Jaypirca (pirtobrutinib)

P2, N=23, Not yet recruiting, Narendranath Epperla

P3, N=250, Active, not recruiting, Loxo Oncology, Inc. | Recruiting --> Active, not recruiting

P2, N=60, Recruiting, Inhye Ahn | Not yet recruiting --> Recruiting | Initiation date: Sep 2024 --> Apr 2024

P3, N=250, Active, not recruiting, Loxo Oncology, Inc. | Recruiting --> Active, not recruiting

P2, N=0, Withdrawn, Loxo Oncology, Inc. | N=200 --> 0 | Not yet recruiting --> Withdrawn

P2, N=60, Not yet recruiting, Inhye Ahn

P1/2, N=860, Active, not recruiting, Loxo Oncology, Inc. | Trial completion date: Apr 2024 --> Jan 2028 | Trial primary completion date: Apr 2024 --> Sep 2027

Findings suggest that brexu-cel may offer clinically and statistically significant benefits regarding objective response, complete response, and progression-free survival compared to pirtobrutinib among patients with R/R MCL after prior cBTKi therapy. Given the short follow-up and high degree of censoring in BRUIN, an analysis incorporating updated BRUIN data may provide more definitive overall survival results.

P2, N=50, Not yet recruiting, M.D. Anderson Cancer Center

P2; N=50; Not yet recruiting; Sponsor:C. Babis Andreadis

P1, N=28, Completed, Eli Lilly and Company

P1, N=16, Completed, Eli Lilly and Company

P1, N=31, Completed, Eli Lilly and Company

Six drugs (abrocitinib, baricitinib, deucravacitinib, ritlecitinib, tofacitinib, upadacitinib) are used for the treatment of inflammatory diseases (atopic dermatitis, rheumatoid arthritis, psoriasis, alopecia areata, and ulcerative colitis)...The following seven drugs received FDA approval in 2023: capivasertib (HER2-positive breast cancer), fruquintinib (metastatic colorectal cancer), momelotinib (myelofibrosis), pirtobrutinib (mantle cell lymphoma, chronic lymphocytic leukemia, small lymphocytic lymphoma), quizartinib (Flt3-mutant acute myelogenous leukemia), repotrectinib (ROS1-positive lung cancer), and ritlecitinib (alopecia areata). All of the FDA-approved drugs are orally effective with the exception of netarsudil, temsirolimus, and trilaciclib. This review summarizes the physicochemical properties of all 80 FDA-approved small molecule protein kinase inhibitors including the molecular weight, number of hydrogen bond donors/acceptors, polar surface area, potency, solubility, lipophilic efficiency, and ligand efficiency.

The cBTK-i zanubrutinib shows greater response activity and/or improved PFS in wild-type MYD88, mutated CXCR4, or altered TP53 patients...For patients with acquired resistance to c-BTKi, newer options include the non-covalent BTK-inhibitor pirtobrutinib or the BCL2 antagonist venetoclax. Combinations of BTK-inhibitors with chemoimmunotherapy, CXCR4 and BCL2 antagonists have advanced and are discussed. Algorithms for positioning BTK-inhibitors in treatment-naïve and previously treated WM patients based on genomics, disease characteristics, and co-morbidities are presented.

P2, N=200, Not yet recruiting, Loxo Oncology, Inc. | Trial completion date: Sep 2025 --> Feb 2026 | Initiation date: Nov 2023 --> May 2024 | Trial primary completion date: Jun 2025 --> Jan 2026

P1, N=16, Completed, Eli Lilly and Company

P1, N=16, Completed, Eli Lilly and Company

P1, N=36, Completed, Eli Lilly and Company

P1, N=20, Completed, Eli Lilly and Company

P1, N=9, Completed, Eli Lilly and Company

P1, N=24, Completed, Eli Lilly and Company

P1, N=15, Completed, Eli Lilly and Company

P1, N=16, Completed, Eli Lilly and Company

With the worldwide approval of the oral covalent Bruton tyrosine kinase (BTK) inhibitors ibrutinib and zanubrutinib for treating patients with Waldenström macroglobulinemia (WM), targeted agents have certainly taken center stage in the therapeutic landscape of WM. Novel targeted agents of interest include BCL2 antagonists (e.g., venetoclax and sonrotoclax) and non-covalent BTK inhibitors (e.g., pirtobrutinib and nemtabrutinib), among others. The therapeutic landscape of patients with WM will benefit from the robust participation of patients in clinical trials.

