A phase II multi-arm study of magrolimab combinations in patients with relapsed/refractory multiple myeloma.

Magrolimab is a monoclonal antibody that blocks CD47, a 'do not eat me' signal overexpressed on tumor cells. CD47 is overexpressed in multiple myeloma (MM), which contributes to its pathogenesis. Preclinical studies have shown that CD47 blockade induces macrophage activation, resulting in elimination of myeloma cells, and that there is synergy between magrolimab and certain anticancer therapies. These findings suggest that magrolimab-based combinations may have a therapeutic benefit in MM. This phase II study investigates magrolimab in combination with commonly used myeloma therapies in patients with relapsed/refractory MM and includes a safety run-in phase followed by a dose-expansion phase. Primary end points include the incidence of dose-limiting toxicities and adverse events (safety run-in) and the objective response rate (dose expansion).

Magrolimab is a therapy that blocks a 'do not eat me' signal overexpressed by certain cancers, including multiple myeloma (MM) cells. Studies have shown that blocking this signal leads to destruction of myeloma cells and that this cancer-killing effect may be increased by combining magrolimab with certain additional anticancer therapies. These findings suggest that magrolimab-based combinations may have a therapeutic benefit in MM. This study is investigating magrolimab in combination with commonly used myeloma therapies in patients with MM who have persistent disease despite prior treatment. Goals of the trial include assessing safety and response to treatment. Clinical Trial Registration: NCT04892446 (ClinicalTrials.gov).

A retrospective observational study to evaluate the clinical outcomes and routine management of patients with chronic lymphocytic leukaemia treated with idelalisib and rituximab in the UK and Ireland (RETRO-idel).

Idelalisib (IDL) is an oral first-in-class phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor approved for chronic lymphocytic leukaemia (CLL) alongside rituximab (R) since 2014. However, little data exist on routine practice. The RETRO-idel was a protocol-led, retrospective study of 110 patients [n = 27 front-line (1L)] who received IDL-R. The primary end-point was clinical overall response rate (ORR). The median (range) follow-up of the whole cohort was 30·2 (0·1-51·9) months. The median (range) age was 72 (48-89) years. Tumour protein p53-disruption was common [100% 1L, 32·5% relapsed/refractory (R/R)]. The best ORR (intention-to-treat) was 88·2% (1L 96·3%, R/R 85·5%). Overall, the median event-free survival (mEFS) was 20·3 months and time-to-next treatment was 29·2 months. The mEFS for 1L patients was 18·7 months and R/R patients was 21·7 months. The 3-year overall survival was 56·1% (95% confidence interval 45·7-65·3). IDL was discontinued in 87·3% (n = 96). More patients discontinued due to adverse events in the front-line setting (1L 63·0% vs. R/R 44·6%) and due to progressive disease in R/R patients (20·5% vs. 3·7% in 1L). Lower respiratory tract infection/pneumonia were reported in 34·5% (Grade ≥3, 19·1%), diarrhoea in 30·9% (Grade ≥3, 6·4%), and colitis in 9·1% (Grade ≥3, 5·5%). Overall, these data describe clear efficacy for IDL-R in routine practice. No new safety signals were identified, although careful management of known toxicities is required.

A Phase Ib Study of Single-Agent Idelalisib Followed by Idelalisib in Combination with Chemotherapy in Patients with Metastatic Pancreatic Ductal Adenocarcinoma.

