A Phase 3 Extension Study of Duvelisib and Ofatumumab in Patients With CLL/SLL Previously Enrolled in Study IPI-145-07

This is an open-label, two- arm, extension study designed to enable subjects who have
experienced radiologically- confirmed disease progression in Study IPI-145-07 to receive the
alternative treatment (either IPI-145 or ofatumumab) than what was received during study
IPI-145-07.

Subjects who have previously received ofatumumab in study IPI-145-07 will receive a starting
dose of 25 mg IPI-145 BID continuously in a 21 day cycle for Cycle 1 followed by 28- day
treatment cycles thereafter until disease progression, discontinuation from study
participation, or start of subsequent therapy, whichever comes first.

Subjects who have previously received IPI-145 in study IPI-145-07 will receive a starting
dose of 300 mg ofatumumab on Day 1 followed by seven weekly doses of 2000 mg. Thereafter,
subjects will receive 2000 mg ofatumumab once every month for four months unless disease
progression or unacceptable toxicity occurs. Administration of ofatumumab will not exceed the
12 doses (within 7 cycles).

Inclusion Criteria:

- Received either IPI-145 or ofatumumab while participating in study IPI-145-07 and
experienced radiologically-confirmed disease progression

- Diagnosis of active CLL or SLL that meets at least 1 of the International Workshop on
Chronic Lymphocytic Leukemia (IWCLL) 2008 criteria for requiring treatment

- Measurable disease with a lymph node or tumor mass >1.5 cm in at least one dimension
as assessed by computed tomography (CT)

- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2

- Must meet the following laboratory parameters:

1. Serum aspartate transaminase (AST/SGOT) or alanine transaminase (ALT/SGPT) ≤3 x
upper limit of normal (ULN)

2. Total bilirubin ≤1.5 x ULN

3. Serum creatinine ≤2.0 x ULN

4. Hemoglobin ≥8.0 g/dL with or without transfusion support

5. Platelet count ≥10,000 μL with or without transfusion support

- For women of childbearing potential (WCBP): negative serum β-human chorionic
gonadotropin (βhCG) pregnancy test within 1 week before first dose (WCBP defined as a
sexually mature woman who has not undergone surgical sterilization or who has not been
naturally post-menopausal for at least 24 consecutive months [women ≤55 years] or 12
consecutive months [women >55 years])

- Willingness of male and female subjects who are not surgically sterile or
postmenopausal to use medically acceptable methods of birth control from the first
dose of study drug to 30 days after the last dose of duvelisib and for 12 months after
last dose of ofatumumab. Sexually active men, and women using oral contraceptive
pills, should also use barrier contraception

- Ability to voluntarily sign consent for and adhere to the entire study visit schedule
and all protocol requirements

- Signed and dated institutional review board (IRB)/independent ethics committee
(IEC)-approved informed consent form (ICF) before any study specific screening
procedures are performed

Exclusion Criteria:

- Discontinued study participation in Verastem-sponsored IPI-145-07 study

- Greater than 3 months from confirmed progressive disease on Study IPI-145-07

- History of Richter's transformation or prolymphocytic leukemia

- Autoimmune hemolytic anemia (AIHA) or idiopathic thrombocytopenia purpura (ITP) that
is uncontrolled or requires >20 mg daily (QD) of prednisone (or equivalent) to
maintain hemoglobin >8.0 g/dL or platelets >10,000 μL without transfusion support

- Known central nervous system (CNS) lymphoma or leukemia; subjects with symptoms of CNS
disease must have a negative computed tomography (CT) scan or negative diagnostic
lumbar puncture prior to first dose

- Use of any anticancer medication from documented PD on Study IPI-145-07 to enrollment
(Note: corticosteroids to manage CLL/SLL-related symptoms are allowed)

- Ongoing systemic bacterial, fungal, or viral infections at the time of initiation of
study treatment (defined as requiring IV antimicrobial, antifungal or antiviral
agents) ( Subjects on antimicrobial, antifungal or antiviral prophylaxis are not
specifically excluded if all other inclusion/exclusion criteria are met and there is
no evidence of active infection at Screening and/or Cycle 1 Day 1 (predose))

- Human immunodeficiency virus (HIV) infection

- Prior, current, or chronic hepatitis B or hepatitis C infection

- History of alcohol abuse or chronic liver disease (other than metastatic disease to
the liver)

- Unable to receive prophylactic treatment for pneumocystis and herpes simplex virus
(HSV)

- Baseline QT interval corrected with Fridericia's method (QTcF) >480 ms NOTE: this
criterion does not apply to subjects with a right or left bundle branch block (BBB)

- Concurrent active malignancy other than nonmelanoma skin cancer or carcinoma in situ
of the cervix, bladder, or prostate not requiring treatment. Subjects with previous
malignancies are eligible provided that they have been disease-free for ≥2 years

- History of stroke, unstable angina, myocardial infarction, or ventricular arrhythmia
requiring medication or mechanical control within the last 6 months

- Unstable or severe uncontrolled medical condition (eg, unstable cardiac function,
unstable pulmonary condition), or any important medical illness or abnormal laboratory
finding that would, in the Investigator's judgment, increase the subject's risk while
participating in this study

- Prior surgery or gastrointestinal dysfunction that may affect drug absorption (eg,
gastric bypass surgery, gastrectomy)

- Subjects to receive duvelisib: Administration of medications or foods that are strong
inhibitors or inducers of cytochrome P450 (CYP) 3A within 2 weeks of starting
duvelisib

- Major surgery or invasive intervention within 4 weeks prior to first dose

- Pregnant or breastfeeding women

- Subjects to receive ofatumumab: hypersensitivity to ofatumumab or its excipients.