Phase (Ph) 1/2a study of CLN-081 in patients (pts) with NSCLC with EGFR exon 20 insertion mutations (Ins20)

9007

Background: EGFR ins20-mutant NSCLC has historically been challenging to treat. While new agents targeting EGFR ins20 have recently been approved, adverse events (AEs), particularly wild type (WT) EGFR-related AEs are common. CLN-081 is a novel EGFR tyrosine kinase inhibitor (TKI) with broad activity against EGFR mutations, including ins20, and increased selectivity for ins20 versus WT EGFR. CLN-081 has been granted FDA Breakthrough Therapy Designation for the treatment of pts with EGFR ins20 NSCLC. We present updated results of the initial multicenter Ph1/2a study of CLN-081 in pts with advanced, EGFR ins20-mutant NSCLC, including 39 pts treated in an expanded cohort at the dose of 100 mg twice daily (BID). Methods: Ph1 dose escalation utilized an accelerated titration (AT) and rolling six design. Individual cohorts were expanded in Phase 1 and 2a based on prespecified protocol criteria. Pts were required to have received prior platinum-based chemotherapy. Stable, treated brain metastasis (mets) were allowed. CLN-081 is dosed in 21-day cycles. Results: As of 13 December 2021, 73 pts [median age: 65 (36-82), median lines of prior therapy: 2 (1-9), 28 (39%) with a history of brain mets] received CLN-081 at 30 mg (8), 45 mg (1), 65 mg (14), 100 mg (39), and 150 mg (11), all BID. Treatment-related AEs in ≥ 15% of pts were rash (74%), diarrhea (27%), paronychia (25%), fatigue (19%), anemia (18%), dry skin (18%), nausea (16%). Treatment-related Gr ≥ 3 AEs in ≥ 4 % of pts included anemia (10%), increased ALT (4%), and increased AST (4%). Gr 3 rash and Gr 3 diarrhea were observed in 1 and 2 pts, respectively, at 150 mg BID, while no pts treated at ≤ 100 mg BID experienced Gr 3 rash or diarrhea. Treatment-related dose reductions and discontinuations across all dose levels occurred in 10 pts (14%) and 5 pts (7%) respectively. Among 70 response-evaluable pts across all dose levels, 25 (36%) had a confirmed partial response (PR), 34 (49%) had stable disease (SD), and 3 (4%) had progressive disease as a best response. Seven pts (10%) had a PR that remained unconfirmed; 1 (1%) pt was pending a confirmatory scan. Of 36 response-evaluable pts at 100 mg BID, 14 (39%) had a confirmed PR, 17 (47%) had SD, and 1 (3%) had PD. Three pts had a PR that remained unconfirmed (8%); 1 (3%) pt was pending a confirmatory scan. Notably, among Ph1 pts treated at 100 mg BID (N = 13) in whom longer follow-up is available, the mDOR and mPFS (estimated by Kaplan-Meier) was > 15 months and 12 months, respectively. Disease control (SD ≥ 6 months or any PR) was observed in 12/13 pts (92%). Updated data with additional follow-up will be presented. Conclusions: In pts with heavily-pretreated advanced EGFR ins20 NSCLC, CLN-081 has a manageable safety profile, with anti-tumor activity across the range of doses tested. Further, CLN-081 has demonstrated a favorable clinical profile at the dose of 100 mg BID, with an encouraging objective response rate, response durability, and no Gr 3 rash or diarrhea. Clinical trial information: NCT04036682.

A phase 1 dose-escalation study to investigate the safety, efficacy, pharmacokinetics, and pharmacodynamic activity of CLN-619 (anti-MICA/MICB antibody) alone and in combination with pembrolizumab in patients with advanced solid tumors

TPS2688

Background: The major histocompatibility complex (MHC) class I-related proteins MICA and MICB are stress-inducible, surface glycoproteins that are up-regulated on human tumors. MICA/MICB are ligands for the activating receptor, Natural Killer Group 2 member D (NKG2D) expressed on Natural Killer (NK) cells, CD8+ T cells, γδ T cells and iNKT cells. Proteases in the tumor microenvironment cleave MICA/MICB from the cell surface which enables tumor cells to evade immune cell recognition and destruction by NKG2D-expressing cells. Increased concentrations of shed MICA have been observed in serum from patients across multiple tumor types and correlate with poor survival. CLN-619 is a humanized, clinical-stage, MICA/MICB-specific IgG1 monoclonal antibody that prevents the proteolytic release of MICA/MICB thereby exposing tumor cells for immune destruction through both NKG2D-mediated and antibody-dependent cell-mediated cytotoxicity (ADCC). The antibody has been shown to restore the MICA/MICB-NKG2D axis to promote NK-mediated tumor cell lysis (AACR Annual Meeting abstract 3506, April 2022). In mice bearing MICA/MICB-expressing human tumor xenografts, CLN-619 treatment yielded robust anti-tumor activity at low doses. MICA/MICB is expressed in a wide range of solid tumors. Therefore, CLN-619 is expected to have broad anti-tumor activity. Methods: CLN-619 is being evaluated in an open-label, non-randomized, dose-escalation (phase 1) study as monotherapy, and in combination with pembrolizumab, in patients with advanced solid tumors. Cohort expansion in patients with specific indications as monotherapy and in combination with pembrolizumab will be conducted. The phase 1 study explores ascending intravenous doses of CLN-619 as monotherapy (0.1, 0.3, 1.0, 3.0, 6.0 and 10.0 mg/kg) and in combination with pembrolizumab (200 mg) in 21-day cycles to identify the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D). Key eligibility criteria include 1) histological or cytological diagnosis of cancer and 2) refractory metastatic disease, or locally advanced disease not amenable to local therapy. At the RP2D, CLN-619 monotherapy will be evaluated in non-small cell lung and cervical cancer. In parallel, a cohort of patients will be administered CLN-619 in combination with pembrolizumab. Serum levels of soluble MICA/MICB, identity of MICA/MICB alleles, phenotypes of peripheral blood mononuclear cells, cytokines and tumor biopsies will be investigated for correlative pharmacodynamic and predictive biomarkers. This clinical trial is in progress (NCT05117476) and has completed accrual of three participants at the first dose level. Clinical trial information: NCT05117476.

Short-stay open appendectomy

PURPOSE

This report describes a minimally invasive short-stay open appendectomy technique which improves the length of stay in comparison to traditional open appendectomy and improves the cost of hospitalization in comparison to laparoscopic appendectomy.

