Drug Monograph

Revlimid (Lenalidomide)

lenalidomide — immunomodulatory imide drug (IMiD)

Thalidomide Analogue / Immunomodulator·Oral Capsule·REMS-Restricted
Pharmacokinetic Profile
Half-Life
3–4 hours (normal renal function)
Bioavailability
≥82% (oral)
Protein Binding
~30%
Metabolism
Minimal; not CYP450-mediated
Volume of Distribution
75–125 L (apparent)
Clinical Information
Drug Class
Immunomodulatory imide drug (IMiD)
Available Doses
2.5, 5, 10, 15, 20, 25 mg capsules
Route
Oral
Renal Adjustment
Required (CrCl <60 mL/min)
Hepatic Adjustment
Not studied
Pregnancy
Contraindicated (Boxed Warning / REMS)
Lactation
Not recommended
Schedule / REMS
Lenalidomide REMS program
Generic Available
Yes (from 2022; additional generics 2026)
Rx

Indications for Lenalidomide

IndicationApproved PopulationTherapy TypeStatus
Multiple myeloma (MM) — all linesAdultsCombination with dexamethasoneFDA Approved
MM — maintenance following auto-HSCTAdultsMonotherapy maintenanceFDA Approved
Myelodysplastic syndromes (MDS) — del(5q)Adults; transfusion-dependent anaemia; low/int-1 riskMonotherapyFDA Approved
Mantle cell lymphoma (MCL) — relapsed/refractoryAdults; after ≥2 prior therapies (one including bortezomib)MonotherapyFDA Approved
Follicular lymphoma (FL) — previously treatedAdultsCombination with rituximab productFDA Approved
Marginal zone lymphoma (MZL) — previously treatedAdultsCombination with rituximab productFDA Approved

Lenalidomide is a cornerstone immunomodulatory agent in haematological oncology. First approved in 2005 for MDS, it received its broadest indication in 2015 when the FDA approved lenalidomide with dexamethasone for all lines of multiple myeloma therapy. It is a structural analogue of thalidomide with enhanced immunomodulatory, anti-angiogenic, and direct antineoplastic activity. Because of its teratogenic potential, lenalidomide is available only through the mandatory Lenalidomide REMS program, requiring prescriber certification, patient enrolment, and pharmacy certification.

Off-Label Uses

Myelofibrosis — used as second-line therapy, particularly in patients with del(5q). Evidence quality: Moderate.

Systemic AL amyloidosis — in combination with dexamethasone for relapsed/refractory disease. Evidence quality: Moderate.

Diffuse large B-cell lymphoma (DLBCL) — R² regimen (lenalidomide + rituximab) in non-GCB subtype. Evidence quality: Moderate (RE-MIND trial).

Not Indicated for CLL

Lenalidomide is not indicated and not recommended for the treatment of chronic lymphocytic leukaemia (CLL) outside of controlled clinical trials. A randomised trial showed increased mortality (HR 1.92) with lenalidomide versus chlorambucil in first-line CLL (FDA PI Section 5.5).

Dose

Dosing for Lenalidomide

Adult Dosing by Clinical Scenario

Clinical ScenarioStarting DoseMaintenance DoseMaximum DoseNotes
Multiple myeloma — combination therapy (all lines)25 mg PO daily, Days 1–21 of 28-day cycles25 mg PO daily, Days 1–2125 mg/dayWith dexamethasone (see PI Section 14.1 for specific dex dosing by study); preferred low-dose schedule: 40 mg on Days 1, 8, 15, 22 (FIRST trial); reduce dex for age >75; continue until progression
Plan stem cell mobilisation within 4 cycles if HSCT-eligible
MM — maintenance post-auto-HSCT10 mg PO daily, Days 1–28 continuouslyIncrease to 15 mg daily after 3 cycles if tolerated15 mg/dayInitiate after haematologic recovery (ANC ≥1000, platelets ≥75,000); continue until progression
Continuous dosing (no 7-day rest period)
MDS with del(5q) — transfusion-dependent anaemia10 mg PO daily continuously10 mg PO daily (dose-reduce per haem tox tables)10 mg/dayContinue until progression; 80% of patients require dose delay/reduction; 34% need a second reduction
Detailed dose reduction tables in PI for thrombocytopenia and neutropenia based on baseline counts and timing
Mantle cell lymphoma — relapsed/refractory25 mg PO daily, Days 1–21 of 28-day cycles25 mg PO daily, Days 1–2125 mg/dayMonotherapy; continue until progression; reduce by 5 mg per step for haem toxicity (minimum 5 mg daily)
Follicular lymphoma or marginal zone lymphoma — previously treated20 mg PO daily, Days 1–21 of 28-day cycles20 mg PO daily, Days 1–21Up to 12 cyclesIn combination with rituximab; treatment capped at 12 cycles
Reduce by 5 mg per step for haem toxicity (minimum 5 mg daily)

