Salvage therapies including retreatment with BCMA-directed approaches after BCMA CAR-T relapses for multiple myeloma

ABSTRACT

For patients with relapsed/refractory multiple myeloma with a relapse after B-cell maturation antigen (BCMA)-directed chimeric antigen receptor T-cell therapy (CAR-T), optimal salvage treatment strategies remain unclear. BCMA-directed CAR-T and bispecific antibodies (BsAbs) are now commercially available, and the outcomes for retreatment with BCMA-directed approaches are not well studied. We performed a retrospective analysis of 68 patients with relapsed disease after BCMA-directed CAR-T to evaluate outcomes and responses to salvage therapies. With a median follow-up of 13.5 months, median overall survival from time of relapse until death was 18 months (95% confidence interval [CI], 13.2 to not reached [NR]). Fifty-eight patients received subsequent myeloma-directed therapies, with a total of 265 lines of therapy (LOTs). The overall response rate for firstline salvage therapy was 41% (95% CI, 28-55). Among all LOTs, high response rates were observed among those receiving another BCMA-directed CAR-T (89%), BCMA-directed BsAbs (60%), CD38-directed combinations (80% when combined with BsAb; 50% when combined with immunomodulatory drugs and/or proteasome inhibitors), and alkylator-combinations (50% overall; 69% with high-dose alkylators). Thirty-four patients received at least 1 line of salvage BCMA-directed therapy; median progression-free survival was 8.3 months (95% CI, 7.9 to NR), 3.6 months (95% CI, 1.4 to NR), and 1 month (95% CI, 0.9 to NR) with median duration of response (DOR) of 8 months, 4.4 months, and 2.8 months for subsequent BCMA-directed CAR-T, BsAb, and belantamab mafadotin, respectively. Retreatment with BCMA-directed CAR-T and BsAbs can be effective salvage options after BCMA-directed CAR-T relapse; however, DORs appear limited, and further studies with new combinations and alternative targets are warranted.

Shared decision-making needs, barriers, and facilitators of patients with newly diagnosed advanced cancer in the hospital: a multi-level, mixed-methods study

PURPOSE

Little is known about the shared decision-making (SDM) needs, barriers, and facilitators of patients with newly diagnosed advanced cancer in the hospital. Understanding this may improve SDM and cancer care quality in this vulnerable population.

METHODS

A single-site, mixed-methods study of hospitalized patients with newly diagnosed advanced cancer, caregivers, and oncologists was conducted. After discharge, patient ± caregiver semi-structured interviews exploring SDM needs, barriers, and facilitators regarding their most important upcoming cancer-related decision were conducted. Oncologists were surveyed about patient knowledge and SDM needs using closed- and open-ended questions, respectively. Thematic analysis was performed for qualitative data with a focus on themes unique to or amplified by hospitalization. Descriptive statistics and the Chi-squared test were performed for quantitative data.

RESULTS

Patients and caregivers reported high SDM needs surrounding treatment and prognostic information, leading to decisional conflict. Eight themes emerged: anticipated cancer treatment decisions, variable control preferences in decision-making, high cancer-related information needs and uncertainty, barriers and facilitators to information gathering during and post hospitalization, and decision-making facilitators. Among 32 oncologists, most (56%) reported patients were poorly informed about treatment and prognosis. Oncologists reported variable expectations about patient knowledge after hospitalization, facilitators to patient decision-making, and patient uncertainty while awaiting an outpatient oncologist appointment.

CONCLUSION

Patients newly diagnosed with advanced cancer in the hospital have high SDM needs and experience decisional conflict. This may be due to barriers unique to or exacerbated by hospitalization. Further research is needed to develop strategies to address these barriers and enhance the facilitators identified in this study.

Safety and efficacy of BCMA CAR-T cell therapy in older patients with multiple myeloma

BACKGROUND

Risks of B-cell maturation antigen (BCMA) chimeric antigen receptor T-cell (CAR-T) therapy for patients with multiple myeloma (MM) include cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), cytopenias, and infections. The efficacy and safety of BCMA CAR-T therapy in the geriatric setting, including complications such as falls and delirium which may be more prevalent in older patients, have not been fully analyzed.

OBJECTIVES

To analyze the efficacy and safety of BCMA CAR-T therapy among older patients (age ≥70 at infusion) versus younger patients with MM.

STUDY DESIGN

We analyzed all patients with MM who received any autologous BCMA CAR-T therapy over a 5-year period at our institution. Key endpoints included CRS, ICANS incidence, days to absolute neutrophil count (ANC) recovery, incidence of hypogammaglobulinemia (IgG < 400 mg/dL), infections within 6 months, progression-free survival (PFS), and overall survival (OS).

