Bosutinib shows 'low' vascular, cardiac event risk profile

 In continuation of my update on Bosutinib

Third-generation tyrosine kinase inhibitor (TKI) study findings suggest that bosutinib is associated with a low risk of vascular and cardiac events in patients undergoing first-line or subsequent treatment for chronic myeloid leukaemia (CML).

"The results of this analysis suggest that the vascular and cardiac toxicity profile of bosutinib is distinct relative to other TKIs", write Jorge Cortes, from University of Texas MD Anderson Cancer Center in Houston, USA, and co-authors in the American Journal of Hematology

.

The team collated information on treatment-emergent adverse events (TEAEs) in 570 patients who received second-, third- or fourth-line bosutinib treatment for Philadelphia chromosome-positive CML as part of a phase I/II study.

In addition, the researchers determined the incidence of TEAEs in a phase III study comparing first-line bosutinib in 248 patients with first-line imatinib in 251 patients.

Trial participants were all followed up for at least 2 years and the overall incidence of vascular TEAEs was low, with all-grade and grade 3 or more severe side effects affecting 6.8% and 3.7% of patients given bosutinib, respectively.

First-line bosutinib was associated with a lower rate of vascular TEAEs than second-line or subsequent bosutinib therapy, affecting 4.8% versus 7.7%. First-line imatinib had comparable incidence of both overall and grade 3 and more severe vascular TEAEs to that of first-line bosutinib.

Cerebrovascular TEAEs were reported in 1.8% of patients given bosutinib, again being less common in those given primary bosutinib relative to second-line or later treatment (0.8 vs 2.3%). All-grade and grade 3 or more severe cardiovascular TEAEs occurred in 3.7% and 2.3% of bosutinib-treated patients, occurring at a lower rate in first-line than later treated patients (2.4 vs 4.2%).

Serious vascular TEAEs were reported in 4.2% of bosutinib-treated patients, with grade 3 or more severe events occurring in 3.1%, most commonly coronary artery disease (0.9%) and acute myocardial infarction (0.6%).

Events were less common in newly diagnosed patients than those with refractory or relapsed disease (2.0 vs 5.1%), and there was no significant difference in the incidence or exposure-adjusted rate between the first-line bosutinib and imatinib groups.

Ref : http://onlinelibrary.wiley.com/doi/10.1002/ajh.24360/abstract

Bosutinib shows 'low' vascular, cardiac event risk profile: Third-generation tyrosine kinase inhibitor study findings suggest that bosutinib is associated with a low risk of vascular and cardiac events in patients undergoing first-line or subsequent treatment for chronic myeloid leukaemia.

Cancer drug may inhibit growth of cysts in patients with inherited form of kidney disease

In continuation of my update on bostinib

A cancer drug called bosutinib may inhibit the growth of cysts in patients with autosomal dominant polycystic kidney disease (ADPKD), according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings point to a potential new treatment strategy for affected patients, but the long-term benefits remain to be determined.

 bosutinib

ADPKD is an inherited disorder that affects up to 1 in 1000 people and is characterized by cysts in the kidney and other organs. As patients' kidney volume increases due to cyst growth, they gradually lose their kidney function and often develop kidney failure. Current treatments are primarily supportive, such as focusing on hypertension and other secondary complications.

The inherited mutations that cause ADPKD affect a protein involved in various signaling pathways that often involve enzymes called tyrosine kinases. Therefore, a team led by Vladimir Tesar, MD, PhD (Charles University and General University Hospital, in the Czech Republic) tested the potential of an investigational drug called bosutinib that inhibits a particular tyrosine kinase called Src/Bcr-Abl.

The phase 2 study included patients with ADPKD who were randomized 1:1:1 to bosutinib 200 mg/day, bosutinib 400 mg/day, or placebo. Of 172 patients enrolled, 169 received at least one treatment. The higher dose of bosutinib was not well tolerated.

The annual rate of kidney enlargement was reduced by 66% for patients receiving bosutinib 200 mg/day vs. those receiving placebo (1.63% vs. 4.74%, respectively) and by 82% for all patients receiving bosutinib vs. those receiving placebo (0.84% vs. 4.74%, respectively). The study was not powered to demonstrate a treatment effect on kidney function, but there was no evidence of a benefit associated with bosutinib compared with placebo over the 2-year treatment period.

"The reduction in growth of cysts through treatment with bosutinib was confirmed, although gastrointestinal side effects (primarily diarrhea), which were partly dose-dependent, may represent a substantial drawback for the further development of the drug for patients with ADPKD," said Prof. Tesar.​

Ref : http://jasn.asnjournals.org/content/early/2017/08/23/ASN.2016111232.abstract?sid=4a3bae76-25e3-4cf5-a14f-5b7deac62567

Cancer drug may inhibit growth of cysts in patients with inherited form of kidney disease

Second-line bosutinib offers ‘durable’ response for chronic phase CML patients

In continuation of my update on bosutinib

Four-year results for an ongoing study of second-line bosutinib indicate that the tyrosine kinase inhibitor (TKI) offers long-term efficacy with manageable side effects for patients with chronic phase chronic myeloid leukaemia (CP CML).