LESSONS LEARNED: Although this study of idelalisib in patients with PDAC was limited in size and duration because of early termination, idelalisib exposure resulted in an overall safety profile consistent with studies in hematological malignancies, except that the incidences of diarrhea and colitis were reduced in patients with PDAC. Preclinical studies of the PI3K pathway in PDAC and positive clinical results of PI3K inhibition in other cancers support the continued development of PI3K inhibitors in PDAC. BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal solid tumors and is often refractory to treatment. Phosphatidylinositol-3 kinase (PI3K) δ inhibition influences regulatory immune cell function and improves survival in preclinical PDAC models. Here, idelalisib, an inhibitor of PI3Kδ, was investigated as treatment for metastatic PDAC. METHODS: This was an open-label, multicenter, phase Ib, nonrandomized, dose-escalation study. Study aims were to investigate the maximum tolerated dose, safety, pharmacokinetics/pharmacodynamics, and efficacy of idelalisib alone and in combination with chemotherapeutics-nab-paclitaxel and modified (m)FOLFOX6. RESULTS: Because of early termination, only 16 patients were enrolled in the single-agent idelalisib arm, 12 of whom received at least one dose of idelalisib. The most common treatment-emergent adverse events (≥25%) related to idelalisib (n = 12) were increased aspartate aminotransferase, pyrexia, and maculopapular rash. One patient presented with diarrhea; no cases of colitis were reported. One patient discontinued treatment because of pyrexia and maculopapular rash; two patients died because of disease progression. CONCLUSION: This study was terminated because factors contributing to safety concerns in phase III studies of idelalisib for hematological malignancies were not fully understood. In this small sample of patients with metastatic PDAC, exposure to idelalisib resulted in safety findings consistent with previous studies, with reduced diarrhea/colitis.

Real-world Effectiveness of Azacitidine in Treatment-Naive Patients With Higher-risk Myelodysplastic Syndromes.

INTRODUCTION: Azacitidine (AZA) is an approved frontline therapy for higher-risk myelodysplastic syndromes (HR-MDS); however, poor survival denotes unmet needs to increase depth/duration of response (DOR). METHODS: This retrospective study with patient chart review evaluated AZA effectiveness in 382 treatment-naive patients with HR-MDS from a US electronic health record (EHR)-derived database. Responses were assessed using International Working Group (IWG) 2006 criteria; real-world equivalents were derived from EHRs. Primary endpoint was IWG 2006-based complete remission rate (CRR). Secondary endpoints were EHR-based CRR, IWG 2006- and EHR-based objective response rates (ORRs), duration of CR, DOR, progression-free survival, time-to-next-treatment, and overall survival (OS). RESULTS: Using IWG 2006 criteria, the CRR was 7.9% (n = 30); median duration of CR was 12.0 months (95% CI, 7.7-15.6). In poor cytogenetic risk (n = 101) and TP53 mutation (n = 46) subgroups, CRRs were 7.9% (n = 8) and 8.7% (n = 4), respectively. ORR was 62.8% (n = 240), including a hematologic improvement rate (HIR) of 46.9% (n = 179). Using EHR-based data, CRR was 3.7% (n = 14); median duration of CR was 13.5 months (95% CI, 4.5-21.5). ORR was 67.8% (n = 259), including an HIR of 29.3% (n = 112). Median follow-up was 12.9 months; median OS was 17.9 months (95% CI, 15.5-21.7). CONCLUSIONS: Consistent with other studies, CRRs and median OS with AZA in treatment-naive patients with HR-MDS were low in this large, real-world cohort. Novel agents/combinations are urgently needed to improve these outcomes in HR-MDS.

Phase I Study of GS-3583, an FMS-like Tyrosine Kinase 3 Agonist Fc Fusion Protein, in Patients with Advanced Solid Tumors.

