Ayvakit (avapritinib)

P=N/A, N=61, Completed, CStone Pharmaceuticals | Active, not recruiting --> Completed | Trial completion date: Oct 2025 --> Sep 2024

This literature review, along with clinical expertise and opinion, was used to develop this concise and clinically relevant consensus paper to harmonize the knowledge and clinical practice on GIST management across Canada. The content presented here will help guide healthcare providers, especially in Canada, in terms of approaching and managing GIST.

Avapritinib was effective for molecular biologically positive CBF-AML patients with KIT mutation after allo-HSCT. The main adverse reaction was myelosuppression, which could generally be tolerated.

P1/2, N=37, Active, not recruiting, Blueprint Medicines Corporation | Recruiting --> Active, not recruiting | Trial completion date: Apr 2025 --> Dec 2025

Avapritinib, the first licensed drug in SM capable of disease modification alongside the increasingly potent, oral and highly selective KIT tyrosine kinase inhibitors (TKIs) Bezuclastinib and now Elenestinib have enabled the prospect of long-term remissions...The importance of molecular profiling is being demonstrated in administering combination therapies for SM with an associated haematological neoplasm (AHN), allowing more personalised and streamlined treatment regimes. This review focuses on current management strategies of SM, focusing on state-of-the-art directed therapies, the evidence behind their use with presentation of two clinical cases to highlight key messages.

To our knowledge, this is the first known description of the activity of avapritinib in the treatment of a sporadic mesenteric DT, which is relevant given the limited treatment options for patients with this diagnosis. This clinical finding may be worth exploring in a dedicated clinical trial.

Our findings suggest that PDGFRA is a potential therapeutic target for PHNEC, and its inhibition with Avapritinib may offer clinical benefits to patients with this rare malignancy.

P=N/A, N=60, Active, not recruiting, CStone Pharmaceuticals | Recruiting --> Active, not recruiting | N=200 --> 60

Background: The VOYAGER-trial compared avapritinib (ava) with regorafenib (rego) in patients (pts) with advanced gastrointestinal stromal tumors (GIST) in a 3rd-line setting. In a 3rd-line setting, pathogenic PIK3CA mutations represent the most common genomic event in an oncogenic KIT signaling intermediate but were found in only 4.7% of pts using ctDNA sequencing. The presence of PIK3CA mutations in plasma did not preclude prolonged disease control to ava or rego. Limitations of this analysis are the small sample size and the possibility of clonal hematopoiesis of indeterminate potential (CHIP) as PIK3CA mutations were not confirmed in tumor samples.

Mast cell in bone marrow disappeared, C-KIT mutation and RUNX1-RUNX1T1 fusion gene remained negative. Allo-HSCT sequential avapritinib is an effective treatment for SM patients with RUNX1-RUNX1T1 positive AML.

P1, N=10, Active, not recruiting, Blueprint Medicines Corporation | Completed --> Active, not recruiting | Trial completion date: Apr 2024 --> Sep 2025

Avapritinib has the potential to cause intestinal DDIs via the inhibition of UGT1A1. Additional attention should be paid when avapritinib is coadministered with UGT1A1 substrates.

The common adverse effect of avapritinib is neutropenia, which is well-tolerated. This case series indicates that avapritinib may be effective and safe for preemptive treatment of children with AML with t(8;21) and KIT mutation after allo-HSCT, providing a treatment option for preventing relapse after allo-HSCT.

P1, N=10, Completed, Blueprint Medicines Corporation | Recruiting --> Completed | N=20 --> 10 | Trial completion date: Dec 2023 --> Apr 2024 | Trial primary completion date: Nov 2023 --> Mar 2024

Furthermore, we evaluated the sensitivity of these mutants to three FDA-approved tyrosine kinase inhibitors: imatinib, dasatinib, and avapritinib, which effectively suppressed the constitutive activity of the mutant receptors. Interestingly, K385M was reported in a few cases of brain tumors but not in MGNT. Our results provide valuable insights into the molecular mechanism underlying the activation of PDGFRα by the K385I/L mutations, highlighting their potential as actionable targets in the treatment of myxoid glioneuronal tumors.

P1, N=34, Recruiting, H. Lee Moffitt Cancer Center and Research Institute

P2, N=50, Recruiting, Children's Hospital of Soochow University

Despite the outstanding results of first-line imatinib in advanced GIST, resistance ultimately occurs mainly through secondary mutations in KIT/PDGFRA...However, it is now recognized that the situation is more intricate, with various factors interacting with KIT and PDGFRA, playing a crucial role in the response and resistance to treatments. Future strategies in the management of advanced GIST should integrate driver inhibition with the blockade of other molecules to enhance cell death and establish enduring responses in patients.

