Overview

SL-279252 (PD1-Fc-OX40L) in Subjects With Advanced Solid Tumors or Lymphomas

Status:
Recruiting
Trial end date:
2022-04-05
Target enrollment:
0
Participant gender:
All
Summary
This is a Phase 1 first in human, open label, multi-center, dose escalation and dose expansion study to evaluate the safety, tolerability, PK, anti-tumor activity and pharmacodynamic effects of SL-279252 in subjects with advanced solid tumors or lymphomas.
Phase:
Phase 1
Accepts Healthy Volunteers?
No
Details
Lead Sponsor:
Shattuck Labs, Inc.
Criteria
Inclusion Criteria:

Participants are eligible to be included in the study only if all the following criteria
apply.

1. Subject has voluntarily agreed to participate by giving written informed consent in
accordance with ICH/GCP guidelines and applicable local regulations.

2. Subject has a histologically confirmed diagnosis of one of the following unresectable
locally advanced or metastatic malignancies: melanoma, non-small cell lung cancer
(squamous, adeno, or adeno-squamous), urothelial cancer, squamous cell carcinoma of
the head and neck, squamous cell cervical cancer, gastric or gastro-esophageal
junction adenocarcinoma, squamous cell carcinoma of the anal canal, squamous cell
carcinoma of the skin, renal cell cancer, Hodgkin's lymphoma, and microsatellite
instability high (MSI-H) or mismatch repair deficient (MMRD) solid tumors excluding
CNS malignancies. MSI and MMRD testing results as per institution is acceptable.

- Head and neck cancers: Subjects must have primary tumor locations in the
oropharynx, oral cavity, hypopharynx, or larynx. Primary tumor sites of
nasopharynx, maxillary sinus, paranasal, and unknown primary are excluded.

- Non-small cell lung cancers: Subjects with a known EGFR sensitizing (activating)
mutation or an ALK fusion are excluded.

3. Subject must have received, been intolerant to, or is ineligible for standard therapy
(per local guidelines and approvals) or have a malignancy for which there is no
approved therapy considered standard of care.

4. Age 18 years and older.

5. Has an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 or 1.

6. Has measurable disease by iRECIST (solid tumors) or RECIL 2017 (lymphoma). Refer to
Appendix Sections 16.6 and 16.7 for details on criteria of measurable disease.

7. Has life expectancy of greater than 12 weeks.

8. Laboratory values must meet the following criteria. Laboratory parameter Threshold
value

- Absolute lymphocyte count (ALC) ≥ 0.8 x 109/liter (L)

- Absolute neutrophil count (ANC) ≥ 1.5 x 109/L without growth factor support

- Platelet count ≥ 50 x 109/L

Laboratory parameter Threshold value

- Hemoglobin (Hgb) > 9.0 g/dL with no blood transfusions for at least 5 days prior
to D1 of investigational product (IP; SL-279252)

- Creatinine clearance (CrCl) ≥ 30 milliliter (mL)/min (modified Cockcroft-Gault)

- ALT/AST ≤ 3 x ULN

- Total bilirubin ≤ 1.5 x ULN; subjects with isolated indirect hyperbilirubinemia
are permitted if direct bilirubin ratio is <35% and total bilirubin is ≤ 3.0 x
ULN

- Left ventricular ejection fraction (LVEF) by echocardiogram (ECHO) ≥ lower limit
of normal (LLN) per institutional threshold. If LLN is not defined for a given
institution, then ejection fraction must be ≥50 %.

9. Females of child bearing potential (FCBP) must have a negative serum or urine
pregnancy test within 72 hours of D1 of IP. NOTE: FCBP unless they are surgically
sterile (i.e., have undergone a complete hysterectomy, bilateral tubal
ligation/occlusion, bilateral oophorectomy or bilateral salpingectomy), have a
congenital or acquired condition that prevents childbearing or are naturally
postmenopausal for at least 12 consecutive months (see Appendix Section 16.2 for
additional details). Documentation of postmenopausal status must be provided. FCBP
should use an acceptable method of contraception (see Appendix Section 16.2) to avoid
pregnancy during treatment and for 30 days (which exceeds 5 half-lives) after the last
dose of IP. FCBP must start using acceptable contraception at least 14 days prior to
D1 of IP.

10. Male subjects with female partners must have azoospermia from a prior vasectomy or
underlying medical condition or agree to use an acceptable method of contraception
during treatment and for 30 days (which exceeds 5 half-lives) after last dose of
SL-279252 (see Appendix Section 16.2). Male subjects of reproductive potential must
start using acceptable contraception at least 14 days prior to D1 of treatment with
SL-279252 as per Appendix Section 16.2.

11. All AEs resulting from prior anti-cancer immunotherapy have resolved (NOTE: exceptions
include alopecia, vitiligo, and endocrinopathies adequately treated with hormone
replacement).

