Long-term dasatinib findings support first-line use in CML

In continuation of my update on dasatinib

Final DASISION study findings confirm dasatinib to be an effective, long-term treatment for patients with a new diagnosis of chronic phase-chronic myeloid leukaemia (CP-CML).

 dasatinib

After 5 years, 61% of 259 patients randomly assigned to receive dasatinib 100 mg/day were still taking the tyrosine kinase inhibitor (TKI), while 63% of the 260 patients started on imatinib 400 mg/day continued with their treatment, the investigators report in the Journal of Clinical Oncology.

The primary endpoint of complete cytogenetic response (CCyR) at 5 years had been achieved by 28% of dasatinib-treated patients and 26% of their imatinib-treated counterparts, although the researchers note that these values may have been higher if bone marrow samples had been tested in the patients at the end of the study.

Cumulative 5-year rates of major molecular response (MMR) and molecular responses with a 4.5-log (MR4.5) reduction in BCR-ABL1 transcripts from baseline were also comparable in the dasatinib and imatinib treatment arms, at 76% versus 64%, and 42% versus 33%, respectively, say Jorge Cortes, from the University of Texas MD Anderson Cancer Center in Houston, USA, and co-authors.

Five-year estimated overall survival was 91.0% for the dasatinib group and 90.0% for those given imatinib. And estimated progression-free survival was a corresponding 85.0% and 86.0% with 4.6% and 7.3% of patients transforming to accelerated or blast phase CML during a period of follow-up that continued beyond TKI discontinuation.

In all, 84% of dasatinib-treated patients and 64% of imatinib-treated patients achievedBCR-ABL1 of 10% or less within 3 months of treatment. Compared with patients who did not reach this target, these individuals were more likely to achieve CCyR, MMR and MR4.5over 5 years, had higher rates of overall and progression-free survival, and were less likely to have transformation.

Cortes et al note that no new adverse effects were reported for dasatinib or imatinib by the end of the 5-year study period and just 15% and 11% of adverse effects were grade 3 or 4 in the groups, respectively.

Patients given dasatinib had higher rates of grade 3 or 4 neutropenia (29 vs 24%), anaemia (13 vs 9%) and thrombocytopenia (22 vs 14%) but lower rates of other nonhaematological side effects, except for any grade of pleural effusion (28.0 vs 0.8%). Discontinuation for drug-related side effects occurred in 16% and 7% of dasatinib- and imatinib-treated patients, respectively.

Pulmonary hypertension was reported in 5.0% and 0.4% of the dasatinib and imatinib groups, respectively, with 12 of the 14 diagnoses deemed to be drug related. Arterial ischaemic events were "uncommon" in both groups, affecting 5.0% and 2.0%, respectively.

However, there was a "disproportionate number" of deaths from infection in the dasatinib versus imatinib groups (11 vs 1), with seven deaths reported between 69 days and 4.5 years after dasatinib discontinuation.

"It will be important to prospectively and intentionally look at a possible imbalance in the occurrence of infections and, if present, determine a possible mechanism(s) for dasatinib-related infectious complications", the investigators comment.

"These results suggest that first-line dasatinib should continue to be considered a standard first-line therapy for patients with newly diagnosed CML-CP", the researchers conclude.

While patients given dasatinib were more likely to achieve early treatment milestones, the authors explain that the high rates of CCyR and overall survival in both treatment arms mean a longer follow-up period and larger study population are likely needed to demonstrate any significant difference in survival between the TKIs.

Dasatinib Tops Imatinib for Ph+ Acute Lymphoblastic Leukemia

In continuation of my update on dasatinib and imatinib

Dasatinib is associated with improved survival for pediatric patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL), according to a study published online Jan. 16 in JAMA Oncology.

Shuhong Shen, M.D., Ph.D., from the Shanghai Jiao Tong University School of Medicine, and colleagues conducted an open-label randomized trial at 20 hospitals in China involving patients aged 0 to 18 years with Philadelphia chromosome-positive ALL. Patients were randomly assigned to either daily dasatinib or imatinib (92 and 97 patients, respectively) in the context of intensive chemotherapy without prophylactic cranial irradiation.