STUDY DESIGN

This retrospective analysis reviewed 100 consecutive children treated with traditional open appendectomy and 100 consecutive children treated with a minimally invasive short-stay open technique with local infiltration of bupivacaine hydrochloride. Data collected for each child included age, sex, diagnosis, operative time, return to activity time, complications, length of stay, and hospital charge.

RESULTS

The mean length of stay (LOS) was reduced from 2.7 days for traditional open appendectomy patients to 1.0 day for minimally invasive short-stay open appendectomy. The mean hospital charge (HC) for this short-stay open appendectomy, US dollars 6795, was significantly less than the mean HC for traditional open appendectomy (US dollars 8162), and for laparoscopic appendectomy (US dollars 7668).

CONCLUSION

This short-stay open appendectomy technique offers an efficacious alternative to both traditional open appendectomy and laparoscopic appendectomy.

A prospective randomized phase II trial of GM-CSF priming to prevent topotecan-induced neutropenia in chemotherapy-naive patients with malignant melanoma or renal cell carcinoma

We conducted a phase II randomized trial of recombinant granculocyte-macrophage colony-stimulating factor (GM-CSF) administered before topotecan chemotherapy to determine whether it could prevent myelosuppression and to determine the antitumor activity of this topoisomerase I inhibitor in 53 patients with metastatic malignant melanoma and renal cell cancer. All patients received GM-CSF after topotecan at a dose of 250 microg/m(2) daily for at least 8 days. Patients randomly assigned to receive GM-CSF priming were treated with GM-CSF at 250 microg/m(2) twice daily for 5 days before treatment. Twenty-five patients were randomly assigned to receive GM-CSF priming and 28 to receive topotecan without priming. The primary analysis was restricted to the protective effects seen during the first cycle of therapy. Grade 4 neutropenia occurred in 8 of 23 patients (35%) and grade 3 neutropenia in 5 of 23 patients (22%) randomized to GM-CSF priming, whereas 18 of 26 (69%) and 5 of 26 (19%) patients experienced grade 4 or 3 neutropenia, respectively, without GM-CSF priming (P =.0074). The mean duration of neutropenia was reduced by GM-CSF priming: grade 3 neutropenia from 5.2 +/- 0.7 to 2.8 +/- 0.7 days (P =.0232) and grade 4 neutropenia from 2.7 +/- 0.6 to 1.1 +/- 0.4 days (P = 0.0332). The protective effects of GM-CSF extended to the second cycle of treatment. The incidence of febrile neutropenia was also reduced. Chemotherapy-induced anemia and thrombocytopenia were similar in both groups. One partial response was seen in a patient with melanoma, and one patient with renal cell cancer had complete regression of pulmonary metastases and was rendered disease-free by nephrectomy. (Blood. 2001;97:1942-1946)

A phase II study of carboplatin, cisplatin, interferon-alpha, and tamoxifen for patients with metastatic melanoma

The purpose of this trial was to determine the toxicity and antineoplastic activity of cisplatin, carboplatin, tamoxifen, and interferon-alpha (IFN-alpha) in patients with advanced melanoma. Eleven patients with metastatic melanoma were enrolled. The patients received carboplatin 400 mg/m2 i.v. on day 0; cisplatin 25 mg/m2 i.v. on days 7, 14, and 21; tamoxifen 20 mg p.o. b.i.d. on days 0-27; and interferon-alpha 5 million units/m2 subcutaneously 3 times per week. Cycles were repeated every 28 days. Patients were assessed for tumor response at the end of 2 cycles. Toxicity was severe, with 14 of 24 cycles given requiring some form of dose reduction. Carboplatin dose reductions were related to bone-marrow toxicity, whereas IFN-alpha caused fatigue, arthralgias, myalgias, and fever. The overall response rate was 18% (2 partial responses [PRs]). The combination of cisplatin, carboplatin, tamoxifen, and IFN-alpha is active in advanced melanoma; however, the toxicity is unacceptable.

Intrathyroid parathyroid gland and neonatal primary hyperparathyroidism

Neonatal hyperparathyroidism (NPHP) is exceedingly rare and often fatal. A neonate is presented with a serum calcium concentration of 33 mg/dL, an intrathyroid parathyroid gland, and a family history of hypocalciuric hypercalcemia (FHH). She underwent successful total parathyroidectomy. Six years later, the child is normocalcemic and developmentally normal, requiring calcium and calcitrol replacement. The results of this case support the concept that NPHP is associated with parathyroid hyperplasia and is part of a continuum that includes FHH.

Combination chemotherapy followed by an immunotoxin (anti-B4-blocked ricin) in patients with indolent lymphoma: results of a phase II study

The purpose of this article was to evaluate the antitumor effects of a combination chemotherapy program based on ProMACE (prednisone, methotrexate, doxorubicin [Adriamycin], cyclophosphamide, etoposide) followed by a B cell-specific immunotoxin in the treatment of patients with advanced-stage indolent histology non-Hodgkin's lymphomas. We performed a prospective phase II clinical trial in a referral-based patient population. After confirmation of diagnosis and staging evaluation, 44 patients (10 small lymphocytic lymphoma, 27 follicular lymphoma, 7 mantle cell lymphoma; 30 without prior therapy, 14 previously treated) received six cycles of ProMACE-CytaBOM (cytarabine, bleomycin, vincristine [Oncovin], mechlorethamine) combination chemotherapy (with etoposide given orally daily for five days) followed by a 7-day continuous infusion of anti-B4-blocked ricin immunotoxin at 30 microg/kg/day given every 14 days for up to six cycles. A complete response was achieved in 25 of 44 patients (57%), 21 from the chemotherapy alone, 3 converted from partial to complete response with the immunotoxin, and 1 patient became a complete responder after a surgical procedure to remove an enlarged spleen that was histologically negative for lymphoma. With a median follow-up of 5 years, 14 of 25 complete responders have relapsed (56%); median remission duration was 2 years, and overall survival was 61%. Forty-two percent of the complete responders have been in continuous remission for more than 4 years. The median number of courses of immunotoxin delivered was two usually because of the development of human anti-ricin antibodies. ProMACE-CytaBOM plus anti-B4-blocked ricin does not produce durable complete remissions in the majority of patients with indolent lymphoma. However, the remissions appear quite durable (> 4 years) in about 40% of the complete responders.