P2, N=500, Recruiting, Children's Hospital of Soochow University | Not yet recruiting --> Recruiting

No abstract available

P2, N=500, Not yet recruiting, Children's Hospital of Soochow University

Avapritinib and midostaurin can also temper IgE-mediated degranulation...Recently, the anti Siglec-8 antibody lirentelimab showed promising results in ISM...Long-term safety of TKI needs to be addressed. New drugs under investigation in diseases in which non-neoplastic MCs play a pivotal role can provide important inputs to identify new efficient and safe treatments for MCAS.

Against this background, we solve the crystal structures of avapritinib in complex with wild-type and mutant PDGFRA and stem cell factor receptor (KIT), which provide evidence and understanding of inhibitor binding and lead to the identification of a sub-pocket (Gα-pocket). We utilize this information to design, synthesize and characterize avapritinib derivatives for the determination of key pharmacophoric features to overcome drug resistance and limit potential blood-brain barrier penetration.

Moreover, mutations in Kit exon 9 and 11 are actionable, due to their response to imatinib, while mutations in PDGFRA respond to sunitinib and/or avapritinib. This allows the clinician to have an accurate picture of the genetic changes of the tumor over time. In this work, we aimed to discuss the implications of mutational testing in clinical outcomes, the methods to test ctDNA and the future challenges in the establishment of alternatives of personalized medicine.

P2, N=425, Recruiting, Centre Leon Berard

P=N/A, N=25, Active, not recruiting, Centre Leon Berard | Recruiting --> Active, not recruiting | N=45 --> 25 | Trial completion date: Apr 2025 --> Dec 2024 | Trial primary completion date: Apr 2023 --> Apr 2024

The average monthly cost for the treatment of neoplastic diseases was $17,900 with a price of $44,000 for futibatinib (used to treat cholangiocarcinomas with FGFR2 fusions) and minimum of $5100 for binimetinib (melanoma). The average monthly cost for the treatment of non-neoplastic diseases was $6800 with a maximum of $17,000 for belumosudil (graft vs. host disease) and a minimum of $200 for netarsudil eye drops (glaucoma). There is a negative correlation of the cost of the drugs and the incidence of the targeted disease. Many of these agents are or were designated as orphan drugs meaning that there are fewer than 200,000 potential patients in the United States.

2 patients did not achieve continuous RUNX1: : RUNX1T1 negative after preemptive therapy with Decitabine (DAC) and donor lymph infusion (DLI), and then was treated with Avapritinib, one's RUNX1: : RUNX1T1 fusion achieved continuously negative after 1 month treatment of Avapritinib, the other's achieved continuous negative after 7 months treatment of Avapritinib. Avapritinib is safe and effective in the prophylactic and preemptive treatment of AML with KIT mutation after allo-HSCT in children, which provides a clinical drug for the prevention of relapse after transplantation.

Key exclusion criteria include a diagnosis of acute myeloid leukemia, history of intracranial hemorrhage or risk of major hemorrhage, prior treatment with avapritinib or decitabine with documented progression in SM or AHN component, respectively, or history of treatment with alternative KIT inhibitor or azacitidine within 4 weeks of study treatment initiation. Patients with platelet count ≥ 25 x 10 9/L and < 75 x 10 9/L, will receive lead-in dosing with decitabine or decitabine/cedazuridine with the ability to add avapritinib if sufficient platelet thresholds are achieved. This study will open at 7 sites in the United States and is anticipated to open in January 2024.

Avapritinib showed greater antitumor activity in patients with GISTs harboring KIT ALposABPneg mutations versus KIT OTHERS, and may be considered in the former subpopulation. Patients with KIT exon 9 mutations may also benefit in ³4 line settings.

Cell viability and live cell imaging studies revealed that the loaded NGs are capable of intracellular drug release by showing similar IC values to those of the free drugs. Furthermore, multi-drug-loaded NGs were capable of overcoming BLU-285 resistance in T1-α-D842V + G680R cells, demonstrating the utility of this carrier system.

Refractory T-ALL has not been fully characterized. Alterations in PDGFRA or other targetable kinases may inform therapy for patients with refractory T-ALL who otherwise have limited treatment options. Clinical genomic profiling, in real time, is needed for fully informed therapeutic decision making.

One patient with PDGFRA/KIT amplification developed a spontaneous EGFR gain and a secondary PDGFRA mutation in a cerebellar metastatic lesion that progressed on avapritinib therapy. In summary, we report that avapritinib, a selective, CNS penetrant small molecule inhibitor of PDGFRA has potent activity in preclinical models and produced clinical responses with good tolerability in pediatric and young adult patients with high-grade glioma, suggesting a promising role for avapritinib therapy in HGG patients.