The researchers found that the four-year event-free and overall survival rates were 71.0 and 88.4 percent, respectively, in the dasatinib group and 48.9 and 69.2 percent, respectively, in the imatinib group. The four-year cumulative risk for any relapse was 19.8 and 34.4 percent in the dasatinib and imatinib groups, respectively; the four-year cumulative risk for an isolated central nervous system relapse was 2.7 and 8.4 percent, respectively. There was no difference between the treatment groups in the frequency of severe toxic effects.

"The present study provides promising early outcome data supporting the use of a dasatinib-based regimen for Philadelphia chromosome-positive ALL," write the authors of an accompanying editorial. "It also highlights some key challenges that remain in the management of this disease."

Several authors disclosed financial ties to pharmaceutical companies, including Bristol-Myers Squibb, which manufactures dasatinib.

https://en.wikipedia.org/wiki/Dasatinib

FDA Expands Approval of Sprycel (dasatinib) to Include Treatment of Children with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia in Chronic Phase

In continuation of my update on Sprycel(dasatinib)

Bristol-Myers Squibb Company (NYSE:BMY) announced the U.S. Food and Drug Administration (FDA) has expanded the indication for Sprycel(dasatinib) tablets to include the treatment of children with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) in chronic phase (CP). This approval for Sprycel in pediatric patients with Ph+ CML in chronic phase was granted under priority review, and the indication received orphan drug designation from the FDA. The safety and efficacy of Sprycel in pediatric patients was evaluated in two pediatric studies of 97 patients with CP-CML: an open-label, non-randomized, dose-ranging trial (NCT00306202) and an open-label, non-randomized, single-arm trial (NCT00777036). Among the 97 patients in the two studies, 51 patients (exclusively from the single-arm trial) had newly diagnosed CP-CML, and 46 patients (17 from the dose-ranging trial and 29 from the single-arm trial) were resistant or intolerant to previous treatment with imatinib.

Sprycel is associated with the following Warnings and Precautions: myelosuppression, bleeding-related events, fluid retention, cardiovascular events, pulmonary arterial hypertension, QT prolongation, severe dermatologic reactions, tumor lysis syndrome, embryo-fetal toxicity and effects on growth and development in pediatric patients.¹.

“While chronic myeloid leukemia is rare in children, accounting for less than three percent of all pediatric leukemias, it is often more aggressive in younger patients than in adults and until recently, there have been few available treatment options,”^2,3 said Vickie Buenger, President, Coalition Against Childhood Cancer. “The FDA’s decision to approve the expanded use of Sprycel in children with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase may bring new hope to these patients and their families.”

“Our decision to pursue an expanded indication for Sprycel is indicative of our commitment to exploring pediatric applications within our broad development program,” said Johanna Mercier, head, U.S. Commercial, Bristol-Myers Squibb. “We are pleased this option is now available for appropriate pediatric chronic phase CML patients and their physicians.”

As part of its commitment to children and adolescents with cancer, Bristol-Myers Squibb continues to explore pediatric applications for investigational oncology agents within its broad development program. In addition, Bristol-Myers Squibb supports organizations and initiatives focused on pediatric patients and their families.

Sprycel (dasatinib) Tablets Now Approved in Combination with Chemotherapy in Certain Pediatric Patients with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia

In continuation of my update on Dasatinib

Bristol-Myers Squibb Company (NYSE:BMY)  announced the U.S. Food and Drug Administration (FDA) has expanded the indication for Sprycel ® (dasatinib) tablets to include the treatment of pediatric patients one year of age and older with newly diagnosed Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in combination with chemotherapy.1 Sprycel is the only second-generation tyrosine kinase inhibitor approved for this patient population. The approval, which was granted following priority review by the FDA, is based on data from the Phase 2 study, CA180-372 (NCT01460160).

