Table 2.

Univariate and Multivariate Logistic Regression Models of Covariates Associated with Probability of Success in Phase 2 Trials

Variable	No. of Drugs (Total = 381)	No. of Successful Phase 2 Trials (Total = 130)	OR (95% CI)
			Univariate Analysis	p	Multivariate Analysis	p
Total no. of patients in expansion cohorts
0	269	74	1 (reference)		1 (reference)
2–20	62	30	2.47 (1.40–4.35)	0.002	2.13 (1.14–3.98)	0.019
≥20	50	26	2.85 (1.54–5.29)	0.001	1.91 (0.97–3.753)	0.063
Disease-specific
No	242	70	1 (reference)		1 (reference)
Yes	139	60	1.87 (1.21–2.89)	0.0050	1.72 (1.04–2.85)	0.037
Cytotoxic drug class
Yes	82	25	0.81 (0.48–1.37)	0.43
No	299	105	1 (reference)
Publication year of first phase 1 trial
2006–2008	177	59	1 (reference)
2009–2011	204	71	1.07 (0.70–1.63)	0.77
Malignancy
Hematologic	56	26	1.59 (0.89–2.85)	0.12
Mixed	37	13	0.44 (0.29–0.85)	0.015
Solid tumor	258	91	1 (reference)
Industry sponsorship
Yes	295	111	2.13 (1.21–3.73)	0.009	2.88 (1.46–5.66)	0.0024
No	86	19	1 (reference)		1 (reference)
Involvement of multiple centers in a phase 1 trial
Yes	263	91	1.07 (0.68–1.70)	0.77	0.63 (0.36–1.09)	0.098
No	118	39	1 (reference)		1 (reference)
Total no. of patients in phase 1 trials
5–24	129	29	1 (reference)
25–46	127	45	1.89 (1.09–3.28)	0.024
47–289	125	56	2.80 (1.63–4.82)	0.002
Pooled phase 1 response rate
0%	165	35	1 (reference)		1 (reference)
>0% and <6%	74	29	2.39 (1.32–4.35)	0.0045	1.92 (1.02–3.62)	0.043
≥6% and <20%	85	39	3.15 (1.79–5.55)	<0.001	2.87 (1.57–5.24)	0.0007
≥20%	37	19	3.92 (1.86–8.26)	<0.001	2.46 (1.07–5.64)	0.035
Pooled rate of grade 3–4 toxic effects in phase 1 trials
≥0% and <10%	198	65	1 (reference)
≥10% and <30%	95	29	0.90 (0.53–1.52)	0.69
≥30%	64	28	1.59 (0.89–2.83)	0.11
MTD reached
No	166	49	1 (reference)
Yes	215	81	1.44 (0.94–2.22)	0.097
Any grade 5 toxic effect
Yes	44	14	0.89 (0.45–1.74)	0.73
No	337	116	1 (reference)

Abbreviations: OR, odds ratio; CI, 95% confidence interval; MTD, maximum tolerated dose.