Elevations in serum soluble interleukin-2 receptor levels predict relapse in patients with hairy cell leukemia

PURPOSE

Interferon-alfa, 2'-deoxycoformycin, and 2-chlorodeoxy-adenosine (2-CdA) are effective in the management of patients with hairy cell leukemia. These agents produce remissions in most patients, but relapses occur with all three drugs. The optimal means to follow patients for relapse after treatment has not been determined.

METHODS

We retrospectively examined serial serum soluble interleukin-2 receptor levels (sIL-2R) and absolute granulocyte counts in eight patients with relapsed hairy cell leukemia. All were treated with 2-CdA at the time of relapse. Serum samples were available at 3- to 6-month intervals from 5 to 9 years before relapse and 2-CdA treatment

RESULTS

sIL-2R levels increase only in patients who go on to relapse. sIL-2R levels doubled a mean of 17.1 months (range, 4-36 months) before absolute granulocyte count decreased by 50%.

DISCUSSION

Demonstration of a rising serum sIL-2R level in patients with hairy cell leukemia identified those with an increased risk of relapse who need more frequent observation than patients who maintain a stable sIL-2R level. Early intervention may ameliorate the toxicity of salvage therapy because disease-related neutropenia may be anticipated.

Treatment with tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor increases epidermal Langerhans' cell numbers in cancer patients

Dendritic cells (DCs) initiate primary and stimulate secondary T-cell responses. We conducted a phase I trial of tumor necrosis factor (TNF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with cancer to increase DCs in peripheral blood or skin based on in vitro data that showed that CD34(+) hematopoietic precursors require these cytokines to mature into functional antigen-presenting DCs. Eleven patients were treated for 7 days with GM-CSF, 125 microg/m(2) twice daily as subcutaneous injections, and TNF-alpha as a continuous infusion at dose levels of 25, 50, or 100 microg/m(2)/day. The maximum tolerated dose of TNF-alpha was 50 microg/m(2)/day with this dose of GM-CSF; dose-limiting toxicities occurred in both patients treated with 100 microg/m(2)/day. One became thrombocytopenic and the other had transient confusion. Epidermal Langerhans' cells were quantitated by S100 staining of skin biopsies and DC precursors in peripheral blood by colony-forming unit dendritic (CFU-dendritic) assays. S100-positive cells in the epidermis doubled after treatment (2.55 S100(+) cells/high-power field before treatment to 6.05 after treatment, p = 0.029). CFU-dendritic in peripheral blood increased after treatment in 3 colorectal cancer patients but not in 3 patients with melanoma. CD11c(+) or CD123(+), HLA-DR(bright), lineage-negative dendritic cell precursors were not increased in peripheral blood mononuclear cells. This trial demonstrates that treatment with TNF-alpha and GM-CSF can increase the number of DCs in the skin and the number of dendritic cell precursors in the blood of some patients with cancer. This approach may increase the efficacy of vaccination to tumor antigens in cancer patients.

Abrogation of the hematological and biological activities of the interleukin-3/granulocyte-macrophage colony-stimulating factor fusion protein PIXY321 by neutralizing anti-PIXY321 antibodies in cancer patients receiving high-dose carboplatin

This dose-escalation study was performed to evaluate the hematologic activity, biological effects, immunogenicity, and toxicity of PIXY321 (an interleukin-3/granulocyte-macrophage colony-stimulating factor fusion protein) administered after high-dose carboplatin (CBDCA) treatment. Patients with advanced cancers received CBDCA at 800 mg/m2 intravenously on day 0 of repeated 28-day cycles. In part A of the study, patients were treated with CBDCA alone during cycle 1 and then received PIXY321 on days 1 through 18 of cycle 2 and later cycles. In part B, patients received 18 days of PIXY321 beginning on day 1 of all CBDCA cycles, including cycle 1. PIXY321 was administered subcutaneously in 2 divided doses. Total doses of 135, 250, 500, 750, and 1,000 micrograms/m2/d were administered to successive cohorts of 3 to 6 patients in part A. In part B, patient groups received PIXY321 doses of 750, 1,000, and 1,250 micrograms/m2/d. The hematologic effects of PIXY321 were assessed in the first 2 cycles of therapy. Anti-PIXY321 antibody formation was assessed by enzyme-linked immunosorbent assay (ELISA) and neutralization assay. Of the 49 patients enrolled, 31 were fully evaluable for hematologic efficacy. When comparing the first B cycle (cycle B-1; with PIXY321) with the first A cycle (cycle A-1; without PIXY321), the fusion protein had no significant effect on platelet nadirs or duration of platelets less than 20,000/microL but was able to speed the time of recovery of platelet counts to 100,000/microL (15 v 20 days; P =.01). Significant improvements in neutrophil nadir and duration of ANC less than 500 were observed in cycles A-2 and B-1 (with PIXY321) as compared with cycle A-1 (without PIXY321). Initial PIXY321 prophylaxis (cycle A-2 and cycle B-1), enhanced the recovery of ANC to greater than 1,500/microL by an average of at least 8 days as compared with cycle A-1 (without PIXY321; P </=.004). However, positive PIXY321 hematologic effects were lost in the second course of PIXY321 among patients treated in part B. ELISA analysis showed that 92% of patients had developed neutralizing anti-PIXY321 antibodies by the completion of 2 PIXY321-containing cycles. The incidental action of PIXY321 to depress serum cholesterol levels was also abrogated during cycle B-2. We conclude that PIXY321 was active in speeding hematologic recovery but that neutralizing anti-PIXY321 antibody formation suppressed the hematologic and biochemical effects by the second cycle of PIXY321 administration. The immunogenicity of this fusion protein provides a cautionary warning that clinical development of bioengineered human molecules requires thorough testing for immune neutralization.

Phase I trial of anti-CD3-stimulated CD4+ T cells, infusional interleukin-2, and cyclophosphamide in patients with advanced cancer

PURPOSE

We performed a phase I trial to determine whether in vivo expansion of activated CD4+ T cells was possible in cancer patients. 111Indium labeling was used to observe trafficking patterns of the infused stimulated CD4+ T cells. The influence of cyclophosphamide (CTX) dosing on immunologic outcome was also examined.