2 cells did not respond to the BTK-inhibitors ibrutinib, zanubrutinib or pirtobrutinib but were sensitive to the BCL2 inhibitor venetoclax. BCWM. 2 represents a novel, BTK-inhibitor resistant, BCL2 inhibitor sensitive WM cell line that demonstrates MYD88 (S243N) and LYN (I297N) somatic activating mutations, and deletions of 6q. BCWM.

Using the TME system, we have demonstrated that modeled drug response correlates well with patient clinical response to BTK inhibitor ibrutinib and BCL2 inhibitor venetoclax...To test the hypothesis, we exposed CLL cells in the TME model system to covalent and noncovalent BTKi including ibrutinib, zanubrutinib, and pirtobrutinib at clinically achievable concentrations...Furthermore, plerixafor blocks ibrutinib-driven CIC in cell lines as well as in primary CLL cells...B. One CLL cell was captured halfway in.

In January 2023, the reversible BTK inhibitor pirtobrutinib was approved by the FDA for the treatment of relapsed or refractory MCL...ResultsNemtabrutinib demonstrated comparable growth inhibitory activity to ibrutinib in MCL cell lines with IC 50 values at micromolar concentrations (IC 50 = 0...The result demonstrated that nemtabrutinib enhanced the effector function and anti-MCL activity of anti-CD19 CAR T cells. ConclusionNemtabrutinib demonstrated favorable anti-MCL efficacy in both in vitro and in vivo studies, the promising synergistic effects observed in combination with CAR T cells warrants further investigation in both preclinical and clinical settings.

For example, BTK C481S mutation is well known as a resistant mutation to covalent BTK inhibitors and several mutations of BTK (such as T474I and L528W mutation) have recently been reported in relapsed or refractory CLL patients with acquired resistance to pirtobrutinib, a non-covalent BTK inhibitor...ONO-7018 and tirabrutinib were orally administered to the mice twice a day... ONO-7018 would provide novel therapeutic strategies to overcome the BTK inhibitor acquired resistance and enhance the antitumor effect of BTK inhibitors in clinic. Phase 1 study of ONO-7018 (NCT05515406) is currently ongoing.

P1, N=12, Not yet recruiting, Medical College of Wisconsin | Initiation date: Oct 2023 --> Feb 2024

Pirtobrutinib continues to demonstrate durable efficacy in pre-treated R/R CLL/SLL pts treated with a prior covalent BTKi, regardless of prior therapy, reason for prior BTKi discontinuation, age, high-risk TP53 mutations, C481 mutational status, and/or del(17p). It was well tolerated with low rates of discontinuation due to drug-related toxicity.

Pts received 1 or more cBTKi: ibrutinib (n=44, 90%), acalabrutinib (n=10, 20%) or zanubrutinib (n=1, 2%). Whether similar resistance patterns would manifest if pirtobrutinib was utilized prior to cBTKi treatment remains uncertain. Figure 1.

Pirtobrutinib continues to show durable efficacy and a favorable safety profile in heavily pre-treated R/R MCL pts with prior cBTKi therapy. Responses were observed in pts with high-risk disease features including pts with blastoid/pleomorphic variants, elevated Ki67 index, and TP53 mutations.

While acknowledging the inherent limitations of an unanchored indirect comparison, our findings suggest that brexu-cel offers clinically and statistically significant efficacy benefits in terms of ORR, CR, and PFS compared to pirtobrutinib in patients with R/R MCL after prior cBTKi therapy. Both treatments were not statistically different in terms of OS and DOR although the estimated hazard ratios indicated a favorable trend for brexu-cel; however, given the relatively shorter follow-up and the high degree of censoring in BRUIN, an updated analysis incorporating longer follow-up data with more events from BRUIN could provide more reliable results. Although efforts were made to ensure a robust approach to the selection of prognostic factors for inclusion in the model, the possibility of some residual confounding variables cannot be completely ruled out.

In addition, a patient-derived xenograft (PDX) mouse model was also used for evaluating single agent and combination efficacy of BTKis and zilovertamab (Zilo)...Treatment with single BTKi at 2-10 µM (Ibrutinib, zanubrutinib, acalabrutinib or pirtobrutinib) significantly induced cytotoxicity in the TP53Mut MCL cells, and the cell death was remarkedly increased when BTKi was combined with Zilo at 25-50 µg/ml...Conclusion Dual targeting of BTK and ROR1 signaling pathways augmented efficacy selectively in preclinical MCL models with TP53Mut. These data provide insights to develop tailored therapeutics to improve patient outcome for patients with TP53 mutation.

