary tumors, and cognitive impairment requires longer follow-up. Herein, we report the results of this trial at a median follow-up of 88 months. As main findings, MATRix was associated with excellent long-lasting outcome, with a 7-year OS of 21%, 37%, and 56% respectively for arms A, B, and C. Notably, patients treated with MATRix and consolidation had a 7-year OS of 70%. The superiority of arm B on arm A suggests a benefit from the addition of rituximab. Comparable efficacy of WBRT and ASCT was confirmed. Salvage therapy was ineffective; benefit was recorded only in patients with late relapse re-treated with methotrexate. Eight (4%) patients developed a second cancer. Importantly, MATRix and ASCT did not result in higher non-relapse mortality or second tumors incidence. Patients who received WBRT experienced impairment in attentiveness and executive functions, whereas patients undergoing ASCT experienced improvement in these functions as well as in memory and quality of life.

A hierarchical approach to combine histological grade and immunohistochemical factors to identify high-risk luminal breast cancers.

BackgroundThe luminal subtype accounts for ~70% of newly diagnosed breast cancer patients. Although it has a better prognosis, approximately 30% of them develop a late relapse. Identifying those patients is of interest to improve treatment decisions.MethodsA retrospective observational, single-centre study based on data from medical records of 572 non-metastatic (I–III) invasive ductal breast carcinoma patients, 448 with luminal tumours and 124 with triple-negative tumours. Kaplan–Meier, Cox regression and time-dependent Cox regression were carried out to obtain the prognosis value of risk factors.ResultsDuring a median observation of 5.5 years, 105 distant metastasis events and 105 all-cause deaths were observed. In addition to known clinicopathological factors (i.e., age, tumour size and lymph node metastasis), the high semi-quantitative expression of both hormone receptors was associated with distant metastasis-free survival (DMFS) (adjusted hazard ratio (HaR): 0.524 (0.316–0.867), p = 0.012) and overall survival (OS) (adjusted HaR: 0.486 (0.286–0.827), p = 0.008). The stratified analysis made it possible to identify risk modification factors. Subsequent stratification by histological grade, Ki-67 and semi-quantitative PR expression or, mainly, the composite semi-quantitative expression of hormone receptors (cHR) enabled the identification of luminal breast cancer patients of adjuvant schema at higher risk for metastasis and death. However, initial analyses including patients of neoadjuvant therapy pointed to a path of subsequent stratification by cHR and histological grade, also enabling grouping of luminal breast cancer patients with similar prognosis for DMFS (cHR ≤ 4+ G2 or G3 versus triple-negative, adjusted HaR: 0.703 (0.415–1.189), p = 0.189) and OS (cHR ≤4+ G2 or G3 versus triple-negative, adjusted HaR: 0.662 (0.403–1.088), p = 0.104).ConclusionThe semi-quantitative expression of both cHR, Ki-67 proliferation index and histological grade can identify luminal breast cancer patients at greater risk of developing metastasis and death when combined in a hierarchical fashion, and could be useful for a better prognosis stratification in services from low- and middle-income countries.

Long-term Outcomes With Ibrutinib Treatment for Patients With Relapsed/Refractory Mantle Cell Lymphoma: A Pooled Analysis of 3 Clinical Trials With Nearly 10 Years of Follow-up.

Long-term Outcomes With Ibrutinib Treatment for Patients With Relapsed/Refractory Mantle Cell Lymphoma: A Pooled Analysis of 3 Clinical Trials With Nearly 10 Years of Follow-up.

Longitudinal relapse pattern of patients with first-episode schizophrenia-spectrum disorders and its predictors and outcomes: A 10-year follow-up study.

This study explored the 10-year pattern of relapse of patients with first-episode schizophrenia-spectrum disorders (FES), predictors and outcomes of early and late relapse. Patients received EIS (N=148) in Hong Kong between 1 July 2001 and 30 June 2002 were matched with those who entered standard care (N=148) one year before. Relapse information over 10 years were obtained and 209 patients were interviewed at 10-year follow-up. Predictors of early relapse ([ER] relapse in initial three years) and late relapse group ([LR] relapse in year 4-10) and their differential outcomes were explored. Fifty-six patients (26.8%) were relapse-free over 10 years with more EIS patients. Among the relapsed patients, 63.6% were ER patients who had the poorest longitudinal outcomes, including higher suicide attempts, violence episodes, more hospitalization and lower employment, whereas the LR patients do not differ much from the no relapse group. Relapse-free patients required less hospitalization in the first episode and lower antipsychotic dosage. The LR patients had less positive symptoms in year one but longer first-episode hospitalization and higher antipsychotic dosage. Delaying the first relapse may help to improve the long-term outcomes. Good response to antipsychotic medications was associated with relapse-free over long-term. However, sufficient antipsychotic medications with good symptomatic control during the early stage of the illness is crucial for relapse prevention for other patients. These findings highlight illness heterogeneity and the importance in differential use of antipsychotics in relapse prevention.

Outcomes of relapsed/refractory diffuse large B-cell lymphoma and influence of chimaeric antigen receptor T trial eligibility criteria in second line-A population-based study of 736 patients.

SummarySeveral recently published trials investigate novel therapies for relapsed/refractory diffuse large B‐cell lymphoma (R/R DLBCL). To estimate the benefit of these therapies in the real‐world setting, comprehensive data on patients treated in clinical routine are needed. We report outcomes for 736 R/R DLBCL patients identified among all curatively treated DLBCL patients in Sweden in the period 2007–2014. Survival and associations with disease characteristics, second‐line treatment and fulfilment of chimaeric antigen receptor (CAR) T‐cell trial criteria were assessed. Median overall survival (OS) was 6.6 months (≤70 years 9.6 months, >70 years 4.9 months). Early relapse (≤12 months) was strongly associated with selection of less intensive treatment and poor survival. Among patients of at most 70 years of age, 63% started intensive second‐line treatment and 34% received autologous stem cell transplantation (ASCT). Two‐year OS among transplanted patients was 56% (early relapse ≤12 months 40%, late relapse >12 months 66%). A minority of patients 76 years (n = 178/506, 35%) fitted CAR T trial criteria. Median progression‐free survival (PFS) for patients with early relapse fitting trial criteria was 4.8 months. In conclusion, most R/R DLBCL manifest early and are often ineligible for or cannot complete intensive regimens resulting in dismal survival. Real‐world patients eligible for CAR T trials also did poorly, providing a benchmark for efficacy of novel therapies.