Renal Dose Adjustments

Renal Function (CrCl)MM Combination / MCLFL / MZLMM Maintenance / MDSNotes
CrCl 30–60 mL/min10 mg once daily10 mg once daily5 mg once dailyMay escalate to 15 mg after 2 cycles if tolerated (MM/FL/MZL)
CrCl <30 mL/min (no dialysis)15 mg every other day5 mg once daily2.5 mg once dailyClose monitoring for haematologic toxicity
CrCl <30 mL/min (on dialysis)5 mg once daily5 mg once daily2.5 mg once dailyAdminister dose after dialysis on dialysis days
4-h haemodialysis removes ~31% of lenalidomide
Clinical Pearl: Stem Cell Mobilisation Timing

Lenalidomide impairs stem cell mobilisation. In HSCT-eligible patients, plan collection within the first 4 cycles of lenalidomide-containing therapy. Delayed mobilisation after prolonged lenalidomide exposure may result in inadequate CD34+ cell yields and compromise transplant feasibility (FDA PI Section 5.12).

PK

Pharmacology of Lenalidomide

Mechanism of Action

Lenalidomide exerts its therapeutic effects through binding to cereblon (CRBN), a substrate receptor of the CRL4CRBN E3 ubiquitin ligase complex. This binding redirects the ubiquitin ligase to degrade specific transcription factors, most notably the lymphoid transcription factors Ikaros (IKZF1) and Aiolos (IKZF3), leading to direct cytotoxicity in myeloma cells and enhanced T-cell and NK-cell activation. In del(5q) MDS, lenalidomide selectively targets casein kinase 1α (CK1α), a haploinsufficient gene product in del(5q) cells, for ubiquitin-dependent degradation, providing the molecular basis for the exquisite sensitivity of del(5q) MDS to lenalidomide. Additionally, lenalidomide possesses anti-angiogenic properties through inhibition of VEGF and bFGF, modulates cytokine production (increasing IL-2 and IFN-γ, decreasing TNF-α and IL-6), and enhances antibody-dependent cellular cytotoxicity (ADCC).

ADME Profile

ParameterValueClinical Implication
AbsorptionRapidly absorbed; Tmax 0.5–6 h (median ~1 h); oral bioavailability ≥82%; linear, dose-proportional PK; food reduces Cmax by ~50% and AUC by ~20%May be taken with or without food (food effect deemed clinically insignificant by FDA); swallow capsules whole, do not open or crush
DistributionVd 75–125 L (apparent); protein binding ~30%; distributes into semen (undetectable 3 days after stopping)Low protein binding means dialysis can remove the drug (~31% per 4-h session); semen distribution necessitates male contraception requirements
MetabolismMinimal hepatic metabolism; not a CYP450 substrate, inhibitor, or inducer; two minor metabolites (5-hydroxy-lenalidomide, N-acetyl-lenalidomide, each <5% of dose)No dose adjustment needed for mild hepatic impairment; no CYP450-based drug interactions expected; safe for polypharmacy from a PK interaction standpoint
Eliminationt½ 3–4 h (normal renal function); 9–10 h (moderate/severe RI); ~16 h (ESRD); ~82% excreted unchanged in urine within 24 h; 90% of radioactive dose recovered in urineRenal function is the primary determinant of exposure; dose reduction required for CrCl <60 mL/min; short half-life means no accumulation with daily dosing
SE

