I'll admit that YABTKi is not a recognised CLL related acronym, (acronym lists are here healthunlocked.com/cllsuppo... ), but perhaps it should be! I've attempted in this post to keep tabs on the growing list of BTK inhibitor (BTKi) drugs on trial after ibrutinib's success, with each endeavouring to be more selective (i.e. have less side effects) and/or avoiding the known resistance development risks.
Thank you to the many contributors assisting me to keep this post current!
Background
See Jm954 's posts Next Generation BTK Inhibitors and why we need them healthunlocked.com/cllsuppo...
The twenty year development of ibrutinib, comparison with acalabrutinib and zanubrutunib and much more!
nature.com/articles/s41375-...
The Development of Bruton’s Tyrosine Kinase (BTK) Inhibitors from 2012 to 2017: A Mini-Review (very technical)
researchgate.net/publicatio...
Below, I've listed whether the BTKi drugs bond covalently or non-covalently. Of the currently approved BTKi treatments for CLL, acalabrutinib, ibrutinib and zanubrutinib all bond covalently. Pirtobrutinib, bonds non-covalently. BTK Degraders are covered in this reply: healthunlocked.com/cllsuppo...
*** Very Important with respect to cardio risks ***
Managing the cardiovascular risk of Bruton's Tyrosine Kinase Inhibitors in chronic lymphocytic leukemia
healthunlocked.com/cllsuppo...
Vascular Impact of Cancer Therapies: The Case of BTK (Bruton Tyrosine Kinase) Inhibitors (June 2021)
healthunlocked.com/cllsuppo... (discussion)
ahajournals.org/doi/full/10... (paper)
Not CLL specific and rather technical, with excellent information on cardiovascular side effect management with BTKi treatments. It's worth referencing this to your CLL specialist and cardiologist if you have concerns about bleeding, bruising, blood thinners, heart fibrillation, high blood pressure and so on.
Second-Generation BTK Inhibitors Hit the Treatment Bullseye With Fewer Off-Target Effects healthunlocked.com/cllsuppo...
There are recognised dermatological toxicities associated with ibrutinib, which are less of an issue with second generation BTKis.
healthunlocked.com/cllsuppo...
One of the off target effects is on BTK in platelets, reducing clotting effectiveness, thereby increasing the risk of bleeding. Occasional patches of small bleeds under the skin (petechiae), and an increased tendency to bruise, are generally of no concern, but larger bleeds can be serious.
Bleeding Risk With Antiplatelets and Bruton's Tyrosine Kinase Inhibitors in Patients With Percutaneous Coronary Intervention
jscai.org/article/S2772-930...
Very technical report: ncbi.nlm.nih.gov/labs/pmc/a...
Research suggests Pirtobrutinib may provide a safe and manageable risk of bleeding in those requiring antithrombotic therapy
healthunlocked.com/cllsuppo...
Pre ASH2020 presentation by three CLL specialists: Drs Ian W. Flinn, Susan M. O'Brien, and John Pagel. titled: "Addressing the Medical Need in CLL: How BTK Inhibitors Are Improving Outcomes"
healthunlocked.com/cllsuppo...
CLL: New Horizons With BTK Inhibitors - Clinical Care Options (registration)
Four downloadable slide sets:
1. Overview of the BCR Pathway and BTK in Tumor Development
2.BTK Inhibitors: Future Directions
3. BTK Inhibitors in Treatment-Naive CLL
4. BTK Inhibitors in Relapsed/Refractory CLL
clinicaloptions.com/oncolog...
Which is the best BTKi therapy for you?
Free patient registration with OncLive) for the following two presentations from November 2023
Data Continue to Refine Frontline BTK Inhibitor Selection in CLL - Dr Richard Furman
onclive.com/view/data-conti...
Dr Furman has previously noted that the treatment naive group from the original phase II ibrutinib study has an 83% progression free survival at 7 years.
Addressing Intolerance and Resistance to BTK Inhibition Is Next Frontier in CLL Drug Development - Dr Anthony Mato
onclive.com/view/addressing...
