Diminished humoral and cellular responses to SARS-CoV-2 vaccines in patients with chronic lymphocytic leukemia

Previous studies have demonstrated low rates of seroconversion to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines in patients with chronic lymphocytic leukemia (CLL). In this national collaboration of 11 cancer centers in the United States, we aimed to further characterize and understand vaccine-induced immune responses, including T-cell responses, and the impact of CLL therapeutics (#NCT04852822). Eligible patients were enrolled in 2 cohorts (1) at the time of initial vaccination and (2) at the time of booster vaccination. The serologic response rates (anti-S) from 210 patients in the initial vaccination cohort and 117 in the booster vaccination cohort were 56% (95% confidence interval [CI], 50-63) and 68% (95% CI, 60-77), respectively. Compared with patients not on therapy, those receiving B-cell-directed therapy were less likely to seroconvert (odds ratio [OR], 0.27; 95% CI, 0.15-0.49). Persistence of response was observed at 6 months; anti-S titers increased with the administration of booster vaccinations. In the initial vaccination cohort, positive correlations were observed between the quantitative serologic response and CD4 T-cell response for the Wuhan variant and, to a lesser degree, for the Omicron variant (Spearman P = 0.45 Wuhan; P = 0.25 Omicron). In the booster vaccination cohort, positive correlations were observed between serologic responses and CD4 T-cell responses for both variants (P = 0.58 Wuhan; P = 0.57 Omicron) and to a lesser degree for CD8 T-cell responses (P = 0.33 Wuhan; P = 0.22 Omicron). Although no deaths from coronavirus disease 2019 (COVID-19) have been reported after booster vaccinations, patients should use caution as newer variants emerge and escape vaccine-induced immunity. This trial was registered at www.clinicaltrials.gov as #NCT04852822.

Efficacy of checkpoint inhibition after CAR-T failure in aggressive B-cell lymphomas: outcomes from 15 US institutions

Checkpoint inhibitor (CPI) therapy with anti-PD-1 antibodies has been associated with mixed outcomes in small cohorts of patients with relapsed aggressive B-cell lymphomas after CAR-T failure. To define CPI therapy efficacy more definitively in this population, we retrospectively evaluated clinical outcomes in a large cohort of 96 patients with aggressive B-cell lymphomas receiving CPI therapy after CAR-T failure across 15 US academic centers. Most patients (53%) had diffuse large B-cell lymphoma, were treated with axicabtagene ciloleucel (53%), relapsed early (≤180 days) after CAR-T (83%), and received pembrolizumab (49%) or nivolumab (43%). CPI therapy was associated with an overall response rate of 19% and a complete response rate of 10%. Median duration of response was 221 days. Median progression-free survival (PFS) and overall survival (OS) were 54 and 159 days, respectively. Outcomes to CPI therapy were significantly improved in patients with primary mediastinal B-cell lymphoma. PFS (128 vs 51 days) and OS (387 vs 131 days) were significantly longer in patients with late (>180 days) vs early (≤180 days) relapse after CAR-T. Grade ≥3 adverse events occurred in 19% of patients treated with CPI. Most patients (83%) died, commonly because of progressive disease. Only 5% had durable responses to CPI therapy. In the largest cohort of patients with aggressive B-cell lymphoma treated with CPI therapy after CAR-T relapse, our results reveal poor outcomes, particularly among those relapsing early after CAR-T. In conclusion, CPI therapy is not an effective salvage strategy for most patients after CAR-T, where alternative approaches are needed to improve post-CAR-T outcomes.

Outcomes and factors impacting use of axicabtagene ciloleucel in patients with relapsed or refractory large B-cell lymphoma: results from an intention-to-treat analysis

Data on real-world outcomes of axicabtagene ciloleucel (axi-cel) therapy for relapsed/refractory large B-cell lymphoma (R/R LBCL) are limited. In this intent to treat (ITT) analysis, we reviewed records of 38 consecutive patients with R/R LBCL for whom axi-cel was intended. Twenty-seven (71%) patients received axi-cel and 11 (29%) did not. Patients in the non-axi-cel group had a higher hematopoietic cell transplantation comorbidity index (HCT-CI) (median 4 vs. 2, p = .04). Median overall survival for the ITT, axi-cel and non-axi-cel group was 10 (95% CI, 3.7 to 13), 13 (95% CI, 7.7 to N.R.) and 1 (95% CI, 0.4 to 3.7) month(s) respectively. Factors limiting axi-cel use were disease progression, sepsis, manufacturing failure and socioeconomic barrier in 6 (55%), 3 (27%), 1 (9%) and 1 (9%) patient(s) respectively. Additional strategies are needed to ensure all LBCL patients for whom chimeric antigen receptor (CAR) T-cell therapy is prescribed can receive this treatment.

