This is a Phase 1, open-label, dose-escalation study to evaluate the safety, tolerability,
PK, PD and clinical activity of AB928 in combination with AB122 in participants with advanced
Dose escalation of AB928 in combination with AB122 will be assessed in participants with
advanced malignancies. In this dose escalation combination study participants will receive
oral administration of AB928 as well as iv infusion of AB122.
Overall duration of treatment will depend on how well the treatment is tolerated. Treatment
may continue until unacceptable toxicity or progressive disease or other reasons specified in
1. Male or female participants ≥ 18 years
2. Must have at least 1 measurable lesion per RECIST v1.1.
3. Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
4. Must have received standard of care, including potentially curative available
therapies or interventions.
5. Confirm that an archival tissue sample is available and ≤ 6 months old; if not, a new
biopsy of a tumor lesion must be obtained.
6. Adequate organ and marrow function
Dose escalation only:
7. Pathologically confirmed non-small cell lung cancer, squamous cell carcinoma of the
head and neck, renal cell carcinoma, breast cancer, colorectal cancer, melanoma,
bladder cancer, ovarian cancer, endometrial cancer, Merkel cell carcinoma, or
gastroesophageal cancer that is metastatic, advanced or recurrent with progression for
which no alternative or curative therapy exists or standard therapy is not considered
appropriate by the participant and treating physician (reason must be documented in
Dose expansion only:
8. Patients with advanced clear-cell RCC or metastatic castration-resistant prostate
cancer who must have relapsed during anti-PD-1 monotherapy
9. ccRCC patients may have received up to 2 prior lines of therapy, one of which must
have included an anti-PD-(L)1 based therapy and must not have progressed within 16
weeks during an anti-PD-(L)1 therapy.
10. mCRPC patients must have progressed during or following treatment with an androgen
synthesis inhibitor who have also had one prior line of a taxane-containing regimen or
the physician and participant consider the taxane-containing regimen to be
inappropriate. mCRPC patients must be naive to any immunotherapy (including but not
limited to anti-PD-(L)1 or anti-CTLA-4 antogonists, sipuleucel-T, etc.).
1. Use of any live vaccines against infectious diseases (eg, influenza, varicella) within
4 weeks (28 days) of initiation of investigational product.
2. Underlying medical conditions that, in the Investigator's or Sponsor's opinion, will
make the administration of investigational product hazardous (eg, interstitial lung
disease, active infections requiring antibiotics, recent hospitalization with
unresolved symptoms) or obscure the interpretation of toxicity determination or AEs,
or concurrent medical condition requiring the use of immunosuppressive medications or
immunosuppressive doses of systemic or absorbable topical corticosteroids.
3. Has known psychiatric or substance abuse disorders that would interfere with
cooperation with the requirements of the trial.
4. Is pregnant or breastfeeding or expecting to conceive or father children within the
projected duration of the study, starting with the pre-screening or screening visit
through 90 days after the last dose of AB928 in combination with AB122.
5. Any active or documented history of autoimmune disease, or history of a syndrome that
required systemic steroids or immunosuppressive medications, except for vitiligo or
resolved childhood asthma/atopy. Participants with asthma who require intermittent use
of bronchodilators (such as albuterol) will not be excluded from this study.
6. Prior malignancy active within the previous year except for locally curable cancers
that have been apparently cured, such as basal or squamous cell skin cancer,
superficial bladder cancer or carcinoma in situ of the cervix, breast, or prostate
7. Dose escalation: Prior treatment with an anti-PD-L1, anti-PD-1, anti-CTLA-4, or other
immune checkpoint inhibitor or agonist as a monotherapy or in combination;
8. Use of other investigational drugs (drugs not marketed for any indication) within 28
days or at least 5 half-lives (whichever is longer) before investigational product