Side Effects of Lenalidomide

≥20%Very Common (MM Setting)
Adverse EffectIncidenceClinical Note
Diarrhoea≥20%Among the most frequent GI effects; manage with loperamide
Fatigue / asthenia≥20%Common across all indications; dose-related
Constipation≥20%May reflect concurrent dexamethasone or opioid use
Neutropenia≥20% (Grade 3/4: up to 59% maintenance)Dose-limiting toxicity; requires CBC monitoring per indication-specific schedules
Thrombocytopenia≥20% (Grade 3/4: up to 38% maintenance)Monitor for bleeding; dose interruption/reduction per protocol
Anaemia≥20%May require transfusion support or ESA use (note: ESA increases VTE risk)
Muscle cramps / spasms≥20%Often nocturnal; magnesium supplementation may help
Peripheral oedema≥20%Differentiate from cardiac or renal causes
Upper respiratory infection / nasopharyngitis≥20%Reflects immunomodulatory effect; assess for serious infection
Rash≥15–20%Usually mild; discontinue for SJS/TEN or Grade 4 rash
1–10%Common
Adverse EffectIncidenceClinical Note
Deep vein thrombosis7.4% (relapsed MM with Rd vs 3.1% placebo)Part of the class-wide thrombotic risk; thromboprophylaxis required (see Serious tier for full VTE details)
Pulmonary embolism3.7% (relapsed MM with Rd vs 0.9% placebo)Can be fatal; advise patients to report sudden dyspnoea or chest pain immediately
HypothyroidismReportedThyroid disorders observed; monitor TSH if symptoms develop (PI Section 5.13)
Elevated liver enzymes2% serious (MM)Part of hepatotoxicity spectrum; stop lenalidomide for significant LFT elevation
Tremor≥5% (MM)Listed among common MM adverse reactions; usually mild
SeriousSerious Adverse Effects (Regardless of Frequency)
Adverse EffectEstimated FrequencyTypical OnsetRequired Action
Venous thromboembolism (DVT, PE)DVT 7.4% vs 3.1%; PE 3.7% vs 0.9% (relapsed MM)Median 2.8 months to first eventThromboprophylaxis recommended for all patients; based on individual risk assessment (aspirin, LMWH, or warfarin)
Arterial thromboembolism (MI, stroke)MI 1.7% vs 0.6%; stroke 2.3% vs 0.9%VariableModify risk factors; immediate cardiology/neurology referral
Severe neutropenia (Grade 3/4)48% (MDS); 43% (MCL); up to 59% (MM maintenance)MDS: median 42 days (range 14–411)Dose interruption per protocol; G-CSF support if needed; MDS recovery median 17 days
Severe thrombocytopenia (Grade 3/4)28–54% (indication-dependent)MDS: median 28 days (range 8–290)Dose interruption per protocol; platelet transfusion if needed; MDS recovery median 22 days
Second primary malignancies (SPM)AML/MDS: 0.4% (Rd); 5.3% (with melphalan); 7.5% (post-HSCT maintenance)Variable; requires long-term surveillanceMonitor for development of SPM; weigh benefit vs. risk; risk highest with alkylating agent combinations
Embryo-fetal toxicityTeratogenic in primates at all doses testedAny exposure during pregnancyAbsolute contraindication in pregnancy; REMS program mandatory; 2 forms of contraception; 2 negative pregnancy tests before starting
Hepatotoxicity (including fatal hepatic failure)15% any hepatotoxicity; 2% serious (MM)VariableMonitor liver enzymes periodically; stop lenalidomide for elevated LFTs; may restart at lower dose after normalisation
Severe cutaneous reactions (SJS, TEN)Rare; can be fatalVariablePermanently discontinue; do not rechallenge; dermatology referral
Tumour lysis syndromeRare; fatal cases reportedEarly cycles; high tumour burdenMonitor electrolytes, uric acid, renal function in high-risk patients; prophylactic hydration and allopurinol
Tumour flare reactionReported in CLL and lymphoma (including fatal)Early treatment cyclesMonitor in MCL; characterised by tender lymphadenopathy, fever, rash; not an indication for CLL use
DiscontinuationDiscontinuation & Dose Modification Rates
MDS (del 5q)
80% required dose delay/reduction
Primary reason: Haematologic toxicity (Grade 3/4 in 80%); 34% needed a second dose adjustment
MM (without thromboprophylaxis)
21.5% thrombotic events
Context: vs 8.3% with placebo+dex; median time to first event 2.8 months; thromboprophylaxis now standard
VTE Prophylaxis: Mandatory Consideration

All patients receiving lenalidomide with dexamethasone should receive thromboprophylaxis. The choice of agent (aspirin, LMWH, or warfarin) should be based on individual patient risk assessment. Without prophylaxis, thrombotic events occurred in 21.5% of patients. With prophylaxis in the NDMM FIRST study, the overall thrombotic event rate was reduced to 17.4% (FDA PI Section 5.4). ESA and oestrogen-containing therapies further increase thrombosis risk and should be used with caution.

