Impact of Treatment Modality and Route of Administration on Cytokine Release Syndrome in Relapsed or Refractory Multiple Myeloma: A Meta-Analysis

B-cell maturation antigen (BCMA)-targeting immunotherapies (e.g., chimeric antigen receptor T cells (CAR-T) and bispecific antibodies (BsAbs)) have achieved remarkable clinical responses in patients with relapsed and/or refractory multiple myeloma (RRMM). Their use is accompanied by exaggerated immune responses related to T-cell activation and cytokine elevations leading to cytokine release syndrome (CRS) in some patients, which can be potentially life-threatening. However, systematic evaluation of the risk of CRS with BCMA-targeting BsAb and CAR-T therapies, and comparisons across different routes of BsAb administration (intravenous (i.v.) vs. subcutaneous (s.c.)) have not previously been conducted. This study utilized a meta-analysis approach to compare the CRS profile in BCMA-targeting CAR-T vs. BsAb immunotherapies administered either i.v. or s.c. in patients with RRMM. A total of 36 studies including 1,560 patients with RRMM treated with BCMA-targeting CAR-T and BsAb therapies were included in the analysis. The current analysis suggests that compared with BsAbs, CAR-T therapies were associated with higher CRS incidences (88% vs. 59%), higher rates of grade ≥ 3 CRS (7% vs. 2%), longer CRS duration (5 vs. 2 days), and more prevalent tocilizumab use (44% vs. 25%). The proportion of CRS grade ≥ 3 may also be lower (0% vs. 4%) for BsAb therapies administered via the s.c. (3 studies, n = 311) vs. i.v. (5 studies, n = 338) route. This meta-analysis suggests that different types of BCMA-targeting immunotherapies and administration routes could result in a range of CRS incidence and severity that should be considered while evaluating the benefit-risk profiles of these therapies.

International society of Pharmacometrics Mentorship Program (IMP): feedback survey from the first cohort of mentor-mentee pairs

The International Society of Pharmacometrics (ISoP) Mentorship Program (IMP) aims to help professionals at all career stages to transition into the pharmacometrics field, move to a different role/area within pharmacometrics, or expand their skillsets. The program connects mentees at various stages of their careers with mentors based on established criteria for mentor-mentee matching. Pairing mentees with appropriate mentors ensures strong alignment between mentees' interests and mentors' expertise as this is critical to the success and continuation of the relationship between the mentor and mentee. Once mentors and mentees are connected, they are strongly encouraged to meet at least once per month for an hour. The mentor and mentee have the freedom to tailor their sessions to their liking, including frequency, duration, and topics they choose to focus on. Mentees are encouraged to clearly define their goals to help direct their mentor-mentee relationship and conversations. Mentees and mentors alike are given the opportunity to provide feedback about the program to the ISoP Education Committee through surveys and testimonials. Due to the program's infancy, structured guidelines for mentor-mentee sessions are still being developed and instituted using the program evaluation described in this paper.

Optimizing benefit/risk in oncology: Review of post-marketing dose optimization and reflections on the road ahead

Oncology therapies shifted from chemotherapy to molecularly targeted agents and finally to the era of immune-oncology agents. In contrast to cytotoxic agents, molecularly targeted agents are more selective, exhibit a wider therapeutic window, and may maximally modulate tumor growth at doses lower than the maximum tolerated dose (MTD). However, first-in-patient oncology studies for molecularly targeted agents continued to evaluate escalating doses using limited number of patients per dose cohort assessing dose-limiting toxicities to identify the MTD which is commonly selected for further development adopting a 'more is better' approach that led to several post-marketing requirement (PMR) studies to evaluate alternative, typically lower, doses or dosing frequencies to optimize the benefit-risk profile. In this review, post-marketing dose optimization efforts were reviewed including those required by a regulatory pathway or voluntarily conducted by the sponsor to improve efficacy, safety, or method of administration. Lessons learned and future implications from this deep dive review are discussed considering the evolving regulatory landscape on dose optimization for oncology compounds.

Pharmacokinetic Comparability of Risankizumab Formulations in Prefilled Syringe and Auto-injector for Subcutaneous Injection

PURPOSE

Risankizumab is a humanized immunoglobulin G1 monoclonal antibody that inhibits the p19 subunit of interleukin 23 from interacting with its receptor for the treatment of moderate to severe plaque psoriasis. The aim of this Phase I biopharmaceutics bridging study was to evaluate the pharmacokinetic comparability, immunogenicity, and tolerability of the risankizumab 90 mg/mL prefilled syringe (PFS) and the risankizumab 150 mg/mL PFS and auto-injector (AI) in healthy subjects.

METHODS

Healthy subjects received one 150-mg dose of risankizumab in 1 of 3 ways (226 subjects randomized 3:3:1 to 3 treatment arms): 150 mg/mL by PFS × 1 SC injection, 90 mg/mL by PFS × 2 SC injections, or 150 mg/mL by AI × 1 SC injection, and were followed up for 140 days after dosing for the collection of pharmacokinetic, immunogenicity, and tolerability data.