Targeting Bruton’s Tyrosine Kinase in CLL , Inhye E. Ahn and Jennifer R. Brown (June 2021)
frontiersin.org/articles/10...
Covalent BTK mutations better understood as a result of studying those who progressed on acalabrutinib or ibrutinib in the ELEVATE R/R trial
healthunlocked.com/cllsuppo...
BTK inhibitor challenges by Dr. Nicole Lamanna (February 2022)
healthunlocked.com/cllsuppo...
Acalabrutinib Showcases Long-Term Tolerability Across B-Cell Malignancies
Richard R. Furman, MD, discusses the findings from the analysis and highlights the differences between first and second-generation BTK inhibitors in CLL.
onclive.com/view/acalabruti...
Understanding Mechanisms of Non-covalent BTKi Resistance
healthunlocked.com/cllsuppo...
Bodily fluids, intercourse, pregnancy, etc.
healthunlocked.com/cllsuppo...
Here's my current List and status of BTKi drugs. How many have I missed?
1. Acalabrutinib/Calquence (covalent) Approved in USA, Australia for first and subsequent line treatments. (In mid 2021, we had about 5 years of accumulated treatment data for CLL.)
Meta-analysis: Acalabrutinib showed better PFS and OS than other frontline CLL therapies, October 7, 2020
mdedge.com/hematology-oncol...
Acalabrutinib Shows Superior PFS, Safety Over Other Treatments in Relapsed/Refractory CLL (ASH2021)
onclive.com/view/acalabruti...
CALQUENCE Met Primary Efficacy Endpoint in Head-to-Head Trial Against ibrutinib in CLL
biospace.com/article/releas...
"In this first head-to-head trial of BTKis in CLL, Aca demonstrated non-inferior PFS with less cardiotoxicity and fewer discontinuations due to AEs vs Ib"
meetinglibrary.asco.org/rec...
Relatively low risk of cardiovascular adverse events with acalabrutinib in chronic lymphocytic leukemia
healthunlocked.com/cllsuppo...
Relapsed/Refractory trial results after 41 months (median experience)
ashpublications.org/blood/a...
NCCN recommend Acalabrutinib for all patients with relapsed/refractory CLL, including:
• Patients with or without del17p/TP53 mutations
• Frail patients with significant comorbidity OR patients aged ≥65 and younger patients with significant comorbidities
• Patients aged <65 years old without significant comorbidities
Community discussion: healthunlocked.com/cllsuppo...
Acalabrutinib Monotherapy in Hematologic Malignancies: Updated Safety and Efficacy Results
clinicaloptions.com/oncolog...
2. DTRMWXHS-12 (DTRM-12) Phase Ia/Ib
clinicaltrials.gov/ct2/show...
3. Ibrutinib/Imbruvica (covalent) (First approved) Where this all started, following FDA approval for MCL in November 2013 and CLL in July 2014. (In early 2024, we have about 13 years of accumulated treatment data for CLL.)
Long-term safety of single-agent ibrutinib in patients with chronic lymphocytic leukemia in 3 pivotal studies (from ASH 2019) See the visual abstract which illustrates how the adverse event profile considerably improves year by year with the exception of high blood pressure.
How I manage ibrutinib intolerance and complications in patients with CLL - Drs Debra Stephens and John Byrd
ashpublications.org/blood/a...
ashpublications.org/bloodad...
Ibrutinib continued to effectively control CLL in 61% of patients after a median of 6.5 years in one long term follow-up:
healthunlocked.com/cllsuppo...
Towards personalised management of CLL? Ibrutinib study reveals new way to gauge patients’ response to treatment
healthunlocked.com/cllsuppo...
First-line treatment with ibrutinib has meaningfully improved the poor prognosis in the high-risk TP53 population (ASH2020): cancernetwork.com/view/john...
Member experiences: healthunlocked.com/cllsuppo...
healthunlocked.com/cllsuppo...
FDA has also approved an oral suspension of ibrutinib for those who struggle to take capsules or tablets cllsociety.org/2024/03/fda-...
