The study was terminated based on interim results and all subjects were off study at that time. No major safety or tolerability concerns

The purpose of this study is to determine whether P276-00 is safe and effective in treatment of Mantle Cell Lymphoma that is recurred after or not responding to at least one previous line of treatment.

Despite response rates of up to 97% with first-line standard or high-intensity chemotherapy, with or without stem-cell transplantation, most patients of mantle cell lymphoma (MCL)relapse.Prognosis of MCL after first relapse is very poor with median survival of around 1 to 2 years. Therefore, novel therapies are required for relapsed and/or refractory MCL.Overexpression of Cyclin D1 as a result of t(11;14)(q13;q32) translocation is the hallmark of MCL.It is postulated that Cyclin D1 may also have an oncogenic role independent of pRb in MCL.Therefore, inhibition of Cdk4-Cyclin D1 is a potentially promising target in MCL. P276-00 is a potent Cdk4-Cyclin D1 inhibitor worth exploring for its efficacy in MCL. Hence, this Phase II study is planned to examine the efficacy and safety of P276-00 in the treatment of patients with relapsed and/or refractory MCL.

This is an open-label, single-arm, 2-stage trial. Approximately 35 patients are planned to be enrolled into the study to obtain a total of 25 efficacy evaluable patients (patients who complete at least 2 cycles of study treatment and have tumor measurements at the end of 2 cycles). A total of 15 efficacy evaluable patients are planned to be treated in Stage I of the study. If ≥1 response (CR or PR) of any duration or ≥2 stable disease (SD) for ≥4 cycles are seen in the Stage I, then the study will continue into Stage II, in which additional patients will be treated until there are 10 additional efficacy evaluable patients.The study is divided into 3 periods: Screening, Treatment, and Follow-up. During the Screening Period, patients will provide written informed consent and be evaluated for inclusion and exclusion criteria. During the Treatment Period, patients will be administered P276-00 as intravenous (iv) infusion on Days 1 to 5 of each 21-day cycle for a minimum of 6 cycles and a maximum of 12 cycles, or until progressive disease (PD) or unacceptable toxicity occurs. Safety and efficacy evaluations will be done on Days 1 to 5 and 11 of each cycle, and on Day 21 of every 2 cycles. Pharmacokinetic (PK) assessments will be done on Cycle 1, Day 1 (pre-dose and post-dose time points), and optional biomarker assessments will be done pre-dose within 4 weeks of Day 1 and post-dose on Day 4 or 5. The End-of-Last-Cycle Visit will occur at the end of Cycle 6, or if the patient continues study treatment beyond Cycle 6, it will occur at the end of the patient's last cycle; if the patient discontinues early, these assessments will be done as an Early Exit Visit. The Follow-up Visit will occur 4 weeks (±1 week) after the End-of-Last-Cycle Visit (or Early Exit Visit) for final safety assessments.Objective response rate is the primary end point for this study. Response evaluation will be performed using the International Working Group (IWG) revised response criteria for malignant lymphoma.

Inclusion Criteria:

• Age ≥18 years
• Histological diagnosis of MCL and presence of either nuclear Cyclin D1 positivity by immunohistochemistry or t(11;14) by fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), or conventional karyotyping
• Documented progression or relapse after at least 1 line of prior chemotherapy
• Presence of measurable disease
• ECOG performance status 0, 1, or 2
• Life expectancy of at least 3 months
• Ability to understand and the willingness to sign a written informed consent document (ICD)
• Full recovery from all prior treatment toxicities of Common Terminology Criteria for Adverse Events (CTCAE) Grade ≤ 1

Exclusion Criteria:

• Prior radiation therapy, chemotherapy or biologic/targeted anticancer agents within 4 weeks of study drug administration
• Prior treatment with monoclonal antibodies or any radio- or toxin- immunoconjugates within 3 months of study drug administration; however, a patient who has had rituximab treatment within 3 months and has had PD after such treatment is allowed in the study.
• Prior allogeneic stem cell transplantation within 1 year of study drug administration
• Current or prior CNS lymphoma
• QTc > 450 msec
• Unstable angina, myocardial infarction, CHF or stroke within previous 6 months of study drug administration
• Presence of active and serious comorbidity and uncontrolled illness other than MCL
• History of other prior malignancies except for properly treated basal cell or squamous cell carcinoma of skin, in situ cervical cancer, in situ breast cancer or early stage prostate cancer
• Hemoglobin <8.0 gm/dL
• Absolute neutrophil count <1000/mm3
• Platelet count <50,000/mm3
• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) >3 × institutional upper limit of normal (ULN) (> 5 × institutional ULN if liver is involved with lymphoma or if patient has Gilbert's Disease)
• Total bilirubin, >1.5 × institutional ULN (> 3 × institutional ULN if liver is involved with lymphoma or if patient has Gilbert's Disease)
• Serum creatinine >1.5 × institutional ULN
• Patients known to be suffering from infection with human immunodeficiency virus (HIV), tuberculosis, Hepatitis C or Hepatitis B
• Pregnant or lactating women
• Women of childbearing potential or men not willing to use at least 2 approved methods of contraception (one of which being a barrier method) after signing the ICD, during the entire study and for at least 4 weeks following withdrawal from the study