FINDINGS

Risankizumab concentration-time profiles overlapped with comparable pharmacokinetic parameters across all treatment arms, indicating similar pharmacokinetic characteristics. The CIs with both formulations and forms of administration were within the bioequivalence range of 0.80-1.25 across all measures of exposure. The prevalence of treatment-emergent anti-drug antibodies and the percentages of subjects who reported at least 1 treatment-emergent adverse event were comparable across all treatment arms.

IMPLICATIONS

Bioequivalence was established between risankizumab 150 mg/mL PFS and 90 mg/mL PFS, and between 150 mg/mL PFS and AI, along with comparable immunogenicity profiles across all 3 treatment arms. Risankizumab 150 mg SC delivered by PFS or AI was well tolerated, with comparable safety profiles across all treatment arms, and no new safety risks were identified.

Oligonucleotide-Based Drug Development: Considerations for Clinical Pharmacology and Immunogenicity

The field of oligonucleotide (OGN)-based therapeutics has been growing dramatically in the past decade, providing innovative platforms to develop agents for the treatment of a wide variety of clinical conditions. OGN agents have unique physicochemical properties and pharmacokinetic/pharmacodynamic characteristics. This review considers findings from the literature and information on new molecular entities submitted to the US Food and Drug Administration as OGN-based therapeutics. In addition, the article discusses several challenging issues from the perspective of clinical pharmacology, emphasizing the potential of immunogenicity, the effect of renal impairment on OGN exposure, drug-drug interactions, and the utility of pharmacokinetic/pharmacodynamic modeling. The field of OGN-based therapeutics is in evolution and will benefit from further studies as well as clinical experience to formulate guidelines and promote the development of this class of agents.

Modeling effects of dexamethasone on disease progression of bone mineral density in collagen-induced arthritic rats

A mechanism-based model was developed to characterize the crosstalk between proinflammatory cytokines, bone remodeling biomarkers, and bone mineral density (BMD) in collagen-induced arthritic (CIA) rats. Male Lewis rats were divided into five groups: healthy control, CIA control, CIA receiving single 0.225 mg kg⁻¹ subcutaneous (SC) dexamethasone (DEX), CIA receiving single 2.25 mg kg⁻¹ SC DEX, and CIA receiving chronic 0.225 mg kg⁻¹ SC DEX. The CIA rats underwent collagen induction at day 0 and DEX was injected at day 21 post-induction. Disease activity was monitored throughout the study and rats were sacrificed at different time points for blood and paw collection. Protein concentrations of interleukin (IL)-1β, IL-6, receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase 5b (TRACP-5b) in paws were measured by enzyme-linked immunosorbent assays (ELISA). Disease progression and DEX pharmacodynamic profiles of IL-1β, IL-6, RANKL, and OPG were fitted simultaneously and parameters were sequentially applied to fit the TRACP-5b and BMD data. The model was built according to the mechanisms reported in the literature and modeling was performed using ADAPT 5 software with naïve pooling. Time profiles of IL-1β and IL-6 protein concentrations correlated with their mRNAs. The RANKL and OPG profiles matched previous findings in CIA rats. DEX inhibited the expressions of IL-1β, IL-6, and RANKL, but did not alter OPG. TRACP-5b was also inhibited by DEX. Model predictions suggested that anti-IL-1β therapy and anti-RANKL therapy would result in similar efficacy for prevention of bone loss among the cytokine antagonists.

Modeling pharmacokinetics/pharmacodynamics of abatacept and disease progression in collagen-induced arthritic rats: a population approach

The PK/PD of abatacept, a selective T cell co-stimulation modulator, was examined in rats with collagen-induced arthritis (CIA) using a nonlinear mixed effect modeling approach. Male Lewis rats underwent collagen induction to produce rheumatoid arthritis. Two single-dose groups received either 10 mg/kg intravenous (IV) or 20 mg/kg subcutaneous (SC) abatacept, and one multiple-dose group received one 20 mg/kg SC abatacept dose and four additional 10 mg/kg SC doses. Effects on disease progression (DIS) were measured by paw swelling. Plasma concentrations of abatacept were assayed by enzyme-linked immunosorbent assay. The PK/PD data were sequentially fitted using NONMEM VI. Goodness-of-fit was assessed by objective functions and visual inspection of diagnostic plots. The PK of abatacept followed a two-compartment model with linear elimination. For SC doses, short-term zero-order absorption was assumed with F = 59.2 %. The disease progression component was an indirect response model with a time-dependent change in paw edema production rate constant (k in ) that was inhibited by abatacept. Variation in the PK data could be explained by inter-individual variability in clearance and central compartment volume (V 1 ), while the large variability of the PD data may be the result of paw edema production (k in 0 ) and loss rate constant (k out ). Abatacept has modest effects on paw swelling in CIA rats. The PK/PD profiles were well described by the proposed model and allowed evaluation of inter-individual variability on drug- and DIS-related parameters.