“Overall, these findings highlight the therapeutic potential of bosutinib as second-line therapy in IM-R [imatinib resistant] or IM-I [imatinib intolerant] CP CML patients”, say Tim Brümmendorf (Universitätsklinikum der RWTH Aachen, Germany) and co-investigators.

In the phase I/II trial, bosutinib 500 mg/day was given for a median of 24.8 months to 196 IM-R and 90 IM-I patients; 59% of 264 evaluable patients achieved or maintained a major cytogenetic response (MCyR) for at least 4 weeks, including 59% of the IM-R and 61% of the IM-I groups.

Of the 248 patients without a complete cytogenetic response (CCyR) at baseline, 57% achieved a MCyR and 47% a CCyR during bosutinib therapy. And 14 of the 16 patients with a baseline CCyR maintained this response for between 12 and 288 weeks; two discontinued bosutinib because of adverse events (AEs) and were not reassessed.

The median times to MCyR and CCyR were 12.3 and 24.0 weeks, respectively.

The 4-year cumulative incidences of MCyR and CCyR, at 59% and 49%, respectively, were similar to the previously reported 2-year figures of 59% and 48%, prompting the authors to suggest that “most initial responses occur within 2 years from bosutinib treatment initiation.”

The rate of cumulative progression or death during treatment was an estimated 19% at 4 years.

The Kaplan–Meier-estimated probability of maintaining MCyR at 4 years was found to be high for the whole population and the IM-R and IM-I groups, at 74.5%, 69.3% and 86.3%, respectively, and the median duration of this response had not yet been reached.

Second-line bosutinib offers ‘durable’ response for chronic phase CML patients

Fourth-line bosutinib ‘appropriate’ after prior CML treatment failure, intolerance

In continuation of my update on bosutinib

A Spanish study suggests that bosutinib can help improve or maintain response in patients with chronic myeloid leukaemia (CML) after treatment failure of three previous tyrosine kinase inhibitors (TKI).

Researcher Juan Luís Steegmann (Hospital Universitario de la Princesa, Madrid, Spain) and colleagues analysed medical records of 30 chronic phase CML patients with Philadelphia chromosome-positive disease given bosutinib under the Spanish Compassionate Use programme after discontinuing imatinib, dasatinib and nilotinib as a result of resistance or intolerance.

Of the 15 patients without a complete cytogenetic response at baseline, defined as after TKI use but before bosutinib initiation, two (13.3%) achieved it following bosutinib treatment.

Fourth-line bosutinib ‘appropriate’ after prior CML treatment failure, intolerance

EMA has accepted Pfizer's regulatory submissions for review of two investigational compounds crizotinib and bosutinib

European Medicines Agency (EMA) has accepted Pfizer's regulatory submissions for review of two investigational compounds  crizotinib, an oral first-in-class anaplastic lymphoma kinase (ALK) inhibitor, for the treatment of patients with previously treated ALK-positive advanced non-small cell lung cancer (NSCLC); and bosutinib for the treatment of adult patients with newly diagnosed Philadelphia chromosome positive (Ph+) chronic myeloid leukemia (CML) in the chronic phase. 

Crizotinib

                                                                                               Bosutinib

Dr. Andreas Penk, president of Pfizer Oncology Europe, claims that,

"With the EMA submissions for crizotinib and bosutinib, we are one step closer to potentially bringing two promising agents to patient populations in areas of significant unmet medical need"......

Bafetinib demonstrates significant inhibition of glioblastoma multiforme cell lines (preclinical trials)..

The treatment of chronic myeloid leukemia (CML)  changed  dramatically with the emergence of the ABL tyrosine kinase inhibitor (TKI) imatinib mesilate. However, primary and secondary imatinib resistance has been frequently reported, particularly in patients with advanced-stage disease. To override imatinib resistance, three second-generation ABL TKIs, i.e., dasatinib, nilotinib and bosutinib, were developed. Bafetinib (see structure source : Chemblink :INNO-406, NS-187) is a dual ABL/Lyn inhibitor developed by the team at Kyoto University Hospital in collaboration with Nippon Shinyaku. 

Bafetinib was 25-55 times more potent than imatinib in blocking BCR/ABL autophosphorylation, while otherwise retaining specificity for ABL and Lyn. Bafetinib had antiproliferative effects against cells bearing wild-type or most mutated BCR/ABL proteins, except T315I, and also inhibited BCR/ABL-positive leukemic cell growth in the central nervous system. A phase I study on bafetinib was completed and the agent was well tolerated and demonstrated clinical activity across a range of doses. Responses occurred even in the setting of a heavily pretreated population, thus making bafetinib a viable option for CML therapy.

Recently  CytRx Corporation, announced that its drug candidate bafetinib (formerly known as INNO-406) demonstrated statistically significant inhibition of glioblastoma multiforme cell lines in a preclinical trial. The company believe that bafetinib could be efficacious in several hematological cancers and  it is  preparing to begin evaluating bafetinib in a Phase 2 proof-of-concept clinical trial in high-risk B-cell chronic lymphocytic leukemia (B-CLL) this quarter, as well as a Phase 2 clinical trial in advanced prostate cancer next quarter.... 

Ref : http://www.cytrx.com/inno_406.html