Prospective Study Testing a Simplified Paclitaxel Premedication Regimen in Patients with Early Breast Cancer

Assessing Outcomes of Tapering 12-Hour and 6-Hour Dexamethasone Prior to Paclitaxel Infusions in Patients With Breast Cancer

BACKGROUND

Paclitaxel has a boxed warning for causing severe hypersensitivity reactions, however, the majority (95%) of these reactions occur during the first or second infusion. Corticosteroids can reduce the incidence of paclitaxel hypersensitivity reactions from 30% to around 1%-3% but are not without adverse effects. Current practice at our institution is to prescribe dexamethasone 20 mg to be given orally 12 and 6 hours prior to paclitaxel infusion, however, some medical oncology providers have elected to decrease or omit dexamethasone premedication.

METHODS

This retrospective study analyzed dexamethasone dose adjustment(s) prior to paclitaxel and the incidence of hypersensitivity reactions. Patients were included if they were ≥19 years, had breast cancer, received ≥3 doses of paclitaxel as part of (neo)adjuvant therapy, and received reduced or omitted oral dexamethasone prior to paclitaxel between January 1, 2015, and July 31, 2023. The primary outcome was incidence of rescue medication administration in those with reduced or omitted premedication dexamethasone. Secondary outcomes included dexamethasone prescribing practices and the incidence of corticosteroid-associated insomnia and hyperglycemia.

RESULTS

The analysis included 306 infusions (corticosteroid reduction: 283; omission: 23). A hypersensitivity reaction requiring the administration of rescue medications occurred in 5 infusions in the reduction group (1.6%) and 0 infusions in the omission group, leading to a 1.6% overall incidence of infusions requiring the administration of rescue medications.

CONCLUSION

In conclusion, decreasing home dexamethasone prior to paclitaxel infusions did not increase the incidence of hypersensitivity reactions compared to rates reported in the literature.

Docetaxel rechallenge in HER2-negative metastatic breast cancer: a real-world study of previously discontinued patients for non-progression reasons

PURPOSE

This study aimed to evaluate the efficacy and safety of docetaxel rechallenge in HER2-negative metastatic breast cancer (MBC) patients who discontinued docetaxel for reasons other than disease progression.

PATIENTS AND METHODS

We retrospectively analyzed HER2-negative MBC patients treated with docetaxel-based therapy (DBT) at our institution from 2010 to 2020. Objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were assessed. Multivariate Cox regression and propensity score matching analysis (PSMA) were used to minimize bias.

RESULTS

Among 600 patients, 369 only received docetaxel once (control group), while 231 (38.5%) received docetaxel rechallenge as second or later-line therapy (rechallenge group). In the second-line rechallenge subset (143 patients), ORR was 51.0%, and PFS was 6.7 months. Multivariate analysis showed that a response to initial DBT (stable disease [SD] vs. complete response/partial response [CR/PR]: odds ratio [OR] 2.615, 95% confidence interval [CI] 1.373-4.981; p = 0.03) independently predicted the ORR. Beyond second-line rechallenge, the ORR and PFS were 37.5% and 5.6 months, respectively. After PSMA, the rechallenge group demonstrated significantly improved OS compared to the control group: 50.5 months vs. 46.0 months (Hazard Ratio [HR] 0.632; 95% CI 0.455-0.878; p = 0.006). The toxicities reported were manageable, primarily hematologic, with grade 3-4 events occurring in 19.5% of cases.

CONCLUSION

This study suggests that docetaxel rechallenge may be an effective and tolerable later-line treatment option for patients with HER2-negative MBC, particularly those who responded to initial DBT. However, further prospective, randomized controlled research is needed to fully evaluate its impact on disease response in this patient population.