PATIENTS AND METHODS

Patients with advanced solid tumors or non-Hodgkin's lymphoma received CTX at 300 or 1,000 mg/m2 intravenously (i.v.). Leukapheresis was performed to harvest peripheral-blood mononuclear cells (PBMCs) either just before the CTX dose, or when the patient was either entering or recovering from the leukocyte nadir induced by CTX. An enriched population of CD4+ T cells was obtained by negative selection. The CD4+ T cells were activated ex vivo with anti-CD3, cultured with interleukin-2 (IL-2) for 4 days, and adoptively transferred. After adoptive transfer, patients received IL-2 (9.0 x 10(6) IU/m2/d) by continuous infusion for 7 days.

RESULTS

The absolute number of CD4+, CD4+/DR+, and CD4+/CD45RO+ T cells increased in a statistically significant fashion in all cohorts after the first course of therapy. The degree of CD4 expansion was much greater than CD8 expansion, which resulted in a CD4:CD8 ratio that increased in 26 of 31 patients. The greatest in vivo CD4 expansion occurred when cells were harvested as patients entered the CTX-induced nadir. One complete response (CR), two partial responses (PRs), and eight minor responses were observed. Trafficking of 111Indium-labeled CD4 cells to subcutaneous melanoma deposits was also documented.

CONCLUSION

CD4+ T cells can be expanded in vivo in cancer patients, which results in increased CD4:CD8 ratios. The timing of pheresis in relation to CTX administration influences the degree of CD4 expansion. Tumor responses with this regimen were observed in a variety of tumors, including melanoma and non-Hodgkin's lymphoma; a high percentage of patients had at least some tumor regression from the regimen that produced the greatest CD4+ T-cell expansion.

Development of rheumatoid arthritis after treatment of large granular lymphocyte leukemia with deoxycoformycin

The association of T-cell large granular lymphocyte (LGL) leukemia and rheumatoid arthritis is well described and it is now recognized that these patients and patients with Felty's syndrome represent different aspects of a single disease process. Most patients have rheumatoid arthritis at the time of diagnosis of LGL leukemia. This is the first detailed report of the development of rheumatoid arthritis after the diagnosis and treatment of LGL leukemia as well as the first report of rheumatoid arthritis that occurred in association with deoxycoformycin treatment. It is likely that the beneficial sustained normalization of neutrophil counts as a result of deoxycoformycin treatment played a significant role in the development of this complication. Hematological improvement occurred despite molecular genetic evidence of persistence of the abnormal T-cell clone. The role of the clonally expanded T cells in the pathogenesis of neutropenia and rheumatoid arthritis is discussed.

Interleukin 1 alpha increases serum leptin concentrations in humans

Leptin, the protein product of the ob gene, regulates appetite and body weight in animals. Endotoxin and cytokines, induced by endotoxin, interleukin (IL) 1 and tumor necrosis factor, increase expression of leptin in mice and hamsters. We measured serum leptin concentrations in patients with cancer before and after administration of recombinant human IL-1 alpha. Fourteen patients received IL-1 alpha at one of three dose levels (0.03, 0.1, or 0.3 microgram/kg.day) for 5 days. Serum leptin concentrations increased in all but two patients within 24 h after the first dose. The increase in leptin was correlated directly with IL-1 alpha dose (P = 0.0030). Despite continued administration of IL-1 alpha, serum leptin concentrations returned to pretreatment levels by day 5 of therapy. An increase in serum leptin concentrations may be one mechanism by which anorexia is induced by IL-1 alpha. However, tachyphylaxis of the leptin response suggests that other mechanisms also are involved.

Anterior exposure of spinal deformities and tumors: a 20-year experience

Data from 505 patients (1976 through 1995) who underwent anterior spinal exposure were retrospectively analyzed. There were 222 boys and 283 girls with a mean age of 14.5 years; 166 had thoracic exposure (T), 300 thoracoabdominal (TA), 44 retroperitoneal (R), and 7 transperitoneal (TP); 17 had repeat exposure (5 had initial exposure elsewhere); 70% had scoliosis, 25% kyphosis, 27% a neuromuscular disorder (NMD) and 6.7% a tumor. Average intensive-care-unit stay was 2.5 days, 6.2 days for NMD (P < .05); average ileus was 3.4 days, 4.1 days for NMD (P < .05); and average length of stay was 15.4 days for all patients, 19.3 days for NMD (P < .05). Mechanical ventilation over 96 hours was required in 31 patients, 66% had an NMD (P < .05). The morbidity rate was 9.8%, 10.1% for NMD; the morbidity rate was zero for tumor and repeat exposures. Mortality was zero. Over half of the vessel injuries (57%) and the urinary tract infections (60%) occurred in NMD patients. Differences between the 1976 through 1985 period and the 1986 through 1995 period were a shorter length of stay and a majority of one-stage combined exposures in the latter period. The authors conclude that anterior exposure of spinal deformities is well tolerated by most pediatric patients, and that this technique is easily adaptable to the resection of retroperitoneal and thoracolumbar tumors.

Topotecan and the treatment of recurrent ovarian cancer: is there a role for granulocyte colony-stimulating factor?

Topotecan (Hycamtin; SmithKline Beecham Pharmaceuticals, Philadelphia, PA) a new chemotherapeutic agent for the treatment of patients with advanced carcinoma of the ovary after failure of initial or subsequent therapy, is a specific, potent inhibitor of the enzyme topoisomerase I. Myelosuppression is the dose-limiting toxicity of topotecan, and can interfere with the administration of the recommended dose/schedule of the drug by delaying the next cycle of chemotherapy or by requiring a reduction in the dose. The results from clinical studies suggest that routine granulocyte colony-stimulating factor therapy is not needed when topotecan is administered at the recommended dose of 1.5 mg/m2/d for 5 days. However, patients should be carefully monitored, as some may benefit from hematopoietic growth factor support on subsequent cycles.

Modified Nissen fundoplication for reduction of fundoplication failure

Failure of the Nissen fundoplication can be secondary to disruption of the wrap or slippage of the stomach upward within the wrap. A modification of the Nissen fundoplication was devised and implemented between 1982 and 1995 to eliminate these complications. This report describes the modification and the results. Commonly, the Nissen fundoplication uses a single anterior row of sutures securing the wrapped stomach to the esophagus. This modification reinforces the wrap with two additional rows of suture, one right lateral and one left lateral, each further anchoring the wrapped stomach to the esophagus. This retrospective analysis compares the Nissen and modified Nissen fundoplications performed at our institution. Fundoplication operations were considered a failure if they required a reoperation secondary to wrap disruption or stomach slippage. Data were analyzed using the chi 2 method. A total of 948 fundoplication procedures were performed; 326 Nissen and 622 modified Nissen. Follow-up ranged from 0.5 to 13 years (mean, 6 years). Thirteen wrap disruptions and six stomach slippages occurred in the Nissen group (5.8%); 10 wrap failures and no stomach slippages occurred in the modified Nissen group (1.6%), P < .05. The authors conclude that this modification of the Nissen fundoplication significantly reduces wrap disruptions and stomach slippages.

