The PD-1- and LAG-3-targeting bispecific molecule tebotelimab in solid tumors and hematologic cancers: a phase 1 trial

Tebotelimab, a bispecific PD-1×LAG-3 DART molecule that blocks both PD-1 and LAG-3, was investigated for clinical safety and activity in a phase 1 dose-escalation and cohort-expansion clinical trial in patients with solid tumors or hematologic malignancies and disease progression on previous treatment. Primary endpoints were safety and maximum tolerated dose of tebotelimab when administered as a single agent (n = 269) or in combination with the anti-HER2 antibody margetuximab (n = 84). Secondary endpoints included anti-tumor activity. In patients with advanced cancer treated with tebotelimab monotherapy, 68% (184/269) experienced treatment-related adverse events (TRAEs; 22% were grade ≥3). No maximum tolerated dose was defined; the recommended phase 2 dose (RP2D) was 600 mg once every 2 weeks. There were tumor decreases in 34% (59/172) of response-evaluable patients in the dose-escalation cohorts, with objective responses in multiple solid tumor types, including PD-1-refractory disease, and in LAG-3+ non-Hodgkin lymphomas, including CAR-T refractory disease. To enhance potential anti-tumor responses, we tested margetuximab plus tebotelimab. In patients with HER2+ tumors treated with tebotelimab plus margetuximab, 74% (62/84) had TRAEs (17% were grade ≥3). The RP2D was 600 mg once every 3 weeks. The confirmed objective response rate in these patients was 19% (14/72), including responses in patients typically not responsive to anti-HER2/anti-PD-1 combination therapy. ClinicalTrials.gov identifier: NCT03219268 .

Safety of AFM11 in the treatment of patients with B-cell malignancies: findings from two phase 1 studies

BACKGROUND

The prognosis for patients with relapsed and/or refractory (R/R) non-Hodgkin's lymphoma (NHL) or acute lymphoblastic leukaemia (ALL) remains poor, with existing treatments having significant side effects. Developed for the treatment of these cancers, AFM11 is a tetravalent, bispecific humanised recombinant antibody construct (TandAb®) designed to bind to human CD19 and CD3 and lead to the activation of T cells inducing apoptosis and killing of malignant B cells.

METHODS

Two open-label, multicentre, dose-escalation phase 1 studies evaluated the safety, pharmacokinetics and activity of AFM11 in patients with R/R CD19-positive B cell NHL (AFM11-101) and in patients with CD19 + B-precursor Philadelphia-chromosome negative ALL (AFM11-102). Adverse events (AEs) were assessed and recorded; imaging (NHL) or bone marrow assessment (ALL) were used to evaluate response. Additional pharmacodynamic assays undertaken included cytokine release analysis and B-cell and T-cell depletion.

RESULTS

In AFM11-101, 16 patients with R/R NHL received AFM11 in five different dose cohorts. Of which, 14 experienced drug-related treatment-emergent AEs (TEAEs) [including five serious AEs (SAEs)], five patients experienced dose-limiting toxicity (DLT) and ten patients discontinued the study. The high number of neurological events led to a decrease in infusion frequency during the study. No objective response to treatment was observed. In AFM11-102, 17 patients with R/R ALL received AFM11 in six different dose cohorts. Thirteen patients experienced drug-related TEAEs (including four SAEs), DLTs occurred in two patients and five patients discontinued the study. An objective response was recorded in three patients. The maximum tolerated dose could not be determined in either study due to early termination.

CONCLUSIONS

AFM11 treatment was associated with frequent neurological adverse reactions that were severe in some patients. In ALL, some signs of activity, albeit short-lived, were observed whereas no activity was observed in patients with NHL; therefore, further clinical development was terminated.

TRIAL REGISTRATION

NCT02106091 . Safety Study to Assess AFM11 in Patients With Relapsed and/or Refractory CD19 Positive B-cell NHL. Registered April 2014. NCT02848911 . Safety Study to Assess AFM11 in Patients With Relapsed or Refractory Adult B-precursor ALL. Registered July 2016.

Older patients (aged ≥60 years) with previously untreated advanced-stage classical Hodgkin lymphoma: a detailed analysis from the phase III ECHELON-1 study