4. Luxeptinib/CG-806 (non-covalent) Phase 1a/b
cancernetwork.com/chronic-l...
aptose.com/product-pipeline...
cancer.gov/publications/dic...
Six patients at 65mg dose who harboured the C481S resistance mutation achieved a highly impressive 67% partial remission rate.
5. Nemtabrutinib (ARQ 531) (MK1026) (non-covalent)
Merck has initiated the pivotal phase 3 randomized BELLWAVE-011 clinical trial (NCT06136559) evaluating nemtabrutinib versus investigator's choice of ibrutinib or acalabrutinib in patients with previously untreated CLL and SLL. Global recruitment of the trial has begun, with patients now enrolling.
healthunlocked.com/cllsuppo...
healthunlocked.com/cllsuppo...
Study to assess the safety and tolerability and to confirm the dose of nemtabrutinib in combination with venetoclax in participants with R/R CLL/SLL. clinicaltrials.gov/study/NC...
6. Orelabrutinib - ICP-022 (covalent)
InnoCare Pharma has announced that its BTK inhibitor orelabrutinib received approval from the China National Medical Products Administration (NMPA) in two indications: the treatment of patients with relapsed/refractory chronic lymphocytic leukemia (CLL) /small lymphocytic lymphoma (SLL), and the treatment of patients with relapsed/refractory mantle cell lymphoma (MCL).
businesswire.com/news/home/...
Updated Phase 2 study report from ASH2020
ash.confex.com/ash/2020/web...
R/R study for B-cell malignancies (CLL included) at MDA/Mayo and a few other USA locations. clinicaltrials.gov/ct2/show...
A multi-site comparison using an unanchored matching-adjusted indirect comparison (MAIC) was performed on R/R (Relapsed/Refractory) CLL/SLL patients for two of the BTKi contenders from China - zanubrutinib and orelabrutinib. The abstract from this paper Indirect comparisons of efficacy of zanubrutinib versus orelabrutinib in patients with relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma or relapsed or refractory mantle cell lymphoma pubmed.ncbi.nlm.nih.gov/374... notes:-
MAIC result showed zanubrutinib demonstrated favorable PFS over orelabrutinib for R/R CLL/SLL patients.
7. Pirtobrutinib (Jaypirca) /LOXO-305 (non-covalent) (First Non-covalent approved)
cllsociety.org/2023/12/pirt...
Works on patients with acquired resistance to available BTKis and venetoclax Starting at the 50 mg QD dose, Pirtobrutinib delivered >IC90 target coverage for wild-type and C481S-mutated BTK, based on estimates from cell-based potencies
More on Pirtobrutinib and resistance development from ASH2024 healthunlocked.com/cllsuppo...
Delays progression for a median of approximately 2 years, or 2.5 years among venetoclax-naive subjects
healthunlocked.com/cllsuppo...
Pirtobrutinib also shows efficiency against Richter's Transformation!
healthunlocked.com/cllsuppo...
Eli Lily are so confident about pirtobrutinib, they have started two late-stage clinical trials pitting it against Imbruvica.
healthunlocked.com/cllsuppo...
Members Osprey69, steve5441 and UKfulloflife are in a LOXO-305 trial: clinicaltrials.gov/ct2/resu...
healthunlocked.com/cllsuppo...
There's also the trial "Pirtobrutinib (LOXO-305) Consolidation for MRD Eradication in Patients With CLL/SLL Treated With Venetoclax":
clinicaltrials.gov/ct2/show... to determine the effectiveness of pirtobrutinib) and venetoclax for relapsed/refractive CLL/SLL
Fixed-duration pirtobrutinib plus venetoclax, rituximab promising in CLL (ASH2023)
healio.com/news/hematology-...
Finally, see Pirtobrutinib: A New Hope for patients with BTK-inhibitor refractory lymphoproliferative disorders
healthunlocked.com/cllsuppo...
8. Spebrutinib (AVL-292, CC-292) (covalent) Phase 1 and no longer in development for CLL
9. Tirabrutinib/ONO-4059 (covalent) for non-Hodgkin lymphoma and/or CLL. Renamed GS-4059 and now in trial NCT02457598 Phase 1
oncnet.com/news/tirabrutini...