Int

Drug Interactions with Lenalidomide

Lenalidomide has a favourable drug interaction profile because it is not metabolised by CYP450 enzymes, is not a P-glycoprotein substrate of clinical significance, and is primarily renally eliminated. The main interaction concerns are pharmacodynamic, centred on additive thrombotic risk and monitoring of co-administered drugs whose levels may change.

ModerateDigoxin
MechanismLenalidomide increases digoxin Cmax by 14%; mechanism not fully characterised
EffectModestly increased peak digoxin levels
ManagementMonitor digoxin plasma levels periodically during co-administration
FDA PI
ModerateErythropoiesis-Stimulating Agents (ESAs)
MechanismAdditive prothrombotic effect; ESAs increase erythropoiesis and blood viscosity
EffectIncreased risk of venous and arterial thromboembolism
ManagementUse ESAs based on benefit-risk decision; ensure thromboprophylaxis is in place
FDA PI
ModerateOestrogen-containing therapies (HRT, oral contraceptives)
MechanismAdditive prothrombotic effect from exogenous oestrogen
EffectFurther increased VTE risk on top of lenalidomide-associated thrombosis
ManagementUse based on benefit-risk assessment; non-oestrogen contraception preferred for pregnancy prevention
FDA PI
MajorPembrolizumab (or any PD-1/PD-L1 inhibitor)
MechanismUnknown; combination of IMiD + checkpoint inhibitor + dexamethasone resulted in excess mortality in MM trials
EffectIncreased mortality; trials halted
ManagementDo not combine lenalidomide + dexamethasone with PD-1/PD-L1 inhibitors for MM
FDA PI · KEYNOTE-183/185
Mon

Monitoring for Lenalidomide

  • CBC with DifferentialMM: weekly ×2 cycles, Days 1+15 Cycle 3, then q4wk; MDS: weekly ×8 wk, then ≥monthly; MCL: weekly Cycle 1, q2wk Cycles 2–4, then monthly; FL/MZL: weekly ×3 wk Cycle 1, q2wk Cycles 2–4, then monthly
    Routine
    Haematologic toxicity is dose-limiting. Follow indication-specific CBC schedules exactly. Dose interrupt/reduce per protocol for Grade 3/4 neutropenia or thrombocytopenia.
  • Pregnancy Testing2 negative tests before starting (10–14 days apart, second within 24 h of first dose); weekly ×4 wk, then q4wk (regular cycles) or q2wk (irregular)
    Routine
    Mandatory REMS requirement for all females of reproductive potential. Must be documented before each prescription.
  • Renal FunctionBaseline and periodically
    Routine
    Primary route of elimination is renal; dose adjustment required for CrCl <60 mL/min. Renal impairment common in MM (~50% of patients).
  • Liver Function TestsPeriodically
    Routine
    Hepatotoxicity reported in 15% (any grade); serious in 2%. Stop lenalidomide for elevated LFTs; may restart at lower dose after normalisation.
  • Signs of VTE / ATEEach cycle
    Trigger-based
    Advise patients to report leg swelling, chest pain, shortness of breath, arm weakness, or sudden severe headache immediately. Ensure thromboprophylaxis is prescribed.
  • Second Primary MalignanciesLong-term surveillance
    Trigger-based
    AML/MDS risk increased, especially with alkylating agents. Age-appropriate cancer screening; haematology review for unexplained cytopenias.
  • Thyroid FunctionPeriodically
    Trigger-based
    Thyroid disorders (hypothyroidism and hyperthyroidism) reported; monitor TSH if symptoms develop.
CI

Contraindications & Cautions for Lenalidomide

Absolute Contraindications

  • Pregnancy — Lenalidomide is a thalidomide analogue; teratogenic in primates at all doses. Limb abnormalities observed. Contraindicated in females who are pregnant (Boxed Warning, PI Section 4.1).
  • Severe hypersensitivity to lenalidomide — Including angioedema, SJS, or TEN. Do not rechallenge (PI Section 4.2).