“We recognize the urgency around developing and delivering therapies for children and young adults living with cancer, and today’s approval is an important example of our commitment to pediatric oncology,” said Jeffrey Jackson, Ph.D., development lead, hematology, Bristol-Myers Squibb. “Building on our previous indication for children with Ph+ chronic myeloid leukemia in chronic phase, we’re pleased to bring Sprycel tablets to a second type of pediatric leukemia. This approval will give physicians another treatment option to offer appropriate pediatric patients with Ph+ ALL.”

Sprycel is associated with the following Warnings and Precautions: myelosuppression, bleeding-related events, fluid retention, cardiovascular events, pulmonary arterial hypertension, QT prolongation, severe dermatologic reactions, tumor lysis syndrome, embryo-fetal toxicity and effects on growth and development in pediatric patients.1 Please see detailed Important Safety Information below.

The efficacy of Sprycel tablets in combination with chemotherapy was evaluated in a single cohort of the Phase 2, multicenter, single-arm CA180-372 study, which included 78 pediatric patients with newly diagnosed B-cell precursor Ph+ ALL.1,2 At three years, the study demonstrated an event-free survival (EFS) binary rate of 64.1% (95% confidence interval [CI]: 52.4 to 74.7).1 Event-free survival is defined as the time from the start of Sprycel to lack of complete response at the end of the third high-risk block, relapse, secondary malignancy or death from any cause.

Of the 81 patients evaluated for safety, fatal adverse reactions occurred in three patients (4%), and eight (10%) experienced adverse reactions leading to treatment discontinuation, including fungal sepsis, hepatotoxicity of graft versus host disease, thrombocytopenia, CMV infection, pneumonia, nausea, enteritis and drug hypersensitivity.1 The most common serious adverse reactions (incidence ≥10%) were pyrexia, febrile neutropenia, mucositis, diarrhea, sepsis, hypotension, infections (bacterial, viral and fungal), hypersensitivity, vomiting, renal insufficiency, abdominal pain and musculoskeletal pain.1

“As treatments have advanced in recent years, we’ve seen improvements in outcomes for pediatric patients with Ph+ ALL overall, but there remains a need for additional options,”3 said Stephen Hunger, MD, lead study author, chief of the division of oncology and director of the Center for Childhood Cancer Research at Children’s Hospital of Philadelphia. “The Phase 2 CA180-372 trial was particularly informative because it was designed to limit the use of cranial irradiation and stem cell transplant. In the study, Sprycel plus chemotherapy demonstrated a three-year event-free survival benefit. These results show that Sprycel is an effective medication for physicians to consider for children and adolescents with Ph+ ALL.”1,4

Acute lymphoblastic leukemia is characterized by chromosomal abnormalities and genetic alterations involved in the differentiation and proliferation of lymphoid precursor cells.5 The most common childhood cancer in the United States, ALL represents 20% of all cancers diagnosed in persons aged less than 20 years, or more than 3,000 new cases each year.6 Three percent of children who have ALL have the Ph+ subtype, which means they have a chromosome alteration that results in a specific mutation of the BCR-ABL gene.3

“Coping with a pediatric cancer diagnosis, including searching for and identifying the right treatment regimen, can take a physical and emotional toll on patients and their families,” said Vickie Buenger, president of the Coalition Against Childhood Cancer (CAC2). “The availability of another option is a welcome step forward for those affected by this disease.”

In addition to this pediatric approval, Sprycel is approved for use in children one year of age and older with Ph+ chronic myeloid leukemia (CML) in chronic phase (CP).

Taxoxifen combined with dasatinib reverses chemo-resistance in breast cancer cells

Researchers from Thomas Jefferson University Hospita,  found that taxoxifen combined with dasatinib, a protein-tyrosine kinase inhibitor, reverses the chemo-resistance caused by cancer-associated fibroblasts in the surrounding tissue by normalizing glucose intake and reducing mitochondrial oxidative stress, the process that fuels the cancer cells. 

In this study, researchers sought to better understand drug resistance by looking at the metabolic basis in an ER (+) cell line and cancer-associated fibroblasts.  Researchers claim that the  resistance to chemotherapeutic agents is a metabolic and stromal phenomenal  and the drug combination had an "antioxidant effect" in these types of cancer cells.  