10. TG1701 (covalent) Phase 1 (Discontinued)
TG-1701 alone and in combination with U2 (Umbralisib and Ublituximab), has an encouraging safety profile with clinical and pharmacodynamic activity at all dose levels evaluated.
healthunlocked.com/cllsuppo...
CLLerinOz was on a TG-1701 clinical trial
11. Vecabrutinib/SNS-062 (non-covalent) Phase 1b (Phase 2 is not proceeding)
Although vecabrutinib continues to exhibit an excellent safety profile, there is insufficient evidence of activity in BTK-inhibitor resistant B-cell malignancies to advance the drug into the planned Phase 2 portion of the trial.
healthunlocked.com/cllsuppo...
12. Zanubrutinib/Brukinsa (covalent) Phase 2 (Approved)
The (USA) National Comprehensive Cancer Network (NCCN) updated their physician guidelines to recommend Zanubrutinib for first and second line treatment for CLL/SLL on 3rd December 2020
healthunlocked.com/cllsuppo...
The European Medicines Agency has accepted for review 2 new indication applications for zanubrutinib as a therapeutic option for CLL and marginal zone lymphoma patients.
onclive.com/view/zanubrutin...
"Zanubrutinib has found a role in everyday practice, such as in patients who have continued to benefit from inhibition of the BTK pathway but have developed an intolerance to ibrutinib (Imbruvica), Ma explains. Moreover, zanubrutinib is beneficial in patients who are not candidates for acalabrutinib (Calquence), including those patients who need to remain on a proton pump inhibitor and need long-term antacid medication, Ma adds."
onclive.com/view/dr-ma-on-u...
Zanubrutinib Shows Worth Against Standard CLL Drugs
medscape.com/viewarticle/97...
From the ALPINE Relapsed/Refractory trial Study:- Over 60% of patients were aged 65 years or older and around 70% were men, with no significant differences between treatment groups.
Patients were randomized 1:1 to zanubrutinib or ibrutinib until disease progression or study withdrawal.
After a median follow-up of 15 months, the overall response rate was significantly higher with zanubrutinib than ibrutinib, at 78.3% versus 62.5% (P = .0006).
Subgroup analysis confirmed that the effect was seen regardless of age, sex, disease stage, number of prior lines of therapy, mutation status, or bulky disease.
Patients treated with zanubrutinib experienced more grade ≥ 3 adverse events than those given ibrutinib, at 55.9% versus 51.2%, although they had fewer adverse events leading to treatment discontinuation, at 7.8% versus 13.0%.
Brukinsa provides patients with CLL with improvements in response and reduced rates of atrial fibrillation or flutter compared to ibrutinib, in head to head comparison, funded by BeiGene
At a median follow-up of 15 mo, ORR was significantly higher with zanubrutinib vs ibrutinib. ORR was higher in patients with del11q (83.6% vs 69.1%) and del17p (83.3% vs 53.8%) with zanubrutinib, as were overall 12-mo PFS (94.9% vs 84.0%, and OS rates (97.0% vs 92.7%).
The rate of atrial fibrillation/flutter, a pre-specified safety endpoint, was significantly lower with zanubrutinib vs ibrutinib.
healthunlocked.com/cllsuppo...
cancernetwork.com/view/inte...
In the Phase 3 trial SEQUOIA trial of Zanubrutinib vs Bendamustine and Rituximab in Previously Untreated CLL/SLL, zanubrutinib resulted in superior progression-free survival vs bendamustine plus rituximab.
clinicaloptions.com/oncolog...
Ongoing Trial Evaluates zanubrutinib in BTK-Intolerant B-Cell Malignancies - Dr Ian Flinn
onclive.com/view/ongoing-tr...
cllsociety.org/2022/04/ash-...
Conversations with Dr Con Tam: healthunlocked.com/cllsuppo...
Overview by Joanna M Rhodes and Anthony R Mato (Dec 2020)
dovepress.com/zanubrutinib-...