Pharmacokinetics, pharmacodynamics and toxicities of methotrexate in healthy and collagen-induced arthritic rats

Methotrexate (MTX) is an anchor drug used to treat rheumatoid arthritis (RA), but responsiveness is variable in effectiveness and toxicity. Methotrexate and its polyglutamate conjugates (MTXPG(n)) in red blood cells (RBC) have been associated with patient response. In the current study, 13 collagen-induced arthritic (CIA) rats and 12 healthy rats were given subcutaneous doses of either saline or 0.3 or 1.5 mg/kg per 2 days of MTX from day 21 to 43 post-induction. Blood samples were obtained at various times to measure MTX in plasma, and MTX and MTXPG(n) in RBC. Effects on disease progression were indicated by body weight and paw size. After multiple-doses, RBC MTX reached steady-state (82.4 nm) within 4 days. The MTXPG(2) and MTXPG(3) in RBC kept increasing until the end of the study, attaining 12.5 and 17.7 nm. Significant weight loss was observed after dosing with 1.5 mg/kg/2 days, whereas moderate effectiveness was observed after dosing with 0.3 mg/kg/2 days. A pharmacokinetic/pharmacodynamic/disease (PK/PD/DIS) model with indirect mechanisms and transduction components incorporating plasma MTX, RBC MTX and RBC MTXPG(n) concentrations, and paw size was developed using naïve data pooling and ADAPT 5. The PK/PD in CIA rats dosed at 0.3 mg/kg/2 days were captured well by our proposed model. Methotrexate showed modest (I(maxd) = 0.16) but sensitive (IC(50d) = 0.712 nm) effectiveness on paw edema. The higher dose produced toxicity. The proposed model offers improved understanding of the effects of methotrexate on rheumatoid arthritis.

Pharmacokinetic/pharmacodynamic modeling in inflammation

Inflammation is an array of immune responses to infection and injury. It results from a complex immune cascade and is the basis of many chronic diseases such as arthritis, diabetes, and cancer. Numerous mathematical models have been developed to describe the disease progression and effects of anti-inflammatory drugs. This review illustrates the state of the art in modeling the effects of diverse drugs for treating inflammation, describes relevant biomarkers amenable to modeling, and summarizes major advantages and limitations of the published pharmacokinetic/ pharmacodynamic (PK/PD) models. Simple direct inhibitory models are often used to describe in vitro effects of anti-inflammatory drugs. Indirect response models are more mechanism based and have been widely applied to the turnover of symptoms and biomarkers. These, along with target-mediated and transduction models, have been successfully applied to capture the PK/PD of many anti-inflammatory drugs and describe disease progression of inflammation. Biologics have offered opportunities to address specific mechanisms of action, and evolve small systems models to quantitatively capture the underlying physiological processes. More advanced mechanistic models should allow evaluation of the roles of some key mediators in disease progression, assess drug interactions, and better translate drug properties from in vitro and animal data to patients.

Cytochrome P450 expression and regulation in CYP3A4/CYP2D6 double transgenic humanized mice

Analysis of the developmental and sexual expression of cytochrome P450 drug-metabolizing enzymes is impeded by multiple and varied external factors that influence its regulation. In the present study, a CYP2D6/CYP3A4-double transgenic (Tg-CYP2D6/CYP3A4) mouse model was employed to investigate hepatic CYP2D6 and CYP3A4 ontogeny and sexual dimorphism. Both age and sex have considerable effects on hepatic CYP3A4 protein expression in 3- to 8-week-old transgenic mice, whereas neither factor alters CYP2D6 content. Constitutive CYP2D6 expression resulted in 2- to 3-fold higher dextromethorphan O-demethylase activity in Tg-CYP2D6/CYP3A4 mouse liver microsomes compared with wild-type mice. In contrast, expression of CYP3A4 in transgenic mouse livers did not increase dextromethorphan N-demethylase and midazolam 1'-hydroxylase activities. Pretreatment with pregnenolone 16alpha-carbonitrile (PCN) and 1,4-bis-2-(3, 5-dichloropyridyloxy)-benzene (TCPOBOP) elevated CYP3A4 expression in double transgenic mice. Interestingly, induction of hepatic CYP3A4 was greater in females than age- and treatment-matched males. Consequently, the increase in midazolam 1'-hydroxylase activity was markedly higher in 8-week-old female mice than in corresponding males (8-fold versus 6-fold for PCN treatment and 6-fold versus 5-fold for TCPOBOP). Furthermore, increases in testosterone 6beta-hydroxylase activity after CYP3A induction were relatively lower compared with those in midazolam 1'-hydroxylation for age-, sex-, and treatment-matched mice. The difference in CYP3A4 expression and induction between male and female mice suggests that women may be more susceptible to CYP3A4-mediated drug-drug interactions, and the extent of drug-drug interactions could be substrate dependent.