A phase I randomized study of subcutaneous adjuvant IL-2 in combination with an autologous tumor vaccine in patients with advanced renal cell carcinoma

We performed a prospective, randomized study to determine whether subcutaneous administration of interleukin-2 (IL-2) in combination with an autologous renal cell vaccine is feasible and can potentiate antitumor immunity. Seventeen patients with metastatic renal cell carcinoma underwent surgical resection with preparation of an autologous tumor cell vaccine. Patients were vaccinated intradermally twice at weakly intervals with 10(7) irradiated tumor cells plus bacillus Calmette-Guérin, and once with 10(7) tumor cells alone. Patients were randomized to one of three groups: no adjuvant IL-2, low-dose IL-2 (1.2 x 10(6) IU/m2), or high-dose IL-2 (1.2 x 10(7) IU/m2). IL-2 was administered subcutaneously on the day of vaccination and the subsequent 4 days. Immune response was monitored by delayed-type hypersensitivity (DTH) response to tumor cells as compared with normal autologous renal cells. Sixteen of 17 patients received vaccine therapy. Four patients developed cellular immunity specific for autologous tumor cells as measured by DTH responses; two had received no IL-2 and two had received high-dose IL-2. There were two partial responses (PR) noted, both in patients who received high-dose IL-2. One responding patient was DTH(+) and one was negative. A third patient who was DTH(+) after vaccination with no IL-2 had a dramatic PR after receiving IL-2 subcutaneously in a subsequent protocol. Prospective testing of response to recall antigens indicated that only 5 of 12 tested patients were positive, including both clinical responders. These data suggest that subcutaneously administered adjuvant IL-2 does not dramatically augment the immunologic response to autologous renal cell vaccines as determined by the development of tumor-specific DTH response.

Phase I study of subcutaneously administered interleukin-2 in combination with interferon alfa-2a in patients with advanced cancer

PURPOSE

Although high-dose interleukin-2 (IL-2) can produce durable remissions in a subset of responding patients with renal cell carcinoma (RCC), this occurs in the setting of significant toxicity. The purpose of this study is to define the maximum-tolerated dosage (MTD) of IL-2 and interferon alfa-2a (IFN alpha-2a) that can be administered chronically on an outpatient basis.

PATIENTS AND METHODS

Fifty-three patients with advanced cancer of variable histology with good prognostic features were treated in six cohorts. Patients in cohorts one through five received IL-2 (1.5 or 3.0 x 10(6) million units (mU)/m2) Monday through Friday and IFN alpha-2a (1.5 or 3 x 10(6) mU/m2) daily for a 4-week cycle. In cohort six, IFN alpha-2a was given three times a week. Immunologic monitoring, including serum levels of soluble IL-2 receptor (sIL-2R) and neopterin, flow cytometry, and natural killer cell (NK) activity, were measured. Patients were evaluated for toxicity, response, and survival.

RESULTS

Almost all patients developed grade I/II toxicities commonly associated with cytokine therapy. Symptoms were most severe with the first treatment of each week. Dose-limiting toxicities included grade III fatigue, hypotension, and creatinine elevations. The MTD was 1.5 mU/m2 daily x 5 given subcutaneously repeated weekly for IL-2 and 1.5 mU/m2 daily subcutaneously (dose level 3) for IFN. Six of 25 assessable patients with RCC (24%) achieved a partial response (PR), including four of eight patients who were previously untreated. There were no objective responses in patients with other tumors, including 12 melanoma patients.

CONCLUSION

IL-2 and IFN alpha-2a can be given with tolerable toxicities on an outpatient basis and shows significant activity in patients with metastatic RCC.

Influence of interleukin-2 regimens on circulating populations of lymphocytes after adoptive transfer of anti-CD3-stimulated T cells: results from a phase I trial in cancer patients

The adoptive transfer of anti-CD3-stimulated T killer (T-AK) cells was tested with different bolus and infusional interleukin-2 (IL-2) regimens, and anti-CD3 stimulation procedures to determine immunologic and antitumor effects in patients with a variety of advanced cancers. Indium-111 labeling was used to observe traffic patterns of the infused T-AK. Autologous peripheral blood mononuclear cells were obtained by leukapheresis. Cyclophosphamide (300 mg/m2) was given to most patients immediately after leukapheresis. The harvested cells were activated ex vivo with anti-CD3 overnight or for 4 days, at which time cells were reinfused and an IL-2 regimen was begun. Treatment was repeated 28 days later. This treatment regimen induced significant increases in leukocytes, lymphocytes, and eosinophils in patients in most treatment cohorts. Circulating lymphocytes were predominantly CD3+ T cells with preferential expansion of the CD8+ subset. Patients receiving cells stimulated in vitro for 4 days had significant T-cell lymphocytosis with either infusional or bolus plus infusional IL-2 regimens. T-cell viability was decreased in culture after a second 4-day stimulation with anti-CD3 at day 28; this decrease could be prevented by adding IL-2 to the culture media. Cells stimulated overnight required both bolus and infusional IL-2 to show an atypical lymphocytosis in vivo. Overnight-stimulated T-AK did not show decreases in in vitro viability at the day 28 restimulation. Indium-III-labeled cells trafficked to the liver, spleen, and bone marrow. No increase in uptake was observed in tumor deposits. There were 2 patients with partial responses, 5 with minor responses, 19 with stable disease, and 88 with progressive disease. The length of in vitro anti-CD3 stimulation, and the dose and timing of IL-2 administration in vivo results in different circulating leukocyte populations after adoptive T-AK infusion. Generally, the CD8+ T-cell subset was preferentially expanded by this treatment approach. Repeated ex vivo stimulation with anti-CD3 may cause cell death.