Patients with a history of prior TKI therapy (e.g., avapritinib, midostaurin) are permitted in the trial. Enrollment in Part 1 of the Apex trial is complete. Patients enrolled in Part 1 of the Apex trial are generally representative of the population of patients with AdvSM based on patient characteristics and markers of disease. Part 1 includes a small subset of patients with prior use of TKIs.

While there are numerous examples of KIT TKIs that do not inhibit FLT3 (imatinib, avapritinib, dasatinib), to date, all clinically active FLT3 TKIs (quizartinib, gilteritinib, midostaurin, sorafenib) fail to spare KIT inhibition...Compared to FF-10101 and gilteritinib, BGS-2456 exhibited the least amount of hematologic toxicity, facilitating in vitro proliferation and differentiation of normal hematopoietic progenitor cells even at 100x EC50 concentration against Molm14 cells... This is the first description of a potent and exquisitely specific FLT3 inhibitor that spares KIT inhibition and displays no myelosuppression in vitro at >100x EC50 concentration. The potent inhibitory effects of BGS-2456 on both D835Y and F691L mutants support its promise as a best-in-class TKI for the treatment of FLT3-mutant AML. Efforts to molecularly dissect the basis of the high degree of selectivity of BGS-2456 are ongoing.

A gain-of-function KIT D816 V mutation is the primary oncogenic driver found in about 90% of all patients with AdvSM. Midostaurin, an oral multikinase inhibitor with activity against KIT D816V, and avapritinib, an oral selective KIT D816V inhibitor are approved for AdvSM.

"CStone Pharmaceuticals...announced that the AYVAKIT® (avapritinib) companion diagnostic (CDx) kit, known as 'Human platelet-derived growth factor receptor alpha (PDGFRA) Gene D842V Mutation Detection Kit', developed in partnership with Genetron Holdings Limited (Genetron Health) has been approved by the China National Medical Products Administration (NMPA). This CDx kit is the first companion diagnostic product co-developed through the bridging pathway in China to gain regulatory approval following the release of the companion diagnostic guidelines by NMPA. It is used to detect PDGFRA gene mutations in gastrointestinal stromal tumor (GIST) for patients receiving treatment with AYVAKIT."

The proposed approach was effectively employed for determining the stated pharmaceuticals in plasma with a high percentage of recovery ranging from 96.87 to 98.09 and pharmaceutical formulations with a percentage of recovery equal to 102.11 ± 1.05 %. In addition, the study was extended to a pharmacokinetic study of AVP with twenty human volunteers as a step for AVP management in therapeutic cancer centers.

As of today, five agents hold regulatory approval for the treatment of GIST: imatinib, sunitinib, regorafenib, ripretinib, and avapritinib. Herein, we review currently available evidence for the management of GIST. This clinical practice guideline has been developed by a multidisciplinary expert panel (oncologist, pathologist, surgeon, molecular biologist, radiologist, and representative of patients' advocacy groups) from the Spanish Group for Sarcoma Research, and it is conceived to provide, from a critical perspective, the standard approach for diagnosis, treatment, and follow-up.

An exception is represented by patients with tumours harbouring the imatinib-insensitive PDGFRA D842V mutation who would be better treated with avapritinib...While an increase in the dose of imatinib to 800 mg is an option for the second line, sunitinib is usually considered the standard of care...Regorafenib and ripretinib are the standards of care in the third and fourth lines, respectively. The recent development of various systemic treatment options allows for a more personalised approach based on the molecular profile of the GIST, patient characteristics, and the profile of medications' adverse events. A multidisciplinary approach is paramount since combining systemic treatment with locoregional treatment options and supportive care is vital for long-term survival.

Apart from approved drugs (imatinib, sunitinib, regorafenib, ripretinib, and avapritinib, we evaluated cabozantinib, pazopanib, dasatinib, and sorafenib... Preclinical testing suggests that dose-escalation of or retreatment with imatinib is not effective in exon 11 mutant GIST with secondary mutations. Pazopanib appears highly ineffective against any secondary mutation but shows notable activity in exon 9 mutant GIST. Cabozantinib is the only drug with strong activity against the gatekeeper T670I and the AL D820Y mutation.

Different KIT mutation types and signaling pathways atlerations were detected in progression samples of KIT-mutant GISTs after avapritinib or ripretinib failure compared with baseline, which may be associated with mechanism of resistance.