A Novel Self-Assembled Paclitaxel Nanodispersion Facilitates Rapid In-Vitro/In-Vivo Dissociation and Protein Binding

The study aims to prepare and characterize a novel paclitaxel (PtX) preconcentrate formulation using polymer and lipid excipients that forms nanodispersion upon dilution. The goal was to understand the mechanism of nanodispersion formation and its properties. The water-insoluble PtX was dissolved in organic solvents containing ethanol, polyethylene glycol (PEG400), povidone (PVP), caprylic acid (CA), and sodium cholesterol sulfate (CS). This formulation was diluted in 5% w/v dextrose medium to form PtX nanodispersion, which was assessed for particle size, stability, in-vitro/in-vivo dissociation and protein binding. Transmission electron microscopy (TEM), Small Angle Neutron Scattering (SANS), and Molecular Dynamics (MD) simulations were used to analyse the structure of the nanoparticles. The formulation was a clear, slightly yellow solution. The PtX nanodispersion displays particle size of ~ 100 nm with a zeta potential of -25, and the pH of 4.0. It displayed nearly spherical coacervate nanoparticles with a sponge-like structure, lacking internal structure order as revealed by TEM and SANS. MD simulations confirmed self-assembly of PtX and excipients forming nanoparticles. In vitro dissociation studies in simulated plasma demonstrated rapid dissociation of nanodispersion, releasing free PtX that immediately binds to plasma proteins. In vivo studies in rabbits corroborated these findings, showing rapid dissolution. The results present a novel formulation design that forms sponge-like coacervate nanoparticle due to complimentary interactions of the excipients that otherwise are unable to self-assemble under similar conditions of dilution. This alternative formulation solves the limitations of currently marketed PtX products and can provide its effective delivery in clinical settings.

Effect of Switching the Histamine-1 Receptor Antagonist Clemastine to Cetirizine in Paclitaxel Premedication Regimens: The H1-Switch Study

PURPOSE

Premedication, including a histamine-1 receptor (H1) antagonist, is recommended to all patients treated with paclitaxel chemotherapy to reduce the incidence of hypersensitivity reactions (HSRs). However, the scientific basis for this premedication is not robust, which provides opportunities for optimization. Substitution of intravenously administered first-generation H1 antagonist for orally administered second-generation H1 antagonist could reduce side effects, and improve efficiency and sustainability. This study investigates the efficacy and safety of substituting intravenous clemastine for oral cetirizine as prophylaxis for paclitaxel-induced HSRs.

METHODS

This single-center, prospective, noninferiority study compares a historic cohort receiving a premedication regimen with intravenous clemastine to a prospective cohort receiving oral cetirizine. Primary end point of the study is HSR grade ≥3. The difference in incidence was calculated together with the 90% CI. We determined that the two-sided 90% CI of HSR grade ≥3 incidence in the oral cetirizine cohort should not be more than 4% higher (ie, the noninferiority margin) compared with the intravenous clemastine cohort.

RESULTS

Two hundred and twelve patients were included in the oral cetirizine cohort (June 2022 and May 2023) and 183 in the intravenous clemastine cohort. HSR grade ≥3 incidence was 1.6% (n = 3) in the intravenous clemastine cohort and 0.5% (n = 1) in the oral cetirizine cohort, resulting in a difference of -1.2% (90% CI, -3.4 to 1.1).

CONCLUSION

Premedication containing oral cetirizine is as safe as premedication containing intravenous clemastine in preventing paclitaxel-induced HSR grade ≥3. These findings could contribute to optimization of care for patients and improve efficiency and sustainability.

Pectin based hydrogel with covalent coupled doxorubicin and limonin loading for lung tumor therapy

Self-healing hydrogels have shown great application potential in drug delivery for anti-tumor therapy and tissue engineering. In this research, Doxorubicin (DOX) was coupled onto the oxidized pectin (pec-Ald) to prepare DOX grafted pec-AD and used to fabricate self-healing hydrogel for lung cancer therapy combined with novel herbal medicine extract limonin targeting lung cancer cells. The hydrogel was prepared with P(NIPAM195-co-AH54) cross-linking and the hydrazone bond cross-linked hydrogel showed good mechanical property and self-healing behavior. With pectin composition, the hydrogel was still biodegradable catalyzed by enzyme and in vivo. The hydrogel formed fast fit for injectable application and the hydrogel itself showed moderate lung cancer inhibition activity. With limonin loading, the hydrogel showed synergistic lung cancer therapy with the tumor growth greatly inhibited. The covalent coupling of DOX and loaded limonin in the hydrogel decreased in vivo toxicity and the hydrogel degraded on time. With biodegradability and improved lung cancer therapy efficiency, this DOX grafted self-healing hydrogel could find great potential application in cancer therapy in near future.