Polatuzumab Vedotin for Relapsed/Refractory Aggressive B-cell Lymphoma: A Multicenter Post-marketing Analysis

INTRODUCTION

Polatuzumab vedotin is approved therapy in the United States for relapsed/refractory diffuse large B-cell lymphoma in combination with bendamustine and rituximab (Pola+BR). However, the safety and efficacy of Pola+BR outside of a clinical trial setting is unknown.

PATIENTS AND METHODS

We analyzed use of pola-based therapy at 5 centers in the United States, including dose, response rates, progression-free survival (PFS), survival, and toxicity.

RESULTS

Sixty-nine patients with aggressive B-cell lymphoma, including 66 with diffuse large B-cell lymphoma/high-grade B-cell lymphoma and 84% refractory to prior therapy, were treated. Responses occurred in of 50%, including 24% complete response. Median duration of response was 5.1 months, PFS was 2.0 months, and survival was 5.3 months, at 4 months median follow-up. Inferior PFS was associated with prior refractory disease (median, 57 days vs. not reached; P = .003) and lack of response to Pola+BR (PFS, 27 days vs. 152 days; P < .001). Discontinuation owing to planned cellular therapy was seen in 36% and owing to toxicity occurred in 12%; unplanned hospitalizations occurred in 36%.

CONCLUSIONS

We conclude that commercial Pola is applied to highly refractory lymphomas at our centers, often with intent to bridge to subsequent therapy. Although some clinical benefit was observed, efficacy was inferior to clinical trial data, especially among those with refractory disease.

Assessment of the Efficacy of Therapies Following Venetoclax Discontinuation in CLL Reveals BTK Inhibition as an Effective Strategy

PURPOSE

Venetoclax-based therapy is a standard-of-care option in first-line and relapsed/refractory chronic lymphocytic leukemia (CLL). Patient management following venetoclax discontinuation remains nonstandard and poorly understood.

EXPERIMENTAL DESIGN

To address this, we conducted a large international study to identify a cohort of 326 patients who discontinued venetoclax and have been subsequently treated. Coprimary endpoints were overall response rate (ORR) and progression-free survival for the post-venetoclax treatments stratified by treatment type [Bruton's tyrosine kinase inhibitor (BTKi), PI3K inhibitor (PI3Ki), and cellular therapies].

RESULTS

We identified patients with CLL who discontinued venetoclax in the first-line (4%) and relapsed/refractory settings (96%). Patients received a median of three therapies prior to venetoclax; 40% were BTKi naïve (n = 130), and 81% were idelalisib naïve (n = 263). ORR to BTKi was 84% (n = 44) in BTKi-naïve patients versus 54% (n = 30) in BTKi-exposed patients. We demonstrate therapy selection following venetoclax requires prior novel agent exposure consideration and discontinuation reasons.

CONCLUSIONS

For BTKi-naïve patients, selection of covalently binding BTKis results in high ORR and durable remissions. For BTKi-exposed patients, covalent BTK inhibition is not effective in the setting of BTKi resistance. PI3Kis following venetoclax do not appear to result in durable remissions. We conclude that BTKi in naïve or previously responsive patients and cellular therapies following venetoclax may be the most effective strategies.See related commentary by Rogers, p. 3501.

Tumor Lysis, Adverse Events, and Dose Adjustments in 297 Venetoclax-Treated CLL Patients in Routine Clinical Practice

PURPOSE

Clinical trials of venetoclax reported negligible rates of clinical tumor lysis syndrome (TLS) in patients with chronic lymphocytic leukemia (CLL) when using an extended dose escalation schedule. We aimed to understand TLS prophylaxis, rates of select adverse events (AE), and impact of dosing modifications in routine clinical practice.

EXPERIMENTAL DESIGN

This retrospective cohort study included 297 CLL venetoclax-treated patients outside of clinical trials in academic and community centers. Demographics, baseline disease characteristics, venetoclax dosing, TLS risk and prophylaxis, and AEs were collected.

RESULTS

The group was 69% male, 96% had relapsed/refractory CLL, 45% had deletion chromosome 17p, 84% had unmutated IGHV, 80% received venetoclax monotherapy, and median age was 67. TLS risk was categorized as low (40%), intermediate (32%), or high (28%), and 62% had imaging prior to venetoclax initiation. Clinical TLS occurred in 2.7% of patients and laboratory TLS occurred in 5.7%. Pre-venetoclax TLS risk group and creatinine clearance independently predict TLS development in multivariable analysis. Grade 3/4 AEs included neutropenia (39.6%), thrombocytopenia (29.2%), infection (25%), neutropenic fever (7.9%), and diarrhea (6.9%). Twenty-two patients (7.4%) discontinued venetoclax due to an AE. Progression-free survival was similar regardless of number of dose interruptions, length of dose interruption, and stable venetoclax dose.