Ibrutinib, Zanubrutinib, Orelabrutinib were administered in 55.3%,18.3% and 17.9% of patients respectively, in addition to 6 patients with Acalabrutinib and one with Loxo-305, among them 47.7% (125/262) received BTKi as first line treatment...Venetoclax-based regimen might be an effective salvage therapy which could showed a benefit trend in PFS as compared to other post BTKi therapy (10.1 months vs 3.1 months, p= 0.1818)...Acquired BTK/PLCG2 mutations remained to be key drivers of BTKis resistance and BTKC481S mutation was the dominant mutation, while BTKT474 mutation was only detected in Orelabrutinib-resistant patients. The prognosis was rather poor for relapsed patients especially for RTs, treatment strategy after disease progression remains to be optimized.

Introduction Resistance to covalent (ibrutinib, acalabrutinib and zanubrutinib) and non-covalent BTK inhibitors (pirtobrutinib) is an emerging clinical challenge...Methods TAI-SHAN1 (NCT05844956; CTR20220558) and TAI-SHAN5 (NCT05824585) are phase 1 dose escalation and expansion studies in patients with r/r B-NHL...The combination of BBB penetration, dual inhibition of LYN/BTK and potential to overcome C481S mutant CLL and other covalent BTKi resistant lymphomas suggest this may be a useful agent. Updated data will be presented at the meeting.

We performed whole exome sequencing on matched tumor and normal samples from 19 CLL patients treated with BTK inhibitors (Ibrutinib, Ibr, 42% (8/19); Acalabrutinib, Acala, 21% (4/19) and Pirtobrutinib, Pirto, 37% (7/19))...The ibr cohort had no prior BTKi therapy whereas 1 patient in the acala cohort had received spebrutinib, another cBTKi...The approach of combining WES data with growth pattern modeling can help unravel the complexities of tumor evolution and drug resistance for the different classes of BTKi. Data on comparative clone growth rates will be presented at the meeting.

We compared the efficacy and safety profiles of narazaciclib with three health authority-approved CDKi (palbociclib, abemaciclib or ribociclib) in association with covalent (ibrutinib, acalabrutinib) and non-covalent (pirtobrutinib, ARQ-531) BTKi, across a panel of 10 MCL cell lines with distinct sensitivity to the first-in-class BTKi, ibrutinib. In conclusion, our findings demonstrate that narazaciclib is safe and effective as a single agent in preclinical models of MCL, including BTKi-resistant cases. Its combination with ibrutinib achieved a synergistic tumoricidal effect in vitro and in vivo, accelerating cell cycle blockade and reverting the metabolic reprogramming characterizing MCL refractoriness to BTKi therapy.

Pirtobrutinib continues to demonstrate durable efficacy and a favorable safety profile in heavily pre-treated R/R MCL pts with prior cBTKi therapy. High ORRs were observed in pts who had PD on a prior cBTKi, and in pts with high-risk disease features including blastoid/pleomorphic variants, elevated Ki-67 index, and TP53 mutations.

There was considerable discordance between HCP and expert treatment choices for various case scenarios in multiple educational activities; for example, for patient cases without del(17p)/TP53-mutated/IGHV-mutated CLL and bulky disease with diminished creatinine clearance, experts would recommend acalabrutinib with or without obinutuzumab for 77% of scenarios, while HCPs selected this treatment 35% of the time (Table)...One half of responding HCPs (52%) were able to identify characteristics that would qualify a patient for inpatient administration of the initial doses of venetoclax because of increased risk of tumor lysis syndrome (n = 48). Finally, among 213 HCPs participating in educational activities from September 2022 to June 2023, 43% were aware of recent data regarding the use of pirtobrutinib, an investigational noncovalent BTK inhibitor, for treating patients with CLL... Our data suggest that many HCPs are challenged to optimally incorporate contemporary treatment recommendations into the care of patients with CLL and struggle to maintain knowledge of investigational therapies that may affect the treatment landscape in the near future. Continuing educational activities designed to improve the knowledge, competence, and confidence of HCPs in the care of CLL would benefit patients with this disease. A more detailed data analysis of treatment trends and knowledge by geographic location and role on the care team will be presented.

Fixed-duration pirtobrutinib combined with venetoclax ± rituximab was well tolerated and demonstrated sufficiently promising efficacy to warrant further investigation in pts with R/R CLL. The BRUIN CLL-322 phase 3 trial comparing PVR vs VR in previously treated CLL is currently enrolling pts (NCT04965493).