PURPOSE: GS-3583, an FMS-like tyrosine kinase 3 (FLT3) agonist Fc fusion protein, expanded conventional dendritic cells (cDC) in the periphery of healthy volunteers, suggesting potential for GS-3583 to increase cDCs in the tumor microenvironment and promote T cell-mediated antitumor activity in cancer patients. This phase Ib open-label study assessed GS-3583 in adults with advanced solid tumors. PATIENTS AND METHODS: Multiple escalating doses of GS-3583 (standard 3+3 design) were administered intravenously on days 1 and 15 of cycle 1 and day 1 of each subsequent 28-day cycle for up to 52 weeks. Dose-limiting toxicity (DLT) was evaluated during the first 28 days of GS-3583 at each dose level. RESULTS: Thirteen participants enrolled in four dose-escalation cohorts, after which the study was terminated following safety review. Median (range) age was 71 (44-79), and 7 (54%) participants were male. There were no DLTs. Seven participants had grade ≥3 AEs; 2 participants had grade 5 AEs, including a second primary malignancy (acute myeloid leukemia) considered treatment-related. Dose-dependent increase in GS-3583 serum exposure was observed in the dose range of 2-20 mg with GS-3583 accumulation at higher dose levels. Expansions of cDCs occurred at all four doses with a dose-dependent trend in the durability of the cDC expansion. CONCLUSIONS: GS-3583 was relatively well tolerated and induced dose-dependent expansion of cDCs in the periphery of patients with advanced solid tumors. However, development of a second primary malignancy provides a cautionary tale for the FLT3 agonist mechanism. See related commentary by Raeder and Drazer, p. 2857.

A regulatory perspective of clinical trial applications for biological products with particular emphasis on Advanced Therapy Medicinal Products (ATMPs).

The safety of trial subjects is the tenet that guides the regulatory assessment of a Clinical Trial Authorization application and applies equally to trials involving small molecules and those with biological/biotechnological products, including Advanced Therapy Medicinal Products. The objective of a regulator is to ensure that the potential risk faced by a trial subject is outweighed by the potential benefit to them from taking part in the trial. The focus of the application review is to assess whether risks have been identified and appropriate steps taken to alleviate these as much as possible. Other factors are also taken into account during a review, such as regulatory requirements, and emerging non-clinical and clinical data from other trials on the same or similar products. This paper examines the regulatory review process of a Clinical Trial Authorization application from the perspectives of Quality, Non-Clinical and Clinical Regulatory Assessors at the Medicines and Healthcare products Regulatory Agency. It should be noted that each perspective has highlighted specific issues from their individual competence and that these can be different between the disciplines.

Azacitidine Monotherapy in Patients With Treatment-Naïve Higher-risk Myelodysplastic Syndrome: A Systematic Literature Review and Meta-analysis.

BACKGROUND: The global incidence of myelodysplastic syndromes (MDS) has been estimated as 0.06 to 0.26/100,000. Since their introduction, hypomethylating agents have played a central role in the treatment of MDS, with heterogeneous real-world outcomes. MATERIALS AND METHODS: We assessed and synthesized clinical outcomes of azacitidine (AZA) monotherapy in treatment-naïve patients with higher-risk MDS. A systematic literature review was conducted by searching MEDLINE, Embase, and CENTRAL to identify randomized clinical trials (RCTs) and observational studies, both prospective and retrospective, reporting complete remission (CR), partial remission (PR), overall survival (OS), duration of response (DOR), time-to-response (TTR), and myelosuppressive adverse events (AEs) for patients treated with AZA monotherapy. Noncomparative meta-analyses were used to summarize effects. RESULTS: The search identified 3250 abstracts, of which 34 publications describing 16 studies (5 RCTs, 3 prospective, and 8 retrospective observational) were included. Across all studies, pooled CR was 16%; PR was 6%; Median OS was 16.4 months; median DOR was 10.1 months; median TTR was 4.6 months. Proportions of grade 3/4 anemia and thrombocytopenia AEs were 10% and 30%. CONCLUSIONS: The effectiveness and efficacy of AZA monotherapy-as measured by CR and median OS-was limited. These findings highlight a significant unmet medical need for effective treatments for patients with higher-risk MDS.

Retrospective Analysis of the Impact of Adverse Event-Triggered Idelalisib Interruption and Dose Reduction on Clinical Outcomes in Patients With Relapsed/Refractory B-Cell Malignancies.