RESULTS

Of 83 analyzed patients (age range 33-77), 22 (27%) were aged ≥70 at infusion. The older cohort had lower creatinine clearances (median 67.3 vs 91.9 mL/min, p<0.001) and a higher proportion of patients with performance status ≥1 (59% vs 30%, p=0.02) but were otherwise similar. Rates of any-grade CRS, any-grade ICANS, and days to ANC recovery were similar between groups. Rates of baseline hypogammaglobulinemia were 36% in older patients and 30% in younger patients (p=0.60), while post-infusion hypogammaglobulinemia occurred in 82% vs 72% respectively (p=0.57). Infections occurred in 36% (n=8) of the older cohort versus 52% (n=32) of the younger cohort (p=0.22). There were no statistically significant differences between the older and younger cohorts in terms of documented falls (9% vs 15%, p=0.72) or non-ICANS delirium (5% vs 7%, p=1.0). Median PFS was 13.1 months in older patients (95% CI 9.2-not reached [NR]) vs 12.5 months in younger patients (95% CI 11.3-22.5, p=0.42. Median OS was not reached in the older cohort (95% CI: NR-NR) vs 31.4 months in the younger cohort (95% CI 24.8-NR) with p=0.04. However, age ≥70 was not a significant predictor of OS after adjusting for high-risk cytogenetics, triple-class refractoriness, extramedullary disease, and bone marrow plasma cell burden.

CONCLUSIONS

While limited by small sample size and unmeasured confounders, our retrospective analysis did not demonstrate significant increases in CAR-T toxicity among older patients. This included toxicities associated with geriatric populations such as falls and delirium. Our paradoxical finding of borderline better OS among patients aged ≥70, which was not significant in regression modeling, may have been due to selection bias in favor of disproportionately healthy CAR-T candidates in the geriatric population. Overall, BCMA CAR-T remains a safe and effective option for older patients with MM.

Association of biomarkers and outcomes in patients (pts) with metastatic urothelial carcinoma (mUC) treated with immune checkpoint inhibitors (ICIs)

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Background: ICIs form the backbone of treatment for mUC. However, only a minority of pts benefit and additional biomarkers of ICI response are needed. Methods: In our institution, we identified mUC pts treated with ICI monotherapy who had next generation sequencing (NGS). Somatic alterations present in ≥10% of pts ( ARID1A, CCND1, CDKN2A, CDKN2B, ERBB2, FGF3, FGF4, FGF19, FGFR3, KDM6A, MDM2, MLL2, PIK3CA, RB1, TERTp, TP53, TSC1), as well as DNA-damage response (DDR) alterations and tumor mutational burden (TMB) were analyzed as biomarkers. These biomarkers were individually evaluated in separate multivariate models while accounting for clinical factors including age, BMI, ECOG PS, primary tumor location, histology, hemoglobin, neutrophil to lymphocyte ratio and albumin. Multivariate cox regression and logistic regression models were used to measure hazard ratios (HR) and odds ratios (OR) for overall survival (OS), progression-free survival (PFS) and observed response rate (ORR). Results: Among 152 mUC ICI-treated pts, 107 had NGS data (FoundationOne, UCSF500, Strata), including 85 with TMB data. For the 107 pts with NGS, median age was 70 yrs, majority were male (69, 64%), Caucasian (70, 65%), had pure urothelial histology (57, 53%), and had first-line ICI (55, 51%). ORR was 35%, median PFS was 3.9 mos (95% CI: 2.6-7.5 mos), and median OS was 17.4 mos (95% CI: 14.1-30.6 mos). Biomarkers associated with improved outcomes to ICI, independent of relevant clinical factors, included alterations in ARID1A and DDR, as well as high TMB (>10 Mut/Mb). Inferior outcomes were seen in pts with CDKN2B, KDM6A, FGF3, FGF4, and FGF19 alterations (Table). Conclusions: In this large retrospective multivariate analysis controlling for clinical factors in ICI-treated mUC pts, we found multiple biomarkers associated with improved or inferior outcomes. These hypothesis-generating findings can inform clinical decision making and trial design for mUC pts treated with ICIs, and should be validated in larger cohorts. [Table: see text]

Association of biomarkers and response to immune checkpoint inhibitors (ICIs) in patients with metastatic urothelial carcinoma (mUC) with high and low tumor mutation burden (TMB)