Zanubrutinib effective in CLL/SLL regardless of del 17 p status
haematologica.org/article/v...
onclive.com/conference-cove...
Member experiences (including two early trial members, with 5 years experience on zanubrutinib, with one switching to Venetoclax)
healthunlocked.com/cllsuppo...
healthunlocked.com/cllsuppo...
healthunlocked.com/cllsuppo...
healthunlocked.com/cllsuppo...
Comparison side effects, second generation BTKs (Mainly reports on zanubrutinib vs ibrutinib, with a brief mention of acalabrutinib)
healthunlocked.com/cllsuppo...
13. Rocbrutinib (LP-168 a combined covalent and non-covalently binding BTKi inhibitor Phase 1 clinical trial
healthunlocked.com/cllsuppo...
Phase 1 trial results
healthunlocked.com/cllsuppo....
healthunlocked.com/user/dah... and thompsonellen were on LP-168 clinical trials. gardening-girl has identified patents that seem to cover the properties of this new small molecule inhibitor:-
The present invention relates to a class of potent and selective Btk inhibitors which are rationally designed to not only irreversibly inhibit the WT BTK but also reversibly inhibit the C481S mutant BTK. Thus, the compounds of the present invention may be useful in treating the patients resistant/refractory to the first generation BTK inhibitors such as Ibrutinib and ACP-196(Acalabrutinib), particularly with BTK C481S mutation.
cllsociety.org/2024/06/safe...
Resistance-Associated Mutations in CLL Patients Treated With Novel Agents
In 80% of patients with ibrutinib failure, acquired mutations in BTK and PLCG2 genes were detected. No common resistance-associated mutations or deregulated signaling pathways have been reported in idelalisib failure. Acquired mutations in the BCL2 gene were detected in patients who had failed on venetoclax.
Resistance-associated mutations tend to occur between the second and fourth years of treatment and may be detected several months before clinical relapse.
Also discussed is the development of next-gen agents for CLL patients who have developed resistance to current inhibitors.
healthunlocked.com/cllsuppo...
14. TL-895 is a highly potent, selective, orally available, covalent inhibitor of Bruton tyrosine kinase (BTK) and bone marrow tyrosine kinase X-linked (BMX), under development for treatment of myelofibrosis and chronic lymphocytic leukemia." (added June 2023)
healthunlocked.com/cllsuppo...
15. TT-01488
3036 Phase 1 Study of TT-01488, a Novel, Non-Covalent, Reversible BTK Inhibitor, in Patients with Relapsed or Refractory B-Cell Malignancies
ash.confex.com/ash/2024/web...
Adverse Events From Ibrutinib in Real-World CLL: More Research Needed
Dr Stefano Molica, MD, of Ospedaliera Pugliese-Ciaccio, Italy, and colleagues recently published data from an analysis looking at changes in glycemia, cholesterol, triglycerides, and HDL in 43 patients with CLL who received single-agent ibrutinib. This real-world analysis had several interesting outcomes.
cancertherapyadvisor.com/ho...
Study Explores Causes of Bleeding in Patients on Ibrutinib
healthunlocked.com/cllsuppo...
Can long term ibrutinib patients stop treatment? This MSK sponsored trial aims to find out!
clinicaltrials.gov/ct2/show...
Estimated enrollment 75 patients, commencing 22nd December 2020. MSK, New York is recruiting. The trial is also available in North Carolina and Pennsylvania.
Adding the BAFF receptor antibody Ianalumab may be another way
healthunlocked.com/cllsuppo...
BTK inhibitor therapy for patients with CLL/SLL- treatment barriers BTK inhibitors in CLL/SLL & adverse events- Dr. Javier Pinilla Ibarz
healthunlocked.com/cllsuppo...
This pinned BTKi post includes references to other important BTKi posts
healthunlocked.com/cllsuppo...
Generic Imbruvica?healthunlocked.com/cllsuppo... (Probably not until the early 2030s )
COVID related FAQ from CLL Specialists (with specific reference to BTK and other treatments)
healthunlocked.com/cllsuppo...