Endocrine effects of IL-1 alpha and beta administered in a phase I trial to patients with advanced cancer

Previous primate and rodent studies suggested that interleukin-1 alpha (IL-1 alpha) caused changes in the secretion of pituitary, adrenal, thyroid, and gonadal hormones, as well as acute-phase reactants. Plasma samples were obtained after IL-1 alpha and beta treatment in cancer patients to document the changes in endocrine function suggested by the animal models. Successive groups of patients were treated at IL-1 alpha doses of 0.01, 0.03, 0.1, 0.3, and 1.0 microgram/kg, given daily as a 15-min intravenous bolus. IL-1 beta was given at 0.1 microgram/kg by the same route and time course. After the first dose of IL-1, statistically significant elevations of a.m. and p.m. cortisol, growth hormone (GH), and prolactin (PRL) occurred. Thyroid-stimulating hormone (TSH) and C-reactive protein (CRP) were elevated by the sixth treatment day. Testosterone decreased significantly in male patients. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were more variable but decreased in most patients. The changes in cortisol, GH, PRL, TSH, CRP, FSH, LH, and testosterone resolved after treatment and did not result in clinically apparent endocrinopathies. Bolus doses of IL-1 alpha and beta cause significant changes in many endocrine laboratory parameters and influence the in vivo activities of multiple homeostatic endocrine functions in human beings.

Phase II trial of interleukin 1 alpha and indomethacin in treatment of metastatic melanoma

BACKGROUND

The rising incidence of malignant melanoma and the lack of curative therapies for metastatic disease represent a therapeutic challenge. New agents effective in treating this disease are needed.

PURPOSE

Because of the additive antitumor effects of interleukin 1 alpha (IL-1 alpha) and indomethacin in vivo, we conducted a phase II trial of this combination in patients with melanoma. We used the recommended dose determined from our phase I trial to ascertain the antitumor activity of the combination.

METHODS

From August 1, 1990, through July 28, 1992, 49 patients entered the study. They were stratified into two groups based on the presence of visceral (n = 14) and nonvisceral (n = 35) metastases. The patients received 7 days of both IL-1 alpha (O.1 micrograms/kg per day by intravenous bolus) infusion) and indomethacin (50 mg orally every 8 hours). At least two cycles of therapy, repeated at 21-day intervals, were planned. Additional treatment was given to those patients who had stable or responding lesions. A chi-squared test for homogeneity of proportions was used to compare groups on several measures. All P values resulted from two-sided tests.

RESULTS

Fever, chills, and hypotension were among the most common side effects. None of the 14 patients with visceral metastases responded to the treatment. Of the 35 patients with non-visceral metastases, three showed a partial response for 6 months each and one showed a complete response for more than 34 months; the response rate was 11% (95% confidence interval [CI] = 5%-26%). All responding patients required phenylephrine for treatment of IL-1 alpha-induced hypotension, whereas six (19%) of 31 of the nonresponding patients with nonvisceral metastases required phenylephrine (P = .0008). The response rate in women was higher; three of 10 women (30%; 95% CI = 11%-60%) responded, whereas one of 25 men (4%; 95% CI = 0%-20%) responded (P = .029). All three women were positive for human leukocyte antigen (HLA) B7 expression (P = .011).

CONCLUSIONS

The combination of IL-1 alpha and indomethacin has minimal antitumor activity in melanoma patients. All responses were confined to patients with nonvisceral metastases. IL-1 alpha-induced hypotension, gender, and HLA B7 expression were positively associated with response.

IMPLICATIONS

Administration of higher doses of IL-1 alpha alone has been shown to produce hypotension in a large proportion of patients but can be given safely with phenylephrine support. Because of the association of hypotension with antitumor activity, treatment with higher IL-1 alpha doses alone may be a strategy for attaining better response rates.

Myositis associated with interleukin-2 therapy in a patient with metastatic renal cell carcinoma

BACKGROUND

Interleukin-2 (IL-2) has been used successfully in the treatment of some patients with metastatic renal cell carcinoma and melanoma, with a partial response rate of 15%-20%. It produces a well documented spectrum of side effects. Autoimmune diseases have been associated with IL-2 immunotherapy and the development of autoimmune thyroiditis may correlate with antitumor clinical response.

METHODS

A patient with metastatic renal cell carcinoma is described who developed a polymyositis-like myopathy after an autologous tumor vaccine and IL-2 therapy.

RESULTS

The patient had a delayed response for 15 months after developing this previously unreported toxicity.

CONCLUSIONS

To the authors' knowledge, this represents the first reported case of necrotizing myositis in association with IL-2 therapy. Subsequent continuous partial response of the advanced malignancy was observed for 15 months. In this case, IL-2 may have broken tolerance to both normal muscle cells and tumor cells.

Erythropoietin production. A potential marker for interleukin-2/interferon-responsive tumors

BACKGROUND

Interleukin-2 (IL-2) recently was approved by the Food and Drug Administration for the treatment of renal cell cancer. It is effective in a small minority of patients, but no markers identify individuals likely to respond to treatment.

METHODS

Two polycythemic patients with erythropoietin-producing renal cell cancer and three other polycythemic patients with renal cell cancer were treated with the combination of IL-2 and alpha-interferon (alpha-IFN).

RESULTS

All five patients achieved a partial or complete remission. In both patients in which it was measured, the erythropoietin level decreased significantly with treatment, and the polycythemia resolved in all patients. Hypothyroidism developed in two patients, and transient hyperthyroidism developed in another.

CONCLUSION

These results contrast with those achieved with IL-2 alone or in combination with lymphokine-activated killer cells, for which a 15% response rate was seen in patients with renal cell cancer and polycythemia. Although less than 5% of renal cell tumors produce erythropoietin, its production may identify a subset of individuals with renal cell cancer responsive to IL-2 and alpha-IFN.