• Subjects that were discontinued from prior PD-1/L1 therapy due to immune-related
adverse events are not eligible

12. Recovery from toxicities from prior anti-cancer treatments including surgery,
radiotherapy, chemotherapy or any other anti-cancer therapy to baseline or ≤ Grade 1.
(NOTE: Low-grade toxicities (e.g., alopecia, ≤ Grade 2 lymphopenia, ≤ Grade 2
hypomagnesemia, ≤ Grade 2 neuropathy) may be allowed at the discretion of the
investigator if considered clinically insignificant. Please consult the Sponsor
Medical Monitor to discuss these cases).

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

1. Has received more than two prior checkpoint inhibitor containing treatment regimens
(regimen refers to either monotherapy or combination immunotherapies) or has had prior
treatment with an OX40 agonist.

• Prior PD-1/L1 therapy is not required.

2. Refractory to last PD-1/L1 inhibitor-based therapy which is defined as disease
progression within 3 months of treatment initiation.

• Subjects must have had clinical benefit (stable disease or response) to last PD-1/L1
inhibitor-based therapy for at least three months to be eligible.

3. Any anti-cancer therapy within the time intervals noted below prior to first dose (D1)
of SL-279252.

Therapy Washout period Chemotherapy 3 weeks Hormonal therapy 3 weeks PD-1/L1 inhibitor
and other immunotherapies not otherwise specified 3 weeks Tumor vaccine 4 weeks
Cell-based therapy 8 weeks Other mAbs or biologic therapies 3 weeks Major surgery 2
weeks Radiation (except palliative intent which does not require washout) 2 weeks

4. Concurrent chemotherapy, immunotherapy, biologic or hormonal therapy is prohibited.
Concurrent use of hormones for non-cancer related conditions is acceptable.

5. Use of corticosteroids or other immunosuppressive medication, current or within 14
days of D1 of IP with the following exceptions (i.e., the following are allowed during
treatment with or within14 days of D1 of IP):

- Topical, intranasal, inhaled, ocular, intraarticular corticosteroids

- Physiological doses of replacement steroid (e.g., for adrenal insufficiency)
provided ≤ 10 mg/day of prednisone or equivalent

- Steroid premedication for hypersensitivity reactions (HSRs; e.g., reaction to IV
contrast)

6. Receipt of live attenuated vaccine within 28 days of D1 of IP.

7. Active or documented history of autoimmune disease (autoimmune disease does not refer
to irAEs; for irAEs see inclusion criteria #11). Exceptions include Type I diabetes,
vitiligo, alopecia areata or hypo/hyperthyroidism.

8. Active pneumonitis (i.e. drug-induced, idiopathic pulmonary fibrosis,
radiation-induced, etc.).

9. Ongoing or active infection (e.g., no systemic antimicrobial therapy for treatment of
infection within 5 days of D1 of IP).

10. Symptomatic peptic ulcer disease or gastritis, active diverticulitis, other serious
gastrointestinal (GI) disease associated with diarrhea within 6 months of D1 of IP.

11. Clinically significant or uncontrolled cardiac disease including any of the following:

- Myocarditis

- Unstable angina within 6 months from D1 of IP

- Acute myocardial infarction within 6 months from D1 of IP

- Uncontrolled hypertension

- New York Heart Association (NYHA) Class II, III or IV congestive heart failure

- Clinically significant (symptomatic) cardiac arrhythmias (e.g., sustained
ventricular tachycardia, second- or third- degree atrioventricular block without
a pacemaker, circulatory collapse requiring vasopressor or inotropic support, or
arrhythmia requiring therapy)

12. Untreated central nervous system (CNS) or leptomeningeal metastases. Subjects with
treated CNS metastases must have completed definitive treatment (radiotherapy and/or
surgery) > 2 weeks prior to D1 of IP and no longer require steroids.

13. Women who are breast feeding.

14. Psychiatric illness/social circumstances that would limit compliance with study
requirements and substantially increase the risk of AEs or compromised ability to
provide written informed consent.

15. Another malignancy that requires active therapy and that in the opinion of the
investigator and Sponsor would interfere with monitoring of radiologic assessments of
response to IP.

16. Has undergone allogeneic stem cell transplantation or organ transplantation.

17. Known history or positive test for human immunodeficiency virus, or positive test for
hepatitis B (positive for hepatitis B surface antigen [HBsAg]) or hepatitis C virus
([HCV]; if HCV antibody (Ab) test is positive check for HCV ribonucleic acid [RNA]).

- (NOTE: Hepatitis B virus (HBV): Subjects who are hepatitis B core antibody
[HBcAb] positive, but HBsAg negative are eligible for enrollment. HCV: Subjects
who are HCV Ab positive, but HCV RNA negative are eligible for enrollment).