Effective and tolerable treatments are needed for older patients with classical Hodgkin lymphoma. We report results for older patients with classical Hodgkin lymphoma treated in the large phase III ECHELON-1 study of frontline brentuximab vedotin plus doxorubicin, vinblastine, and dacarbazine (A+AVD) versus doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). Modified progression-free survival per independent review facility for older versus younger patients (aged ≥60 vs. <60 years) was a pre-specified subgroup analysis; as the ECHELON- 1 study was not powered for these analyses, reported P-values are descriptive. Of 1,334 enrolled patients, 186 (14%) were aged ≥60 years (A+AVD: n=84, ABVD: n=102); results below refer to this age group. Modified progression-free survival per independent review facility was similar in the two arms at 24 months (A+AVD: 70.3% [95% confidence interval (CI): 58.4–79.4], ABVD: 71.4% [95% CI: 60.5–79.8], hazard ratio (HR)=1.00 [95% CI: 0.58–1.72], P=0.993). After a median follow-up of 60.9 months, 5-year progression-free survival per investigator was 67.1% with A+AVD versus 61.6% with ABVD (HR=0.820 [95% CI: 0.494–1.362], P=0.443). Comparing A+AVD versus ABVD, grade 3/4 peripheral neuropathy occurred in 18% versus 3%; any-grade febrile neutropenia in 37% versus 17%; and any-grade pulmonary toxicity in 2% versus 13%, respectively, with three (3%) pulmonary toxicity-related deaths in patients receiving ABVD (none in those receiving A+AVD). Altogether, A+AVD showed overall similar efficacy to ABVD with survival rates in both arms comparing favorably to those of prior series in older patients with advanced-stage classical Hodgkin lymphoma. Compared to ABVD, A+AVD was associated with higher rates of neuropathy and neutropenia, but lower rates of pulmonary-related toxicity. Trials registered at ClinicalTrials.gov identifiers: NCT01712490; EudraCT number: 2011-005450-60.

Acalabrutinib: a highly selective, potent Bruton tyrosine kinase inhibitor for the treatment of chronic lymphocytic leukemia

Inhibiting the activity of Bruton tyrosine kinase (BTK) prevents the activation of the B-cell receptor (BCR) signaling pathway, which in turn prevents both B-cell activation and BTK-mediated activation of downstream survival pathways. Acalabrutinib is an orally available, highly selective, next-generation inhibitor of BTK. Based on the results of two key phase 3 trials (ELEVATE-TN in patients with previously untreated chronic lymphocytic leukemia [CLL] and ASCEND in patients with relapsed or refractory CLL), which demonstrated superior progression-free survival while maintaining favorable tolerability, acalabrutinib was granted US Food and Drug Administration (FDA) approval in 2019 for the treatment of patients with CLL. Acalabrutinib appears to offer similar efficacy but a significantly improved tolerability profile to first-generation agents. Acalabrutinib is a good candidate to combine with other anti-cancer therapies, including B-cell lymphoma 2 inhibitors and monoclonal antibodies, a factor that may help to further improve clinical outcomes in CLL.

Ibrutinib does not have clinically relevant interactions with oral contraceptives or substrates of CYP3A and CYP2B6

Ibrutinib may inhibit intestinal CYP3A4 and induce CYP2B6 and/or CYP3A. Secondary to potential induction, ibrutinib may reduce the exposure and effectiveness of oral contraceptives (OCs). This phase I study evaluated the effect of ibrutinib on the pharmacokinetics of the CYP2B6 substrate bupropion, CYP3A substrate midazolam, and OCs ethinylestradiol (EE) and levonorgestrel (LN). Female patients (N = 22) with B‐cell malignancies received single doses of EE/LN (30/150 μg) and bupropion/midazolam (75/2 mg) during a pretreatment phase on days 1 and 3, respectively (before starting ibrutinib on day 8), and again after ibrutinib 560 mg/day for ≥ 2 weeks. Intestinal CYP3A inhibition was assessed on day 8 (single‐dose ibrutinib plus single‐dose midazolam). Systemic induction was assessed at steady‐state on days 22 (EE/LN plus ibrutinib) and 24 (bupropion/midazolam plus ibrutinib). The geometric mean ratios (GMRs; test/reference) for maximum plasma concentration (C_max) and area under the plasma concentration‐time curve (AUC) were derived using linear mixed‐effects models (90% confidence interval within 80%‐125% indicated no interaction). On day 8, the GMR for midazolam exposure with ibrutinib coadministration was ≤ 20% lower than the reference, indicating lack of intestinal CYP3A4 inhibition. At ibrutinib steady‐state, the C_max and AUC of EE were 33% higher than the reference, which was not considered clinically relevant. No substantial changes were noted for LN, midazolam, or bupropion. No unexpected safety findings were observed. A single dose of ibrutinib did not inhibit intestinal CYP3A4, and repeated administration did not induce CYP3A4/2B6, as assessed using EE, LN, midazolam, and bupropion.

