Efficacy, tolerability, and safety of risedronate in Japanese patients with Paget's disease of bone

Safety and effectiveness of risedronate in Paget's disease of bone: postmarketing surveillance study in Japan

INTRODUCTION

We conducted an all-case postmarketing surveillance study between 2008 and 2017 to evaluate the safety and effectiveness of risedronate for Paget's disease of bone (PDB) in Japan.

MATERIAL AND METHODS

This study registered all patients who received once-daily risedronate 17.5 mg for the treatment of PDB and collected data over a 48-week follow-up period per treatment cycle for each patient.

RESULTS

The safety analysis set included 184 patients (mean age, 63.7 years), 81 (44.0%) of whom previously received a bisphosphonate. Of them, 41 (22.3%) experienced 72 adverse drug reactions (ADRs), and 8 (4.3%) experienced 14 serious ADRs. Common ADRs included gastrointestinal disorders (20 patients, 10.9%) and hypocalcemia (6 patients, 3.3%). The effectiveness analysis set included 182 patients, 124 of whom completed only one treatment cycle and 58 of whom completed multiple treatment cycles. The proportions of patients who normalized serum alkaline phosphatase (ALP) concentration were 71.1% (113/159 patients) and 67.3% (33/49 patients) for the first and second treatment cycles, respectively. The relapse rate according to ALP levels after the end of treatment for the first cycle was 5.0% (95% confidence interval [CI] = 2.1-11.5) at 24 weeks and 12.9% (95% CI = 7.5-21.7) at 40 weeks. Regarding pain relief, the achievement rates were 70.0% (49/70 patients) and 30.8% (4/13 patients) for the first and second treatment cycles, respectively.

CONCLUSION

To conclude, risedronate 17.5 mg/day is safe and effective for treating patients with PDB in daily practice.

Dental students' knowledge of medication-related osteonecrosis of the jaw

Objectives:

The aim of this study was to evaluate and assess knowledge and attitude of dental students about medication-related osteonecrosis of the jaw (MRONJ), to optimize future training programs in this field.

Materials and Methods:

A cross-sectional study was administrated. Ninety-eight participants agreed to complete an anonymous questionnaire. It was divided into two sections: the first section was about general information such as interviewer's gender and date of birth; the second section included questions about bisphosphonates (BPs), others medication associated to osteonecrosis of the jaw (ONJ), risk factors, and prevention of osteonecrosis. Descriptive statistics were computed and the odds ratio was used to compare the odds for the groups.

Results:

Ninety-nine percent of participants declared to know BPs, but only 26.9% of 4^th year and 34.8% of 6^th year students knew the correct definition of MRONJ. Almost all of students identified the importance to report, in anamnesis, the use of BPs, as well as to check-up patients before the beginning of treatment; on the other hand, the knowledge about how invasive dental treatment might be carried out in patients under therapy was not adequate. In addition, half of the students did not recognize any active principle or commercial name of BPs. The situation was even worse regarding alternative drugs involved in ONJ.

Conclusions:

These findings are alarming and the lack of knowledge about MRONJ suggests that greater educational efforts should be performed about this pathology at undergraduate level.

Clinical efficacy of oral risedronate therapy in Japanese patients with Paget's disease of bone

