DuoBody-CD3xCD20 induces potent T-cell-mediated killing of malignant B cells in preclinical models and provides opportunities for subcutaneous dosing

Background

DuoBody®-CD3xCD20 (GEN3013) is a full-length human IgG1 bispecific antibody (bsAb) recognizing CD3 and CD20, generated by controlled Fab-arm exchange. Its Fc domain was silenced by introduction of mutations L234F L235E D265A.

Methods

T-cell activation and T-cell-mediated cytotoxicity were measured by flow cytometry following co-culture with tumour cells. Anti-tumour activity of DuoBody-CD3xCD20 was assessed in humanized mouse models in vivo. Non-clinical safety studies were performed in cynomolgus monkeys.

Findings

DuoBody-CD3xCD20 induced highly potent T-cell activation and T-cell-mediated cytotoxicity towards malignant B cells in vitro. Comparison of DuoBody-CD3xCD20 to CD3 bsAb targeting alternative B-cell antigens, or to CD3xCD20 bsAb generated using alternative CD20 Ab, emphasized its exceptional potency. In vitro comparison with other CD3xCD20 bsAb in clinical development showed that DuoBody-CD3xCD20 was significantly more potent than three other bsAb with single CD3 and CD20 binding regions and equally potent as a bsAb with a single CD3 and two CD20 binding regions. DuoBody-CD3xCD20 showed promising anti-tumour activity in vivo, also in the presence of excess levels of a CD20 Ab that competes for binding. In cynomolgus monkeys, DuoBody-CD3xCD20 demonstrated profound and long-lasting B-cell depletion from peripheral blood and lymphoid organs, which was comparable after subcutaneous and intravenous administration. Peak plasma levels of DuoBody-CD3xCD20 were lower and delayed after subcutaneous administration, which was associated with a reduction in plasma cytokine levels compared to intravenous administration, while bioavailability was comparable.

Interpretation

Based on these preclinical studies, a clinical trial was initiated to assess the clinical safety of subcutaneous DuoBody-CD3xCD20 in patients with B-cell malignancies.

Funding

Genmab

How to improve eRehabilitation programs in stroke care? A focus group study to identify requirements of end-users

BACKGROUND

A user-centered design approach for eHealth interventions improves their effectiveness in stroke rehabilitation. Nevertheless, insight into requirements of end-users (patients/informal caregivers and/or health professionals) for eRehabilitation is lacking. The aim of this study was to identify end-user requirements for a comprehensive eHealth program in stroke rehabilitation.

METHODS

Eight focus groups were conducted to identify user requirements; six with patients/informal caregivers and two with health professionals involved in stroke rehabilitation (rehabilitation physicians, physiotherapists, occupational therapists, psychologists, team coordinators, speech therapist). The focus groups were audiotaped and transcribed in full. Direct content analysis was used to identify the end-user requirements for stroke eHealth interventions concerning three categories: accessibility, usability and content.

RESULTS

In total, 45 requirements for the accessibility, usability and content of a stroke eRehabilitation program emerged from the focus groups. Most requirements concerned content (27 requirements), followed by usability (12 requirements) and accessibility (6 requirements). Patients/informal caregivers and health professionals each identified 37 requirements, respectively, with 29 of them overlapping.

CONCLUSIONS

Requirements between stroke patients/informal caregivers and health professionals differed on several aspects. Therefore, involving the perspectives of all end users in the design process of stroke eRehabilitation programs is needed to achieve a user-centered design.

TRIAL REGISTRATION

The study was approved by the Medical Ethical Review Board of the Leiden University Medical Center [P15.281].

Physical activity after mild traumatic brain injury: What are the relationships with fatigue and sleep quality?

OBJECTIVES

To determine self-reported physical activity (PA) levels and relationships with fatigue and sleep quality in adolescents and young adults after mild traumatic brain injury (mTBI).

SETTING

Follow-up 6-18 months after visiting the emergency department of one of 2 general hospitals.

PARTICIPANTS

Forty-nine adolescents and young adults aged 12-25 years (mean 18.4 years), 22 (45%) male with mTBI.

DESIGN

Cross-sectional survey study.

MAIN OUTCOME MEASURES

The Activity Questionnaire for Adults and Adolescents (AQuAA), with results dichotomized into meeting or not meeting Dutch Health Enhancing PA recommendations (D-HEPA), the Checklist Individual Strength (CIS, 4 subscores) and the Pittsburgh Sleep Quality Index (PSQI, total score) were administered.