BACKGROUND: Idelalisib is a phosphatidylinositol 3-kinase δ inhibitor approved for relapsed/refractory follicular lymphoma, a type of indolent non-Hodgkin lymphoma (iNHL), and chronic lymphocytic leukemia (CLL). Idelalisib-triggered adverse events (AEs) may be managed with treatment interruption and/or dose reduction, potentially extending therapy duration and increasing the likelihood of continued response. PATIENTS AND METHODS: Post hoc analyses were conducted to evaluate clinical outcomes after AE-induced idelalisib interruption for 125 patients with iNHL and 283 with CLL. RESULTS: Progression-free survival (PFS) was longer for patients with iNHL who experienced ≥ 2 interruptions versus those with 0 interruptions who discontinued idelalisib or study because of AEs (hazard ratio 0.33; P = .0212). Both PFS and overall survival were longer for patients with CLL with ≥ 2 interruptions versus 0 interruptions in those who discontinued therapy because of an AE (hazard ratio PFS 0.50, overall survival 0.41; P < .005). Clinical benefits persisted for patients with CLL who experienced treatment interruption after receiving idelalisib for ≥ 6 months. Supplementing interruption with dose reduction did not worsen clinical outcomes. However, time off therapy of ≥ 8% may diminish the clinical benefit of treatment interruption. CONCLUSION: Idelalisib interruption and dose reduction were associated with enhanced clinical outcomes for patients with relapsed/refractory iNHL or CLL who experienced an AE, supporting this management strategy when indicated.

Outcomes of patients with up to 6 years of follow-up from a phase 2 study of idelalisib for relapsed indolent lymphomas.

The phase 2 study of idelalisib monotherapy for indolent non-Hodgkin lymphomas (iNHLs) was completed in 2018; final efficacy and safety data with up to 6.7 years long-term follow-up are reported. Patients with iNHL refractory to both rituximab and an alkylating agent were enrolled and received 150 mg idelalisib twice daily (N = 125). Idelalisib resulted in an overall response rate of 57.6% with 34.4% continuing therapy for ≥12 months. The median progression-free survival and duration of response were 11.0 and 11.8 months for follicular lymphoma, 22.2 and 20.4 months for lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (LPL/WM), and 6.6 and 18.4 months for marginal zone lymphoma (MZL). Median overall survival after extended follow-up was 48.6 (95% CI 33.9, 71.7) months. Long-term follow-up did not reveal new safety concerns. These data indicate beneficial outcomes with longer follow-up after idelalisib for treatment of iNHL including in patients with LPL/WM and MZL.

Idelalisib immune-related toxicity is associated with improved treatment response.

Idelalisib is associated with increased occurrence of immune-related adverse events (irAEs). Clinical observations suggest a correlation between immune checkpoint inhibitor-induced irAEs and survival outcomes in patients with solid tumors; however, this relationship in hematologic malignancies is not well understood. In a post hoc analysis of 3 registrational trials, we explored the relationship between Grade ≥3 diarrhea/colitis and alanine/aspartate transaminase (ALT/AST) elevation incidences and efficacy endpoints in patients with indolent non-Hodgkin lymphoma (iNHL), follicular lymphoma (FL), and chronic lymphocytic leukemia treated with idelalisib. Grade ≥3 diarrhea/colitis was associated with higher overall response rate (ORR) and longer progression-free survival (PFS) for all subgroups. Grade ≥3 ALT/AST elevations were associated with improved duration of response and overall survival for all subgroups and improved ORR and PFS for patients with FL or iNHL. Our analysis in hematologic malignancies showed a trend correlating idelalisib-induced Grade ≥3 irAEs with improved efficacy.

Neuroprotective interaction produced by xenon and dexmedetomidine on in vitro and in vivo neuronal injury models.