CONCLUSIONS

These data provide insights into current use of venetoclax in clinical practice, including TLS rates observed in clinical practice. We identified opportunities for improved adherence to TLS risk stratification and prophylaxis, which may improve safety.

Maintenance rituximab or observation after frontline treatment with bendamustine-rituximab for follicular lymphoma

Bendamustine (B) with rituximab (R) is a standard frontline treatment for medically fit follicular lymphoma (FL) patients. The safety and efficacy of maintenance rituximab (MR) after BR induction has not been formally compared to observation for FL, resulting in disparate practice patterns. Prospective trials have shown benefit of MR after R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) or R-CVP (rituximab, cyclophosphamide, vincristine, prednisone), yet recent data from the GALLIUM study comparing outcomes of patients treated with chemotherapy with R or obinutuzumab (G) showed higher than anticipated fatal adverse events with BR/BG. In order to assess the efficacy and tolerability of MR after BR, we retrospectively collected data on 640 newly diagnosed patients treated with FL. We found that patients who achieved partial remission (PR) after ≥4 cycles of BR had improved duration of response (DOR) with MR vs. no maintenance, whereas those in complete remission did not. These findings were confirmed in a validation cohort. In the entire study population, the known fatal adverse event rate after BR was 2·5% and did not significantly differ in those receiving MR versus no maintenance. [Correction added on 14 January 2019, after online publication: The preceding sentence has been corrected in this current version.] Within the limitations inherent to retrospective analysis, these data suggest that FL patients with a PR to BR experience prolongation of remission with MR with an acceptable safety profile.

Real-world outcomes and management strategies for venetoclax-treated chronic lymphocytic leukemia patients in the United States

Venetoclax is a BCL2 inhibitor approved for 17p-deleted relapsed/refractory chronic lymphocytic leukemia with activity following kinase inhibitors. We conducted a multicenter retrospective cohort analysis of patients with chronic lymphocytic leukemia treated with venetoclax to describe outcomes, toxicities, and treatment selection following venetoclax discontinuation. A total of 141 chronic lymphocytic leukemia patients were included (98% relapsed/refractory). Median age at venetoclax initiation was 67 years (range 37-91), median prior therapies was 3 (0-11), 81% unmutated IGHV, 45% del(17p), and 26.8% complex karyotype (≥ 3 abnormalities). Prior to venetoclax initiation, 89% received a B-cell receptor antagonist. For tumor lysis syndrome prophylaxis, 93% received allopurinol, 92% normal saline, and 45% rasburicase. Dose escalation to the maximum recommended dose of 400 mg daily was achieved in 85% of patients. Adverse events of interest included neutropenia in 47.4%, thrombocytopenia in 36%, tumor lysis syndrome in 13.4%, neutropenic fever in 11.6%, and diarrhea in 7.3%. The overall response rate to venetoclax was 72% (19.4% complete remission). With a median follow up of 7 months, median progression free survival and overall survival for the entire cohort have not been reached. To date, 41 venetoclax treated patients have discontinued therapy and 24 have received a subsequent therapy, most commonly ibrutinib. In the largest clinical experience of venetoclax-treated chronic lymphocytic leukemia patients, the majority successfully completed and maintained a maximum recommended dose. Response rates and duration of response appear comparable to clinical trial data. Venetoclax was active in patients with mutations known to confer ibrutinib resistance. Optimal sequencing of newer chronic lymphocytic leukemia therapies requires further study.

Optimal sequencing of ibrutinib, idelalisib, and venetoclax in chronic lymphocytic leukemia: results from a multicenter study of 683 patients

Background

Ibrutinib, idelalisib, and venetoclax are approved for treating CLL patients in the United States. However, there is no guidance as to their optimal sequence.

Patients and methods

We conducted a multicenter, retrospective analysis of CLL patients treated with kinase inhibitors (KIs) or venetoclax. We examined demographics, discontinuation reasons, overall response rates (ORR), survival, and post-KI salvage strategies. Primary endpoint was progression-free survival (PFS).