Paget's disease of bone (PDB) is a chronic disorder characterized by localized bone regions with excessive bone turnover. Although oral risedronate (17.5 mg daily for 8 weeks) was recently approved in Japan, its efficacy is not well understood. We retrospectively examined the efficacy of oral risedronate in PDB patients in a clinical setting. Eleven patients whose serum alkaline phosphatase (ALP) level exceeded the upper limit of the normal range were treated. Patients whose ALP levels normalized and remained so for 12 months after therapy initiation were defined as responders. Treatment was repeated if bone pain recurred or if serum ALP levels increased at least 25% above the nadir. Six patients (55%) were responsive to the therapy. A higher prevalence of skull lesions, higher serum calcium levels at treatment initiation and antecedent treatments of bisphosphonates were predictors of resistance against the therapy. Fresh frozen serum samples obtained from some treatment sessions were evaluated for metabolic bone markers such as bone-specific ALP (BAP), type I procollagen N-terminal pro-peptide (PINP), N-treminal crosslinking telopeptide of type I collagen and C-treminal crosslinking telopeptide of type I collagen (CTX). A significant reduction of P1NP preceded that of serum ALP levels in the responders, which was followed by a similar occurrence for BAP and osteocalcin (BGP) levels. A temporary decrease in CTX levels was noted. No significant changes in markers (including ALP level) were observed in non-responder and repeat-treatment groups. P1NP levels may be more useful than ALP levels in assessing treatment efficacy. Repeat treatment effectiveness for the repeat-treatment group was limited.

Paget disease of bone in Japanese patients: a report of three cases

Paget disease of bone (PDB) is a bone metabolic disorder causing pain, fractures, and deformity. Its incidence is estimated to be 1 to 2% in Caucasians older than 55 years, but in Asian populations the incidence is rare. We report on 2 female and one male Japanese patients aged 46 to 73 years with PDB. One patient had monostotic disease with pain around the shoulder and the other 2 were asymptomatic. All patients had elevated alkaline phosphatase (ALP) levels (range, 629-957 U/L). Two patients responded to oral bisphosphonate treatment and achieved normalised ALP levels and pain relief. One patient with polyostotic disease did not show any change in ALP levels. The diagnosis of the disease and the indications for bisphosphonate treatment are discussed.

Midterm outcome of risedronate therapy for patients with Paget's disease of bone in the central part of Japan

Although Paget's disease of bone (PDB) is common in western countries, it is extremely rare in Asian ones including Japan. Recently, oral risedronate (17.5 mg once daily) was approved in Japan as a treatment of PDB besides calcitonin and etidronate. However, there are few data regarding the efficacy of this agent, dose for patients with PDB in Japan, or the durability of its effect. The purpose of this study was to evaluate the midterm outcome of oral risedronate (17.5 mg once daily) for patients with PDB in Japan. Seventeen patients with PDB were treated with risedronate (17.5 mg once daily) for 8 weeks. Efficacy and its durability were accessed based on serum total alkaline phosphatase (ALP) and symptoms. Risedronate effectively suppressed bone turnover evaluated with serum total ALP in all patients. In 8 of 10 patients with bone pain, risedronate reduced the pain. On the other hand, tinnitus and hearing loss did not disappear but somewhat improved. None of the patients suffered severe complications. Seven of 17 patients required readministration of oral bisphosphonate (risedronate, six; alendronate, one) due to elevated total ALP at 27 months (mean ranging from 9 to 39 months) after the initial administration of risedronate. Treatment of oral risedronate (17.5 mg once daily) for 8 weeks is safe and effective for patients with PDB in Japan. However, the durability of its effect is limited in some patients.

In vitro and in vivo antiplasmodial activities of risedronate and its interference with protein prenylation in Plasmodium falciparum

The increasing resistance of malarial parasites to almost all available drugs calls for the identification of new compounds and the detection of novel targets. Here, we establish the antimalarial activities of risedronate, one of the most potent bisphosphonates clinically used to treat bone resorption diseases, against blood stages of Plasmodium falciparum (50% inhibitory concentration [IC50] of 20.3±1.0 μM). We also suggest a mechanism of action for risedronate against the intraerythrocytic stage of P. falciparum and show that protein prenylation seems to be modulated directly by this drug. Risedronate inhibits the transfer of the farnesyl pyrophosphate group to parasite proteins, an effect not observed for the transfer of geranylgeranyl pyrophosphate. Our in vivo experiments further demonstrate that risedronate leads to an 88.9% inhibition of the rodent parasite Plasmodium berghei in mice on the seventh day of treatment; however, risedronate treatment did not result in a general increase of survival rates.