What to do when a BTKi stops working?
Kerry Rogers, MD, The Ohio State University, Columbus, OH, gives an excellent summary of the options that might be considered in this VJHemOnc ASH2021 conference interview:
Dr Rick Furman:
healthunlocked.com/cllsuppo...
Screening and monitoring of the BTK C481S mutation in a real-world cohort of patients with relapsed/refractory chronic lymphocytic leukaemia
healthunlocked.com/cllsuppo...
A decade of improvement in Chronic Lymphocytic Leukemia treatments means a shorter life expectancy is no longer a given
healthunlocked.com/cllsuppo...
To complete the picture of common CLL drug alternatives, we have the following growing list:
healthunlocked.com/cllsuppo...
Jennifer Brown, MD on new treatments; Is there still a place for ibrutinib? (2024)
healthunlocked.com/cllsuppo...
Jennifer Woyach, MD, Associate Professor in the Division of Hematology at The Ohio State University
1) Highlights Role of BTK Inhibition in Treatment Landscape for CLL (along with Ventoclax, Obinutuzumab, Rituximab)
targetedonc.com/view/expert...
2) Reflects on the changing BTKi landscape
targetedonc.com/view/jennif...
Dr Woyach's take home message: "I would just say that CLL is advancing very rapidly. We have a lot of drugs that are very effective, and I think the most important thing is that we shouldn't become complacent with the success that we've had so far. We should continue to work to develop new trials to put patients on track and to continue to optimize therapy for patients with CLL."
My Perspective on 3 Questions I Am Asked on BTK Inhibitors for CLL - Dr Ian Flinn, Director, Lymphoma Research Program, Sarah Cannon Research Institute Nashville, Tennessee. Source: Addressing the Medical Need in CLL: How BTK Inhibitors Are Improving Outcomes
clinicaloptions.com/oncolog... Answers on Ibrutininb vs Acalabrutinib or Zanubrutinib, adding an anti- CD20 to BTKi treatment. Note comment on extreme lymphocytosis (very high lymphocyte count) on BTKi's:- "Lymphocytosis can occur in patients with CLL during BTK inhibitor therapy and can be extreme; some clinicians use this as a rationale for adding an anti-CD20 antibody to a patient’s CLL regimen. That said, I have only rarely seen this to be a real issue in my patients with CLL—frankly, I worry more about infusion‑related reactions that occur by administering an anti-CD20 antibody to a patient with such a high white blood cell count than I worry about the potential of lymphocytosis harming the patient. In general, I do not see lymphocytosis as a good reason to add an anti-CD20 antibody to a BTK inhibitor."
In the paper All in the family: back-to-back kinase inhibitors for the treatment of chronic lymphocytic Leukemia, by Meghan C Thompson, Lindsey E Roeker and Anthony R Mato, haematologica.org/article/v... the authors argue that the growing range of BTK inhibitors are making it possible to switch BTKi drugs when intolerance is an issue, rather than the classic approach of switching to another drug class:- "...these studies challenge the traditional sequencing paradigm of switching drug classes in the setting of CLL therapy discontinuation for intolerance."
Can I take a drug holiday from a BTKi
patientpower.info/chronic-l...
“For Brukinsa, as well as other drug in this class called BTK inhibitors, the response of your leukemia continues to get better with time. Even as far as seven years into treatment, people taking these drugs have improvements in their CLL,” Dr. Rogers (The James - Ohio State Uni) said. “That is why BTK inhibitors are planned as continuous treatments, rather than fixed duration ones where you stop treatment.”
Finally, for those concerned at running out of treatment options, cujoe posted this Year in Review: Chronic Lymphocytic Leukemia - MedPage Today 12/10/2024
healthunlocked.com/cllsuppo...
Then there's this early 2025 paper
Improving Treatment Options for Patients with Double Refractory CLL - patients who progressed after treatment with both cBTKis and BCL2i
Discussion post: healthunlocked.com/cllsuppo...
Neil
Last update 21 Feb 2025