Impact of Antiresorptive Agents on Maxillary Bones: a Narrative Literature Review

Antiresorptive drugs operate in the bone metabolism modulation and are widely used in the treatment of bone metastases and bone losses related to hormonal deficiency. Although this therapy shows satisfactory results, there are adverse effects associated with its use, such as osteonecrosis of the jaws. Medication-related osteonecrosis of the jaws (MRONJ) is, therefore, a serious and challenging condition with important implications in dentistry. The aim was to conduct a narrative literature review on anti-resorptive drugs and their latest repercussions on the maxillary bones. The review was carried out through a bibliographic search using Decs/Mesh descriptors of interest, in Portuguese and English, in the PubMed, Virtual Health Library (VHL) and Scielo databases. After applying the inclusion and exclusion criteria, a total of 33 studies were selected for analysis. It can be noticed that therapy with anti-resorptive agents is complex, especially in dental practice, since MRONJ is a complication that is difficult to manage. Regarding the therapeutic options, these are divided into conservative, surgical or adjuvant therapy, however, there are no protocols in the literature, and there is no consistency regarding the indication of the suspension of the drug administration - "Drug Holiday". Thus, it is important that the multidisciplinary team seeks strategies that minimize complications and promote control over the use of these drugs. In addition, there is a need for investigations that contribute with guidelines for the management and control of adverse effects resulting from therapy with antiresorptive drugs. Keywords: Bone Density Conservation Agents. Diphosphonates. Denosumab. Bisphosphonate-Associated Osteonecrosis of the Jaw. ResumoAs drogas antirreabsortivas atuam na modulação do metabolismo ósseo e são indicadas para o tratamento de metástases ósseas e perdas ósseas relacionadas à deficiência hormonal. Ainda que esta terapia apresente resultados satisfatórios, observam-se efeitos adversos associados ao seu uso, como a osteonecrose dos maxilares. A osteonecrose dos maxilares associada ao uso de medicamentos (OMAM) é, portanto, uma condição séria e desafiadora com implicações importantes na Odontologia. O objetivo foi realizar uma revisão narrativa de literatura sobre as drogas antirreabsortivas e suas respectivas repercussões nos ossos maxilares. A revisão foi realizada através de busca bibliográfica utilizando descritores Decs/Mesh de interesse, em português e inglês, nas bases de dados PubMed, Biblioteca Virtual de Saúde (BVS) e Scielo. Após aplicação dos critérios de inclusão e exclusão, um total de 33 trabalhos foram selecionados para análise. Pode-se constatar que a terapia com agentes antirreabsortivos é complexa, sobretudo na prática odontológica, visto que a OMAM é uma complicação de difícil manejo. Em relação às condutas terapêuticas para esta condição, divide-se em terapia conservadora, cirúrgica ou adjuvante, todavia, não existem protocolos validados na literatura, bem como não há consistência quanto à indicação do intervalo de suspensão da administração da droga - “Drug Holiday”. Desse modo, é importante que a equipe multidisciplinar busque estratégias que minimizem as complicações e promovam o controle no uso dessas drogas. Além disso, nota-se a necessidade de realizar investigações que contribuam com diretrizes para o manejo e controle dos efeitos adversos decorrentes da terapia com medicamentos antirreabsortivos. Palavras-chave: Conservadores da Densidade Óssea. Bisfosfonatos. Denosumabe. Osteonecrose Associada a Bisfosfonatos.

Effects of Preoperative Drug Holiday On Sequester Separation and Treatment Outcome in Cancer Patients With Medication-Related Osteonecrosis of The Jaw

We aimed to investigate whether antiresorptive agent drug holidays contributed to the formation of sequester separation and treatment outcome in medication-related osteonecrosis of the jaw (MRONJ) patients whose primary disease was malignancy. A total of 105 MRONJ patients with malignant tumors as the primary disease who underwent surgery at Nagasaki University Hospital and Kansai Medical University Hospital from January 2009 to December 2020 were included. We recorded patient age, sex, primary disease (solid cancer, non-solid cancer), MRONJ stage, type and administration period of antiresorptive agents, presence of diabetes, corticosteroid use, drug holiday period, white blood cell count, serum, albumin, serum creatinine, outcomes, and computed tomography findings. We examined the relationship between a drug holiday and sequester separation and outcome. Drug holiday of more than 90 days (P=0.629) was not a significant factor for sequester separation in the univariate analysis. In the multivariate analysis, steroid use (P=0.009) and serum albumin (P=0.003) were extracted as factors affecting prognosis; withdrawal for more than 90 days (P=0.98) was not a significant factor. MRONJ patients with cancer as the primary disease should be operated early without drug holidays if their general condition is relatively good, clinical symptoms are strong, and quality of life is improved.