Xenon, an NMDA receptor antagonist and dexmedetomidine (Dex), an alpha(2)-adrenoceptor agonist, both exhibit neuroprotective effects. We investigated the nature of their interaction. In vitro: a primary co-culture of neuronal and glial cells derived from neonatal mice was exposed to oxygen and glucose deprivation (OGD) and the resulting neuronal injury was assessed by the release of lactate dehydrogenase (LDH). In vivo: Postnatal rats aged 7 days underwent right common carotid artery ligation followed by 90 min of hypoxia. The area of infarction was assessed at four days post-injury by morphological criteria. Long-term neurological function was evaluated at 30 days post-injury by testing co-ordination on rotarod. Both xenon and Dex concentration-dependently reduced LDH release with IC50 values of 42% atm (95% CI: 35-52) and 0.10 microM (95% CI: 0.08-0.16), respectively. Isobolographic analysis showed that combined effect of xenon and Dex in vitro was additive. In vivo, a combination of xenon and Dex, at doses that are individually not neuroprotective, produced significant neuroprotective effect as measured by reduction in area of infarction. The long-term neurological function data corroborated these morphological data. Our study demonstrates that the combination of xenon and Dex offers neuroprotection additively in vitro and synergistically in vivo.

Dexmedetomidine produces its neuroprotective effect via the alpha 2A-adrenoceptor subtype.

Which of the three alpha2-adrenoceptor subtypes of alpha2A, alpha2B, or alpha2C mediates the neuroprotective effect of dexmedetomidine was examined in cell culture as well as in an in vivo model of neonatal asphyxia. Dexmedetomidine dose-dependently attenuated neuronal injury (IC50=83+/-1 nM) in neuronal-glial co-cultures derived from wild-type mice; contrastingly, dexmedetomidine did not exert neuroprotection in injured cells from transgenic mice (D79N) expressing dysfunctional alpha2A-adrenoceptors. An alpha2A-adrenoceptor subtype-preferring antagonist 2-[(4,5-Dihydro-1H-imidazol-2-yl)methyl]-2,3-dihydro-1-methyl-1H-isoindole maleate (BRL44408) completely reversed dexmedetomidine-induced neuroprotection, while other subtype-preferring antagonists 2-[2-(4-(2-Methoxyphenyl)piperazin-1-yl)ethyl]-4,4-dimethyl-1,3-(2H,4H)-isoquinolindione dihydrochloride (ARC239) (alpha2B) and rauwolscine (alpha2C) had no significant effect on the neuroprotective effect of dexmedetomidine in neuronal-glial co-cultures. Dexmedetomidine also protected against exogenous glutamate induced cell death in pure cortical neuron cultures assessed by flow cytometry and reduced both apoptotic and necrotic types of cell death. Likewise this neuroprotective effect was antagonised by BRL44408 but not ARC239 or rauwolscine. Dexmedetomidine exhibited dose-dependent protection against brain matter loss in vivo (IC50=40.3+/-6.1 microg/kg) and improved the neurologic functional deficit induced by the hypoxic-ischemic insult. Protection by dexmedetomidine against hypoxic-ischemic-induced brain matter loss was reversed by the alpha2A-adrenoceptor subtype-preferring antagonist BRL44408; neither ARC239 nor rauwolscine reversed the neuroprotective effect of dexmedetomidine in vivo. Our data suggest that the neuroprotective effect of dexmedetomidine is mediated by activation of the alpha2A adrenergic receptor subtype.

alpha2-Adrenoceptor agonists: shedding light on neuroprotection?

Although alpha(2)-adrenoceptor agonists are widely used for analgesia, anxiolysis, sedation, sympatholysis and as anaesthetic-adjuncts for many years, their potential use as neuroprotectants has so far been confined to laboratory experiments. Despite the large body of evidence from both in vivo and in vitro studies, their exact neuroprotective mechanisms remain elusive. Herein, we review the available literature pertaining to the neuroprotective effect of alpha(2)-adrenoceptor agonists and the possible biochemical and physiological cascades involved in their mechanisms of action. The remarkable safety profile of alpha(2)-adrenoceptor agonists and their high potency of neuroprotection should prompt clinical trials to evaluate their neuroprotective efficacy in humans.