Type 2 diabetes mellitus compromises the survival of diffuse large B-cell lymphoma patients treated with (R)-CHOP - the PLRG report

Comorbidities impair the prognosis of diffuse large B-cell lymphoma (DLBCL). Type 2 diabetes mellitus (DMT2) increases the risk of other comorbidities, e.g., heart failure (HF). Thus, we hypothesized that pre-existing DMT2 may negatively affect the outcome of DLBCL. To verify this, DLBCL patients treated with (R)-CHOP were enrolled. 469 patients were eligible, with a median age of 57 years; 356 patients had advanced-stage DLBCL. 126 patients had high-intermediate and 83 high-risk international prognostic index (IPI). Seventy-six patients had DMT2, 46 HF; 26 patients suffered from both DMT2 and HF. In the analyzed group DMT2 or HF significantly shortened overall survival (OS) and progression free survival (PFS): the 5-year OS for patients with DMT2 was 64% vs 79% and for those with HF: 49% vs 79%. The 5-year PFS for DMT2 was 50.6% vs 62.5% and for HF 39.4% vs 63.2%. The relapse/progression incidence was comparable between groups; the non-relapse/progression mortality (NRPM) was significantly higher solely in DMT2 patients (5-year NRPM 22.5% vs 8.4%). The risk of death was higher in patients with higher IPI (HR = 1.85) and with DMT2 (HR = 1.87). To conclude, pre-existing DMT2, in addition to a higher IPI and HF, was a negative predictor for OS and PFS.

Mechanisms and clinical course of cardiovascular toxicity of cancer treatment I. Oncology

The opening session of Second International Colloquium on Cardio-Oncology addressed two areas of vital interest. The first reviewed new thoughts related to established agents. While anthracycline cardiotoxicity has been studied and reviewed extensively, ongoing research attempting to understand why it appears the mechanism(s) of toxicity differs from that of oncologic efficacy continue to evoke comment and intriguing speculation. Better understanding of the role of β-topoisomerase II in toxicity has advanced our understanding of the cascade of events that lead to heart failure. Additionally, the cardioprotective role of dexrazoxane fits well with our new understanding of how β-topoisomerase II works. Beyond the anthracyclines, new insight is providing us insight to better understand the impact on cardiac function seen with other agents including those targeting HER2 and several tyrosine-kinase inhibitors. Unlike the anthracyclines, these agents affect cardiac function in ways that are less direct, and therefore have different characteristics and should be thought of in alternate ways. This new knowledge regarding established agents furthers our understanding of the spectrum of cardiotoxicity and cardiac dysfunction in the cancer patient. The session also addressed cardiovascular toxicities of newer and established agents beyond myocardial dysfunction including effects on the vasculature. These agents cause changes that may be temporary or permanent, and that range from subclinical to life-threatening. The session ended with a discussion of the cardiac effects of immune checkpoint inhibitors. These agents can cause rare and sometimes fatal cardiac inflammation, for which long-term follow up may be required.

Consolidation with 90Y ibritumomab tiuxetan radioimmunotherapy in mantle cell lymphoma patients ineligible for high dose therapy: results of the phase II multicentre Polish Lymphoma Research Group trial, after 8-year long follow-up

Polish Lymphoma Research Group performed a phase-II trial to test whether ⁹⁰Y ibritumomab tiuxetan radioimmunotherapy (Y90) may constitute an alternative consolidation for mantle cell lymphoma patients unfit for high-dose therapy. Forty-six patients were consolidated with Y90 following response to the 1st (n = 34) or 2nd line (n = 12) (immuno)chemotherapy. Majority of the patients had advanced disease (stage IV and presence of B-symptoms in 85% and 70%, respectively) and high MIPI (5.8, range 4-7). Consolidation with Y90 increased the complete remission (CR) rate obtained by the 1st line therapy from 41% to 91% and allowed for median PFS of 3.3 and OS of 6.5 years. In the first relapse, CR rate increased from 16% to 75%, while median PFS and OS totaled 2.2 and 6.5 years, respectively. At 8 years, 30% of patients, consolidated in the 1st line CR were alive, without relapse. Toxicity associated with Y90 is manageable, more severe after fludarabine-based regimens.

Genetic heterogeneity in primary and relapsed mantle cell lymphomas: Impact of recurrent CARD11 mutations

The genetic mechanisms underlying disease progression, relapse and therapy resistance in mantle cell lymphoma (MCL) remain largely unknown. Whole-exome sequencing was performed in 27 MCL samples from 13 patients, representing the largest analyzed series of consecutive biopsies obtained at diagnosis and/or relapse for this type of lymphoma. Eighteen genes were found to be recurrently mutated in these samples, including known (ATM, MEF2B and MLL2) and novel mutation targets (S1PR1 and CARD11). CARD11, a scaffold protein required for B-cell receptor (BCR)-induced NF-κB activation, was subsequently screened in an additional 173 MCL samples and mutations were observed in 5.5% of cases. Based on in vitro cell line-based experiments, overexpression of CARD11 mutants were demonstrated to confer resistance to the BCR-inhibitor ibrutinib and NF-κB-inhibitor lenalidomide. Genetic alterations acquired in the relapse samples were found to be largely non-recurrent, in line with the branched evolutionary pattern of clonal evolution observed in most cases. In summary, this study highlights the genetic heterogeneity in MCL, in particular at relapse, and provides for the first time genetic evidence of BCR/NF-κB activation in a subset of MCL.