Relative Contraindications (Specialist Input Recommended)

  • Chronic lymphocytic leukaemia (CLL) — Increased mortality observed in a randomised trial (HR 1.92); not recommended outside controlled clinical trials.
  • Severe renal impairment without appropriate dose adjustment — AUC increases 200–400% in moderate-to-severe RI; dose reduction mandatory.
  • High thrombotic risk without feasible anticoagulation — Consider whether the benefit of lenalidomide outweighs the VTE/ATE risk if thromboprophylaxis cannot be administered.

Use with Caution

  • High tumour burden — Risk of tumour lysis syndrome (fatal cases reported); monitor electrolytes, hydrate, and consider allopurinol prophylaxis.
  • MCL patients — Higher early mortality rate observed; careful patient selection required.
  • Lactose intolerance — Capsules contain lactose; evaluate risk-benefit.
  • HSCT-eligible patients on prolonged treatment — Impaired stem cell mobilisation after >4 cycles; early transplant centre referral recommended.
FDA Boxed WarningEmbryo-Fetal Toxicity

Lenalidomide is a thalidomide analogue. Thalidomide causes severe, life-threatening birth defects. Lenalidomide caused limb abnormalities in monkey offspring at all doses tested. Pregnancy must be excluded before starting treatment, and two forms of contraception are required. Available only through the Lenalidomide REMS program.

FDA Boxed WarningHematologic Toxicity

Significant neutropenia and thrombocytopenia occur across all indications. In del(5q) MDS, 80% of patients experienced Grade 3/4 haematologic toxicity, and 80% required dose delays or reductions. CBC monitoring on indication-specific schedules is mandatory.

FDA Boxed WarningVenous and Arterial Thromboembolism

Significantly increased risk of DVT, PE, MI, and stroke in patients receiving lenalidomide with dexamethasone. Thromboprophylaxis is recommended for all patients. Without prophylaxis, 21.5% of relapsed MM patients experienced thrombotic events versus 8.3% with placebo. Advise patients to seek immediate medical care for symptoms of thrombosis.

Pt

Patient Counselling for Lenalidomide

Purpose of Therapy

Lenalidomide is a capsule taken by mouth that works by modifying the immune system, directly killing cancer cells, and starving tumours of their blood supply. It is used to treat multiple myeloma, certain bone marrow disorders (MDS), and some types of lymphoma. Treatment duration varies by indication but may continue for years in myeloma.

How to Take

Take capsules whole at approximately the same time each day, with or without food. Do not open, break, or chew capsules. Store at room temperature. Do not donate blood during treatment or for 4 weeks after stopping.

Pregnancy Prevention (REMS)
Tell patientThis drug can cause severe birth defects. Females must use two forms of contraception starting 4 weeks before treatment, during treatment, during any breaks, and for 4 weeks after stopping. Males must use a latex condom for any sexual contact with females who could become pregnant, during treatment and for 4 weeks after stopping. Males must not donate sperm.
Call prescriberImmediately if pregnancy is suspected or confirmed; if a condom breaks during sexual contact; or if unable to comply with contraception requirements.
Blood Clot Risk
Tell patientThere is an increased risk of blood clots including in the legs (DVT) and lungs (PE), as well as heart attacks and strokes. You will likely be prescribed a blood thinner to reduce this risk. Stay well hydrated and avoid prolonged immobility.
Call prescriberImmediately for leg pain or swelling, sudden chest pain, difficulty breathing, arm or leg weakness, or sudden severe headache.
Infection & Bleeding Risk
Tell patientThis drug lowers blood cell counts, increasing susceptibility to infections and bleeding. Regular blood tests are essential. Practice good hand hygiene and avoid close contact with sick individuals.
Call prescriberFor fever ≥38°C (100.4°F), unusual bruising or bleeding, persistent sore throat, or signs of infection.
Skin Reactions
Tell patientMild rash is relatively common. However, rare but serious skin reactions (blistering, peeling, mouth sores with rash) can occur and require immediate medical attention.
Call prescriberImmediately for widespread rash with blistering or peeling, mouth ulcers with skin rash, or rash with fever.
Ref