Results

A total of 683 patients were identified. Baseline characteristics were similar in the ibrutinib and idelalisib groups. ORR to ibrutinib and idelalisib as first KI was 69% and 81%, respectively. With a median follow-up of 17 months (range 1-60), median PFS and OS for the entire cohort were 35 months and not reached. Patients treated with ibrutinib (versus idelalisib) as first KI had a significantly better PFS in all settings; front-line [hazard ratios (HR) 2.8, CI 1.3-6.3, P = 0.01], relapsed-refractory (HR 2.8, CI 1.9-4.1, P < 0.001), del17p (HR 2.0, CI 1.2-3.4, P = 0.008), and complex karyotype (HR 2.5, CI 1.2-5.2, P = 0.02). At the time of initial KI failure, use of an alternate KI or venetoclax had a superior PFS when compared with chemoimmunotherapy. Furthermore, patients who discontinued ibrutinib due to progression or toxicity had marginally improved outcomes if they received venetoclax (ORR 79%) versus idelalisib (ORR 46%) (PFS HR .6, CI.3-1.0, P = 0.06).

Conclusions

In the largest real-world experience of novel agents in CLL, ibrutinib appears superior to idelalisib as first KI. Furthermore, in the setting of KI failure, alternate KI or venetoclax therapy appear superior to chemoimmunotherapy combinations. The use of venetoclax upon ibrutinib failure might be superior to idelalisib. These data support the need for trials testing sequencing strategies to optimize treatment algorithms.

Age dependence of the radiosensitivity of glial progenitors for In vivo fission-neutron and X irradiation

O-2A progenitor cells are the stem cells of the myelin-forming oligodendrocytes in the central nervous system. In the epithermal reactor beams used for boron neutron capture therapy (BNCT) for treatment of brain tumors, fission neutrons are a contaminating component. To estimate the radiosensitivity of the O-2A progenitors for fission neutrons, an in vivo-in vitro clonogenic assay was used. Radiosensitivity of progenitors obtained from the spinal cord of 1- or 5-day-old rats or the optic nerve of 2- or 12-week-old rats for 1 MeV fission neutrons was compared to that for 300 kVp X rays. Dose-survival curves were fitted according to the linear-quadratic model. The resulting beta component was very small to negligible. Progenitor cells obtained from rats of different ages show differences in radiosensitivity, characterized by different alpha values. RBE values for fission neutrons were 3.5 for 1-day-old spinal cord, 3.2 for 5-day-old spinal cord, 3.0 for 2-week-old optic nerve, and 4.3 for 12-week-old optic nerve. These high RBE values indicate the importance of minimizing the fast-neutron component in the epithermal neutron beams used for BNCT.

Medical management of perianal Crohn's disease

Perianal disease is a frequent complication necessitating both medical and surgical management in Crohn's disease. Fissures, fistulae, or abscesses are found in approximately 36% of patients; occur more often in the ileocolonic and colonic disease; and may precede the onset of intestinal symptoms (Farmer et al, Gastroenterology 68:627-635, 1975; Rankin et al, Gastroenterology 77:914-920, 1979; Gray et al, Gut 6:515-524, 1965; and Homan et al, Arch Surg 111:1333-1335, 1976). To approach perianal manifestations, the physician must identify the anatomic location of the disease, treat the suppurative complications, and consider a long-term approach to palliation of chronic inflammatory sequelae. This article will review the medical management of perianal Crohn's disease and indications for surgery.

Healing of transsphincteric perianal fistulas in Crohn's disease using a new technique

OBJECTIVES

Transsphincteric perianal fistulas in Crohn's disease are often refractory to medical therapy and difficult to treat surgically. Our objective was to determine whether a new method of anal fistulotomy was effective in healing these fistulas.

METHODS

In this new method, the internal opening of the fistula tract was displaced distally to the region of the anal mucosa in 26 patients with Crohn's disease.

RESULTS

Healing was achieved within 5 weeks of surgery in 45/49 (92%) of the fistulas and was not influenced by perioperative medication, site of preexisting Crohn's disease, or condition of the rectum. There has been no alteration of preoperative continence.

CONCLUSIONS

We conclude that this method is highly effective in treating transsphincteric perianal fistulas in Crohn's disease.

Regulation of a hevein-like gene in Arabidopsis

An Arabidopisis cDNA clone was isolated that encodes a protein similar to the antifungal chitin-binding protein hevein from rubber tree latex. This hevein-like (HEL) mRNA was inducible by either turnip crinkle virus infection or ethylene treatment. In addition, expression was moderately inducible by treatment with the resistance-inducing compounds salicylic acid and 2,6-dichlorisonicotinic acid. The 786-bp cDNA contains an open reading frame of 212 codons. The deduced amino acid sequence contains a putative signal sequence of 21 amino acids followed by a 43-amino-acid cysteine-rich lectin domain and a 129-amino-acid carboxy-terminal domain. The predicted protein is approximately 70% identical to hevein, to the wound-inducible WIN1 and WIN2 proteins from potato, and to PR-4, a pathogenesis-related protein from tobacco.