High-dose carfilzomib achieves superior anti-tumor activity over low-dose and recaptures response in relapsed/refractory multiple myeloma resistant to lowdose carfilzomib by co-inhibiting the ß2 and ß1 subunits of the proteasome complex.

Optimal carfilzomib dosing is a matter of debate. We analyzed the inhibition profiles of proteolytic proteasome subunits ß5, ß2 and ß1 after low-dose (20/27 mg/m2) versus high-dose (≥36 mg/m2) carfilzomib in 103 pairs of peripheral blood mononuclear cells from patients with relapsed/refractory (RR) multiple myeloma (MM). ß5 activity was inhibited (median inhibition >50%) in vivo by 20 mg/m2, whereas ß2 and ß1 were co-inhibited only by 36 and 56 mg/m2, respectively. Coinhibition of ß2 (P=0.0001) and ß1 activity (P=0.0005) differed significantly between high-dose and low-dose carfilzomib. Subsequently, high-dose carfilzomib showed significantly more effective proteasome inhibition than low-dose carfilzomib in vivo (P=0.0003). We investigated the clinical data of 114 patients treated with carfilzomib combinations. High-dose carfilzomib demonstrated a higher overall response rate (P=0.03) and longer progression-free survival (PFS) (P=0.007) than low-dose carfilzomib. Therefore, we escalated the carfilzomib dose to ≥36 mg/m2 in 16 patients who progressed during low-dose carfilzomib-containing therapies. High-dose carfilzomib recaptured response (≥ partial remission) in nine (56%) patients with a median PFS of 4.4 months. Altogether, we provide the first in vivo evidence in RRMM patients that the molecular activity of high-dose carfilzomib differs from that of low-dose carfilzomib by coinhibition of ß2 and ß1 proteasome subunits and, consequently, high-dose carfilzomib achieves a superior anti-MM effect than low-dose carfilzomib and recaptures the response in RRMM resistant to low-dose carfilzomib. The optimal carfilzomib dose should be ≥36 mg/m2 to reach a sufficient anti-tumor activity, while the balance between efficacy and tolerability should be considered in each patient.

Salvage therapy with "Dara-KDT-P(A)CE" in heavily pretreated, high-risk, proliferative, relapsed/refractory multiple myeloma.

The multi-agent therapy "VDT-PACE" represents an established regimen in relapsed/refractory multiple myeloma (RRMM). Here, we report on our experience with a "modified VDT-PACE" incorporating new generation anti-MM agents daratumumab and carfilzomib ("Dara-KDT-P(A)CE"). We retrospectively analyzed 38 patients with RRMM treated with "Dara-KDT-P(A)CE". The median age was 62 (range 45-82) years, and the patients were heavily pretreated with a median of 5 (range 2-12) prior lines of therapy. Twenty-one (55%) patients suffered from penta-refractory MM. High-risk cytogenetics was present in 31 (81%) patients. The patients received a median of 2 (range 1-10) cycles of this therapy, and the overall response rate (ORR) was 70%. Patients with penta-refractory MM and high-risk cytogenetics showed similar ORR of 65% and 79%, respectively. The median progression-free survival (PFS) and overall survival were 4.1 (95% CI 2.7-5.4) and 8.4 (95% CI 6.7-10.0) months, respectively. Patients with lactate dehydrogenase >250 IU/L showed significantly shorter PFS in comparison with others patients (p = 0.006). We used this regimen as bridging therapy prior to chimeric antigen receptor T-cell infusion in four patients. In conclusion, "Dara-KDT-P(A)CE" is an effective salvage therapy for patients with heavily pretreated, multi-refractory, high-risk RRMM lacking alternative options.

Th17.1 cell driven sarcoidosis-like inflammation after anti-BCMA CAR T cells in multiple myeloma.

Pseudo-progression and flare-up phenomena constitute a novel diagnostic challenge in the follow-up of patients treated with immune-oncology drugs. We present a case study on pulmonary flare-up after Idecabtagen Vicleucel (Ide-cel), a BCMA targeting CAR T-cell therapy, and used single-cell RNA-seq (scRNA-seq) to identify a Th17.1 driven autoimmune mechanism as the biological underpinning of this phenomenon. By integrating datasets of various lung pathological conditions, we revealed transcriptomic similarities between post CAR T pulmonary lesions and sarcoidosis. Furthermore, we explored a noninvasive PET based diagnostic approach and showed that tracers binding to CXCR4 complement FDG PET imaging in this setting, allowing discrimination between immune-mediated changes and true relapse after CAR T-cell treatment. In conclusion, our study highlights a Th17.1 driven autoimmune phenomenon after CAR T, which may be misinterpreted as disease relapse, and that imaging with multiple PET tracers and scRNA-seq could help in this diagnostic dilemma.

Modulation of the rubber hand illusion by transcranial direct current stimulation over the contralateral somatosensory cortex.

In the rubber hand illusion (RHI), illusory bodily ownership is induced by synchronous touch of a participant's hidden hand and a visible surrogate. This paradigm allows investigating how the brain resolves conflicting multisensory evidence during perceptual inference. Previous studies suggest that the conflict between visual and proprioceptive information preceding the RHI is solved by attenuation of the somatosensory input. To investigate whether excitability-decreasing transcranial direct current stimulation (cathodal tDCS) over the primary somatosensory cortex may enhance the RHI, thirty healthy subjects underwent RHI without (baseline) and during tDCS. Each subject received cathodal, anodal, and sham stimulation at independent sessions on three separate days. The RHI paradigm was applied at six interval distances between the real and artificial hand. Occurrence of the RHI was evaluated by a questionnaire (illusion score) and the perceived hand misplacement (relative drift). Compared to sham, neither cathodal, nor anodal tDCS induced significant changes of the illusion score. However, cathodal tDCS was associated with significantly higher illusion scores compared to anodal stimulation. The relative drift was comparable between stimulation modes. Our findings point to a differential impact of cathodal vs. anodal tDCS over the somatosensory region on RHI perception. This may indicate that an attenuation - in contrast to an enhancement - of somatosensory precision might pave the way for the integration of an artificial limb into one's body schema.