Interstitial pressure of subcutaneous nodules in melanoma and lymphoma patients: changes during treatment

Interstitial pressure (IP) is a physiological variable that may have its greatest influence on the transport of high-molecular-weight therapeutic agents. IP in tumor nodules was measured in patients with metastatic melanoma or non-Hodgkin's lymphoma to determine the influence of this physiological variable on treatment outcome. The wick-in-needle technique was used to measure IP at time points before and after treatment with a variety of immunotherapy and chemotherapy regimens. Selected patients had IP measurements during chemotherapy or immunotherapy infusions. Ultrasound or computed tomography was used to evaluate the size of the studied lesions and their relationship to normal structures. The mean baseline IP in melanoma nodules (n = 22) and lymphoma nodules (n = 7) was 29.8 and 4.7 mm Hg, respectively (P = 0.013 for the difference between tumor types). In a subset of melanoma nodules for which IP had been measured before and after treatment, the IP increased significantly over time for nonresponding melanoma lesions from a baseline of 24.4 to 53.9 mm Hg after treatment (P = 0.005) and decreased in melanoma lesions that responded to treatment where the mean baseline and post-treatment IPs were 12.2 and 0 mm Hg, respectively (P = 0.001 for the difference in IP profiles between responding and nonresponding lesions). Six of seven lymphoma nodules responded completely to chemotherapy or radiation. The single nodule that did not respond had a baseline IP of 1 mm Hg that increased to 30 mm Hg after treatment. Tumor IP differs significantly between melanoma and non-Hodgkin's lymphoma. The changes in IP over time differ significantly between responding and nonresponding melanoma lesions. IP that increases during treatment appears to be associated with tumor progression in these tumor types.

The effects of treatment with interleukin-1 alpha on platelet recovery after high-dose carboplatin

BACKGROUND

Thrombocytopenia is a frequent side effect of cancer chemotherapy and commonly limits attempts to escalate drug doses. To determine whether interleukin-1 alpha could ameliorate carboplatin-induced thrombocytopenia, we combined it with high-dose carboplatin in 43 patients with advanced neoplasms.

METHODS

High-dose carboplatin (800 mg per square meter of body-surface area) was administered alone to a control group. Subsequent patients were randomly assigned to receive the same dose of carboplatin with interleukin-1 alpha, administered either before or after carboplatin. Interleukin-1 alpha was given intravenously at a dose of 0.03, 0.1, or 0.3 microgram per kilogram of body weight per day for five days.

RESULTS

Carboplatin alone consistently produced thrombocytopenia with a median nadir of 19,000 platelets per cubic millimeter and a median of 10 days with less than 100,000 platelets per cubic millimeter. All 15 patients receiving interleukin-1 alpha before carboplatin had similar findings. In contrast, 5 of the 15 patients given one of the two higher doses of interleukin-1 alpha after carboplatin had minimal thrombocytopenia (nadir, 91,000 to 332,000 platelets per cubic millimeter). In the 10 patients given 0.3 microgram of interleukin-1 alpha per kilogram after carboplatin treatment, the platelet count recovered to 100,000 per cubic millimeter significantly earlier than in either the control group (P = 0.002) or the patients who received interleukin-1 alpha before carboplatin (P = 0.003), with the median times to recovery in the three groups being 16, 21, and 23 days, respectively. At the highest dose of interleukin-1 alpha, toxicity was substantial (but reversible), requiring inpatient support for hypotension, supraventricular arrhythmias, and pulmonary-capillary leak.

CONCLUSIONS

Interleukin-1 alpha can accelerate the recovery of platelets after high-dose carboplatin therapy and may be clinically useful in preventing or treating thrombocytopenia induced by chemotherapy.

Intensive therapy with cisplatin, interleukin-2 and interferon-alpha-2a in patients with metastatic melanoma. A phase II Study

OBJECTIVE

Based upon their individual clinical activity and combined effects in animal models or in vitro, we wished to evaluate a regimen of cisplatin, interferon-alpha, and IL-2 in patients with metastatic melanoma.

DESIGN

Phase II pilot study.

SETTING

Referral-based US Government clinical research unit.

PATIENTS

Nine patients with metastatic malignant melanoma.

INTERVENTION

Cisplatin 75-100 mg/m2 was administered intravenously over 30 minutes on days 1 and 8. Interferon-alpha 2a 5 Mu/m2 body surface area (BSA) was given subcutaneously for 4 days beginning 1 day before each dose of cisplatin. Beginning on day 15 and day 22, IL-2 was administered by intravenous continuous infusion at 3 Mu/m2 BSA/d for 96 hours and by daily intravenous bolus concurrent with daily subcutaneous doses of interferon-alpha 2a.

MAIN OUTCOME MEASURES

Antitumor response and toxicities.

RESULTS

The study was stopped due to renal and hematopoietic toxicity and severe, delayed nausea and vomiting associated with the cisplatin-interferon treatment. Three of 9 patients achieved a partial response (duration 2.5, 4, 14+ months), and an additional patient had a 50% reduction in measurable tumor volume before undergoing resection of residual disease. Overall response rate was 45%.

CONCLUSION

This regimen was associated with excessive toxicity, and the lack of complete responses in a patient cohort with favorable characteristics for response (good performance status, predominance of skin and lymph node metastatic sites) suggests that it had no advantage over less toxic treatment regimens.

REGISTRATION

National Cancer Institute/Cancer Therapy Evaluation Program T89-0137.

The toxic and hematologic effects of interleukin-1 alpha administered in a phase I trial to patients with advanced malignancies

PURPOSE

A phase I trial was undertaken because interleukin-1 alpha (IL-1 alpha) possesses antiproliferative, immunostimulatory, antiinfection, myeloprotective, and myelorestorative properties that could be beneficial in cancer treatment.

PATIENTS AND METHODS

In this phase I trial, IL-1 alpha was administered intravenously (IV) during a 15-minute period daily for 7 days to patients with advanced solid malignancies.

RESULTS

The maximum-tolerated dose (MTD) of IL-1 alpha alone was 0.3 microgram/kg. A second group of patients received indomethacin plus IL-1 alpha based on preclinical studies, which indicated that indomethacin could abrogate IL-1 alpha-induced hypotension; however, the MTD of IL-1 alpha plus indomethacin was 0.1 microgram/kg lower than IL-1 alpha alone. Fever, chills, headache, nausea, vomiting, and myalgia were common but were not dose-limiting. Hypotension resulted from a marked decrease in systemic vascular resistance and required pressors at 0.3 and 1.0 micrograms/kg IL-1 alpha. Dose-limiting toxicities included hypotension, myocardial infarction, confusion, severe abdominal pain, and renal insufficiency. IL-1 alpha treatment caused a significant, dose-related increase in the total WBC count (mainly segmented neutrophils and neutrophilic bands). Bone marrow cellularity increased because of enhanced numbers of relatively mature myeloid cells and megakaryocytes. Platelet counts decreased during therapy but were significantly elevated above baseline values 1 to 2 weeks posttreatment; this may have been an effect of IL-6 that was shown to be induced by IL-1 alpha treatment. Significant increases in triglycerides, cortisol, C-reactive protein, thyroid-stimulating hormone and decreases in cholesterol, testosterone, and protein-C were observed with treatment.