RESULTS

Twenty-five participants (51%) did not meet the D-HEPA recommendations. After adjusting for sex, BMI and age, not meeting the recommendations was associated with a higher CIS Total Score (OR 1.04 95%CI 1.01, 1.07) but not with PSQI Total Score (OR 0.99, 95%CI 0.80, 1.21).

CONCLUSIONS

In adolescents and young adults with mTBI the level of reported PA is associated with fatigue but not with sleep quality. It remains to be established whether interventions aiming to promote PA should primarily be focused on PA or fatigue or both.

Cytomegalovirus pleuropericarditis after orthotopic liver transplantation

Cytomegalovirus (CMV) reactivation is a common complication after liver transplantation. In patients with CMV infection, indicated by a positive CMV DNA titer, the presence of any clinical symptom is termed CMV disease. The most common organ affected in CMV disease is the gastrointestinal tract, causing esophagitis, gastritis, enteritis or colitis. CMV infection of the pleura and pericard has been reported in immunocompromised patients, but is rarely seen following liver transplantation.We report a case of a 59-year-old male who developed CMV pleuropericarditis after liver transplantation. Initial ganciclovir treatment did not improve the patient's symptoms and therapy was switched to Foscarnet which ultimately resulted in resolution of infection. However, a few weeks after Foscarnet cessation, the patient again developed bilateral pleural effusion. Ultimate biochemical and clinical response was achieved with IV ganciclovir treatment. The patient was discharged from the hospital with oral Valganciclovir for 3 weeks and has since remained relapse free for >1 year.

Do rehabilitation tools cover the perspective of patients with rheumatoid arthritis? A focus group study using the ICF as a reference

BACKGROUND

Despite the advocated use of rehabilitation tools in clinical rehabilitation of with rheumatoid arthritis (RA) patients, little is known about the representation of the patient perspective in these tools.

AIM

Aim of the study was to explore the experiences of RA patients with rehabilitation and the coverage by rehabilitation tools.

DESIGN AND POPULATION

Qualitative focus group study with RA patients about experiences with rehabilitation.

SETTING

Rheumatology rehabilitation clinic of a Dutch university hospital.

METHODS

Focus groups were tape recorded and transcribed verbatim. From the meaningful units, concepts were extracted and linked to the International Classification of Functioning, Disability and Health (ICF). Rehabilitation tools validated for RA were identified using a structured literature search. Using the ICF as common framework, we determined for each concept identified in the focus groups the coverage by each rehabilitation tool.

RESULTS

Nineteen patients participated in 4 focus groups. Fifty-one concepts were identified in 368 meaningful units derived from the transcribed data. From the literature the ICF Core Sets for RA, Canadian Occupational Performance Measure, Rehabilitation Activities Profile and WHO Disability Assessment Schedule II were elected. The concepts from the focus groups were best covered by the ICF Core Sets (44 out of 51; 86%), followed by the WHODAS II (39%), RAP (35%) and COPM (16%).

CONCLUSION

With the exception of the ICF Core Sets for RA, current rehabilitation tools poorly cover the RA patients' perception on rehabilitation.

CLINICAL REHABILITATION IMPACT

The ICF Core Sets can serve as a checklist to guide multidisciplinary assessment, goal-setting and evaluation in RA rehabilitation.

Fc-Fc interactions of human IgG4 require dissociation of heavy chains and are formed predominantly by the intra-chain hinge isomer

Human IgG4 antibodies are remarkable not only because they can dynamically exchange half-molecules (Fab-arm exchange) but also for their ability to interact with the Fc part of IgG4 and other IgG subclasses. This rheumatoid factor-like binding of IgG4 does not appear to take place spontaneously, because it is only observed to solid-phase or antigen-bound IgG. We hypothesized that Fc-Fc interactions might involve (partial) dissociation of heavy chains. We investigated the molecular basis of these Fc-Fc interactions, and found that the structural features important for the exchange reaction also control the Fc binding activity. In particular, if arginine-409 in the CH(3)-CH(3) interface in IgG4 is mutated to lysine (the equivalent in IgG1), Fc-Fc interactions are formed 3 orders of magnitude less efficiently compared to the wild-type. This mutation was previously found to increase the CH(3)-CH(3) interaction strength in IgG4. Furthermore, of the two hinge isomers of IgG4, the intra-chain (non-covalently linked) form was found to form Fc-Fc interactions, but not the inter-chain form. Together, these results demonstrate that Fc-Fc interactions of IgG4 involve (partial or complete) dissociation of heavy chains. The promiscuity to other IgG subclasses suggests that IgG4 might act as scavenger to IgG molecules with impaired structural integrity.