A Multi-Institutional Randomized Controlled Trial to Investigate Whether Zoledronate Prevents Bone Loss After Discontinuation of Denosumab: The Study Protocol of Denosumab Sequential Therapy (DST) Trial

Background: Though denosumab is an effective treatment for osteoporosis, the rebound effect after discontinuation has drawn investigators' attention. It includes a dramatic loss of gained bone mineral density (BMD) and an increased risk of vertebral fractures. This prospective multi-institutional randomized controlled trial aims to investigate whether zoledronate prevents loss of BMD after discontinuation of denosumab. The trial was registered as Denosumab Sequential Therapy (DST) trial in March 2019 at clinicaltrials.gov, with the identifier NCT03868033.Methods: The study is conducted at National Taiwan University Hospital and its branches. Patients who have continuously received denosumab treatment for two or more years are surveyed for eligibility. Baseline characteristics and questionnaires of life quality are recorded after recruitment. BMD, circulating levels of bone turnover markers (BTMs), including serum N-terminal propeptide of type 1 collagen (P1NP) and C-terminal telopeptide (CTX), are checked before the stratified randomization to 4 groups. Biological sex and the T-scores are used to create 4 strata. The participants in group 1 adhere to regular denosumab therapy for another 2 years. All the other patients receive on-time zoledronate treatment in the first year. The participants in group 2, 3, and 4 have on-time denosumab, on-time zoledronate and drug holiday in the second year, respectively. BMDs are checked annually. Pre-scheduled checkpoints of BTMs are also arranged. For patient safety, rescue treatment with another injection of zoledronate will be applied to the patients on drug holiday if the CTX levels raise above the pre-specified threshold, 0.573 ng/mL for women and 0.584 ng/mL for men. The primary outcomes are the percentage changes of BMDs in lumbar spine, total hip and femoral neck. The secondary outcomes include the changes of serum level of the BTMs, new osteoporotic fractures, extra zoledronate injections needed in group 4 and the differences of quality of life.Discussion: We aim to provide evidence whether zoledronate prevents bone loss after denosumab cessation. To our knowledge, the study has the largest sample size. No other randomized controlled study included all the three different treatment strategies and a positive control. It is also the first associated randomized controlled trial outside Europe.

Planned drug holiday in a cohort study exploring the effect of lenvatinib on differentiated thyroid cancer.

6070 Background: Lenvatinib is now available for unresectable radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC). However, toxicities are considerable and require frequent dose interruption and modification. Recently, planned drug holidays, which are dose interruptions in accordance with the timing of severe or intolerable adverse events, have been proposed to avoid severe adverse events due to lenvatinib (Tahara M.ESMO Open 2018). Our retrospective study demonstrated that progression-free survival (PFS) and overall survival (OS) were significantly longer in patients who used planned drug holidays than those who did not (Matsuyama C et.al, 2020 Annual Meeting of the Japan Association of Endocrine Surgeons). Methods: In this prospective observational study, patients with curatively unresectable and progressive RAI-refractory DTC were treated with lenvatinib in a real-world clinical setting. Lenvatinib was administered orally at a dose of 24 mg daily. Dose modification for toxicities were permitted. Primary endpoint was OS, and secondary endpoints were time to treatment failure (TTF), time to failure of strategy (TFS), PFS with clinical progressive disease, response rate, quality of life, safety, and patient reports. This study was registered with UMIN Clinical Trials Registry (UMIN000022243). Results: 262 patients were accrued. Of 255 evaluable, 153 were female; median age was 70 (range 27.0-88.0); histology was papillary thyroid carcinoma/follicular thyroid carcinoma/poorly DTC in 204/45/4; previous therapy was surgery/RAI/molecular targeted drug in 246/164/14; reason for initiation of lenvatinib was disease progression/unsuitable for RAI in 241/4. 1-year OS was 85.6% (95%CI: 80.6-89.4%); 1-year TTF rate was 74.9% (95%CI: 69.1-79.8%); 1-year TFS rate was 80.8% (95%CI: 75.4-85.2%); and 1-year PFS rate was 84.4% (95%CI: 79.3-88.4%). Overall response by RECIST was 3 (1.2%) in CR and 151 (61.9%) in PR. Most common grade 3 or 4 toxicities were hypertension (61.4%), hand foot syndrome (10.2%), fatigue (9.1%), anorexia (8.3%) and diarrhea (4.7%). Grade 5 toxicities occurred in 4 patients (fistula, hypoxia, respiratory failure, trachea stenosis). Of 253 patients evaluable for efficacy, 73 used planned drug holidays. TTF, TFS and PFS were significantly longer in patients who used planned drug holiday than those who did not (Table). Conclusions: Planned drug holiday for lenvatinib demonstrated significantly better clinical outcomes, including TTF, TFS and PFS, than daily oral administration. These data further support use of a planned drug holiday in RAI-refractory DTC patients receiving lenvatinib. Clinical trial information: 000022243. [Table: see text]