CONCLUSION

We conclude that at doses of IL-1 alpha that can be given safely to cancer patients, significant, potentially beneficial hematopoietic effects occur.

Efficient synthesis of adeno-associated virus structural proteins requires both adenovirus DNA binding protein and VA I RNA

We have shown previously that replication of defective parvoviruses [adeno-associated viruses (AAV)] requires several early adenovirus (Ad) gene products [J. E. Janik, M. M. Huston, and J. A. Rose (1981) Proc. Natl. Acad. Sci. USA 78, 1925-1929]. To examine their possible roles in the transcription and translation of AAV mRNA, 293-31 cells, a human embryonic kidney cell line that constitutively expresses the Ad early region IA and IB gene products, were transfected with a pBR325 plasmid (pLH1) that contains a duplex AAV2 DNA segment (0.03-0.97 map units) which encompasses the promoters and coding sequences necessary for expression of all AAV polypeptides. When cells were transfected with pLH1 alone, both spliced and unspliced AAV-specific cytoplasmic RNAs accumulated. These transcripts were capable of directing synthesis of the three AAV capsid polypeptides in vitro, whereas in vivo synthesis of AAV protein was not detected by immunofluorescence or immunoprecipitation. When cells were cotransfected with pLH1 and intact Ad DNA, the level of cytoplasmic AAV RNA was enhanced and AAV protein was synthesized in vivo. Additional experiments demonstrated that in vivo AAV protein synthesis also could be induced when pLH1 was cotransfected with plasmids that contain the Ad DNA-binding protein (pDBP) and VA I RNA (p2BalM) genes; however, a low level of in vivo AAV capsid protein was occasionally detected in cotransfections with pLH1 and a plasmid that contains both VA I and VA II RNA coding sequences (p2SalC). Cotransfection of pLH1 and pDBP or pLH1 and p2SalC showed complex alterations in the steady-state patterns of AAV cytoplasmic transcripts. In both cases, increased levels of transcripts, particularly the 2.3-kb spliced species, were detected in comparison to levels seen in cells transfected with pLH1 alone. Despite these increases, however, there was little, if any, induction of AAV protein synthesis unless both the DNA-binding protein (DBP) and VA I RNA coding sequences were present in cotransfection with pLH1. We conclude that, in 293-31 cells, the Ad VA I RNA and DBP gene products regulate AAV capsid protein synthesis at least at two levels: (i) by increasing the steady-state levels of structural protein transcripts in the cytoplasm, especially the spliced species, and (ii) by enhancing the translation of these messages.

Adeno-associated virus proteins: origin of the capsid components

The three primary capsid proteins (A, B, and C) of adeno-associated viruses have been shown previously to contain overlapping amino acid sequences (R. McPherson and J. Rose, J. Virol. 46:523-529, 1983). In the present study we demonstrate definitively that these proteins are encoded in the right half of the adeno-associated virus 2 genome, and one or both of the smallest adeno-associated RNA species (2.3- or 2.6-kilobase RNA) account for their synthesis. Protein A (90 kilodaltons) apparently initiates from a site within the intervening sequence, which is intact in the larger (unspliced) 2.6-kilobase mRNA, and may read through one or more termination codons, including a strong stop signal (UAA) that lies 31 bases downstream from the end of the intervening sequence. Proteins B (72 kilodaltons) and C (60 kilodaltons) are not derived from protein A but apparently originate from independent, in-frame initiations that lie downstream from the splice junction. It thus seems likely that production of the three adeno-associated virus capsid proteins involves at least two mRNA species. The B and C proteins presumably arise from the spliced 2.3-kilobase RNA, whereas protein A should be generated by the 2.6-kilobase RNA or a hitherto unidentified spliced RNA species.

Herpes simplex virus types 1 and 2 completely help adenovirus-associated virus replication

In addition to adenoviruses, which are capable of completely helping adenovirus-associated virus (AAV) multiplication, only herpesviruses are known to provide any AAV helper activity, but this activity has been thought to be partial (i.e., AAV DNA, RNA, and protein syntheses are induced, but infectious particles are not assembled). In this study, however, we show that herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are in fact complete AAV helpers and that AAV type 2 (AAV2) infectivity yields can approach those obtained when coinfections are carried out with a helper adenovirus. AAV helper activity was demonstrated in KB cells with two HSV-1 strains (11124 and 17MP) and an HSV-2 strain (HG52). Each herpesvirus supported AAV2 multiplication with comparable efficiency. AAV2 multiplication was similarly efficient in HSV-1 coinfections of HeLa cells, whereas lower yields were obtained in HEp-2 and primary human embryonic kidney cells. HSV-1 also supported AAV1 multiplication in HeLa cells but, at corresponding multiplicities of infection, AAV1 grew less efficiently than AAV2. Comparisons of the time courses of AAV2 DNA, RNA, and protein syntheses after coinfection with either adenovirus type 5 or HSV-1 revealed that, in each case, the onset of synthesis and attainment of maximal synthesis rate occurred earlier in coinfections with HSV-1. These findings demonstrate the linkage of AAV macromolecular synthesis to an event(s) in the helper virus cycle. Aside from this temporal association, helper-related differences in AAV macromolecular synthesis were not apparent.

Locations of adenovirus genes required for the replication of adenovirus-associated virus

We have used DNA transfection to identify several regions of the adenovirus genome needed to induce replication of the defective parvovirus, adenovirus-associated virus (AAV). Previous studies have indicated that only early adenovirus functions are needed to aid the replication of AAV. In this report, we demonstrate that three restriction endonuclease fragments of adenovirus DNA are necessary for production of infectious AAV in 293-31 cells (an adenovirus type 5-transformed human embryonic kidney cell line). These fragments map from 28.5 to 29.4, 59.5 to 75.9, and 89.7 to 100 map units on the adenovirus type 2 genome and correspond to the locations of the VAI RNA gene, early region 2, and early region 4, respectively. The 293-31 cell line, which has been found to express early region 1A and 1B proteins, alone is incapable of supporting AAV replication or even AAV DNA synthesis. Additional experiments with adenovirus type 5 host range mutants (group I, hr1 and group II, hr7) indicate, however, that early region 1A provides an essential function(s) for AAV replication, whereas early region 1B probably does not.