Trial of Intratumoral Injections of TTI-621 in Subjects With Relapsed and Refractory Solid Tumors and Mycosis Fungoides

This is a multicenter, open-label, phase 1 study conducted to test intratumoral injections of
TTI-621 in patients that have relapsed and refractory percutaneously accessible solid tumors
or mycosis fungoides.

TTI-621 (SIRPα-IgG1 Fc) is a soluble recombinant fusion protein created by directly linking
the sequences encoding the N-terminal CD47 binding domain of human SIRPα with the Fc domain
of human immunoglobulin (IgG1). TTI-621 acts by binding human CD47 and preventing it from
delivering an inhibitory "do not eat" (antiphagocytic) signal to macrophages.

The study will be performed in two different parts: Dose Escalation and Dose Expansion.

During the escalation part of the study, TTI-621 was studied at 3 different dose levels and
at different dosing frequencies to characterize safety, tolerability, pharmacokinetics, and
to determine the maximum tolerated dose (MTD).

During the expansion part of the study, TTI-621 will be studied in an expanded group of
patients at the maximum feasible dosing regimen determined in the escalation phase. After
completion of their initial assigned therapy, subjects may receive continuation with TTI-621.
The expansion phase will further define safety and characterize efficacy of TTI-621 alone and
in combination with other anti-cancer therapies.

Inclusion Criteria:

- Histologically or cytologically documented, injectable cancer lesion (limited to solid
tumors and mycosis fungoides)

- Adequate renal function

- Adequate coagulation function

- Adequate hepatic function

- Disease that has progressed on standard therapy or for whom there is no other therapy
option available

Exclusion Criteria:

- Central nervous system involvement

- Significant cardiovascular disease

- Active autoimmune disease

- Active hepatitis B or C or a history of HIV infection

- Uncontrolled infection

- History of hemolytic anemia or bleeding diathesis