Microtubule-Targeting Agents: Disruption of the Cellular Cytoskeleton as a Backbone of Ovarian Cancer Therapy

Microtubules are dynamic polymers composed of α- and β-tubulin heterodimers. Microtubules are universally conserved among eukaryotes and participate in nearly every cellular process, including intracellular trafficking, replication, polarity, cytoskeletal shape, and motility. Due to their fundamental role in mitosis, they represent a classic target of anti-cancer therapy. Microtubule-stabilizing agents currently constitute a component of the most effective regimens for ovarian cancer therapy in both primary and recurrent settings. Unfortunately, the development of resistance continues to present a therapeutic challenge. An understanding of the underlying mechanisms of resistance to microtubule-active agents may facilitate the development of novel and improved approaches to this disease.

The utility of H2 receptor antagonists in preventing infusion-related reactions to paclitaxel chemotherapy

BACKGROUND

Paclitaxel has a risk of infusion-related reactions (IRRs) and despite no prospective evidence, is often given with premedication including a corticosteroid, H1 antagonist, and H2 antagonist (H2RA). Backorders impacted the supply of intravenous H2RAs at our center, and it was removed as routine premedication. The authors compared the incidence of IRR in patients treated without H2RA to patients receiving standard H2RA premedication.

METHODS

The authors reviewed outpatients starting paclitaxel at the Ottawa Hospital from December 2019 to October 2021. Two cohorts were created: patients treated without H2RA premedication (intervention), and those receiving standard H2RA (control). Demographics, treatment, and IRR information were collected retrospectively. Primary end point was rate of grade ≥2 IRRs during first two doses of paclitaxel.

RESULTS

A total of 182 patients were treated without H2RA premedication, compared to 184 control patients treated during non-backorder periods. Baseline characteristics included: median age, 63 years; 86% female; and primary tumor 52% breast/24% gynecologic/10% gastric/esophageal/8% lung/6% other. There were no significant differences between cohorts in baseline characteristics. There was no difference in the rate of grade ≥2 IRR between cohorts; 12.1% (22 of 182; 95% confidence interval [CI], 7.7%-17.7%) for patients treated without H2RA, and 15.1% (28 of 185; 95% CI, 10.3%-21.1%) for control patients. The rate of grade ≥3 IRRs were also similar, 4.4% in intervention cohort versus 3.8% in control cohort.

CONCLUSIONS

The removal of H2RAs from premedication for paclitaxel did not result in an increased incidence of IRRs. The use of H2RAs in preventing IRRs to paclitaxel should be re-evaluated.

Self-healing pectin/cellulose hydrogel loaded with limonin as TMEM16A inhibitor for lung adenocarcinoma treatment

Lung cancer as one of the highest incident malignant tumors did not receive satisfactory chemotherapy due to lack of specific drug targets and targeted drugs. This study screened a new effective lung tumor inhibitor limonin from herbal medicine, which inhibited proliferation and promoted apoptosis of lung adenocarcinoma cells by targeting specific high expressed TMEM16A ion channel. Moreover, a novel biodegradable self-healing hydrogel was prepared from acylhydrazide functionalized carboxymethyl cellulose (CMC-AH) and oxidized pectin (pec-CHO) to reduce the side effects of the limonin to the body. The hydrogels showed fast gelation, good biocompatibility and sustained limonin release property. The limonin-loaded hydrogel significantly inhibited the growth of lung adenocarcinoma in xenografts mice because the limonin inhibited the proliferation, migration and promoted apoptosis of LA795 cells, and eliminated the acute toxicity through sustained release from the hydrogel. Combined the antitumor performance of the limonin and sustained release of pec-CHO/CMC-AH hydrogel, this limonin/hydrogel system achieved satisfactory antitumor effect and eliminated side effects in vivo. Therefore, this system has great potential application for enhanced lung adenocarcinoma therapy.