Researchers showed that ER (+) cancer cells alone responded to tamoxifen but when co-cultured with human fibroblasts had little to no effect. Similarly, dasatinib, a chemotherapy drug used to treat leukemia patients who can no longer benefit from other medications, had no effect on fibroblasts alone or cancer cells. Together, however, the drugs prevented the cancer cells co-cultured with the fibroblasts from using high-energy nutrients from the fibroblasts. Researchers conclude that, 

"The drugs have no effect when they are used alone-it's in unison when they effectively kill the cancer cells in the presence of fibroblasts and combination resulted in nearly 80 percent cell death" 

Ref: http://www.jeffersonhospital.org/News/leukemia-drug-reverses-tamoxifen-resistance-in-breast-cancer-cells.aspx

Sprycel (Dasatinib) for ovarian cancer ?

Dasatinib, is a cancer drug produced by Bristol-Myers Squibb and sold under the trade name Sprycel. Dasatinib is an oral dual BCR/ABL and Src family tyrosine kinases inhibitor approved for use in patients with chronic myelogenous leukemia (CML) after imatinib treatment and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). It is also being assessed for use in metastatic melanoma. Its named after Jagabandhu Das, who was a member of the large discovery and development team at Bristol Myers Squibb.

Recently, researchers with UCLA's Jonsson Comprehensive Cancer Center found that Sprycel, significantly inhibited the growth and invasiveness of ovarian cancer cells and also promoted their death. The drug, when paired with a chemotherapy regimen, was even more effective in fighting ovarian cancer in cell lines in which signaling of the Src family kinases, associated with the deadly disease, is activated. The researchers are excited because of the fact that "recent gene expression studies have shown that about one-third of women have ovarian cancers with activated Src pathways", so the drug could potentially help 7,000 ovarian cancer patients every year. Gottfried Konecny (lead researcher) said, it also inhibits the focal adhesion kinase and ephrin receptor, (drug is known to inhibit in many pathways) also associated with ovarian cancer. Though clinical trials are still to be established , its a remarkable achievement. More details .....

PF-114 shows promise in therapy-resistant CML, Ph-positive ALL

PF-114, a selective tyrosine kinase inhibitor (TKI), is active against native and mutated forms of the BCR–ABL oncogene in Philadelphia chromosome (Ph)-positive leukaemias, according to preclinical cellular and in vivo results published in Leukemia.

Martin Ruthardt, from Goethe University in Frankfurt, Germany, and colleagues found that PF-114 was more selective than the second-generation TKIs dasatinib and nilotinib as well as the third-generation TKI ponatinib, which they speculate could reduce the potential for adverse effects.

At a 100 nM concentration, equivalent to an active plasma concentration, PF-114 inhibited at least 90% activity of 11 kinases compared with 47 and 36 kinases suppressed by ponatinib and dasatinib, respectively. Nilotinib blocked only four kinases at this concentration, but extrapolating the data to its clinically relevant concentration of 4 µM resulted in the number of inhibited kinases increasing to 21.

In cell-free assays, PF-114 inhibited not only native ABL kinase but also versions of the enzyme harbouring various clinically relevant mutations, including T315I. The agent also suppressed the proliferation of Ph-positive cell lines derived from patients with chronic myeloid leukaemia (CML) or acute lymphatic leukaemia (ALL).

Additionally, PF-114 was effective against patient-derived long-term cultures, including those responsive and resistant to TKIs as well as one with nonmutational TKI-resistance.

Treatment with PF-114 significantly increased the median survival of mice transplanted with cells expressing the native or T315I mutant form of p185BCR–ABL, inducing a CML-like disease, compared with untreated mice, from 28 days to 39 days and 68 to 132 days, respectively.

Ref : http://www.nature.com/leu/journal/vaop/ncurrent/full/leu2014326a.html

PF-114 shows promise in therapy-resistant CML, Ph-positive ALL

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

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