The dose levels of lenalidomide were explored, and dose escalation of lenalidomide followed the 3+3+3 dose escalation schema. A Dose Level Review Committee evaluated safety data following completion of each dose observation period of the Phase 1b portion.

All-Treated Analysis Population (Phase 1b): participants who received any dose of study drug(s).

An adverse event (AE) is any untoward medical occurrence, which does not necessarily have a causal relationship with treatment. A serious AE is any untoward medical occurrence that at any dose: results in death; is life-threatening; requires in-patient hospitalization > 24 hours or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect; is an important medical event. AEs that started or worsened during the treatment-emergent period and all possibly related or related AEs were considered TEAEs. Related events were those that were considered possibly related or related to study drug per investigator's judgment. Events were graded per the national Cancer Institute's Common Terminology Criteria for Adverse Events, version 4.03: Grade 1=mild; grade 2=moderate; grade 3=severe; grade 4=life-threatening; grade 5=death.

All-Treated Analysis Population (Phase 1): participants who received any dose of study drug(s).

The ORR was defined as the percentage of participants who achieve either a partial response (PR) or complete response (CR), according to the Revised International Working Group Response Criteria for Malignant Lymphoma or Lugano Classification (Cheson 2014), as assessed by the investigator in response-evaluable population. The 95% confidence interval (CI) was calculated using the exact method.

Response-Evaluable Population: participants who had measurable disease at baseline and had at least 1 adequate post-treatment disease assessment by the investigator.

The ORR was defined as the percentage of participants who achieve either a PR or CR, according to the Revised International Working Group Response Criteria for Malignant Lymphoma (Cheson 2007), as assessed by the Investigator in response-evaluable population, where CR=disappearance of all evidence of disease and PR=regression of measurable disease and no new sites. The 95% CI was calculated using the exact method.

Response-Evaluable Population: participants who had measurable disease at baseline and had at least 1 adequate post-treatment disease assessment by the investigator.

The CR rate was defined as the percentage of participants who achieve a CR, according to the Revised International Working Group Response Criteria for Malignant Lymphoma (Cheson 2007), as assessed by the Investigator in response-evaluable population, where CR=disappearance of all evidence of disease, as assessed by the Investigator.

Response-Evaluable Population: participants who had measurable disease at baseline and had at least 1 adequate post-treatment disease assessment by the investigator.

The CR rate was defined as the percentage of participants who achieve a CR, according to the Revised International Working Group Response Criteria for Malignant Lymphoma or Lugano Classification (see Cheson, 2014 for detailed criteria) in response-evaluable population, as assessed by the Investigator.

Response-Evaluable Population: participants who had measurable disease at baseline and had at least 1 adequate post-treatment disease assessment by the investigator.

DOR is defined as the time from the date of the first documented response (CR or PR) to the first documented evidence of disease progression (PD) according to the Revised International Working Group Response Criteria for Malignant Lymphoma or Lugano Classification (Cheson 2014) or death from any cause. For participants who had achieved an overall response but did not die or progress at the time of analysis, DOR was censored on the date of the last adequate post-baseline disease assessment, or on the date of the first occurrence of response (CR or PR) if there was no disease assessment afterwards. 2-sided 95% CI is estimated by Kaplan-Meier method.

All-Treated Analysis Population (Phase 2): participants who received any dose of study drug(s). Participant who achieved Overall Response.

PFS is defined as the time from the date of the first dose of study drug to confirmed PD according to the Revised International Working Group Response Criteria for Malignant Lymphoma or Lugano Classification (Cheson 2014) or death from any cause, whichever occurred first. For participants without disease progression or death, PFS data was censored at the date of the last tumor assessment. 2 sided 95% CI is estimated by Kaplan-Meier method.

All-Treated Analysis Population (Phase 2): participants who received any dose of study drug(s).

OS is defined as the time from the date of the first dose of study drug to the date of death due to any cause. For participants not known to have died at or prior to the database lock date, OS data was censored at the date last known alive. Participants who withdrew consent prior to study closure were censored on the date of the consent withdrawal. 2-sided 95% CI was estimated by Kaplan-Meier method.

All-Treated Analysis Population (Phase 2): participants who received any dose of study drug(s).

An adverse event (AE) is any untoward medical occurrence, which does not necessarily have a causal relationship with treatment. A serious AE is any untoward medical occurrence that at any dose: results in death; is life-threatening; requires in-patient hospitalization > 24 hours or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect; is an important medical event. AEs that started or worsened during the treatment-emergent period and all possibly related or related AEs were considered TEAEs. Related events were those that were considered possibly related or related to study drug per investigator's judgment. Events were graded per the national Cancer Institute's Common Terminology Criteria for Adverse Events, version 4.03: Grade 1=mild; grade 2=moderate; grade 3=severe; grade 4=life-threatening; grade 5=death.

All-Treated Analysis Population (Phase 2): participants who received any dose of study drug(s).