A Study of LY3321367 Alone or With LY3300054 in Participants With Advanced Relapsed/Refractory Solid Tumors

Inclusion Criteria:

- For Ph1a monotherapy and combination cohorts, histologic or cytologic confirmation of
advanced solid tumor.

- For Phase 1a and 1b, prior PD-1 or PD-L1 therapy or other immunotherapy is allowed, if
the following criteria are met:

- Must not have experienced a toxicity that led to permanent discontinuation of
prior immunotherapy.

- Must have completely recovered or recovered to baseline prior to screening from
any prior AEs occurring while receiving prior immunotherapy.

- Must not have experienced a Grade ≥3 immune-related AE or an immune-related
neurologic or ocular AE, pneumonitis or cardiomyopathy of any grade while
receiving prior immunotherapy.

- Must not have required immunosuppressive agents, other than corticosteroids for
the management of an adverse event and not currently requite maintenance doses of
>10 milligrams (mg) prednisone (or equivalent) per day.

- Must have at least 1 measurable lesion assessable using standard techniques by
Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1).

- Must have provided tumor tissue sample, as follows:

- For participants entering Ph1a: have submitted, if available, an archival tumor
tissue sample.

- For participants entering Ph1b: have submitted, a sample from a newly obtained
core or excisional biopsy of a tumor lesion or a recent biopsy defined by 6
months of study enrollment (Ph1b).

- Must have a performance status of 0 to 1 on the Eastern Cooperative Oncology Group
(ECOG) scale.

- Must have adequate organ function.

- Have an estimated life expectancy of 12 weeks, in judgement of the investigator.

Exclusion Criteria:

- Have symptomatic or uncontrolled brain metastases, spinal cord compression, or
leptomeningeal disease requiring concurrent treatment, including but not limited to
surgery, radiation, and/or corticosteroids (participants receiving anticonvulsants are
eligible).

- Have received a live vaccine within 30 days before the first dose of study treatment.

- If female, is pregnant, breastfeeding, or planning to become pregnant.

- Have a history or current evidence of any condition, therapy, or laboratory
abnormality that might interfere with the participant's participation.

- Have moderate or severe cardiovascular disease.

- Have a serious concomitant systemic disorder that would compromise the participant's
ability to adhere to the protocol, including active or chronic infection with human
immunodeficiency virus (HIV), active hepatitis B virus (HBV), active hepatitis C virus
(HCV), active autoimmune disorders, or prior documented severe autoimmune or
inflammatory disorders requiring immunosuppressive treatment.

- Use of escalating or chronic supraphysiologic doses of corticosteroids or
immunosuppressive agents (such as, cyclosporine). [Use of topical, ophthalmic,
inhaled, and intranasal corticosteroids permitted].

- Bowel obstruction, history or presence of inflammatory enteropathy or extensive
intestinal resection.

- Evidence of interstitial lung disease or noninfectious pneumonitis.