A Phase 3 interventional study of Pirtobrutinib and Ibrutinib in Chronic Lymphocytic Leukemia, Leukemia, Lymphocytic and Leukemia, B-cell, sponsored by Loxo Oncology, Inc.. Recruiting at 143 sites in 23 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-17.
Sponsored by Loxo Oncology, Inc. (part of Eli Lilly and Company) · Phase 3, Interventional, and Treatment
The purpose of Part 1 of this study is to compare the efficacy and safety of pirtobruitinib (LOXO-305) to ibrutinib in participants with CLL/SLL; participants may or may not have already had treatment for their cancer. The purpose of Part 2 of this study evaluates pirtobrutinib monotherapy in treatment-naïve participants with CLL/SLL with 17p deletions. Participation could last up to six years for Part 1. Participation could last up to 2 years for Part 2.
2,036 studies on the registry are indexed under Leukemia, Lymphocytic, Chronic, B-Cell; 237 are open to participants now.
This study's planned enrollment of 737 is above the median of 39 across 1,603 interventional studies indexed under Leukemia, Lymphocytic, Chronic, B-Cell.
Browse Leukemia, Lymphocytic, Chronic, B-Cell studies →Loxo Oncology, Inc. is the lead sponsor of 17 studies on the registry; 2 are open to participants now.
Of its 8 completed or terminated interventional studies of FDA-regulated products, 7 (88%) have results posted.
First submitted after Loxo Oncology, Inc. became part of Eli Lilly and Company.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Adequate organ function
Exclusion Criteria:
Part 2: participants must be treatment naïve
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive pirtobrutinib orally.
Drug: Pirtobrutinib
Participants will receive ibrutinib orally.
Drug: Ibrutinib
Participants will receive pirtobrutinib orally.
Drug: Pirtobrutinib
Administered orally.
Also known as: LOXO-305, LY3527727
Administered orally.
Percentage of Participants Achieving Complete Response (CR), Complete Remission with Incomplete Hematologic Recovery (Cri), Nodular Partial Remission (nPR) or Partial Response (PR): Overall Response Rate (ORR) Part 1
ORR as assessed by independent review committee (IRC) per International Workshop on Chronic Lymphocytic Leukemia (iwCLL) 2018 criteria
Time frame: Baseline to best overall response the best response recorded from Cycle 1 Day 1 until data cutoff date, PD, or start of new anticancer treatment, whichever is the earliest] (approximately 3 years and 5 months)
Percentage of Participants Achieving Complete Response (CR), Complete Remission with Incomplete Hematologic Recovery (CRi), Nodular Partial Remission (nPR) or Partial Response (PR): Overall Response Rate (ORR) Part 2
ORR as assessed by independent review committee (IRC) per International Workshop on Chronic Lymphocytic Leukemia (iwCLL) 2018 criteria
Time frame: Baseline to best overall response the best response recorded from Cycle 1 Day 1 until data cutoff date, PD, or start of new anticancer treatment, whichever is the earliest (Approximately 2 years and 3 months)
IRC-assessed Progression-Free Survival (PFS)
PFS by IRC per iwCLL 2018 criteria
Time frame: Randomization to PD (per iwCLL 2018 criteria) or death from any cause (approximately 5 years 8 months)
Investigator assessed Progression-Free Survival (PFS)
PFS by Investigator per iwCLL 2018 criteria
Time frame: Randomization to PD (per iwCLL 2018 criteria) or death from any cause (approximately 5 years 8 months)
Event-Free Survival (EFS)
EFS by IRC per iwCLL 2018 criteria
Time frame: Randomization to first occurrence of treatment discontinuation due to adverse event/toxicity, treatment-emergent atrial fibrillation or atrial flutter of any grade, progressive disease (PD) or death (approximately 4 years)
Duration of Response (DOR)
DOR by IRC and Investigator by iwCLL 2018 Criteria.
Time frame: Time from the date of the first documented response of CR, CRi, nPR or PR to the earlier of documentation of definitive PD (per iwCLL 2018 criteria) or death from any cause (approximately 2 years)
Overall Survival (OS)
OS
Time frame: Randomization to death from any cause (approximately 6 years)
Time to Next Treatment (TTNT)
TTNT
Time frame: Randomization to initiation of the next systemic anticancer therapy for CLL/SLL or death from any cause, whichever occurs first (approximately 6 years)
Time to Worsening (TTW) of CLL/SLL Related Symptoms
Using symptom questions identified from the EORTC item library. The range of raw scores for these items could be from 0 to 52 with highest score being worse symptoms.
Time frame: Randomization to time to worsening symptoms (approximately 4 years)
Comparative Tolerability
Comparative Tolerability measured by proportion of time with high side-effect burden
Time frame: From Baseline to Treatment Discontinuation for Any Reason (approximately 4 years)
Percentage of Participants Achieving DOR Part 2
DOR as assessed by IRC and Investigator defined as the time from the date of the first documented response of CR, CRi, nPR, or PR to the earlier of the documentation of definitive PD per iwCLL 2018 criteria or death from any cause.
Time frame: Time from the date of the first documented response of CR, CRi, nPR, or PR to the earlier of the documentation of definitive PD or death from any cause] (Approximately 2 years)
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Showing the first 100 of 143 sites across 23 countries. Choose a country and city above to see the rest.
Plan to share: Yes — Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.
Supporting information: Study protocol, Statistical analysis plan, Clinical study report
Time frame: Data are available 6 months after the primary publication and approval of the indication studied in the US and European Union (EU), whichever is later. Data will be indefinitely available for requesting.
Access criteria: A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.
Data sharing details ↗ · vivli.org
Started Jul 2022 (actual). Primary completion is estimated for Oct 2027, 63 months after the start.
Of 57 industry-sponsored phase 3 interventional studies under Leukemia, Lymphocytic, Chronic, B-Cell, half reached primary completion within 53 months of starting (the median), counting those still running; a quarter within 41 and three quarters within 73. This study's planned 63 months is above that.
Counting every sponsor, half of 83 studies reached it within 59 months; a quarter within 43 and three quarters within 76.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
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Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Pirtobrutinib
Leukemia, Lymphocytic, Chronic, B-Cell →