Sources

Regulatory (PI / SmPC)
  1. Revlimid (lenalidomide) capsules. Full Prescribing Information. Bristol-Myers Squibb (Celgene). Revised March 2023. FDA LabelPrimary source for all dosing, boxed warnings, adverse reactions, REMS requirements, and renal dose adjustments in this monograph.
  2. Lenalidomide REMS Program. Information available at lenalidomiderems.com.Official REMS program website for prescriber certification, patient enrolment, and pharmacy requirements.
Key Clinical Trials
  1. Benboubker L, Dimopoulos MA, Dispenzieri A, et al. Lenalidomide and dexamethasone in transplant-ineligible patients with myeloma (FIRST/MM-020). N Engl J Med. 2014;371(10):906-917. doi:10.1056/NEJMoa1402551FIRST trial establishing continuous Rd as standard first-line therapy for transplant-ineligible NDMM patients.
  2. Weber DM, Chen C, Niesvizky R, et al. Lenalidomide plus dexamethasone for relapsed multiple myeloma in North America. N Engl J Med. 2007;357(21):2133-2142. doi:10.1056/NEJMoa070596MM-009 pivotal trial establishing Rd as standard for relapsed MM, demonstrating superior TTP and OS vs dexamethasone alone.
  3. Dimopoulos M, Spencer A, Attal M, et al. Lenalidomide plus dexamethasone for relapsed or refractory multiple myeloma (MM-010). N Engl J Med. 2007;357(21):2123-2132. doi:10.1056/NEJMoa070594International companion trial to MM-009 confirming efficacy of Rd in relapsed/refractory MM.
  4. List A, Dewald G, Bennett J, et al. Lenalidomide in the myelodysplastic syndrome with chromosome 5q deletion. N Engl J Med. 2006;355(14):1456-1465. doi:10.1056/NEJMoa061292Pivotal MDS-003 trial demonstrating 67% transfusion independence rate and 45% cytogenetic response in del(5q) MDS patients.
  5. McCarthy PL, Holstein SA, Petrucci MT, et al. Lenalidomide maintenance after autologous stem-cell transplantation in newly diagnosed multiple myeloma: a meta-analysis. J Clin Oncol. 2017;35(29):3279-3289. doi:10.1200/JCO.2017.72.6679Meta-analysis of 3 RCTs (CALGB 100104, IFM 2005-02, GIMEMA RV-MM-PI-0209) confirming PFS and OS benefit of lenalidomide maintenance post-ASCT.
  6. Leonard JP, Trneny M, Izutsu K, et al. AUGMENT: a phase III study of lenalidomide plus rituximab versus placebo plus rituximab in relapsed or refractory indolent lymphoma. J Clin Oncol. 2019;37(14):1188-1199. doi:10.1200/JCO.19.00010AUGMENT trial establishing R² (lenalidomide + rituximab) as standard for relapsed FL and MZL.
Guidelines
  1. National Comprehensive Cancer Network (NCCN). Clinical Practice Guidelines in Oncology: Multiple Myeloma. Version 5.2024. NCCNCurrent NCCN guidelines incorporating lenalidomide across all lines of MM therapy and maintenance.
Mechanistic / Basic Science
  1. Krönke J, Udeshi ND, Narla A, et al. Lenalidomide causes selective degradation of IKZF1 and IKZF3 in multiple myeloma cells. Science. 2014;343(6168):301-305. doi:10.1126/science.1244851Landmark mechanistic study identifying cereblon-mediated degradation of Ikaros and Aiolos as the molecular basis for lenalidomide activity in MM.
  2. Krönke J, Fink EC, Hollenbach PW, et al. Lenalidomide induces ubiquitination and degradation of CK1α in del(5q) MDS. Nature. 2015;523(7559):183-188. doi:10.1038/nature14610Discovery of CK1α as the del(5q)-specific target of lenalidomide, explaining its selective efficacy in this MDS subtype.
Pharmacokinetics / Special Populations
  1. Chen N, Zhou S, Palmisano M. Clinical pharmacokinetics and pharmacodynamics of lenalidomide. Clin Pharmacokinet. 2017;56(2):139-152. doi:10.1007/s40262-016-0432-1Comprehensive PK review establishing half-life of 3–4 h, renal-dominant elimination, and AUC-matched dose adjustments for renal impairment.
  2. Hoffmann M, Kasserra C, Reyes J, et al. Absorption, metabolism and excretion of [14C]-lenalidomide following oral administration in healthy male subjects. Cancer Chemother Pharmacol. 2012;69(3):789-797. doi:10.1007/s00280-011-1760-3Mass balance study confirming ≥82% oral bioavailability, 90% urinary recovery, and minimal hepatic metabolism of lenalidomide.