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Background: ICIs are frequently used as therapy in mUC, but only a minority of patients (pts) respond to treatment. High TMB is associated with improved outcomes to ICIs. However, much is unknown about biomarkers associated with ICI outcomes in pts with high and low TMB respectively. Methods: We retrospectively identified mUC pts with known TMB status and available next generation sequencing (NGS) results treated with ICI monotherapy at our institution. TMB high was defined as ≥ 10 mutations/Mb, with the rest being TMB low. Somatic alterations present in ≥10% pts ( ARID1A, CCND1, CDKN2A, CDKN2B, ERBB2, FGF3, FGF4, FGF19, FGFR3, KDM6A, MDM2, MLL2, PIK3CA, RB1, TERTp, TP53, TSC1), and presence of DNA damage response (DDR) alterations were assessed as biomarkers of interest. Within the TMB-high and TMB-low pt groups we separately assessed patients based on the presence or absence of these somatic alterations, APOBEC mutational signature and high PD-L1 expression. Log rank test was used to determine differences in overall survival (OS) and progression free survival (PFS) among these groups. P-value ≤0.05 was considered significant. Results: Among 107 mUC pts treated with ICI monotherapy between 12/2014 and 3/2022 who had NGS data (UCSF500, FoundationOne, Strata), 85 pts had TMB data, including 47 TMB high pts and 38 TMB low pts. Among 85 pts with known TMB status, median age was 76 yrs, the majority were male (55, 65%), Caucasian (57, 67%), had pure urothelial histology (46, 55%) and were treated with ICIs in frontline setting (47, 55%). Median OS was 17.2 mos and median PFS was 3.42 mos. In TMB high pts, presence of DDR , MLL2, KDM6A, PIK3CA and TERTp alterations were each associated with improved outcomes, while presence of CDKN2B alterations was associated with inferior outcomes (Table). Among TMB low pts, those with RB1 alterations had shorter mOS (11.3 months vs 17.2 months; p=0.04) compared to wild-type pts. Conclusions: In this single-center retrospective analysis of mUC pts, we identified somatic alterations that were predictive of outcomes with ICI treatment in TMB high and TMB low pts respectively. Further exploration of biomarkers in patients stratified by TMB status is warranted in larger cohorts. [Table: see text]

Predominance of antibody-resistant SARS-CoV-2 variants in vaccine breakthrough cases from the San Francisco Bay Area, California

Associations between vaccine breakthrough cases and infection by different SARS coronavirus 2 (SARS-CoV-2) variants have remained largely unexplored. Here we analysed SARS-CoV-2 whole-genome sequences and viral loads from 1,373 persons with COVID-19 from the San Francisco Bay Area from 1 February to 30 June 2021, of which 125 (9.1%) were vaccine breakthrough infections. Vaccine breakthrough infections were more commonly associated with circulating antibody-resistant variants carrying ≥1 mutation associated with decreased antibody neutralization (L452R/Q, E484K/Q and/or F490S) than infections in unvaccinated individuals (78% versus 48%, P = 1.96 × 10^-8). Differences in viral loads were non-significant between unvaccinated and fully vaccinated cases overall (P = 0.99) and according to lineage (P = 0.09-0.78). Symptomatic vaccine breakthrough infections had comparable viral loads (P = 0.64), whereas asymptomatic breakthrough infections had decreased viral loads (P = 0.023) compared with infections in unvaccinated individuals. In 5 cases with serial samples available for serologic analyses, vaccine breakthrough infections were found to be associated with low or undetectable neutralizing antibody levels attributable to an immunocompromised state or infection by an antibody-resistant lineage. Taken together, our results show that vaccine breakthrough infections are overrepresented by antibody-resistant SARS-CoV-2 variants, and that symptomatic breakthrough infections may be as efficient in spreading COVID-19 as unvaccinated infections, regardless of the infecting lineage.

Transmission, infectivity, and neutralization of a spike L452R SARS-CoV-2 variant

We identified an emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant by viral whole-genome sequencing of 2,172 nasal/nasopharyngeal swab samples from 44 counties in California, a state in the western United States. Named B.1.427/B.1.429 to denote its two lineages, the variant emerged in May 2020 and increased from 0% to >50% of sequenced cases from September 2020 to January 2021, showing 18.6%-24% increased transmissibility relative to wild-type circulating strains. The variant carries three mutations in the spike protein, including an L452R substitution. We found 2-fold increased B.1.427/B.1.429 viral shedding in vivo and increased L452R pseudovirus infection of cell cultures and lung organoids, albeit decreased relative to pseudoviruses carrying the N501Y mutation common to variants B.1.1.7, B.1.351, and P.1. Antibody neutralization assays revealed 4.0- to 6.7-fold and 2.0-fold decreases in neutralizing titers from convalescent patients and vaccine recipients, respectively. The increased prevalence of a more transmissible variant in California exhibiting decreased antibody neutralization warrants further investigation.

Transmission, infectivity, and antibody neutralization of an emerging SARS-CoV-2 variant in California carrying a L452R spike protein mutation

We identified a novel SARS-CoV-2 variant by viral whole-genome sequencing of 2,172 nasal/nasopharyngeal swab samples from 44 counties in California. Named B.1.427/B.1.429 to denote its 2 lineages, the variant emerged around May 2020 and increased from 0% to >50% of sequenced cases from September 1, 2020 to January 29, 2021, exhibiting an 18.6-24% increase in transmissibility relative to wild-type circulating strains. The variant carries 3 mutations in the spike protein, including an L452R substitution. Our analyses revealed 2-fold increased B.1.427/B.1.429 viral shedding in vivo and increased L452R pseudovirus infection of cell cultures and lung organoids, albeit decreased relative to pseudoviruses carrying the N501Y mutation found in the B.1.1.7, B.1.351, and P.1 variants. Antibody neutralization assays showed 4.0 to 6.7-fold and 2.0-fold decreases in neutralizing titers from convalescent patients and vaccine recipients, respectively. The increased prevalence of a more transmissible variant in California associated with decreased antibody neutralization warrants further investigation.